-------
is necessary for the badge to perform the dual function of monitoring whole-body and
eye lens exposures). The lead apron provides a dose reduction, on the average, of
approximately one order of magnitude.
2. Impact of Reduction in Accumulated Exposure Limit
At present, no one in the hospital, to the knowledge of the RSO, has accumulated a
whole-body lifetime exposure in excess of 100 rem. In fact, it is unlikely that a
significant number of personnel would ever potentially exceed this limit. This includes
the cardiac catheterization physicians, who are permitted to wear their film badges
under their lead aprons.
There does exist a regulatory burden (cost risk) associated with the 100 rem proposed
limit. At present, when a new radiation worker is taken on by the hospital, a letter is
sent to request his/her lifetime accumulated dose record from his/her previous
employer. A response may or may not be obtained to this request; but in any case, it is
unlikely that the response would include the exposure accumulated prior to the most
recent employer.
There is not a compliance problem with the current 5(N-18) limit. Given the 5 rem
annual limit, this facility is bound to be in compliance, regardless of the previous
exposure (assuming that none of the prospective employees was exposed prior to 1960
and lacked an exposure history). However, if the 100 rem limit were imposed, this
facility could be out of compliance without knowing it, if the previous record were not
made available or were in error.
In effect, this facility argues that it could be penalized for sloppy or non-existent
recordkeeping by the former employers of its employees. There would be a reluctance
to hire employees until such time that their previous exposure records were made
available, which could involve indefinite delays, thus penalizing the anxious candidate
for employment. (Of course, the other side of this coin is that if employees were made
aware of this situation, pressure would be brought to bear on employers to maintain
accurate records and to provide exposure data to employees.)
32
-------
3. Impact of the Proposed Guidance Relating to Extremities
and Individual Organs
The 5 rem exposure limit on the eye lens and gonads would not pose a problem for this
facility, since workers are currently abiding by this limit and have done so for some
time. For those tasks in which high exposures to the eye are possible (i.e., cardiac
catheterization), high attenuation spectacles are routinely worn. Although eye-level
monitoring has not been performed, safe exposures have been assured by measuring the
attenuation of test beams through the lenses of the spectacles.
This facility has discovered that it is not necessary to purchase expensive (i.e., $400 a
pair), lead-impregnated spectacles from safety equipment suppliers. Apparently, high
index-of-infraction lenses, available for the going price of regular glasses (i.e., $35 a
pair) contain sufficient concentrations of high Z materials to provide beam attenuations
comparable to lead impregnated glass.
As an aside, it was mentioned that nuclear medicine procedures (using Tc-99m, for
example) may eventually replace a large fraction of the cine-mode procedures used in
heart catheterizations. These have the added benefit of substantially reducing the
exposure to both the patient and the workers.
The proposed exposure limits to the hands are probably not a problem. However, some
concern was expressed about exposures to the hands of physicians during fluoroscopic
examinations vis-a-vis existing guidelines. Potential exposures as high as 3 rem/minute
are available in the direct beam, and several fluoroscopic procedures take several
minutes. Yet the highest finger badges reading has been 1.5 rem/month, well within the
proposed guidance on an annual basis.
The problem is that most of the physicians don't like to wear the finger badges, since
they are alleged to reduce finger mobility. Since many physicians do not monitor their
hands, exposures are unknown. Although there is no corroborative evidence, the RSO is
uneasy about compliance in this area.
33
-------
4. Impact of the Proposed Guidance for Potential Exposures
in the Range of 0.3 to 1.0 RPG
Potential for exposures in this range exists in the Divisions of Nuclear Medicine and
Diagnostic X-rays in the Department of Radiology, and in the cardiac catheterization
laboratory in the Department of Cardiology.
The Division of Nuclear Medicine is housed in one long corridor with 12 rooms.
Although the hot lab at the end of the corridor has the potential for the highest
exposures, significant contributions to annual exposures in excess of 1.5 rem cannot be
ruled out for any of the rooms along the corridor. Approximately eight people received
exposures in excess of 1.0 rem in 1980.
The Division handles approximately 30 - 40 patients daily during one 10-hour shift.
Surveys are carried out frequently by personnel from the RSO, but these personnel are
based in a separate building. One individual on the floor would most likely satisfy the
monitoring and supervision provisions imposed by this guideline. There are currently no
medical physicists or health physicists permanently stationed on the floor. It might be
argued that the two physicians and four residents are "equivalent" to "radiation
protection professionals". However, it is unlikely that any of these individuals could
currently pass the medical physics examination administered by the American Board of
Radiology or American Association of Physicists in Medicine.
A similar situation exists in the Division of Diagnostic X-rays. Six special procedures'
rooms are organized in a suite for a 10-hour, single shift operation. Here, however, two
to three individuals would be required to cover all tasks significantly contributing to
potential annual exposures in excess of 1.5 rem. Of course, one of the 12 physicians or
15 residents is always present in each of the rooms. Are these individuals equivalent to
medical physicists? Probably not.
In the cardiac catheterization laboratory, which also operates on one scheduled shift,
one supervisor would be sufficient. Here, however, the question of equivalency is moot!
There are no radiologists among the physicians or residents; cardiologists are not likely
to have the training or experience equivalent to medical physicists.
Emergency procedures are not unusual in all of the above areas. Thus, the supervisor
would have to be on-call, just like the physicians and residents. If a number of them
34
-------
were required, the team concept could be applied. At present, the Radiation Protection
Safety Officer and his assistant are frequently called in at odd hours to monitor unusual
procedures.
5. Impact of the Proposed Guidance for Potential
Exposures in the Range of 0.1 to 0.3 RPG
The hospital currently complies with this guidance. Approximately 500 workers are
individually monitored, with all of the attendant recordkeeping. Frequent surveys are
performed by the RSO, some of which are motivated by the NRC ALAR A program.
Although the Radiation Safety Officer is not Board-certified, he has a Ph.D. in physics
with a specialty in nuclear medicine, incorporating several years of experience in two
major medical institutions. Therefore, he has the equivalent training and experience of
a medical physicist, and clearly is a "radiation protection professional".
6. Impact of Training Requirements
This institution has established an extensive training program in radiation protection
which is administered by the RSO. Each radiation worker gets one hour of training
annually, resulting in at least one course administered each week. Even the nurses, who
are strictly speaking not radiation workers and are not routinely monitored (although
they may request film badges and frequently do), are given 20-minute briefings because
they may be exposed to implant patients.
The most extensive training course, involving two 2-hour lectures, is administered to
individuals involved in research at the medical school. This course, instigated by the
Radiation Safety Committee, must be passed (an examination is administered foUowing
the lecture series) before an individual is permitted to work with radiation sources in
the conduct of research.
Only in the lectures for researchers are levels of risk quantified. At present, it is
estimated that training activities occupy approximately 15% to 20% of the time of the
Assistant Radiation Safety Officer. If levels of risks were to be presented in all of the
radiation protection lectures, an additional 5% of the Assistant Radiation Safety
Officer's time would be required, on the average.
35
-------
7. Impact of the Guidance for Protection of the Unborn
The hospital has been operating under Alternative a for at least four years, and this has
apparently worked satisfactorily. Four women are known by the RSO to be pregnant,
and each of these has elected to be removed from tasks which might expose the unborn
to a dose in excess of 0.5 rem. In three of the four cases, it was possible to shift the
individuals' jobs within their Departments. In the fourth case, it was necessary to
transfer the individual out of her Department (cardiac catheterization).
Considerable concern was expressed about Alternative b. It is possible to manage the
known pregnancies, however it is felt that the "suspected" pregnancies might number in
the hundreds. This Alternative could play havoc with the nursing supervisors. (As an
aside, the new pregnancy test was discussed. Apparently, the HCG test is 98% accurate
and is relatively inexpensive. If this or a similar pregnancy test were adopted, the test
could possibly be worked into the resulting rule so as to prevent the self-serving use of
this guidance.)
The promulgation of Alternative c would result in very strong objections from the
physicians as well as the administrative staff of the hospital. In 1980, 4-5 individuals
on the average, mostly in nuclear medicine, received monthly exposures in excess of 0.2
rem. It is estimated that at least 20 - 30 individuals (mostly females of child-bearing
age) could potentially receive monthly exposures of this magnitude. If these individuals
were to be removed from jobs with potential monthly exposures greater than 0.2 rem,
they could not work in nuclear medicine, cardiac catheterization, or special procedures
in diagnostic X-ray. These departments are very short of personnel. It would be very
difficult to fill these 20 - 30 positions with males or non-fertile females. The labor pool
does not exist because the pay is relatively low and there does not exist a career ladder.
8. Impact of Internal Exposure and Combined External Exposure Guidance
The policy with respect to monitoring for internal exposures varies from group to group.
Much of the program focuses on radioiodine, since the current Radiation Safety Officer
was hired four years ago to control a problem the hospital was experiencing at that
time with radioiodine. Air monitoring (counting of charcoal filters) for radioiodine is
now routinely carried out in the areas in which it is handled. (The only other air
36
-------
concentration measurements in the hospital are performed in the room in which Xe-133
is handled.) Assays are performed on anyone working with free iodine in excess of 500
-jpLCi at a shot. Technologists involved in iodine therapy are encouraged to do an uptake
count within 24 hours of potential exposure. Occasional checks are made of people who
work with radio-immuno-assay. Once a month, routine thyroid uptake counts are made
on everyone in nuclear medicine.
The proposed new MFC's based upon new models (Table Bl of EPA 520/4-81-003) do not
appear to cause a problem at this hospital. However, the required procedure of
combining the exposures to individual organs, as well as adding in the external exposure,
would be a departure from existing practice. This is simply not done at the present
time. It was agreed that this is implicit in the current guidelines, at least when one
combines MFC's, but it is simply not routinely done. It was felt, however, that
combining body burdens, or correspondingly, intake factors, is not implicit in the
current guidance. In the case of body burdens, each organ is currently viewed
independently.
Notwithstanding the foregoing and after quantitative evaluation of the estimated
current internal uptake of radioisotopes at the hospital, it is not expected that the
implementation of the proposed guidance would involve significant costs at this
institution.
9. Impacts of the Reduction of the W.B. RPG to
1.5 Rem/year
In 1980, approximately 30 individuals, or 7% of those monitored (approximately 15% of
those with measurable exposures), received whole-body exposures in excess of 1.0 rem.
Most of these were in the Department of Radiology (only two in cardiac catheteHza-
tion, where the film badge is routinely worn under the lead apron), and it is estimated
that approximately 50% of them were physicians or residents.
It is felt that some of these higher exposures can be reduced by altering work practices.
Rotation of personnel is already routinely carried out in the Division of Nuclear
Medicine.
Although it is difficult to quantify, at least some additional personnel (probably not as
many as 30) would have to be hired in order to comply with a reduced W.B. RPG. The
37
-------
collective dose would no doubt increase. Without conducting a detailed analysis, it was
felt that the purchase of capital equipment to further reduce exposures would be more
expensive than hiring additional personnel.
The difficulty in recruiting sufficient personnel to satisfy this hospital's current needs
was discussed earlier in connection with the guidance relating to the unborn.
It should also be noted that this is a teaching hospital, so that some of the exposures,
particularly to residents, may be higher than would be encountered in a non-educational
environment.
38
-------
A.3 MEDICAL CENTER
This medical center, located in the suburbs of a large metropolitan area, is affiliated
with a major medical school. With approximately 500 beds in the hospital (almost
always at full capacity), there are roughly 3,700 employees. Additionally,
approximately 500 laboratories at the university (80% of them at the medical school),
use licensed radioisotopes in research programs.
Most of the exposures to radiation occur in the Department of Radiology, which is
comprised of three divisions. The Radiotherapy Division has three linear accelerators,
two therapeutic X-ray machines (one of which is very low energy for superficial
therapy), and three X-ray simulators (to set up patients for linear accelerator therapy).
Approximately 70 people in this division are monitored for radiation exposure. Roughly
120 patients are treated daily with the linear accelerators. The Division additionally
performs approximately 100 implants annually (primarily Cs-137, Ir-192 and 1-125).
Approximately 200 employees are monitored in the second division of the Department
of Radiology, Diagnostic Radiology. This Division operates 44 radiographic X-ray
machines, 13 fluoroscopic X-ray machines, and four CAT scanners. Roughly 5,000 -
6,000 patients undergoing 6,000 - 7,000 examinations are seen monthly. The third
division, Nuclear Medicine, performs approximately 350 scans monthly and monitors
approximately 40 individuals.
The second department that uses ionizing radiation is Cardiology. With approximately
90 monitored employees, two radiographic and three flouroscopic X-ray machines are
used in the cardiac catheterizations of approximately 200 patients, on the average,
each month. Approximately 100 personnel in the Department of Nursing Services who
may be exposed to patients undergoing brachytherapy are also monitored. Finally,
approximately 600 - 700 individuals who conduct research in hundreds of laboratories at
the University (approximately 80% at the medical center) are monitored.
The monitoring policy is to provide individual monitors to all technologists, dosi-
metrists, faculty, residents, and medical students (also, clerical workers in the Division
of Nuclear Medicine) working in the Department of Radiology. Additionally, all
39
-------
personnel working in the cardiac catheterization laboratory are monitored. Nurses on
floors with patients undergoing brachytherapy (with greater than 10 mg of radium
equivalent), operating room nurses, and pediatric intensive care nurses (who may hold
infants during radiographs) are also monitored. Also, technologists who conduct RIA's
(in the Department of Pathology) are monitored. Every few years, clerical and
maintenance personnel are monitored for a few months' period in order to confirm that
their exposures are negligible. Monitoring is largely accomplished with film
($.45/badge/month), although the results are checked from time-to-time with TLD's (it
is claimed that up to 20 mr/month of high energy photons may be missed with film at
low doses).
Whole-body exposure distributions are given for 1980 in the attached Table. (Whole-
body monitors are worn over the lead apron.) Only one individual received a dose in
excess of 1.0 rem. The actual dose was approximately 3 rem to a technologist involved
in brachytherapy. Most of the exposure was obtained during one incident in which the
individual involved had not been fully trained. Thus the exposure was avoidable. For
personnel involved in brachytherapy, digital dosimeters are routinely assigned, so that a
real time estimate of exposures may be obtained. This has had a significant impact in
lowering doses. The Table includes data on one of the many research groups which is
monitored at the medical center. The exposure distribution for the Biochemistry
Department is typical for this category.
A outside nuclear pharmacist is used to prepare most of the unit dosages for the
Division of Nuclear Medicine. (A molybdenum generator is available to prepare
emergency Tc-99m dosages.) Whole-body exposures to in-house nuclear medicine
personnel did not decrease significantly after the hospital went to an external supplier.
Rather, the whole-body exposures previously received when preparing unit dosages were
traded off for exposures obtained from inspecting the shipments when they arrive from
the supplier. Approximately 80% of the exposure obtained in nuclear medicine comes
from imaging.
This facility has a substantial Radiation Safety Office (RSO). The Director has a Ph.D.
in biophysics. Of the four to five professionals reporting to the Director, one has a
Ph.D. in nuclear physics, another an M.S. in radiological physics, and the remainder
bachelor's degrees in basic sciences. Although none of these professionals is certified in
health physics, each of them has ten years or more of experience in the Office, and
40
-------
WHOLE-BODY EXPOSURES FOR THE YEAR 1980
(Numbers of Individuals)
Exposure Range
(rem)
Less than measurable
^0.10
0.10-0.25
0.25 - 0.50
0.50 - 1.00
M.OO
Radiotherapy
24
25
4
1
0
1
Diagnostic
Radiology
54
63
23
9
3
0
Nuclear
Medicine
10
9
4
0
0
0
Cardiology
30
23
9
3
4
0
Biochem
101
1
0
0
0
0
-------
each could pass the certification examination with relatively little effort. AdditionaUy,
there are four to five technicians in the Office, one of whom with an advanced degree
in physics. Two to three clerical personnel round out the office.
The level of staffers in the RSO has remained constant over the past 10 - 12 years. The
current budget is approximately $450,000 per year. The range of salaries for the
professionals is $27,000 to $42,000. The technicians earn from $15,000 to $27,000
annually. This is somewhat lower than the salaries of radiologic technologists, who
earn between $20,000 and $30,000 annually.
In addition to this medical center, the RSO is also responsible for radiation protection
at a VA hospital in the same community. This is also a teaching hospital affiliated with
the same university. Although the VA hospital is larger (roughly 600 beds), it consumes
less than 20% of the resources of the RSO. Finally, the RSO performs specialized
consulting for two medical centers in adjacent communities (consuming less than 5% of
its resources).
Other radiation professionals are available in the medical center. The Radiotheraphy
Division directly employs five medical physicists; they are involved in therapy planning,
not radiation safety per se. Two are faculty members and three are on the clinical
staff.
With the exception of the radiologic technologists, board-certified radiologists,
and nuclear medicine physicians, radiation workers at the medical center are required
to satisfactorily complete a questionnaire with 50 questions on radiation protection
before they are allowed to work with sources of ionizing radiation. Alternatively, they
may take a five-hour course given monthly; the choice is made by their supervisors. If
the individual fails the questionnaire, he or she is required to attend the formal course.
The course includes a quantitative discussion on levels of risks. A new manual is being
produced which will also cover levels of risk from radiation.
Radiologic technologists are exempt from the test because they must be registered by
the state, which requires its own examination. (This state also requires radiological
physicians to be registered.) Residents in radiotherapy are administered a formal four-
hour course in radiation protection by the RSO. For new residents in nuclear medicine,
42
-------
a one-on-one discussion with an instructor from the RSO is held. Finally, nurses
potentially exposed to patients undergoing brachytherapy are instructed on the princi-
ples of radiation safety by a member of the RSO at their work locations in the ward.
1. Impact of Reduction in W.B. RPG
The reduction in the allowable W.B. RPG from 3 rem/qtr. to 5 rem/yr. would haye no
impact at this medical center. The highest whole-body exposure over the past several
years was 3 rem, received by a technologist involved in brachytherapy in the Division of
Radiotherapy. However, as discussed earlier, this was more in the nature of an incident
than a routine exposure.
2. Impact of Reduction in Accumulated Exposure Limit
The imposition of the proposed accumulated exposure limit would also have no impact
at this facility. Some of the older physicists at the University have accumulated whole-
body exposures in the range of 20 to 30 rem. The accumulated exposures of a few of
the physicians are somewhat in excess of 10 rem. However, there are no accumulated
exposures anywhere near 100 rem, and given the existing radiation protection program
at this facility, there are not likely to be any near this level in the future.
3. Impact of Proposed Guidance Relative
to Extremities and Individual Organs
In 1980, one individual received an exposure to the hands of 20 rem. This was the same
person who received an anomalous whole-body exposure of 3 rem. In general,
individuals likely to receive significant hand exposures wear ring badges. In 1980,
approximately 8% of those who were monitored for whole-body exposure were also
monitored for hand exposures. (Most of the individuals in the Division of Nuclear
Medicine wear finger badges.) Typically, a couple of individuals each year receive
exposures to the hand as high as approximately 3 rem.
Exposures to the eye lens are not routinely monitored. However, occasional checking
with TLD's has revealed that exposures to the eye are roughly comparable to whole-
body exposures measured at the collar. Because most of the angiograms and cardiac
catheterizations are performed by teaching fellows and residents on a part-time basis,
43
-------
exposures measured at the collar level are low. If these procedures were performed on
a full-time basis, annual doses at the collar level as high as 1.2 - 1.8 rem would be
anticipated. Notwithstanding the lack of impact of this proposed guideline, it is felt to
be unwarranted because it is not justified by the available cataract data.
4. Impact of Proposed Guidance for Potential Exposures
in the Range of 0.3 to 1.0 RPG
As discussed earlier, there are no tasks undertaken at this facility for which annual
whole-body exposures are anticipated to exceed 1.5 rem. If angiograms or cardiac
catheterizations were performed on a full-time basis, eye lens exposures would be in
this range. However, as discussed in the previous paragraphs, residents and teaching
fellows perform these procedures on a part-time basis. Thus there would be no cost
impact at this facility from the promulgation of this proposed guideline as a regulation.
Nevertheless, it is felt that this guideline is thoroughly unrealistic. The net result of
this guideline at a typical medical facility would be another individual potentially
exposed. Moreover, the opinion was expressed that the continual presence of this
individual could possibly make workers feel "edgy," resulting in more time spent on
procedures (implying higher exposures) and potentially more accidents. It was felt that
this guideline does not make sense from a radiation protection point of view. After
some discussion, it was generally agreed that most facilities, rather than complying
with the provision of this guideline, would do whatever is required to reduce anticipated
exposures below 1.5 rem (thus possibly accomplishing the desired goal).
5. Impact of Proposed Guidance for Potential Exposures
in the Range of 0.1 to 0.3 RPG
As seen by the data given in the attached Table, some departments (notably diagnostic
radiology and cardiology) expose personnel in this range. Although a small percentage
of the total number of personnel, exposures may nevertheless be "anticipated" in this
range. Personnel monitoring is routinely performed at this facility. Moreover,
supervision is provided by members of the Radiation Safety Office to assure that
exposures are justified and ALARA. Although there are no certified health physicists
on the RSO staff (medical physicists are members of the Radiotherapy Division), it is
44
-------
felt that all or several of the 5-6 professionals in the office have backgrounds and
experience equivalent to certified health physicists. Also, the opinion was expressed
that this guideline is a "reasonable" requirement.
6. Impact of Training Requirements
The existing training program, which was discussed earlier, generally satisfies the
proposed guidelines. The basic course includes an hour of physics, an hour of biological
effects, an hour on surveys and dosimetry, and a half-hour each of regulations and dose
reduction techniques.
7. Impact of the Guidance for the Protection of the Unborn
This facility is currently operating under, and has been for over a decade, the original
Alternative d (keep dose to both males and females less than 0.5 rem in any six-month
period). Moreover, if a fertile female announces that she is pregnant or desires to
become pregnant, she is removed from assignments in brachytherapy, and additional
monitoring is performed in an attempt to keep her exposure as close to zero as possible.
This policy has the whole-hearted support of the faculty.
8. Impact of Internal Exposure and Combined
External Exposure Guidance
This facility conducts an extensive assay program for internal exposures on nuclear
medicine technologists. Once a year, whole-body counts are taken. These counts have
revealed internal exposures, but they have generally dissipated within 24 hours,
implying clearance from the gastro-intestinal tract. Thyroid scans are routinely made
on everyone working with radioiodine (mostly those involved in research). This facility
is operating under the 15 rem/yr. thyroid limit recommended by the NCRP. Using
external counts, thyroid burdens corresponding to 1% of this limit can be readily
detected. Finally, urinalyses are routinely performed for all personnel who work with
greater than 100 mCi of H-3, and when appropriate for those working with P-32 and S-
35, particularly when they are handled in a volatile form.
Ease of compliance with the proposed weighted guidelines (either the EPA weighting
scheme or that recommended by the ICRP) would depend on their interpretation by the
regulators. If the regulators were to require detailed records of internal exposures,
45
-------
there could be considerable difficulty in compliance. At present, reporting is only
required if MFC's are exceeded. But at least a half of internal exposures result from
contamination of the hands. If an assay reveals measurable internal deposition, the
fraction of the permissible body burden is determined presently. The organ dose is
generally not calculated.
Possibly a half dozen times a year a non-negligible body burden is detected at this
facility. To calculate internal organ dose, possibly two person-days of effort might be
required. To get "really good numbers" might require even more effort.
The question is how this provision would be enforced by the regulators. If it were to be
enforced to the same degree that the existing internal exposure guidance is enforced,
there would be no significant costs at this facility, or for that matter, at hospitals in
general. After all, internal dosimetry is rarely done at most facilities.
9. Impact of the Reduction of the W.B. RPG
to 1.5 Rem/yr.
In 1968, the commitment was made at this facility to operate under an internally-
mandated W.B. RPG of 0.5 rem. The Radiation Safety Office was expanded (originaUy
with a budget of approximately $200,000 per year; the current budget, at roughly the
same level of manpower is roughly $450,000 per year*). It took approximately two
years to reach the goal, and a continual effort to maintain it. Moreover, the reductions
in maximum individual exposures were not accomplished at a sacrifice in collective
dose. In fact, the collective dose over the past 12 years has been reduced from
approximately 100 person-rem to approximately 10 person-rem.
These achievements have been attained using few gimmicks and little in the way of
capital expenditures. The method can be best described as a constant ratchet. A lot of
time was spent by RSO staff monitoring individual tasks. The dose-intensive compo-
nents of each task were identified. Procedures were revised for these components,
resulting in lower doses. Once these new procedures were in place, the RSO would
*
Note that the RSO also has responsibilities outside of this medical facility (consuming
an estimated 25% of the resources). See the earlier discussion.
46
-------
make sure that they were continually followed. These procedures could be as simple as
keeping nuclear medicine personnel out of the room during imaging. Personnel were
constantly drilled on the fact that once the patient is injected, the patient is henceforth
a source.
Technology also played a role. The use of syringe shields substantially reduced
occupational exposures in Nuclear Medicine. Also, as discussed earlier, digital
dosimeters in brachytherapy sensitize personnel to accumulated exposures in real time.
Management procedures in the RSO also played an important role. Each professional is
assigned dose reduction goals for a specific division under his or her cognizance.
Annual reviews are based in part on the progress made in achieving these goals. In the
opinion of one of the professionals, personal pride plays as much of a role in motivating
the staff as the potential for financial reward.
Concern was expressed about the nuisance of the reporting requirement should the
lower RPG be exceeded (which has occurred once over the past two years).
47
-------
A.4 SMALL HOSPITAL
This 230-bed hospital is located in a suburb of a relatively large metropolitan area.
Operating at 80 - 85 percent of capacity at the time of the case study, the facility
employs approximately 650 personnel. There are two departments in which radiation
sources are are used — Radiology and Nuclear Medicine.
The Department of Radiology has six fixed diagnostic X-ray machines, one mobile
fluoroscopy unit and three portable diagnostic units. Approximately 45,000 procedures
are performed annually, high for a facility of this size and for the number of machines
available. There is no CAT scanner within the hospital (the radiologists operate one in
their offices outside of the hospital). A therapy program is planned for the future.
Most of the fluorpscopy is performed during the scheduled portion of the week, which is
eight hours, seven days. However, only about one-half of the total number of
procedures are performed during the scheduled hours of the week.
The Department is operated by seven radiologists, who also maintain an outside
practice. Eight part-time radiologists are also affiliated on a part-time basis with the
Department. There are approximately 30 radiologic technologists employed, all of
whom are registered by the American Registry of Radiologic Technologists. The
hospital is affiliated with a community college which trains radiologic technologists.
Other than this program, there is no teaching program or residency within the facility.
The Nuclear Medicine Department is small, with one stationary imaging camera
performing approximately 120 scans per month (down roughly 50 percent from the
period prior to the installation of a CAT scanner in the outside offices of the affiliated
radiologists.) An outside nuclear pharmacy is used to prepare unit dosages, which
consist primarily of Tc-99m, plus small amounts of thallium, gallium, xenon, and 1-131.
The hospital no longer has its own molybdenum generator for the preparation of Tc-99m
dosages. A limited amount of thyroid radiotherapy is also performed with 1-131
(possibly 2-3 times per year). Nearly all procedures are performed during an eight
hour, five-day week.
48
-------
The Department is operated by two full-time pathologists (with no outside practice),
with the assistance of 2 - 3 technologists (two of them registered technologists in
nuclear medicine). Additionally, 6-7 laboratory technologists who perform RIA's and
are officially in a different department are under the radiation protection cognizance
of the Nuclear Medicine Department.
Radiation protection is the separate responsibility of each Department, each of which
maintains its own Radiation Safety Officer (physicians). The Manager of the Radiology
Department (B.S. in Radiology Administration and A.A. in Radiologic Technology; four
years of experience at this hospital) maintains cognizance over personnel outside of
these departments, such as nursing services. He also conducts surveys and coordinates
personnel monitoring for all departments outside of nuclear medicine. He is assisted in
these radiation protection activities by the Chief Technologist in the Department of
Radiology.
Once a year, a certified health physicist is called in to check the X-ray tubes for
leakage. He may also be consulted from time to time on questions relating to shielding.
For example, he was retained to specify the shielding requirements for a new special
procedures' room.
The Chief Technologist in the Nuclear Medicine Department assists the Radiation
Safety Officer (Nuclear Medicine) in coordinating radiation safety. She has an A.A. in
Laboratory Technology augmented by 6 - 8 weeks in a local hospital with a nuclear
medicine department, and approximately nine years of experience in this hospital.
All employees in the Radiology Department, including Aides (file clerks, transport
workers, and darkroom technicians), are monitored for whole-body exposure. Badges
are worn above the apron, on the collar, for all technologists except those assigned to
angiography. The technologists in angiography and all of the radiologists additionally
wear under-the-apron badges. Most (79%) of the annual exposures are less than
measurable. The remainder are less than 0.5 rem, with five individuals receiving
greater than 0.5 rem, the highest exposure of which was approximately 1.5 rem in the
most recent 12-month period (the reading might have been attributable to accidental
exposure of the badge). The exposures to the Aides in the Radiology Department are
usually less than measurable.
49
-------
Only the two personnel in Nuclear Medicine who inject patients receive measurable
whole-body exposures. Over a recent 12-month period, these exposures ranged from 0.5
to 1.0 rem. The technologists who perform RIA's receive no measurable whole-
body exposures.
Approximately 30 nurses assigned to the operating room (because of the potential
exposure from mobile fluoroscopy) to the floor on which brachytherapy patients are
assigned, and to pacemaker surgery, are monitored. All of these exposures were less
than 0.1 rem in a recent 12-month period.
A few badges are also assigned to the cardiologists and anaesthesiologists involved in
pacemaker surgery, and to the EKG technologists and cardiologists involved in thallium
stress testing. Recent annual exposures to these individuals were less than 0.4 rem.
Finally, control badges, which indicated fields less than 0.05 rem per year in a recent
12-month period, are mounted in the intensive care and coronary care rooms.
In total, approximately 70 film badges are assigned to personnel. They are read
monthly by an outside dosimetry service at a cost of $1.25/badge/month.
There is.no formal training program in radiation protection at the hospital. Only
registered technologists are hired, and they are instructed in radiation protection
principles in the course of their two-year training programs. At least one of the
colleges offering such a degree features a one-semester course in health physics.
Student technologists hired by the hospital must pass the registry examination within
six months of the date of their employment.
New hires get a two week orientation in their departments. Additionally, quarterly
staff meetings are held to go over problem areas. Non-radiologist physicians are only
allowed to operate radiation equipment under the supervision of a radiologic technolo-
gist. Nurses and Aides get instruction in the use of the lead-lined apron and where to
stand during procedures involving sources of ionizing radiation.
One of the reasons given for the lack of a formal instructional program in radiation
protection principles is the high turnover rate of nursing staff. If such a program were
initiated, the staff is prepared with a slide show put out by the Bureau of Radiological
Health (however, this may be oriented toward minimization of dose to patients.)
50
-------
Radiologic technologists earn between $13,500 and $17,000 per year. These salaries are
comparable to, and possibly somewhat on the high side of those of ordinary laboratory
technologists.
1. Impact of Reduction in W.B. RPG
There would be no impact at this facility of a change in the W.B. RPG from 3
rem/qtr. to 5 rem/yr. The highest exposure recorded over a recent 12-month period
was approximately 1.5 rem, to a technologist involved in angiography. Angiography is
the highest exposure procedure because the fluoroscope may be on for relatively long
periods of time — possibly as long as one hour. However, even this measured dose was
not indicative of the real whole-body exposure, since it was measured at collar level
and may have been an accidental exposure to the badge. The under-the-apron exposure
for the same individual was .020 rem.
The opinion was expressed that higher exposures are likely to be seen at teaching
hospitals, since residents are not familiar with radiation protection principles. For
similar reasons, high exposures are likely to be recorded for cardiac catheterization.
2. Impact of Reduction in Accumulated Exposure Limit
There would be no impact at this hospital from a reduction in the accumulated exposure
limit from 5(N-18) to 100 rem. The highest accumulated exposure is 4.3 rem to a
physician.
This is a realistic objective for any hospital. A problem could conceivably be
encountered in cardiac catheterization. However, given proper shielding and
instruction, there is no reason why this limit could not be met at any hospital.
This hospital encounters little difficulty in obtaining records from previous employers.
3. Impact of Proposed Guidance Relative to Extremities and Individual Organs
Finger badges are worn in nuclear medicine and RIA. Measured levels in RIA are
negligible. The maximum in nuclear medicine over a recent 12-month period was
approximately 2.5 rem. Hand doses were considerably higher when unit dosages were
prepared in-house. However, the highest annual dose measured by a ring badge at that
time was 4.0 rem, considerably below the proposed 50 rem guideline,
51
-------
There is some suspicion that some of the radiologists may be pushing up against the
limits, since the largest exposure during fluoroscopy is to the hands of the radiologist.
However, hand exposures are not monitored since it is allegedly difficult to wear ring
badges under the sterile gloves.
Eye monitoring has never been carried out. However, there is no reason to believe that
the lens of the eye receives any higher exposures than the monitor worn on the collar.
As discussed earlier, the highest measured exposure to the collar monitor over a recent
12-month period was 1.5 rem. Therefore, the proposed limit of 5 rem to the eye lens
would have no impact at this hospital.
4. Impact of Proposed Guidance for Potential
Exposures in the Range of 0.3 to 1.0 RPG
Unless above-the-apron monitors are considered indicative of whole-body exposures,
exposures to personnel are not "anticipated" in this range. If they were, the only
procedure in which annual exposures would be anticipated to exceed 1.5 rem is
angiography. Over a recent 12-month period, one individual involved in angiography
received approximately 1.5 rem, measured at the collar level.
Roughly 2-3 angiograms are performed daily in one special procedures' room. The
average procedure takes two hours, only approximately 15 - 20 minutes of which is
actual fluoroscopy time. Therefore, it may be conservatively estimated that monitor-
ing would be required under the proposed guideline for a period of 1 - 2 hours per day.
There are presently no personnel in the hospital with backgrounds and experience levels
equivalent to those of health physicists or medical physicists. The closest is the
Manager of Radiology, who has a B.S. in Radiology Administration. Therefore, to
comply with the monitoring and supervision requirements of these guidelines, a full-
time health physicist or medical physicist would have to be hired (subject to the
resolution of the question regarding the whole-body exposure monitor location).
5. Impact of Proposed Guidance for Potential Exposures
in the Range of 0.1 to 0.3 RPG
At least two individuals in Nuclear Medicine and five in Radiology received exposures
over a recent 12-month period in excess of 0.5 rem. Therefore, it may be "anticipated"
that personnel in these two departments would receive annual exposures in excess of 0.1
RPG.
52
-------
The monitoring requirements of the proposed guidelines are currently being carried out.
To a lessor extent, so are the supervision requirements. However, there are no
personnel currently employed by the hospital with backgrounds and experience equiva-
lent to those of health physicists or medical physicists. Therefore, a consultant would
be retained to satisfy this requirement. As discussed earlier, a certified health
physicist is used once a year to check the X-ray tubes. It is envisioned that this
individual would be consulted to ensure that exposures are justified and ALARA. it is
estimated that this could be done on an annual basis in 2 - 3 days, at a consulting cost
of $500 - $1000.
6. Impact of Training Requirements
It is felt that at least in the case of the technologists, instruction in radiation
protection principles is the responsibility of the schools. Ten years ago, the typical
curriculum in radiologic technology did not include instruction in levels of risk.
Currently, a course in health physics, which does include quantification of risk, is
offered.
If nurses were instructed in radiation protection principles, all 300 nurses would have to
be included, because of rotation. A 1 - 2 hour course is envisioned, in which a video
tape would be shown, followed by questions from the floor. The opinion was expressed
that this would be a good thing because of the large number of questions asked routinely
by nurses about radiation and attendant risks.
7. Impact of the Guidance for Protection of the Unborn
Approximately 75% of the technologists and 90% of the nurses are females; nearly all
of the females are of child-bearing age.
At present, if a female in the Radiology Department announces that she is pregnant
(three are currently pregnant), she is excused from any fluoroscopic procedures. This
limits her dose to less than 0.5 rem for the remainder of her pregnancy. Although the
situation has not been encountered in Nuclear Medicine, the dose to a pregnant
technologist could be limited to less than 0.5 rem over a nine-month period by limiting
her activities (i.e., no more injection of patients, even though shielded syringes are
used). This could easily be accomplished.
53
-------
If a technologist announced her intention to become pregnant, she could be pulled out of
fluoroscopy for a month or two (the only procedure for which above-the-apron
exposures in excess of 0.2 rem/mo. are possible). Over a recent 12-month period, two
individuals in the Department of Radiology received above-the-apron exposures in
excess of 0.2 rem in a one-month period. However, it would be impractical to keep
technologists out of fluoroscopy for extended periods of time, as most certainly would
be required under Alternative b. Eventually, they would have to take a leave of
absence. Implementation of Alternative b would be no problem in nuclear medicine,
since there are no jobs in which exposures could exceed 0.2 rem/month.
If under-the-apron measurements were acceptable estimates of whole-body exposures,
there would be no problem in implementating Alternative c, since no one in the
Department of Radiology might be expected to receive an under-the-apron exposure in
excess of 0.2 rem. If not, this hospital would have considerable difficulty in complying
with this guideline.
Remote control fluoroscopy rooms could be installed at an approximate cost of
$450,000 (an existing room could not be adapted). This hospital has three fluoroscopy
rooms. However, angiography would be eliminated because it is impossible to perform
this procedure remotely.
Approximately five technologists (female) work the angiography room. These could be
replaced by five male radiologic technologists, if they could be recruited. There are
probably not enough male technologists in this area to satisfy the demand.
The opinion was expressed (by a female) that Alternative c is not equitable. It is not
fair to hire males exclusively to perform fluoroscopy. Female technologists are aware
of the risks from the start, and if they were not willing to accept the risks, they would
get out of the field.
8. Impact of Internal Exposure and Combined
External Exposure Guidance
)
The only potential for internal exposures in this hospital is in the therapeutic injection
of 1-131 (approximately 200 mCi). Approximately 24 hours after this procedure, a
thyroid uptake scan is performed. However, there have never been measurable uptakes
(in approximately nine years). Moreover, there used to be a lot more 1-131 used in
nuclear medicine. Most of this has been supplanted by Tc-99m.
54
-------
9. Impact of the Reduction of the W.B. RPG to 1.5 Rem/yr.
If under-the-apron measurements were acceptable estimates of whole-body exposures,
this hospital is currently complying with this reduced RPG. If not, the only procedure
for which there might be a problem is angiography. At present, approximately five
technologists and five radiologists work this procedure. A 1.5 rem RPG could be
achieved with rotation of personnel. However, the collective dose would increase.
55
-------
B.1 PRIVATE PRACTICE IN RADIOLOGY
This medium-to-large private medical practice, encompassing two private offices and a
medium-sized, parochial hospital (approximately 450 beds), is located in a suburban
area. The practice includes nine physicians, all radiologists (most of whom are
additionally certified by the American Board of Nuclear Medicine).
The two private offices are located within a mile of the hospital and are open eight
hours a day, five days a week. The offices contain four radiography and fluoroscopy
units and three straight radiography units (two of which are used for mammograms), all
of which are single phase. Soon, a CAT scanner will be added to the list of equipment.
Approximately 60 patients are seen daily. The support staff in these offices is
comprised of seven technologists, four typists/receptionists, and one darkroom
technician. The larger of the two offices is always staffed by a physician; a physician is
usually physically located at the smaller office, or is available on short notice.
The physicians in this private radiology practice also run two of the departments in the
hospital — radiology and nuclear medicine. This includes the monitoring of personnel
and the responsibility for radiation safety. One of the physicians is the Radiation
Safety Officer for the hospital. His responsibilities extend to the use of radiation
sources in the operating room and the emergency room. (The hospital does not perform
radiation therapy — except an occasional thyroid implant — or heart catheterizations.)
The radiology department in the hospital encompasses 13 X-ray units and one CAT
scanner. Angiography is performed in the hospital, but not in the private offices. The
department employs approximately 60 full-time equivalents.
The nuclear medicine department performs approximately 475 scans monthly. Almost
all of the scans are made using Tc-99m. Some gallium is used for scans of the abdomen
and chest; radioiodine is frequently used for thyroid uptake, and xenon for lung scans.
An occasional thyroid therapy is also performed by the nuclear medicine department.
56
-------
Most of radiopharmaceuticals are now purchased from an outside supplier as single unit
dosages. This results in lower exposures to the technologists. Radioiodine dosages are
still prepared within the hospital. The nuclear medicine department employs approxi-
mately 10 full-time equivalents.
It is estimated that approximately 150 patients are seen daily in the hospital. Most of
these patients are seen during regular hours — 7:30 a.m. to 10:30 p.m., five days per
week, plus a half day on Saturday.
It is policy to monitor all physicians and technologists, but not clerical personnel or
nurses. Badges are now worn outside the apron at the collar level, as required by the
state, although at one time it was standard procedure to wear badges under the apron.
It is felt that collar level badging is good radiation protection practice, as long as the
readings are within limits. If not, two badges should be worn, one inside and the other
outside the apron, using the inside badge as a measure of whole-body exposure. As a
matter of fact, double badging is done at this facility for angiography procedures.
It is also standard practice at the hospital to wear ring badges in the nuclear medicine
department. Ring badges are seldom worn in radiology, although a physician performing
arthrograms receives average hand exposures of approximately 0.13 rem/month. The
hand is never placed in the primary beam.
During the year 1980, approximately 80 personnel, including those in the private offices
were badged. Of these, 80% received measurable whole-body exposures. The average
exposures were 0.05 rem to the physicians and 0.1 rem to the technologists. The
maximum exposure was approximately 0.9 rem, to a nuclear medicine technologist. No
personnel received exposures in excess of 1.0 rem.
The technologists are typically female, ranging in age from 20 to 30 years. The salary
range is $10,000 to $15,000 annually.
Although the hospital is not a teaching facility, some of the interns and residents are
drawn from a medical school in the metropolitan area. None of these, however, are
currently in radiology, although some instruction is provided to them about procedures
in radiology.
57
-------
1. Impact of Reduction in W.B. RPG
The reduction in the allowable annual whole-body exposure from 12 rem to 5 rem would
have no impact. The highest annual exposure in 1980 was roughly 0.9 rem, greater than
a factor of five below the proposed limit.
The opinion was expressed that the main problem in radiation safety is the use of
radiation sources by physicians not properly trained in their utilization. These are
usually internists, orthopedists, or cardiologists with small practices who have little or
no appreciation for radiation safety. They do not generally employ trained technolo-
gists, and even the quality of the X-rays is poor.
2. Impact of Reduction in Accumulated Exposure Limit
The reduction of the accumulated exposure limit from 5(N-18) rem to 100 rem would
have no impact. In fact, the opinion was expressed that the accumulated exposure limit
could well be even lower.
In this practice, the highest accumulated lifetime whole-body dose for a physician is 3.7
rem and for a technologist, 11 rem (in nuclear medicine for 15 years). The physician
who founded the practice 15 years ago has accumulated 0.8 rem. (Some of the time
that these whole-body exposure were accumulated, the film badges were worn under the
apron.) This experience suggests that the cumulative exposure limit could be set at 25
rem, although this might be cutting it a trifle thin.
3. Impact of Proposed Guidance Relative to Extremities and Individual Organs
Neither the proposed limit on the hands nor that on the eye would pose a problem. Only
the individuals in nuclear medicine routinely wear ring badges. For these, the maximum
cumulative hand exposure is 43 rem, obtained over a period of 15 years. Thus the
proposed limit is a factor of 15 higher than the high average annual hand exposure.
Although it is possible to get a significant dose to the hands in radiography, the
radiologists are trained to avoid direct exposure to the beam unless lead gloves are
being worn.
58
-------
Dose to the eye has never been directly measured. Assuming that the collar-level
reading is an appropriate surrogate for the eye, the maximum cumulative lens dose is
6.1 rem over ten years, or only approximately 0.6 rem/year, on the average. This
exposure was accumulated by an individual who performs angiograms. Thus, the
proposed 5 rem limit to the eye would not pose a problem for this practice.
If the eye limit were to pose a problem, it could be easily rectified by providing lead
glasses to the staff. The cost would be minimal and there would be little resistance to
wearing them.
4. Impact of Proposed Guidance for Potential Exposures
in the Range of 0.3 to 1.0 RPG
Noone employed by the practice is anticipated to receive an annual whole-body
exposure in excess of 1.5 rem, since there were no whole-body exposures in excess of
1.0 rem in 1980. Therefore, a full-time "radiation protection professional" would not be
required for this practice.
If a supervisor were to monitor procedures involving significant exposures, it is not
clear what would be learned through such monitoring. The dose rate for each procedure
is relatively constant. Therefore, the exposure received is a function of the time spent
on each procedure. This varies, depending on a number of random factors. "If you're
putting in a pacemaker and it takes too long, what do you do, stop?" To summarize, the
opinion was expressed that monitoring during procedures performed by this practice
would accomplish little in reducing occupational radiation exposures.
Another issue relates to the definition of a "radiation protection professional". The
Radiation Safety Officer is a Board-certified radiologist. He studied the physics of
radiation and is interested in radiation safety. However, he is not trained in radiation
protection. Therefore, strictly speaking, his background and experience is not equiva-
lent to that of a "radiation protection professional." Thus, if "radiation protection
professionals" were required to monitor the procedures of this practice, they would
have to start from scratch in employing them. The opinion was expressed that there
aren't enough medical physicists to satisfy the requirements in just this one metropoli-
tan area.
59
-------
5. Impact of the Proposed Guidance for Potential
Exposures in the Range of 0.1 to 0.3 RPG
At present, the practice is monitoring all individuals expected to receive exposures in
excess of 0.5 rem/year. In fact, 20% of those monitored received no measurable
exposure at all in 1980.
The supervision provision of the guidance, however, may pose a problem. Presently, a
part-time physicist is used as a consultant to checkout and calibrate the X-ray units.
He comes in twice a year, but would hardly be defined as "available" for purposes of
ALARA monitoring. Thus, the responsibility for assuring that exposures are justified
and ALARA falls on the shoulders of the Radiation Protection Officer. He keeps up
with NRC guidelines, coordinates with the State, and reviews the radiology literature
relating to radiation protection. On the average, he spends somewhat less than 10% of
his time on radiation safety matters. However, as discussed earlier, he does not
consider himself a "radiation protection professional" or its equivalent. The hospital
has a research committee that reviews new procedures, but it is not interested in
radiation. Therefore, the supervisory function called out in this guideline is not
currently being provided.
6. Impact of Training Requirements
There is no formal training in radiation protection provided to the employees of the
practice, either those in the office or those in the hospital. Weekly conferences are
held in the hospital, but these are rarely concerned with radiation. The technologists do
occasionally attend formal hospital lectures devoted to radiation protection principles.
There are no corresponding lectures for physicians, nurses, or clerical personnel
potentially exposed.
The technologists get training in radiation protection principles during their formal
education. This consists of a two-year program at a junior college. This program
includes quantitative guidance in levels of risk.
7. Impact of the Guidance for Protection of the Unborn
The practice is presently operating within the framework of Alternative a. All female
workers are instructed to inform their supervisors as soon as they know that they are
60
-------
pregnant. If they are in radiology, they are not allowed to do fluoroscopy or portable
X-ray procedures. If they are in nuclear medicine, they are placed elsewhere, or if
there are no available slots, they are asked to take a leave of absence. At present,
there are no known pregnant technologists.
If Alternative b were promulgated, the only workable mechanism would be to ask
women, at the time of hire, if they would avoid jobs with the potential for exposures in
excess of 0.2 rem/month. (The only procedures for which the potential exists for
exposures in excess of 0.2 rem/month are in nuclear medicine, and possibly angiography.
In 1980, noone received an exposure in excess of 0.2 rem in any one month.) If the
answer were affirmative, they wouldn't be hired. If they were hired, and then requested
transfer to other activities not involving potential exposures in excess of 0.2 rem, they
would have to be discharged. It would be too difficult to find other jobs for them within
the hospital.
Alternative c is totally unrealistic and would be unworkable. The biggest problem
would be with the women themselves, who would proclaim that their liberties were
being abridged.
8. Impact of Internal Exposure and Combined External Exposure Guidelines
The only place where internal exposures could be received is in nuclear medicine. At
present, there is no monitoring for internal exposures. However, there are not expected
to be any internal exposures. All Tc-99m dosages are injected. All iodine dosages are
swallowed. The only airborne contamination is from Xe-133, and this is exhaled into a
balloon and allowed to decay. It would be difficult to implement an airborne
contamination control program using MFC's, because the physicians are not accustomed
to working with exponential notation.
9. Impact of the Reduction of the W.B. RPG to 1.5 Rem/year
Because of the relatively low W.B. exposures in this practice, it would be feasible to
reduce the RPG to 1.5 rem/year without a cost impact. However, it is felt that it
would be a mistake to impose this limit at this time. It is cutting it too close for
comfort. It would not allow enough breathing room.
61
-------
B.2 PRIVATE PRACTICE IN NUCLEAR MEDICINE
This is a small private practice in nuclear medicine, which is conducted within the
framework of a large, multi-office pathology practice covering a reasonably large
metropolitan area. Nearly all of the nuclear medicine work is conducted in the main
laboratory, with only an occasional capsule administered in one of the seven branches.
There is an affiliation with the nuclear medicine departments at three moderate-sized
hospitals (one in an adjacent state), but the radiation protection programs at these
facilities are administered by the hospitals (one of which is the subject of a separate
Case Study).
This practice is not typical of the private practice of nuclear medicine in this country.
Only approximately 25% of nuclear medicine is administered by pathologists; most of it
is administered by radiologists (at least 50%); the remainder by a number of specialties.
The trend is toward control of nuclear medicine by the radiologists.
The majority of pathologists (at least 50%) are salaried and work exclusively for
hospitals. Another 30% run hospital pathology laboratories, but do their own billing.
The remainder take a percentage of the pathology lab receipts from the hospital.
There are approximately 25 groups like this practice throughout the country, each
consisting of approximately ten pathologists. It is estimated that there are roughly
10,000 pathologists in the country.
The main laboratory of this practice services approximately 300 patients daily. Out of
this patient load, approximately 100 radio-immuno-assay (RIA) procedures are per-
formed daily. (Several RIA procedures may be performed for a single patient.) The
number of scans, however, averages only approximately ten per week. Additionally,
approximately 20 patients per year are treated for thyroid cancer on an outpatient
basis.
Most of the RIA's use small amounts of 1-125 or 1-131 (generally less than 10^_LCi). Most
of the actual work is performed in well counters. The exposure to personnel is
negligible.
62
-------
The out-of-hospital procedures are limited to intakes of 30 mCi (according to the limits
set by the NRC). For this reason, exposures to office personnel are low. Because of
the intake limitations, the trend is toward hospital practice of nuclear medicine,
exclusively.
Four individuals at the main laboratory come into contact with radioisotopes. These
are three technologists and one of the pathologists. (Only one of the nine pathologists
in the practice is involved in the practice of nuclear medicine.) Two of the three
technologists generally confine their activities to RIA.
Approximately four years ago, the decision was made to buy unit dosages from an
outside nuclear pharmacist. Prior to that time, a molybdenum generator was used to
produce Tc-99m, and exposures were somewhat higher (although primarily to the hands).
It is the policy to provide individual monitors to only those individuals who work with
radioisotopes. The other 47 employees at the main laboratory are not monitored.
Moreover, with one exception, the one or two individuals (generally a receptionist and a
technologist) at each of the seven branches are unmonitored. The exception is a branch
that conducts routine chest X-rays as part of a contract to provide pathology services
to a government agency. Personnel at the branches seldom come into contact with
radioisotopes; when they do, it is only to administer a capsule ( <. 50 |J.Ci) for which a
scan is conducted at a later date at the main laboratory.
When radioisotopes were generated at the main laboratory several years ago, hand
exposures were routinely monitored using ring badges. At that time, it was not unusual
for the ring badges to register dosages in excess of 2.5 rem/year. Now that unit
dosages are purchased from an outside vendor, extremity exposures are believed to be
comparable to whole-body doses. Therefore, only whole-body doses are monitored.
An exposure record for the technologists at the main laboratory is provided in the
attached Table. The cumulative lifetime exposure to the pathologist involved in the
practice of nuclear medicine is roughly 0.4 rem. (The exposures for the year 1980 are
not available.) The changeover from the use of internally-generated unit dosages to the
purchase of unit dosages from an outside vendor occurred in 1978.
The exposures displayed in the Table are not typical for the practice of nuclear
medicine. For example, two of the four technologists employed by one of the hospitals
63
-------
List of Technologists with Highest Accumulation of Whole Body Radiation for 1970-1979
ANNUAL EXPOSURE IN HEM Cumulative
Total Whole Body
1970 71 72 73 74 75 76 77 78 79 1970-79
#1
#2
2 #3
4*
#5
#6
0.30 0.33 1
0.77 1.17 0
0
.
.10
.45
.28
0.24 0.
0.
0.44 0.
0.43
0.
0.
61
28
10
49
15
0.31
0.374
0.077
0.09
0.120
0.484
0.397
0.103
0.053
0.159
0.428
0.436
0.082
0.096
0.291
0
0
0
0
.422 0.226
.329
.012
.39 0.024
6
6
1
0
0
.210
.574
.331
.741
.782
-------
affiliated with this group of pathologists receive on the order of 0.2 rem whole-body
exposure monthly. However, approximately 50 scans are performed weekly in this
hospital, compared with the ten scans per week for the private practice.
Nuclear medicine technologists receive lectures in radiation protection during their
regular training program. They learn about radiation levels, the maintenance of
records, the disposition of radioisotopes, etc. They do not receive formal lectures on
the quantitative levels of risk from radiation.
A formal course in medical technology is also given by this pathology practice. Most of
the trainees have three to four years of college prior to taking the course. The course,
which is one year in duration, is recognized by the American Society of Clinical
Pathology. A normal part of the course is training in RIA. If a specialty in nuclear
medicine technology is desired, experience in imaging is obtained at an affiliated
hospital.
Nuclear medicine technologists earn from $15,000 to $25,000 annually. The salary for a
chief technologist could go as high as $30,000/year.
1^ Impact of Reduction in W.B. RPG
The reduction in the allowable whole-body exposure from 3 rem per quarter to 5 rem
per year is expected to have no immediate impact in this practice. As a matter of fact,
reference to the attached Table indicates that annual exposures are running at least one
order of magnitude lower.
However, concern was expressed about the need for flexibility in the future. Should
some breakthrough occur, resulting in the need for higher exposures, it would be
detrimental to have lost the degree of flexibility provided by the existing limits.
Also, concern was expressed about the imposition of the lower limit on some radiology
departments. As a matter of fact, even the practice of nuclear medicine in hospitals
may well be pushing up against this proposed W.B. limit. As discussed earlier,
technologists at a hospital affiliated with this private practice are receiving exposures
as high as 0.2 rem/month.
65
-------
2. Impact of Reduction in Accumulated Exposure Limit
The limit would have no impact on this private practice of nuclear medicine.
Currently, the highest accumulated exposure for a technologist is more than one order
of magnitude below this limit. The accumulated exposure of the pathologist is in excess
of two orders of magnitude lower.
Although some concern was expressed about the remote possibility that this limit could
restrict future experimental work, less concern was expressed about the proposed
lifetime dose limit than the proposed annual limit. That is because there is intrinsic
flexibility in a cumulative exposure limit that is not available in an annual limit. If an
exposure is relatively high one year, the individual can be removed from work involving
high fields of radiation in subsequent years to limit the cumulative exposure.
3. Impact of Proposed Guidance Relative to
Extremities and Individual Organs
There is no reason to believe that exposures to the lens of the eye are any higher than
measured whole-body doses. However, exposures to the hands, when unit dosages were
prepared in-house, routinely exceeded 2 rem/year, and occasionally ran as high as 0.5
rem/month. Now that outside vendors are being used, hand exposures are comparable
to whole-body exposures. However, exposures to the hand were and are well below the
proposed limits (previously, by roughly one order of magnitude, and now by more than
two orders of magnitude).
4. Impact of Proposed Guidance for Potential
Exposures in the Range of 0.3 to 1.0 RPG
It is not "anticipated" that anyone would receive an annual exposure in excess of 1.5
rem in this private practice of nuclear medicine. Therefore, the impact of this
proposed guideline is negligible.
The reason, however, for the relatively low exposures in this practice is probably the
small number of scans. In an affiliated hospital, where the frequency of scans is a
66
-------
factor of five higher, annual doses are anticipated to be greater than 1.5 rem per year.
Therefore, a supervisor would be required to be present before and during each task
"significantly contributing" to the annual exposure. (It was suggested that holding the
patient's head during a brain scan is the largest single contributor to occupational
exposure in the practice of nuclear medicine.)
The question arose regarding the equivalency of the background and experience of a
nuclear physician to a "radiation protection professional." The physician is present
during each scan (he could presumably carry out the monitoring requirements in the
guidelines in addition to his other duties). The pathologist who practices nuclear
medicine in this practice is also the Radiation Safety Officer. He took courses in
physics in college and, of course, took the required six-months' course in nuclear
medicine required for the NRC license. This course includes training in nuclear physics.
He feels that this background should qualify him to satisfy the "radiation protection
professional" requirements of this guideline. He feels that the M.D. degree plus the
NRC license are sufficient to satisfy this requirement. Moreover, he feels that most
radiologists are also equivalent in background and experience to medical physicists.
(This particular physician has additionally trained more than 700 physicians over a
period of 20 years for the NRC license. This two-week course is sponsored by the
American Society of Clinical Pathologists.)
5. Impact of Proposed Guidance for Potential
Exposures in the Range of 0.1 to 0.3 RPG
Although whole-body exposures in this practice have not exceeded 0.5 rem in several
years, they have come close enough to this limit so that it is reasonable to "anticipate"
annual exposures in this range. The individual exposure monitoring requirement of this
guideline has been satisfied for years. The availability of a "radiation protection
professional" in satisfaction of this guideline hinges on the arguments presented above
regarding the qualifications of the nuclear physician. If the licensed nuclear physician
is indeed equivalent to a medical physicist, as argued in the previous section, then this
private practice would not incur costs resulting from the imposition of guideline. If
not, then an outside consultant would have to be retained and be "on-call", to assure the
"availability" of a "radiation protection professional".
67
-------
6. Impact of Training Requirements
As discussed earlier, the prescribed training course for a nuclear medicine technologist
includes instruction in radiation protection principles. This includes instruction on the
immediate effects of relatively high levels of exposure. No guidance is given, however,
on the long-term stochastic effects, either qualitative or quantitative. Moreover, it is
felt that it would neither be prudent nor productive to include these effects in a routine
training course because of the high degrees of uncertainty involved.
7. Impact of Guidance for the Protection of the Unborn
At present, women who are known to be pregnant are not allowed to work in nuclear
medicine. If a woman working in this practice were to declare herself pregnant, she
would be directed to other tasks not involving the potential exposure to radiation.
Thus, this practice is operating within the constraints of a mandatory version of
Alternative a.
Alternative b is felt to be too restrictive. Most of the medical technologists are female
and most are in the child-bearing years. Although an exposure of 0.2 rem in one month
would be atypical for this practice, it is not unfeasible, and is a regular occurrence in
the nuclear medicine department of an affiliated hospital. Therefore, Alternative b
would prevent these women from being hired in the first place.
Alternative c is felt to be a "disaster". Because of the atypical low exposure levels in
this practice, women are not expected to receive exposures in excess of 0.2 rem/month.
However, in the more typical hospital environment, such exposure levels are routinely
received. Therefore, all women of child-bearing age (the great majority of the
technologists) would have to be removed from their jobs in nuclear medicine. The costs
would be very high, since there are openings for approximately 25,000 medical
technologists at present, and only 12,000 trained technologists are available for these
jobs. At present, there are not enough training programs in existence to turn out
medical technologists in sufficient numbers to satisfy the demand.
8. Impact of Internal Exposure and Combined External Exposure Guidance
Several years ago, when unit dosages were made up in-house, there was concern about
potential internal thyroid exposures. Therefore, thyroid uptake monitoring was
68
-------
performed, but no significant uptakes were measured. At present, there appears to be
little potential for internal exposures.
9. Impact of the Reduction of the W.B. RPG to 1.5 Rem/year
As discussed in previous sections, W.B. exposures in excess of 1.5 rem/year are not
anticipated in this practice. Therefore, although the decrease in flexibility engendered
by this postulated reduction in the RPG was decried, no significant costs would accrue
to this private practice.
The costs at the affiliated hospital, however, would be significant. At least two
technologists receive annual exposures in excess of this level. At least one additional
worker, and most probably two, would have to be recruited and hired. The serious
shortage of medical technologists was discussed in the previous section. If it were
possible to hire additional workers, the collective dose would be expected to increase.
69
-------
C.I LARGE CONTRACT INDUSTRIAL RADIOGRAPHER
This large engineering services firm performs soils testing, materials testing, and non-
destructive testing (NOT) of metals. NDT uses visual, ultrasonic, eddy current,
magnetic particle, dye penetrant, and radiographic techniques. For total volume
testing, radiography and ultrasonics (which has become more widely used since the
acceptance by the American Welding Society in 1969) are used approximately equally.
Overall, roughly 25% of NDT is performed by radiography.
With a total employment of approximately 1,100, the company has 16 offices. Radio-
graphy is performed in nine of the 16 offices. Licenses are required, therefore, by
several agreement states as well as by the NRC. The firm employes approximately 100
licensed radiographers.
Roughly one-half of all radiography in the U.S. is performed by outside contractors,
such as this firm. There are a handful of such large national firms, while each state has
a couple of 10 - 20 person companies that operate regionally. There are also a number of
"mom and pop" firms that do not operate under the two-man team, unwritten rule.
Technicians employed strictly as radiographers, as opposed to technicians who work for
testing firms, generally receive higher annual exposures. This is because these
technicians perform radiography full time, whereas the testing laboratory technicians
may perform a large variety of tasks (i.e., ultrasonics, visual inspections, etc.).
Radiography is performed in the following four modes in this firm:
1. In the laboratory at the firm's facilities. Clients are urged to bring pieces
to the firm's facilities to reduce costs. In this mode, a radiographer may
work alone (others are available, should assistance be needed).
2. On-site radiography at distances up to 30 miles. A minimum of a two-
man team, one of whom must be a licensed radiographer, is always sent.
For these relatively close jobs, film processing may be performed at the
home facility, where an automatic film processor is used.
70
-------
3. On-site radiography at distances beyond 30 miles. At these distances, a
mobile darkroom and possibly an extra technician are generally sent with
the team.
4. Radiography with the client's equipment. Only the people are sent. The
client's sources and darkroom facilities are used.
The firm is licensed to possess 100 Ci sources of Co-60 and Ir-192, and purchases
sources at the 100 Ci level. They are currently in possession of 30 Ir-192 sources and
four Co-60 sources (used for thick/heavy sections). Approximately 10% of the
radiography is performed with approximately 10 X-ray machines. Depleted uranium
collimators are used in conjunction with the radioisotope sources. In addition to
providing a well-defined beam, the collimators provide at least a factor of 10
attenuation.
In conjunction with the firm's soil testing activities, Troxler moisture/density gauges
are also used. These are generally Cf-252 or Am-Be (up to 50 mCi) neutron sources.
The individuals who use these sources are generally not radiographers.
The firm has designated eight individuals as Radiation Safety Officers (RSO's). Each
RSO is responsible for a region, which may be only a single state. The backgrounds of
the RSO's range from senior technicians to professional engineers, and they have
generally been involved in radiography. Each RSO attends a course of at least 40 hours
conducted by Louisiana State University or Gamma Industries (a supplier of sources).
The firm has also designated a Radiation Protection Coordinator, who reports to the
Director of Engineering, who in turn reports to the President. There are. no health
physicists employed by the firm.
All radiographers and radiographer's assistants are monitored. Dosimetry is performed
with TLD's which are read monthly, at a cost of $2.30/mo./badge. Pocket ion chambers
are also worn. Readings from these instruments are taken daily and records turned in
weekly. Roughly 75 personnel are monitored regularly. Approximately 75 additional
individuals are monitored some of the time. Measured whole-body exposure distribu-
tions for the past three years are given in the attached Table. The large number of
monitored employees in the year 1980 is anomalous, and was due to an extraordinarily
large project undertaken during that year.
71
-------
Whole-Body Exposure Distributions
Year
Less than meas.
< 0.1 rem
0.1 - 0.25 rem
0.25 - 0.50 rem
0.50 - 0.75 rem
0.75 - 1.00 rem
1.00 - 2.00 rem
2.00 rem
72
-------
Additionally, the 50 or so employees using Troxler moisture/density gauges are
monitored for gamma exposure (although the sources also have a neutron output). The
exposures to these sources are less than 0.5 rem/yr.
Total labor costs for the firm last year were $20M. The cost for radiographers was
$1.5M. Salaries for radiographers range from $5 to $15/hr. Level ni radiographers, who
are also supervisors, can earn more than $15/hr. The age range of radiographers is 19
to 45 years.
Radiographers and radiographer's assistants receive a minimum of 16 hours of formal
training in the principles of radiation safety and three months of on-the-job training.
They must also pass a written examination in accordance with NRC's rules and
regulations (10 CFR Part 34, Appendix A). Personnel who use the moisture density
gauge receive instruction from the Radiation Safety Officer and some attend a course
given by the vendor.
1. Impact of Reduction in W.B. RPG
The change in the allowable whole-body exposure limit from 3 rem/qtr. to 5 rem/yr is
expected to have no cost impact on this firm. Over the past several years, the highest
whole-body exposure was in the range of 1 - 2 rem.
It is not difficult to keep annual exposures safely below the 5 rem RPG. Action levels
are established within the firm of 18 mr/day, 90 mr/week, and 1.25 rem/qtr. If these
levels are exceeded, the RSO steps in to find out what's going on.
It is not difficult for a radiographer to limit his exposure to 18 mr per day, even if he
shoots as many as 50 - 100 films. It can be done by getting away from the source.
The one situation in which this is difficult is in cross-country pipeline radiography.
Here it is difficult to get away from the source, and it might be difficult to live within a
5 rem RPG. However, the case study firm no longer does cross-country pipeline
radiography on a full-time basis.
The "vagabond radiographer" was mentioned as a potential problem. This is the
individual who goes from job to job performing only radiography. Generally there are
73
-------
no records maintained on this individual. He is quite likely to receive a dose in excess
of 5 rem in a one year period, but not at any single company. Thus there is no control
over this person's exposure. Since there is considerable employment turnover at this
firm, roughly 50% of these transient radiographers may come in and out of the firm in
any one year period.
2. Impact of Reduction In Accumulated Exposure Limit
If records were easy to obtain, this proposed guideline would not be a problem. In fact,
the highest exposure accumulated entirely at the case study firm is approximately 5
rem, for a 20 year employee. However, it is difficult to obtain records from previous
employers, particularly from small firms. Hospitals are also non-responsive. Utilities
are quite responsive.
When records from previous employers are unavailable, it is necessary to assume the
maximum - 5 rem/yr. (15 rem/yr for exposures incurred prior to 1961). Concern was
expressed about the limit if the records are unavailable and it is necessary to assume
the maximum. A perspective employee who is over 40 years of age and is unable to
produce a record of prior exposure might not be able to obtain employment involving
radiation exposure.
3. Impact of Proposed Guidance Relative to Extremities and Individual Organs
The only time that the hand may receive an exposure higher than the whole body is
during source retrieval. For the entire company, this may occur as many as ten times
annually. If it looks like the retrieval may be difficult, involving significant potential
for exposure, the Radiation Safety Officer is consulted. Another individual may be
called in to retrieve the source who can afford the dose. Exposure to the hands during
the retrieval operation is not known because ring badges are not routinely worn.
The loading of the source into the projector does not involve extraordinarily high
exposures to the hand. In a well-designed projector, there is no higher radiation flux at
the entry point of the source than at the other surfaces of the projector. There may
have been problems leading to hand exposures on the old Budd cameras (with certain
types of "pigtails"), since it was possible for the source to be located close to the edge.
74
-------
4. Impact of Proposed Guidance for Potential Exposures in the Range of 0.3 to 1.0 RPG
There were no exposures in excess of 1.5 rem in 1980 and it looks like there will be two
in 1981. In 1978 and 1979, approximately 4% of the workers badged received exposures
in the range 1 to 2 rem. Therefore, it is not clear if exposures to radiographers in this
firm are "anticipated" to exceed 1.5 rem annually.
There are two types of contracts that could lead to annual exposures in excess of 1.5
rem. The first is a long-term job on a construction project, in which some
radiographers must be present (by virtue of their experience) over the entire duration of
the contract. At present, there are two ongoing jobs of this nature. The second
involves radiography at an active nuclear power plant, for which there are several
ongoing contracts. Here the problem is the background radiation from the plant itself.
Only certain individuals who have gone through the security screening and have had the
requisite training can fill these slots. Of course, at the plant, these individuals are
under the cognizance of the utility's radiation protection program, as well as that of the
case study firm. If a radiation protection professional were required, he/she would no
doubt be supplied by the utility.
If professional radiation supervision were required in the field, an average of 10, and
possibly as many as 20 of them could be required at any one time. This is how many
teams are likely to be in the field. However, the opinion was expressed that these
radiation protection professionals would accomplish little in the way of reducing
exposures for this type of operation.
5. Impact of Proposed Guidance for Potential Exposures in the Range of 0.1 to 0.3 RPG
From the exposure data compiled over the past three years, a small percentage of
radiographers received exposures in excess of 0.5 rem (3 to 10 %). Therefore, it would
probably be prudent to "anticipate" exposures in this range.
Personnel monitoring is currently being performed for all radiographers and radiog-
rapher's assistants. Moreover, the supervision requirement in this range is currently
being performed by the Radiation Safety Officers. However, none of the RSO's is
equivalent in background and experience to a health physicist. Therefore, to satisfy the
supervision guideline, a radiation protection professional would have to be retained as a
75
-------
consultant. Alternatively, the state health physicists or those of the source vendors
could be called on.
The opinion was expressed that a health physicist could be beneficially used to advise on
shielding requirements and biological effects. However, unless the individual also had
considerable experience in radiography, he/she would be unable to assist in writing or
altering procedures. Moreover, if it were necessary to retrieve a source, a health
physicist would be of limited usefulness.
6. Impact of Training Requirements
The current program of instruction for radiographers includes a topic on the biological
effects of high levels of exposure. However, instruction on long-term stochastic
effects is not included. Currently, 40 man-hours of each student's time and 20 man-
hours of instructor's time are spent in training. If instruction on long-term, low-level
effects of radiation were to be included in the curriculum, student time would be
increased by 10% and that of the instructors by roughly 10%. The average salary level
of the instructors is approximately $25,000/year.
7. Impact of the Guidance for Protection of the Unborn
At present, one radiographer and one radiographer's assistant are females (both of
child-bearing age). The firm has not as yet formulated a policy relative to radiation
exposure of pregnant woman. If a regulatory requirement were to be imposed on the
firm in this area, voluntary guidance would be preferable.
8. Impact of Internal Exposure and Combined External Exposure Guidance
Only sealed sources are used by the firm. Thus there exists no potential for internal
exposures.
9. Impact of the Reduction of the W.B. RPG to 1.5 Rem/Yr.
Although there were no exposures in excess of 1.0 rem last year, the imposition of a 1.5
rem RPG would pose a problem for this firm. In both 1979 and 1980, there were four
76
-------
exposures in excess of 1.0 rem, and it appears that there will be 3 - 4 in 1981. Thus a
limit of 1.5 rem would be too close for comfort.
The area of the business that might suffer most significantly from this reduced RPG
would be the work at nuclear power plants. It is likely that this line of work might have
to be dropped if the reduced RPG were to be imposed. At present, roughly 10
individuals, each earning approximately $20,000/year, are involved in this work.
77
-------
C.2 SMALL CONTRACT INDUSTRIAL RADIOGRAPHER
This small firm is located in the outlying suburbs of a large metropolitan area. The
firm performs non-destructive testing (NDT) for clients, largely on a time-and-
materials' basis, and is predominant in its geographical area. It has expertise in
ultrasonics, dye penetrant, magnetic particle, and radiography. Approximately 60% of
the radiography utilizes radioisotopes (largely Ir-192), the remainder is X-ray. The firm
is licensed by an Agreement State, and also by the NRG (for out-of-state work).
Equipment is available for 5 - 100 Ci sources, 2 - 50 Ci sources, and 1-18 Ci source.
Currently four sources are being used, all Ir-192, ranging in activity from 28 Ci to 90
Ci. Six X-ray units are operable, ranging in output from 140 kV to 260 kV. Because of
the bulk and set-up time for X-ray radiographs, radioisotopes are preferred. However,
X-rays must be used for thin sections, or light-weight metals, such as aluminum. An
alternative to X-rays is a thulium radioisotope source, but this is seldom used because
of the short (roughly 30 day) half-life and the delivery time. Because of the higher
energy gamma ray, Co-60 is sometimes used instead of Ir-192 for thick, or heavy
sections. However, this is avoided if possible, because of the weight of the projector.
The firm currently employs 15 individuals. These include three senior management
personnel, two of whom are level-3 radiographers, three level-2 radiographers, eight
level-1 radiographers (basically trainees), and one clerical individual. The salary for a
level-1 radiographer is approximately $4.00/hour. Level-2 radiographers earn between
$7.50/hour and $10/hour. Level-3 radiographers can earn considerably higher than
$10/hour; they are qualified to write NDT procedures. One of the level-3 radiographers
also serves as the Radiation Safety Officer.
There are a few national and international NDT companies that are quite large (in
excess of 100 radiographers) and perform testing under contract for others. Many of
the large architect-engineering firms, construction firms, and power plant component
vendors have large in-house NDT departments. It is estimated that about 50% of NDT
is performed under contract with firms that specialize in NDT. Most of the NDT firms,
however, are "gypsies" that literally live out of suitcases; some have as few as 2 to 3
employees.
78
-------
The NRC has recently made it difficult for the gypsy firms by pressuring them to have
at least two individuals at a site. This has been standard practice at this firm since its
inception.
Each technician who starts out at this firm receives a formal training course the first
two days on the job. The course content is in accordance with 10 CFR 34, Appendix A.
It includes several hours of training in radiation protection, including the short-term
biological effects. After this course, each prospective employee must pass an
examination to demonstrate that he/she has mastered the material. It is felt that the
most important questions on this examination are the following:
1. What do you do if the radiographer becomes unconscious while a radio-
isotope radiograph is in process?
2. How do you retract the source?
Additionally, the Radiation Safety Officer frequently makes spot checks of personnel
on-the-job to see that they are abiding by safety procedures.
The surface dose rate of a typical projector containing 100 Ci of Ir-192 is
approximately 0.15 R/hour. The projector weighs approximately 45 pounds. The source
is typically out of the projector for a period of 30 seconds to 5 minutes. Occasionally,
for a thick section, the exposure time may be as high as one hour. It is standard
procedure at this firm to collimate the source, using a lead pig. This not only provides
a better source for radiography, but gives a factor of ten attenuation of the source in
the event that it must be retrieved manually. During the exposure, the radiographer
must remain outside of a roped-off area which marks the 2 mr/hour isodose line. No
protective clothing is worn.
It is company policy to provide a film badge to each employee, including clerical
personnel. In 1980, 26 people were provided dosimeters, four of whom received no
measurable exposure. The average annual exposure was approximately 0.25 rem, and
the maximum was in the range of 1.0 to 2.0 rem. Two individuals were exposed to the
maximum. The exposures were comparable in 1979, although in that year one individual
received an exposure in the range of 2.0 to 3.0 rem. In all cases, the certified
radiographers received the highest doses.
79
-------
1. Impact of Reduction in W.B. RPG
Over the years, this firm has been working under a quarterly limit of 1.25 rem. Only
once in its 14 years of operation has this limit been exceeded. No one has ever been
exposed in excess of 5.0 rem in any calendar year. Therefore, under the current
operating mode, and given no extraordinary circumstances in the future, this guideline
would involve no extra costs to the firm.
However, it is felt that this guideline would eliminate some of the firm's flexibility in
the future, resulting in some unquantifiable costs. If, for example, the firm should be
awarded a large power plant contract, the load on the existing radiographers could be
very high. Under such circumstances, it would not be unusual to process 50 radiographs
in one night. Each of these could involve an exposure to the radiographer as high as
1 mr. The limit could be exceeded if 100 shifts like this were experienced in one year.
A similar high exposure situation could occur if a large operating nuclear power plant
job were obtained. Here, high exposures could be incurred by the staff from the plant
itself while waiting to perform radiographs.
Up until now, this firm has not been busy enough to experience such high loads. But an
optimistic growth scenario could easily result in such a load. Moreover, it takes
approximately two years to train a level-2 radiographer. Thus, such a high load on
existing staff would be unavoidable during high growth periods.
Another scenario that concerns top management is that involving the retrieval of a
loose or stuck source. A bare source can provide dose rates as high as 500 rem/hour at
1 meter! Over the past several years, sources had to be retrieved on two occasions. In
neither of those cases did the exposure to the senior individual who retrieved the source
exceed 0.1 rem. However, this was "lucky", and it is felt that as much as 5 rem could
be received in the event of a difficult retrieval. In that case, this individual would be
unable to perform his senior management role over the remainder of the year, resulting
in a financial disaster to the firm.
2. Impact of Reduction in Accumulated Exposure Limit
The highest accumulated exposure to any individual in the firm is 12 rem, obtained over
an active professional life of 30 years. The second highest accumulated exposure is
80
-------
approximately 6 rem, obtained over 20 years. Therefore, given the current operating
mode, this guideline would involve no extra costs to the firm.
However, concern was still expressed about the potentially restrictive nature of this
guideline.
An extremely busy radiographer could easily receive 3 rem annually. This guideline
would restrict the active work life of this individual to approximately 30 - 35 years.
Admittedly, it would be unusual for an individual to remain active for this length of
time. However, it would be desirable to provide a 40 - 45 year vista for young people
entering the field.
Possibly a technological breakthrough could develop over the next 30 years which would
reduce the unit exposures in radiography. The most likely breakthrough would be the
substitution of ultrasonic examination for radiography. Ultrasonic inspections are
slowly gaining acceptability.
A concern was expressed about the enforcement of the existing 5(N-18) accumulated
exposure limit. The validity of existing data was questioned. A number of individuals
who perform radiography for large firms moonlight on the outside. Their outside
exposures are generally not entered into the data bank for either accumulated or annual
exposures. (They do not like to tell their employer that they are moonlighting!) It was
felt that a national data bank is the only way to enforce accumulated exposure limits.
3. Impact of Proposed Guidance Relative to
Extremities and Individual Organs
There should be no costs to this firm from this guideline. There is no reason to believe
that the lens of the eye receives an exposure in excess of the whole-body dose. One
operation does expose the hand to a significant dose. This involves the connection of
the source to the cable of the projector. The streaming of radiation out of the
projector has been measured to be approximately 1 rem/hour. Based upon the
estimated time to connect the source to the cable (less than 30 seconds) and the number
of times this operation is performed (as high as three times per shift), an individual
could receive an exposure to the tips of the fingers as high as 2 - 3 rem annually. This
is well within existing guidance.
81
-------
4. Impact of Proposed Guidance for Potential
Exposures in the Range of 0.3 to 1.0 RPG
Any of the radiographers could receive annual exposures in excess of 1.5 rem.
Moreover, each time that a radiographer goes out on a job, there exists the potential
for that individual to receive a significant contribution to that annual exposure. The
firm owns three mobile darkrooms, and it is not unusual for two remote jobs to be going
on simultaneously. Therefore, this guideline requires radiation protection supervision at
each of these remote sites.
Although a certified radiographer is highly trained and experienced, he is clearly not a
health physicist or its equivalent. The most experienced individual in the firm in the
principles of radiation safety is the Radiation Safety Officer. He has 20 years of
experience in radiography, and has taken two formal courses in radiation safety, one
administered by the Navy. Nevertheless, he could not pass the health physics' certifi-
cation examination without significant additional training, and his background and
experience are not equivalent to a certified health physicist.
Therefore, two certified health physicists might have to be hired full-time to satisfy
this guideline.
The opinion was expressed that a health physicist would have little to do at a site.
Even if a source retrieval were required, an experienced radiographer (probably level-3)
would have to map out the retrieval operation. Two survey meters and two individuals
are presently available at each remote job. If a retrieval operation cannot be
performed easily, either the projector vendor or the State are called in.
5. Impact of Proposed Guidance for Potential Exposures
in the Range of 0.1 to 0.3 RPG
This guidance requires individual dosimeters and records, and professional radiation
protection supervision to assure exposures are justified and ALARA. Every employee is
monitored and the film badges are processed monthly; thus the former guideline is
clearly satisfied. A supervisor does assure that exposures are justified and ALARA;
however, as discussed earlier, he is not a radiation protection professional. The
individual who performs this function is the Radiation Safety Officer of the firm. Each
82
-------
time a new procedure is carried out in the field, he accompanies the crew and sets up
the procedure. He is completely familiar with existing NDT procedures (he wrote many
of the procedures) and with radiation fields for existing radiographic techniques. For a
specific job, he reviews with the field crew the tradeoff between various NDT
techniques.
It is estimated that the Radiation Safety Officer spends between 20% and 50% of his
time on radiation safety activities. (Management provided the high estimate.)
However, he is not a professional in the field of radiation safety. Therefore, a
consultant would have to be called in to satisfy this guideline. A rough estimate of the
costs is 14 days at $300/day (both of these may be low estimates). Furthermore, the
consultant would have to be available for unscheduled and off-hour work.
6. Impact of Training Requirements
As discussed earlier, the first 16 hours of each technicians' on-the-job time is spent in
training. NRC establishes the requirements. An additional 24 hours of formal training
is required for an aspiring radiographer. Although radiation protection principles are
emphasized, only acute and prenatal biological effects are covered. Adding latent
effects would require approximately an additional 1/2 hour of instruction. For the
number of existing employees, this would cost approximately $200. This Joes not
include the time required for the Radiation Safety Officer to review this material.
7. Impact of the Guidance for Protection of the Unborn
Currently three female technicians work for the firm (one training to be a
radiographer), only one of whom is fertile. She has been instructed to inform
management should she become pregnant, in accordance with NRC Regulatory Guide
8.13, in which case she would be removed from tasks involving the exposure to
radiation. Thus, the firm is currently operating within the guidance of Alternative a.
This firm would have no problem with Alternative b, in which a woman of child-bearing
age could voluntarily remove herself from tasks involving exposures in excels of 0.2
rem/month. The company is small enough so that no female employee would use this as
an excuse to avoid work. Therefore, if a female were legitimately concerned about
potential exposure to the fetus, she would be allowed to express this concern to
management, in which case she would be removed from tasks involving radiography.
83
-------
Alternative c would be unfair to the woman. If removal from radiation fields were to
be mandatory, females of child-bearing age would not be hired. It turns out that the
one fertile female on this firm's staff is highly motivated to do field radiography,
despite the fact that she was hired as a laboratory technician. It is expected that she
would be very upset, and would consider it to be an infringement on her civil rights, if
she were pulled from radiography and not permitted to go out in the field. This would
limit her potential income as well as her ambition.
8. Impact of Internal Exposure and Combined
External Exposure Guidance
The firm uses only sealed sources. Thus, there exists no potential for internal
exposures.
9. Impact of the Reduction of the W.B.
RPG to 1.5 Rem/year
A reduction in the RPG to 1.5 rem/year would involve a substantial cost to the firm.
Although only three individuals were potentially exposed above 1.5 rem over the past
two years, the imposition of a limit at 1.5 rem/year would inhibit the growth of this
company. At present, only three of the personnel are qualified radiographers. These
are the personnel who receive the high exposures. There is no way to substitute other
personnel for those radiographers, or to hire additional radiographers off the street.
Radiographers are trained in-house over a two-year period.
This firm has had poor luck with radiographers hired from other firms. In the larger
firms, individuals are too specialized. In a firm of this size, a radiographer must be a
"jack-of-all-trades." The only way to gain this experience is through in-house training.
Therefore, the imposition of this lower RPG would reduce the existing business level
somewhat (in order to assure that the existing radiographers do not exceed an exposure
of 1.5 rem) and preclude future growth.
84
-------
C.3 IN-HOUSE RADIOGRAPHER
This huge manufacturer of steel and steel products had sales in excess of $7 billion and
84,000 employees in 1981. Radiography is performed at 8 locations that have a total
employment of 17,000. These facilities manufacture ships, tanks, large diameter pipes,
castings and welded structures.
The shipbuilding facilities use both X-rays and isotopes for the inspection of pressure
piping, hulls, and decks. The three facilities, each of which employ roughly 20 - 25 full-
time non-destructive testing (NDT) personnel, have approximately 12 X-ray machines
and 12 radioactive sources (mostly Ir-192, some Co-60). Radiographers (who also
perform other types of NDT) work in teams of 2 -3 man crews, supervised (part-time)
by additional supervisory staff and a manager.
There are several tank and welded structural fabrication facilities which contain a total
of approximately 30 X-ray tubes (200 - 300 KeV) and one 2 1/2 MeV Van de Graaff
accelerator. The X-ray machines at these facilities are likely to be manned by
operators (one or two steps above entry level), rather than radiographers.
Large diameter pipes are manufactured at a single facility that has approximately 15
X-ray tubes. Most of the radiography is performed on a production line basis using
fixed-station fluoroscopes and X-ray machines (150-300 KeV). Approximately 120
personnel are involved.
Dosimetry is performed in-house using TLD's, read monthly. Approximately 600
personnel are monitored, roughly 300 of which are technicians who maintain thickness
gauges. Exposures to these personnel are usually insignificant (well under 100 mrem per
year). In addition, approximately 50 personnel in the various medical departments, 20
laboratory personnel, and 30 researchers are monitored. This leaves approximately 180
workers involved in radiography, approximately one-third of which are actually radio-
graphers.
The 1981 exposure data for workers involved in radiography are given in the Table.
They are broken down into the three categories of facility described earlier. Most of
the exposure in the shipbuilding category is from radioisotopes.
85
-------
WHOLE-BODY EXPOSURE DISTRIBUTIONS FOR 1981
Numbers of Individuals
Shipbuilding Tank Pipe
& Repair Fabrication Fabrication
Less than 100 mrem 19 10 82
100 - 250 mrem 6 2 31
250 - 500 mrem 3 15
500 - 750 mrem 7 10
750 - 1000 mrem 10 00
1000 - 2000 mrem 1 00
Greater than 2000 mrem 0 00
86
-------
It is felt that the exposures experienced at this firm are typical of in-house radiography
nationwide. Exposures at airline manufacturing facilities may be somewhat lower,
whereas boiler manufacturers are likely to expose personnel to somewhat higher doses.
Approximately 50% of all radiography nationwide is estimated to be performed in-
house.
Radiation safety at this firm is the responsibility of the Corporate Health Physicist. He
is a certified* health physicist with over 15 years of experience. He reports to the
Corporate Director of Noise and Radiation Control, who in turn reports to the Manager
of Environmental Health, who reports to a Vice-President in charge of Industrial
Relations. The Corporate Health Physicist is assisted at the corporate level by a
radiologic technician who handles the personnel monitoring program, calibrates the
survey instruments, and performs some field work.
The Corporate Health Physicist develops the corporate radiation protection program
and audits the individual facilities periodically to determine compliance with this
program and with the regulations. His interface at the operating unit is called a
Radiation Safety Coordinator. This individual may be an industrial hygienist, a safety
engineer, a chief radiographer, or a personnel man. Although the Radiation Safety
Coordinator does not report to the Corporate Health Physicist, there is a "dotted line"
relationship.
All industrial hygienists, some of the safety engineers, and some of the Radiography
supervisors attended a 40-hour course in radiation safety conducted by the Corporate
Health Physicist approximately four years ago. Additionally, all of the radiographers at
the shipyards and some of the tank fabrication facilities attend an annual 20-hour
course in radiation protection, including a portion on acute and chronic levels of risk.
When a new employee who will be involved in radiography is hired at the shipyards, he is
given a 1 1/2 hour lecture on radiation safety by his supervisor, and a copy of a
pamphlet describing the regulations, monitoring policy, etc.
Radiation protection instruction at the remaining tank fabrication facilities is spotty.
Periodically, the Corporate Health Physicist conducts a course on radiation safety.
This is usually instigated by a change in management at the facility. Little, if any
instruction in radiation safety is provided by the Coporate Health Physicist at the pipe
*Six years of health physics' experience is a prerequisite to certification. Prior to the
certification examination, this individual took a night course (one night a week)
sponsored by the Health Physics Society for 4 months. During this time, approximately
2 hours a day of independent study were necessary.
87
-------
fabrication facility. Approximately 18 months ago a course was conducted on
successive Saturdays, but attendance was voluntary.
Radiographers at the shipyards receive a base salary of $20,000 per year, although they
can earn as much as $35,000 with overtime. The work at the shipyards, however, tends
to be dirty, and involves a lot of odd hours. At the tank fabrication facilities, where
the conditions are somewhat better, the operators of the X-ray units typically earn
$8.00 - $15.00 per hour.
1. Impact of Reduction in W.B. RPG
There would be no impact from this change in the W.B. RPG, even if the business
climate were to improve substantially. Even though more pictures may be taken in the
case of in-house radiography, exposures are typically lower than for contract radio-
graphy because more time is generally taken for set-up. Pressures are lower; incentives
to radiographers in the contract firm are related to the number of pictures taken,
whereas the in-house radiographer is on salary plus overtime (if the business level is
low, overtime is unavailable).
2. Impact of Reduction in Accumulated Exposure Limit
There is very low turnover in this firm. It is not unusual for a radiographer to have 20
years of experience with the firm, and some employees have been with the firm as long
as 40 years. Because of the relatively low exposure levels, real accumulated exposures
are considerably less than 100 rem, and the establishment of a limit at this level would
pose no problem for this firm. However, because several workers were in this field
prior to 1961 and their exposure records were unavailable (making it necessary to
assume 15 rem/year), the apparent accumulated exposures for a few individuals exceed
100 rem.
3. Impact of Proposed Guidance Relative to
Extremities and Individual Organs
In industrial radiography, exposures to extremities are not expected to be significantly
higher than whole-body exposures (including eye lens). Thus there would be no impact
at this firm from the proposed hand limits.
88
-------
Some concern was expressed, however, about the omission of limits to the forearms,
feet, and ankles, which were specifically addressed by the FRC guidelines. In the
absence of such guidance, the regulators may either establish their own limits or set the
limits to these extremities at the whole-body limit (5 rem/yr). The establishment of a 5
rem/yr. limit to these extremities would be foolhardy because they are invariably
exposed to higher doses than the whole body.
4. Impact of Proposed Guidance for Potential
Exposures in the Range of 0.3 to 1.0 RPG
Although there were no exposures in this range in 1981 (the highest exposure was 1.4
rem), exposures would be "anticipated" in this range at the shipyards if business
conditions were to improve and they went into full production. In fact, roughly six
individuals, or approximately 20% of the radiography workers, would be expected to
receive annual exposures in excess of 1.5 rem. However, exposures are built up
gradually and no single task makes a "significant" contribution to the annual dose.
If radiation protection supervision were required, only one supervisor would be required
during the day. During each of the two night shifts, however, two, or as many as three
supervisors would be required because most of the radiography is performed at night.
Presently, a supervisor supervises each radiography team, but he is only present during
the set-up of the job. A manager is present during the day shift only.
There are at least two individuals on each radiography team. The team leader is
responsible for complying with regulations and for performing such surveys as are
necessary to assure that area dose rates and individual dose limits are being satisfied.
However, there is no individual at the unit level with background and experience
equivalent to that of a health physicist, even though several individuals at some of the
facilities are quite knowledgable in radiation protection. As many as four individuals at
the shipyards know a great deal about radiation monitoring, shielding, etc., although
none of them has a college degree.
The contribution of a professional health physicist during the actual work would be
minimal. Even in the event of a stuck source, an experienced radiographer and his
supervisor should be able to handle the situation. A contribution could be made by
89
-------
having a supervisor on hand who is not production oriented, however, this individual
would not have to be a health physicist. One of the airline manufacturers actually
employs individuals (non-radiographers) who monitor full- or part-time while radio-
graphy is being performed.
5. Impact of Proposed Guidance for Potential
Exposures in the Range of 0.1 to 0.3 RPG
Both the individual monitoring and the supervision requirements of the guidelines are
currently being satisfied at this firm. The Corporate Health Physicist performs
periodic surveys and specifies for the operating units, radiation protection guidelines
consistent with the regulations and with the ALARA principle. The implementation of
this program is carried out by the local Radiation Safety Coordinators and the
performance of the operating units is periodically audited by the Corporate Health
Physicist.
6. Impact of Training Requirements
The requirements on instruction in radiation protection principles and levels of risk is
essentially being carried out at all units except the pipe fabrication facility. Here,
approximately 120 workers, many with no high school education, would require 30 - 40
hours instruction. The facility operates on three shifts. The instruction could be given
in approximately ten sessions. The annual salary of the instructor is approximately
$ . After all of the existing workers were trained, the program could be
maintained by continuing these sessions twice a year, since the employee turnover rate
is low.
7. Impact of the Guidance for Protection of the Unborn
The firm is currently operating under Alternative a, although the number of women
employed in radiography is low. There are 10 females in radiography at the pipe
fabrication facility, one in tank fabrication, and none at the shipyards. Thus there were
no women in 1981 with exposures in excess of 500 mrem.
Currently, females are presented with the NRC Regulatory Guide on the Unborn and
view a film produced by Radiation Management Corporation. Although a female, in
theory, can remove herself from work involving radiation exposure if she is concerned
90
-------
about exposing the unborn to 500 mrem, in practice another job may not be available at
the same pay rate.
The potential for exposures in excess of 0.2 rem per month is essentially zero, even if
business levels were to pick up. Moreover, there are no women radiographers in the
shipyards, at present. Therefore, Alternative b, for all practical purposes, is moot. At
present there are no woment with exposures in excess of 500 mrem; however, if one
were hired at a shipyard, the likelihood becomes real. While the radiographers are part
of the welding department (they are not "brought-up-through the ranks"), they are hired
from throughout the yard or "off the street". So it is likely that under full production, a
woman (women) could be hired.
8. Impact of Internal Exposure and Combined External
Exposure Guidance
All of the radioisotopes used in radiography are sealed sources, so there is no potential
for internal exposure.
9. Impact of the Reduction of the W.-B..RPG
to 1.5 Rem/Yr,
The only operation that would be affected by a reduction in the whole-body RPG to 1.5
rem would be the shipyards, and only at full production. As discussed earlier, it is
estimated that at full production approximately six radiographers would receive doses
above 1.5 rem. Exposures could be reduced below 1.5 rem if an additional two to four
radiographers were hired. This would no doubt increase collective exposure.
91
-------
D.I MANUFACTURER AND DISTRIBUTOR OF CLINICAL AND
RESEARCH RADIOISOTOPES
This manufacturer and distributor of radioisotopes specializes in research and clinical
diagnostic products for the life sciences. Employing 1,700 at three production sites in a
major metropolitan area, the firm services a large fraction of a $175M market. There
are roughly five major competitors.
In the research products line, chemicals are labeled with C-14, H-3, S-35, P-32 (all beta
emitters), 1-131 and 1-125 (gamma emitters). Additionally, small calibration sources
(less than 100 mCi) are manufactured from as many as 100 isotopes. The predominant
radioisotopes in the clinical diagnostics' line are Mo-99 (for generation of Tc-99m), Tl-
201, Ga-67, and Xe-133. Isotopes are made by nuclear transmutation using four
cyclotrons and several outside reactors and accelerators. A linear accelerator is being
constructed to supplement the cyclotrons.
The firm does not manufacture large, multi-curie sources for purposes of irradiation or
radiography (i.e., Co-60, Ir-192, etc). These are all reactor-produced sources. This
industry, dominated by approximately five firms, grosses approximately $25M annually.
A transportation industry, mostly truck, services both industries. An estimated 200 -
500 individuals who transport radioisotopes may be receiving non-negligible exposures.
For example, there are an estimated one million shipments of Mo-99 generators
annually.
Another segment of the radioistope manufacturing industry makes tritium signs, smoke
detector sources, etc. This industry incorporates a number of small firms and has few
employees.
Of the 1,700 employees of this firm, there are roughly 1,300 monitored for radiation
exposure, 700 of whom are potentially exposed and 400 who are "hard core" (people
handling many gamma isotopes in Curie and multi-Curie amounts) radiation workers.
The monitoring policy is two-fold. First, badges are provided to all employees who have
the potential to receive in excess of 25% of the limit (internally established at 5
rem/yr). Second, other employees who will receive less than 25% of the limit are also
monitored. For example, at one of the production facilities in which a large number of
gamma-emitting sources are manufactured, everyone who enters the facility is
92
-------
monitored. External dosimetry is performed with TLD's and electrostatic dosimeters,
which are read weekly by in-house personnel. Individuals who are potentially exposed to
neutrons are also supplied with neutron-sensitive film badges which are processed by an
outside vendor. The in-house dosimetry costs approximately $30,000 per year, higher
than if it were done on the outside. However, the added flexibility is worth the
additional costs. The exposure distributions for the most recent entire year (1980) are
compared with the results from 1977 in the attached Table. In 1978, 69 individuals
received exposures in the range of 1.0 - 2.0 rem, 49 in the range of 2.0 - 5.0 rem, and 7
in excess of 5.0 rem. In 1979, 56 individuals received exposures in the range of 1.0 - 2.0
rem, 33 in the range of 2.0 - 5.0 rem and 7 in excess of 5.0 rem. There has been a
noticable downward shift in the number of high exposures over the past several years,
particularly in excess of 5 rem. Also, the number of exposures in excess of 1.0 rem has
decreased over the past four years from approximately 20% of the total number of
monitored employees to less than 10%.
The exposures to truck drivers who are employed by this firm are also of interest. Of
the 19 drivers who handled radioactive materials in 1979, the average whole-body
exposure was approximately 1.0 rem and the maximum exposure was 1.7 rem. These
were down from an average of 1.3 rem and a maximum of 2.7 rem in 1978. Wrist
exposures to truck drivers were approximately 10-20 percent higher than whole-body
exposures.
Most of the higher exposures are experienced in four activities. These are production
of Mo-99 generators, production and maintenance on accelerators, waste management,
and transportation of radioisotopes.
An extensive internal dosimetry program is also conducted. Approximately 600
employees are given weekly urinalyses. This is the best test for H-3 intake. Weekly
breath analyses on approximately 100 workers are conducted to detect for C-14.
Approximately 50 workers who come into contact with radioiodine are given weekly
thyroid measurements. Annual whole-body counts are conducted on appoximately 400
employees who handle gamma-emitting nuclides. Approximately 6 - 7 of these 15-
minute counts are conducted daily. Finally, special samples are sent out for analysis
for those workers potentially exposed to Ni-63 and Am-241.
The company samples air concentrations of radionuclides at approximately 1,000
locations. The samplers consist of membrane filters, impingers, charcoal filters, and
real time monitors.
93
-------
Whole-Body Exposure Distributions for the Years 1977 and 1980
Exposure Range Number of Individuals
(Rem) 1980 1977
None Measurable 800 328
Less than 0.10 250 81
0.10 - 0.25 80 47
0.25 - 0.50 50 41
0.50 - 0.75 35 25
0.75 - 1.0 23 21
1.0 - 2.0 67 55
2.0 - 5.0 65 82
< 5.0 1 11
94
-------
There are approximately 40 individuals in the radiation safety office, roughly 10 of
whom are dedicated full-time to the management of radioactive wastes. Four of the
professionals have master's degrees (two in radiological health); however, only one of
these individuals is partially certified in health physics. Of the remaining staff,
academic backgrounds range from high school education to bachelor's degrees. Ap-
proximately 15 individuals have bachelor's degrees, mostly in the physical sciences. The
annual budget of the office (exclusive of waste management) is approximately $1M.
This budget has more than doubled, as a percentage of sales, over the last five years.
The Radiation Safety Officer reports to the Director of Environmental Control, who in
turn reports to the Vice-President for Administration. There are three industrial
hygienists in the office of the Director of Environmental Control, one of whom is a
certified health physicist.
Salary scales for the laboratory technologists range from approximately $12 to $20 per
hour. Supervisors can earn as much as $40,000 per year. The salary range for health
physics' personnel is $25,000 to $40,000 per year. Health physics' support personnel
earn from $17,000 to $27,000 per year.
Training is the responsibility of line supervisors. All new employees get a Radiation
Protection Handbook, which describes the internal management structure for radiation
protection, the required procedures for working with radioactive materials, the
regulatory limits, and the procedures in the event of emergencies. NRC Regulatory
Guide 8.29 will be incorporated in this manual. Additionally, new employees attend 16
hours of lectures on safety, 10 hours of which are devoted to radiation safety. Roughly
one hour of the 10 is devoted to levels of risk from radiation, corresponding to the
material in Regulatory Guide 8.29. After attending the course and reading the
handouts, new employees must pass an examination, the level of which is geared to the
job to be performed by the worker.
Additional safety instruction is provided in annual brown-bag lunches tailored to each of
the departments. Although attendance is not mandatory, 95% attendance is typical (the
lunch is provided by the company). Additionally, 3-hour workshops are frequently
conducted for specialized groups of people. Finally, staff members of the Radiation
Safety Office undergo continual training. For the accelerator group, this occupies
approximately four hours per week.
95
-------
1^ Impact of Reduction in W.B. RPG
This firm is currently operating under a self-imposed 5 rem annual limit. However, if
the regulatory limit were to be reduced to 5 rem, it would be necessary to impose a
buffer to assure compliance with the regulation. It is estimated that a 20% buffer
would be satisfactory. Thus, if the W.B. RPG were reduced to 5 rem/yr., this firm
would operate internally with a 4 rem/yr. RPG.
Currently, warning levels are established at various fractions of the RPG, dependent on
the worker's assignment. At 2 rem/qtr., a worker is pulled out of the laboratory. If the
proposed 5 rem RPG were imposed, the new warning level would probably be set at 1.0
rem/qtr. In 1980, 16 workers exceeded 4 rem/yr. (In 1981, this number was decreased to
2.) It is estimated that as many as 6 workers exceed the one rem level each quarter.
These workers are involved in radiopharmaceutical production, accelerator
operations and maintenance, and waste engineering.
In order to comply with a 1.0 rem quarterly limit, the preferable solution would be to
apply new engineering changes. This may be difficult, however, since a number of
recent engineering changes have already been imposed — new transfer equipment in the
hot cells, for example. An increase in the number of radiation safety workers might
also accomplish this. For example, in a period in which radiation safety expenses
increased from approximately one to two percent of sales, the percent of exposures in
excess of 1.0 rem has gone down by a factor of roughly two. A final method for
lowering the quarterly exposures would be that of increasing staff. Possibly 15 new
people would do it. However, this would have the undesirable side effect of increasing
collective dose — possibly by as much as 10%.
2. Impact of Reduction in Accumulated
Exposure Limit
There is some concern about reduction in flexibility due to this proposed guideline.
Currently, there are approximately six people in the company who have more than 100
rem. The maximum lifetime exposure accumulated in the employ of the company,
however, is approximately 50 rem. If a new employee started out at age 18, he could
potentially hit the limit in 25 years. However, this is unlikely under normal conditions.
It is the accidental exposure that is of concern. One hundred and fifty rem would be a
more reasonable limit, providing more flexibility.
96
-------
It was also mentioned that difficulty is sometimes encountered in obtaining records
from previous employers.
3. Impact of Proposed Guidance Relative to
Extremities and Individual Organs
There would be expected to be no impact from the proposed 50 rem per year hand limit.
Approximately 400 employees routinely wear wrist badges and 300 wear ring badges.
The highest recorded hand exposure was 19 rem, obtained by an accelerator worker
under accident conditions. A more typical high annual exposure to the hand is 12 rem.
The proposed limit on exposure to the eye lens would indeed cause a problem. From
independent checks using TLD's on the rims of glasses, the exposure to the eye lens is
roughly a factor of 1.8 higher than the measured whole-body exposure for accelerator
workers. Therefore, in the current operating mode, there would be some overexposures
to the eye lens. Moreover, the firm would incorporate a 20% buffer, as in the W.B.
exposure limit discussed earlier.
There are approximately 15 workers who perform maintenance on accelerators. All of
these personnel receive whole-body exposures in the range of 1.8 to 2.5 rem.
Therefore, one would anticipate eye lens exposures in excess of 4 rem. However,
estimated exposures are so close to this limit that the proposed guidance could probably
be met by tighter monitoring and auditing.
Personnel could wear lead-impregnated glasses, which at the gamma ray energy levels
involved (approximately 1 Mev), would provide an attenuation of roughly 1.2. However,
it is difficult to wear these glasses for accelerator maintenance because vision is
slightly impaired. Face shields would be totally unacceptable.
4. Impact of Proposed Guidance for Potential Exposures
in the Range of 0.3 to 1.0 RPG
As seen in the Table, as many as 10% of the monitored employees may have been in this
range in 1980 (an estimated 9% in 1981). Five activities would contain essentially all of
these personnel. The first is accelerator production and maintenance. An exposure in
excess of 300 mrem could be obtained during an accelerator maintenance task. The
97
-------
four cyclotrons are at most, 100 yards apart (roughly three minutes). They operate on
24-hour shifts. During the day shift, maintenance may be performed on all four
accelerators simultaneously. At night, one individual could oversee all operations.
Thus, six individuals would be required for accelerator supervision. (At present,
monitoring is performed on a spot-check basis.)
The production of Mo-99 generators is performed in one room on one shift. The eight
personnel working in this room could all receive annual exposures in excess of 1.5 rem,
although these exposures would be accumulated relatively uniformly over the course of
a year. One supervisor could cover this room. Currently, a technician monitors the
area. This individual is not equivalent in background and experience to a health
physicist.
Hot waste is handled by approximately 13 workers in one area on one shift. During
waste handling, exposures as high as 100 mrem can be received during a single task.
This area is currently monitored by a technician. This individual is not equivalent in
background and experience to a health physicist.
Approximately 15 workers in the hot processing area can be expected to receive annual
doses in excess of 1.5 rem. The exposure, which could be in excess of 100 mrem during
a single task, is obtained in transfer of samples and in hot cell decontamination. One
supervisor would be required on one shift.
The final group of workers who would be anticipated to receive annual doses in excess
of 1.5 rem are the truck drivers who deliver the Mo-99 generators. The company
employs approximately 20 drivers, and all of them deliver moly generators. The
exposure is received in the process of loading and unloading these sources. At any one
time, as many as 300 shipments may be in progress.
5. Impact of Proposed Guidance for Potential
Exposures in the Range of 0.1 to 0.3 RPG
Both the monitoring and supervision requirements of this guideline are currently being
carried out by the Radiation Safety Office. Therefore, there would be no costs from
this proposed guidance.
98
-------
6. Impact of Training Requirements
This is currently being carried out, including instruction on levels of risk.
7. Impact of the Guidance for
Protection of the Unborn
Approximately 10 to 20 percent of the technologists are women. Most are in the range
of 20 to 40 years of age. At one time, if a woman became pregnant, she would be
pulled out of the laboratory. This is no longer done, because of women's rights. Now
the firm operates under Alternative a. If a woman learns that she is pregnant, she may
request of her supervisor a job involving lower exposures. If she decides to stay on the
job, she is monitored more frequently. Her total nine-month work period is not to
exceed a cumulative dose of 500 mrem (times an administrative safety factor of 0.8).
If Alternative b were promulgated, a study would be performed on exposure levels in
areas from which females request reassignment. The data would be turned over to the
cognizant supervisor. If it were not possible to maintain levels below 0.2 rem/mo., then
the women would be given a leave of absence or told to get another job. There would
be no costs above and beyond Alternative a.
If the mandatory provisions of Alternative c were promulgated, a lot of women who
would like to choose their destinies would be quite upset. At present, an estimated 10
women (probably of child-bearing ages) are potentially exposed to levels in excess of
0.2 rem/mo. These women would have to be discharged and males would have to be
hired in their places.
8. Impact of Internal Exposure and
Combined External Exposure Guidance
The routine assay program for estimation of internal exposure levels has been described
earlier. The airborne concentration measurements (roughly 1,000 sampling points) are
used to determine the need for non-routine assays.
H-3 is the principal isotope that gives significant internal exposures. Last year, four
individuals received internal, whole-body exposures in the range of 200 - 500 mrem, 12
99
-------
individuals received exposures in the range of 50 - 200 mrem, and everyone else
received less than 50 mrem from tritium. Every couple of years, an individual may
receive in excess of 1.0 rem. The highest estimated internal exposure from H-3 was 1.5
rem. However, the individuals handling tritium do not also receive external exposures.
Measurable exposures are also received from radioiodine. Last year, five people
received estimated doses to the thyroid of 0.5 - 1.0 rem, and 200 people received 100
mrem to 500 mrem. The remainder of those working with radioiodine received less than
100 mrem.
Screening is routinely performed for the 100 or so gamma-emitting isotopes. For the
most part, internal doses are less than 1 mrem. If measurable body burdens are
detected by any assay method, doses to critical organs are calculated. Occasionally,
measurable amounts of Se-75, Hg-203, or Co-57 are detected. In one incident, an
individual obtained a lifetime dose commitment from Am-241 of approximately 5 rem.
There has been no incident in which the estimated internal exposure was greater
than 1 rem.
The weighting prescription in the proposed guidelines is not likely to involve additional
costs. Nor is the requirement to add internal to external doses. Internal exposures are
generally low enough to make no difference in compliance with prescribed limits.
However, the mechanics of compliance would no doubt require a computerized
accounting system. It is estimated that such a system could be programmed with
approximately four person-months of effort.
Concern was expressed about calculating internal dose commitments from measured
body burdens for the long-lived nuclides from measurements. The accuracy of the
measurements for some of these nuclides may not be sufficient to assure compliance
with limits. Of particular concern is Sr-90 (a beta emitter). Although less than five
people are potentially exposed and under normal conditions air concentrations are well
below MFC's, the concern is about accident conditions. Urinalysis is the conventional
bioassay technique. The detection limit is 0.2 disintegrations per minute for Am-241,
9. Impact of the Reduction of the
W.B. RPG to 1.5 Rem/yr.
The initial reaction to this guideline is that the firm "would go out of business." Last
year, approximately 130 people, or about 10% of the monitored work force, received
100
-------
exposures in excess of 1.0 rem. This year, it is expected that this number will also be
approximately 10%. About 35 of the individuals receiving exposures in excess of 1 rem
are in the accelerator area. Over the past year, the collective dose in this area has
been reduced by 60%, from 130 person-rem to 50 person-rem. Most of the dose
in this area is from handling of the target and exposure to the residual induced activity
from the machine.
About six years ago, a new handling system was installed on all four machines at a cost
of approximately $75,000. A newly designed system might cost about $150,000 for all
four machines. This would reduce exposures to approximately 15 of the 35 people who
handle targets. The company has R & D programs underway to reduce exposures to the
other 20 workers.
One potential drastic measure to reduce exposures in the accelerator area would be to
buy another accelerator at a cost of $2.5M. This would reduce the usage factor on the
other cyclotrons, allowing more decay time of the short-lived activation products, thus
resulting in lower exposures to accelerator workers.
Mo-99 generator production (approximately eight people) is another area with potential-
ly high exposures. Levels have been reduced substantially over the past several years.
Levels could always be reduced further, but cost estimates are not available.
Another drastic method to reduce exposure levels below 1.5 rem would be to add about
50 personnel. Costs would run approximately $20,000 annually per worker (plus 35%
fringe). Based on experience in the accelerator area, collective dose would increase by
approximately 20%.
101
-------
D.2 MANUFACTURER AND DISTRIBUTOR OF LARGE SOURCES
This firm manufactures high activity Co-60 sources for medical applications (tele-
therapy) and radiation processing (animal feed, medical supply sterilization, and
production of polymers). Additionally, the firms uses its own sources to perform
radiation processing, which comprises approximately 50% of its annual $4M sales.
Most of the firm's competition in the manufacture of large sources (1000 to 10,000 Ci)
is foreign. (Smaller sources for gamma radiography and instrument calibration are
manufactured by a small number of other domestic companies.) In the field of radiation
processing, there are a number of domestic competitors; the largest overall market is
for the sterilization of medical supplies.
Sources are produced by the irradiation of natural cobalt, encapsulated in stainless
steel, in power reactors over a several-year period. Activated sources are shipped back
to the firm in casks containing up to 600,000 Ci of Co-60. Sources are stored in a pool
and transferred to a hot cell for remote handling. Sources to be used in radiation
processing are doubly encapsulated in stainless steel. Sources to be used in teletherapy
must be stripped of the original cladding and melted down into a new configuration.
The meltdown operations are performed in "campaigns" involving as much as 300,000
Ci. Once the campaign has been completed, the hot cell, which has been contaminated
with "hot" chips of cobalt and cladding, must be decontaminated, an operation involving
significant personnel exposures.
c
Hundreds of the sources are configured into "plaques" containing 10 Ci to be used for
in-house radiation processing. The plaques are transferred to one of two radiation
processing cells, where they are stored in pools. Access to the irradiator cells is
controlled; the sources are raised from the pooTs remotely. Accordingly, personnel
exposures from normal radiation processing activities are small.
Teletherapy source installers work in teams of two individuals (an installer and a
helper). Two teams install 60 to 80 sources annually. Installers, who must be quite
skilled and experienced, are licensed.
102
-------
The firm employs approximately 80 individuals; 30 are directly involved in radiation
processing, eight in source production, and six in source installation. Everyone who
goes into the plant regularly is monitored for radiation exposure. Monitoring consists of
a self-reading pocket dosimeter, a TLD processed monthly, and a TLD processed
quarterly. Additionally, a handful of employees wear ring or wrist badges. Whole-body
exposures for the year 1981 are given in the Table.
The Radiation Safety Officer, who reports to the president of the firm, has an advanced
degree in metallurgy and years of experience in radioisotope production and handling.
Two other professionals, one with degrees in physics and nuclear engineering and the
other with a Ph.D. in physics, assist the RSO in radiation protection activities. Four
technicians perform monitoring and decontamination. A radiation safety committee
comprised of three individuals reports directly to the president.
There is no formal training course for new employees, although one is under develop-
ment. New employees are given a briefing of approximately two hours' duration on the
principles of radiation safety. The briefing is conducted informally by the RSO or
another of the firm's professionals. There is some discussion of levels of risk, although
it is not quantitative.
1. Impact of Reduction in W.B. RPG
The firm has been operating with an internally-imposed RPG of 5 rem/year for the past
couple of years, and usually only one individual exceeds this limit each year. Exposures
have steadily come down over the past several years; fifteen years ago, several
individuals were pushing up against the 3 rem limit each quarter.
Despite the firm's success in operating within the limits of the proposed RPG, there is
considerable concern about its establishment as a regulation. This concern relates to
the costs of an overexposure, which is felt to be more likely under the proposed RPG.
In the history of the firm, there have been three reportable overexposures. Although
the measurable costs were high (several thousands of dollars), the intangible costs
related to public perceptions are of primary concern. In the current environment of
high public sensitivity to radiation, the costs of an incident could be very serious.
103
-------
WHOLE-BODY EXPOSURES FOR THE YEAR 1981
Numbers of
Individuals
Less than 0.010 rem 21
0.010 to 0.099 rem 33
0.100 to 0.249 rem 7
0.250 to 0.499 rem 3
0.500 to 0.749 rem 3
0.750 to 0.999 rem 2
1.000 to 1.999 rem 10
2.000 to 2.999 rem 5
3.000 to 3.999 rem 0
4.000 to 4.999 rem 0
5.000 to 5.999 rem 1
Greater than 6.000 rem 0
104
-------
For this reason, the firm would have to operate with an administrative limit consider-
ably below the RPG (possibly at 60% of the regulatory limit) in order to provide a
satisfactory margin of safety. This would jeopardize the effectiveness of a couple of
key technical personnel, who must be available for unusual circumstances, and who can
receive significant fractions of the RPG in a single task.
These concerns are punctuated by a couple of realities in the marketplace. The first is
the competition afforded by a foreign supplier who is in a more favorable regulatory
environment. The second is the competition afforded by electronic sources of ionizing
radiation (in the teletherapy market), which benefit from stricter regulations on
radioisotope sources.
2. Impact of Reduction in Accumulated Exposure Limit
The highest accumulated exposure of an employee of the firm is 76 rem; however, most
of this exposure was received during this individual's 27 years' employment at a
hospital. One of the firm's senior technicians has accumulated 64 rem during his 15
years with the company.
Although it was felt that compliance with the 100 rem limit could be accomplished at
minimal costs, some concern was expressed about the potential for career shortening.
For example, the subject technician is in his mid-thirties and could conceivably
accumulate the additional 35 rem over a seven-year period, thus ending his productive
career with the firm in his early forties. (A move to management is not the answer,
since management also performs hands-on tasks involving exposure to radiation. In
fact, the president frequently performs the initial pass at decontamination of the hot
cell.) For this reason, 150 rem is felt to be a more reasonable accumulated exposure
limit.
3. Impact of Proposed Guidance Relative to Extremities
and Individual Organs
Exposures to the eye have never been measured and recorded. Monitors are normally
worn at the waist, so they are no help in estimating exposures to the head or eyes.
Pocket dosimeters are occasionally taped to the head. Since it is easier to shield the
body than the head during a high exposure rate activity, this is frequently done,
105
-------
resulting in annual head exposures higher, by possibly as much as a factor of two, than
whole-body doses. Since there are few repeatable procedures at this facility,
occasional monitoring at the eye level would not be the answer.
Hand exposures could also be pushing up against the proposed limit. Source installers
and field service personnel wear wrist badges. The highest measured dose was 33 rem,
but this was unusually high. In some of the other operations performed at the facility, a
spot check has revealed that hand doses may be as high as ten times the whole-body
exposure. Handling of waste drums is one of these high exposure activities. If the limit
to the hands were to be reduced, more routine monitoring would be required. The costs
would be $2.70/month/badge, not including the additional recordkeeping.
4. Impact of Proposed Guidance for Potential Exposures
in the Range of 0.3 to 1.0 RPG
Exposures in excess of 1.5 rem/year may be anticipated for personnel involved in three
tasks. The first is the installation of teletherapy sources. Six personnel, organized into
two teams, are involved. In the course of a typical source installation, an exposure of
50 - 75 mrem is obtained. Source installation requires constant travel, and there is high
turnover, particularly for the helpers. The average annual income for an installer is
$40,000; a helper may make approximately $30,000 per year.
The second activity involving anticipated annual exposures in excess of 1.5 rem is in
source fabrication. Three individuals work full-time in source fabrication and others on
the engineering management staff are involved, particularly after a campaign when the
hot cell requires decontamination. All entries to the hot cell are carefully mapped out
well in advance of the actual work. An exposure as high as 1 rem is normally received
on the first entry. Subsequent entries expose individuals in excess of 0.1 rem per pass,
and the total for an individual often is the range of 1 rem for an entire decontamina-
tion.
The third significant exposure activity is waste handling. Approximately six individuals
are involved at one location.
There are no health physicists currently employed by the company. A health physicist
was hired a few years ago, but he was subsequently let go after the occurrence of a
106
-------
series of problems. At least three members of the engineering staff, and possibly as
many as five, could potentially pass the health physics certification examination, given
several months of study.
It was felt that a health physicist would contribute little until he had spent sufficient
time at the plant to become intimately familiar with the operations. Until that time,
which could be as long as one to two years, he could be a detriment to the operation,
particularly if he were required to monitor before and during each Range C task. This
could slow down the operations, resulting in higher collective exposures.
, 5. Impact of Proposed Guidance for Potential
Exposures in the Range of 0.1 to 0.3 RPG
All personnel potentially exposed in excess of 0.5 rem/yr. are currently monitored for
whole-body exposure.
The equivalence of the existing engineering staff to radiation protection professionals is
discussed, in part, in the previous section. Notwithstanding the background and
experience of the existing staff, the Agreement State that licenses this firm does not
consider any of the existing personnel to be a radiation protection professional.
The firm retains a medical physicist, who performs a QA audit monthly at a cost of
$400. He checks the radiation logs, the procedures, and generally reviews the
operations for problems. He does not, however, perform hands-on monitoring or assure
that exposures are ALARA.
6. Impact of Training Requirements
As described earlier, each new employee is given an informal briefing of approximately
two hours duration on radiation protection principles. This briefing does not include
quantitative guidance on levels of risk. However, copies of NRC Regulatory Guide 8.29
"Instruction Concerning Risks from Occupational Radiation Exposure," were recently
distributed to all radiation workers, and are given to all new employees.
107
-------
7. Impact of the Guidance for Protection of the Unborn
The only tasks in which exposures may be received in excess of 0.5 rem over a nine-
month period, or in excess of 0.2 rem in any one month, are source installation, source
fabrication, and waste handling. Women have never been used for any of these tasks,
partly because they all involve heavy physical work. Therefore, there would be no
impact at this firm from the provisions of the guidance for protection of the unborn.
8. Impact of Internal Exposure and Combined
External Exposure Guidance
Internal exposures to airborne Co-60 are possible during hot cell decontamination. The
company has six portable air monitors which are used whenever the hot cell is open.
Respirators are routinely worn when airborne concentrations reach 1/30 of the MFC
Although the Derived Air Concentration for soluble Co-60 in the proposed guidelines is
lower by approximately an order of magnitude than the existing MFC, this should pose
no problem, since the firm is operating under the insoluble limits. The Derived Air
Concentrations for insoluble Co-60 are only approximately 10% lower than the existing
guidelines.
There is no routine bioassay program. For a number of years, employees were sent to
the National Institutes of Health for whole-body counting, but this was discontinued.
One instance of intake was uncovered by the routine "frisking" of an employee using a
sodium iodide crystal. The employee was subsequently sent to NIH for whole-body
counting. It was determined that the employee took in 6 LtCi of Co-60 and received a
dose commitment to the whole body of 10 mrem. This incident demonstrated the
sensitivity of the external monitoring probe to internal deposition.
Routine urinalysis has been considered, but was rejected because of environmental
insults and the inability to deal with insoluble material. Routine whole-body counting is
too expensive; the number of employees is too small to warrant interest on the part of
the companies that provide this service.
108
-------
9. Impact of the Reduction of the W.B. RPG
to 1.5 Rem/Year
In 1981, there were approximately 15 employees with annual exposures in excess of 1.5
rem. If a lid of 1.5 rem were to be imposed, outside personnel would be brought in to
accomplish high exposure tasks, similar to the practice at nuclear power plants. This
"blood bank" type of operation would result in a collective dose considerably higher than
the 34 man-rem accumulated in 1981 by personnel who exceeded an annual dose of 1.5
rem.
This approach could not be used to reduce the exposures to source installers. There are
only a couple of dozen individuals in the world who are qualified to perform this highly
skilled task. It requires two years to train a source installer.
109
-------
E.I LARGE LWR FUEL FABRICATOR
This facility manufactures nuclear fuel for light water-cooled reactors (LWR's) and
employs approximately 2,000 people. The raw material is uranium hexafluoride (UFg),
received in 2 MT containers from the uranium enrichment plants. Enrichment (percent
of U-235) varies up to four percent. The finished products are fuel assemblies ready to
load into LWR's. Intermediate products consist of UO2 powder, UO2 pellets, and fuel
rods (strings of pellets clad in zirconium alloy).
The industry is dominated by five large firms. A few small processors manufacture fuel
for research reactors or high temperature gas-cooled reactors. In these cases, however,
the finished products differ substantially from LWR fuel. Health physics considera-
tions, however, are similar; i.e., the risks are from soluble and insoluble compounds of
the uranium isotopes.
The process is similar in most of the large facilities. For some of the producers, the
conversion to UO0 and the processing of the UO0 into fuel rods are performed at
£t £»
separate sites. Initially, UFg from the enrichment plant is converted to UO2 powder by
a chemical ammonium diuranate (ADU) process. The UC>2 powder is processed (e.g.,
hammermilling, predensification, granulating, blending) to prepare it for subsequent
processing. Pressed UO« pellets are sintered, ground, and loaded into fuel rods. Fuel
rods are assembled into fuel bundles, and the bundles are shipped to various reactor
sites. A large number of support activities, such as laboratory analyses, process
development, maintenance, and waste treatment are also conducted.
This plant was constructed about 14 years ago. A new section of the facility which
recently went into operation has about 50% of the conversion capacity. This section,
because of the near total containment, has very low airborne concentrations of
uranium.
Potential exists in the plant for both internal exposure from inhalation of uranium
compounds and external exposure from the relatively low energy gamma rays emitted
110
-------
by the isotopes of uranium. Most of the potential for internal exposure (inhalation) is at
the front end of the plant, where the UFg (soluble uranium) is treated chemically to
convert it to UO2 powder. Some potential for inhalation persists as the UO9 powder
(insoluble uranium) is milled, blended, and formed into pellets.
The potential for external exposure is at the sites of storage of large quantities of
uranium; i.e., at the UFg cylinder dock (fields as high as 3 mr/hr), at the completed fuel
assembly area (fields as high as 2 mr/hr), and at storage racks of cans of UO2 powder
(fields as high as 2 mr/hr). Normally, people are present in these areas for only brief
periods of time. The highest fields where people normally work is in the fuel bundle
assembly area, where dose rates as high as 0.5 mr/hr can be achieved.
External exposure to radiation can be received from sources other than uranium in the
plant. There are two X-ray machines for radiographic inspection of fuel rods and/or
other assemblies. Another X-ray machine is used for X-ray analytical procedures. Cf-
252 neutron sources are used for non-destructive testing of fuel rods.
A systematic procedure has been developed to establish requirements for both external
and internal dosimetry of personnel. The decision framework is shown in Exhibit 1.
Using this methodology, approximately 1200 personnel are monitored for external
exposure (using TLD's).
The philosophy applied to whole-body counting for the detection of insoluble uranium in
the lung is described in Exhibit 2. Over a recent 12-month period, an irregular number
of employees were counted monthly, 300 were counted quarterly, and 275 were counted
annually. In addition, an extensive urinalysis program for the detection of soluble
uranium is in place. UFg vaporization and hydrolysis operators are required to submit
samples at the end of the shift. Maintenance personnel are required to submit daily
samples if they performed maintenance in vaporization or hydrolysis. Moreover, special
samples are required after UFg (UO2F2) gas leaks, suspected ingestion of soluble com-
pounds, or in the event of an incident in which it is suspected that soluble materials
have been released. Over the last three quarters of 1981, 972 urinalyses were
performed.
Air sampling is extensive throughout the plant. There are about 200 sampling points
with removable filters that are counted every eight-hour shift. Additionally, a
continuous sampling system has been in operation for 2 1/2 years with 33 sampling
111
-------
EXHIBIT 1
DECISION METHODOLOGY FOR DOSIMETRY AND ACCESS CONTROL
i DOCS THE PERSON
HEED ACCESS TO
THE FUEL GROUNDS?
ASSIGN TO •CLEAR*
• HILL THE PERSON
NEED TO HEAR A
RESPIRATOR?
YES
REQUIRE:
• MEDICAL (P2)
• RESPIRATOR ROUTINE (P2>
HILL THE PERSON
BE WORKING WITH _
X-RAY UNITS OR
RADIATION SOURCES
IN EHO OR PCO?
YES
REQUIRE:
• Tl TLD BADGE (PI)
• MEDICAL (P2)
, • WHITE TRAINING
DONI
DONE
REQUIRE:
• IPEP ROUTINE (P3)
• WBC ROUTINE (P2)
• BIOASSAY ROUTINE (P2)
• RED DOT ID BADGE (P2)
ASSIGN ?0 "RED'
(MAY NOT BE REQUIRED
TO HAVE ANY FILM BADGE)
WILL THE PERSON NEED
TO HEAR A RESPIRATOR?
' WILL THE PERSON BE
WORKING IN THE
(AIRBORNE) CONTROLLED
AREA > 4 HRS/WEEK
OJ> > 52 HRS/OTR?
ASSIGN TO •AIR-
REQUIRE:
• Tl TLD BADGE (PI)
• MEDICAL (P2)
HILL THE PERSON NEED TO HEAR
A RESPIRATOR?
REQUIRE:
• MEDICAL (P2)
• RESPIRATOR
ROUTINE (P2I
REQUIRE:
• RESPIRATOR
ROUTINE (P2)
112
-------
EXHIBIT 2
WHOLEBODY COUNTING POLICIES
Counting Frequency:
ASAP (AS SOON AS POSSIBLE)
1. New hires (if the employee has a previous history of
working around radioactive materials) or will be
assigned to the controlled area.
2. Terminations (if a weekly POTENTIAL exposure exists
>25% or TIA >10% for any quarter).
3. Personnel involved in an incident (assigned daily
exposure >400.0E-11 microcuries-hrs/cc).
4. Last WBC >200 micrograms U-235 (if first in a series).
MONTHLY
1. Monthly ASSIGNED airborne exposure >50% (>800
microcuries-hrs/cc).
2. Last WBC >1509 micrograms U-235 until <100 micrograms
U-235.
QUARTERLY
1. Quarterly POTENTIAL airborne exposure >100% (>5200.0E-
11 microcuries-hrs/cc).
2. Last WBC >MDL.
3. Quarterly ASSIGNED airborne exposure >10% (>520.0E-11
microcuries-hrs/cc).
ANNUALLY
1. Quarterly TIA <25% but >10% (52-130 hrs), or
2. Quarterly ASSIGNED airborne exposure <10% (520.0E-11
microcuries-hrs/cc), and
3. A weekly POTENTIAL exposure >25% (>100.0E-11
microcuries-hrs/cc).
113
-------
EXHIBIT 2 (Continued)
NOT REQUIRED
1. Quarterly TIA <10% (<52 hours).
2. All weekly POTENTIAL exposures <25% during quarter
(<100.0E-11 microcuries-hrs/cc) .
POTENTIAL EXPOSURE - No credit taken for respirators.
ASSIGNED EXPOSURE - Credit taken for respirators.
Restriction and Recounting:
WBC RESULT IN
*Mq U-235 ACTION TO BE TAKEN
> 250 RESTRICT and reschedule ASAP.
> 200 Reschedule within 1 to 2 weeks, if second
count > 200, RESTRICT and count monthly
until result < 100.
> 150 Monthly count until < 100.
> MDL Schedule for count following quarter
< MDL No action required.
CONTAMINATION SUSPECTED RESTRICT and reschedule within two (2)
weeks.
WBC = Wholebody count
TIA = Time in area
MDL = Minimum Determinable Level
114
-------
points. The results of the derived airborne concentrations are used to determine
compliance with regulations and the need for special bioassays.
The external exposure distribution for 1980 is given in Exhibit 3. Approximately 5% of
those monitored, or roughly 50 workers, received whole-body exposures in excess of 0.5
rem. Approximately 0.5% of those monitored, or approximately five workers, were
exposed in excess of 1.5 rem. The maximum exposure was approximately 2.5 rem.
The potential exposures to airborne concentrations for a recent 12-month period are
given in Exhibit 4. The current limit is based upon the MFC for insoluble uranium
(1 X 10" JjlCi/ml), multiplied times a 40 hour work week. Approximately 99.5% of the
employees were within these limits. Moreover, these numbers are based upon the
conservative assumptions of insoluble uranium, 2.2% enrichment, respirable particle
size, and no respiratory protection. The new limit in the proposed guidelines, based
upon an MFC for insoluble uranium of 1 X 10" n Ci/ml, is also shown. It can be seen
that under the same conservative assumptions, more than 60% of the potentially
exposed workforce, or about 75 workers, would be over the limit.
Radiation safety is the responsibility of the plant work area managers who report
through the various section managers to the Plant Manager. Reporting to the Manager
of Nuclear Safety Engineering are three health physicists (non-certified) and the
Radiation Safety Officer (B.S. in the physical sciences). Reporting to the Radiation
Safety officer are three shift supervisors, 20 technicians, and six hourly employees.
There is also a Radiation Safety Committee (10 - 12 individuals) which advises the
Manager of Nuclear Safety Engineering. The technicians in Radiation Safety are
expected to complete a course in radiation protection principles, such as that offered by
North American Rockwell Corporation.
All new employees at the facility are required to attend a 4 - 5 hour training session on
the principles of radiation protection, followed by an examination with about 60
questions. The course and examination conform with the requirements laid out in 10
CFR Part 19. The course and testing are repeated annually. The course includes
comparative risk subject matter similar to that given in the article by Dr. Bernard
Cohen in the Journal of Health Physics. However, it does not include material on
probabilities of health effects from low levels of radiation.
115
-------
f>
g
o
LJ
CC
CC
O
Exhibit 3
>MDL EXTERNRL EXPOSURE 1980
5 rem
.50 f
1.5 rem
0.00
0.5 rem
-.50
-1.00 •
0.05 rem •_
-1.50 •
—'tvj in — oj in 09 o cs o o Q CS3 o o in oocnincDtn
... *-• tvjpj^'intDr^.oD O)(7)O)O)***
en o)cn
07 0101
~ PERCENT UNDER
NORMRL PROBRBILITY PLOT
116
-------
Exhibit 4
RIRBORNE EXPOSURE SUMMRRY
120U
1100
_ 1000
7
5 900
X
^\
*J 600
\
j: 700
1
^ 600
%u*
. EXPOSURE i
LO Jk O1
O O Q
O O O
O
Q- 200
100
n .
-r/ i/ f ^ iw O/O I/OU
23520 Man Weeks Reported
•
1 *
*
•
*
1 *
•
*
*
•
*
•
*
•
•
— Existing Limit /
•
/
/
«
__---~~
— Proposed Limit *mf~
fc»oj in — t\i in s
... -*
(9 o o (9 (S a is in oooiincDO)
n ^ tn 10 r^. CD en en en o> • • •
01 en en
en o) en
PERCENT UNDER
NORMRL PROBRBILITY PLOT
117
-------
The salary range for non-exempt workers is approximately $300 - $400 per week
(overtime is at the rate of one and one-half to three times base salary). Exempt
employees span the range of approximately $24,000 to $100,000 per year. Supervisors
in the plant peak out at an annual salary of approximately $45,000. Fringe benefits
amount to approximately 28% of base salary.
1. Impact of Reduction in W.B. RPG
This guideline would have no impact at this facility. The highest whole-body exposure
in 1980 was approximately 2.5 rem. In 1979, there were two exposures in the range of
2-3 rem, but these may have been anomalous.
2. Impact of Reduction in Accumulated Exposure Limit
There would also be no cost impact at this facility if the accumulated exposure limit
were lowered from 5(N-18) to 100 rem. The highest accumulated whole-body exposure
at this facility is in the range of 2 - 3 rem.
3. Impact of Proposed Guidance Relative to
Extremities and Individual Organs
Several employees handle fuel pellets manually in the course of their work, giving rise
to hand exposures potentially higher than whole-body exposures. Test runs indicate that
the subcutaneous layers of the skin may be exposed to beta doses close to the 75 rem
limits. However, the actual exposures as determined by finger ring dosimeters are
below measurable limits. Therefore, there should be no impact from the proposed
reduction in the limit.
The eye lenses of employees at this facility are not expected to be exposed to higher
levels than the whole body.
4. Impact of Proposed Guidance for Potential
Exposures in the Range of 0.3 to 1.0 RPG
The only significant potential for whole-body exposures in this range is during the
changing of Cf-252 and other neutron and gamma ray emitting sources. This is done
118
-------
approximately a dozen times annually, and a single operation takes typically one hour.
The largest source (2 Ci Cf-252) is changed every two years, and the whole procedure
takes approximately eight hours, including pre-planning and equipment setup. During
these operations, a technician from the Radiation Safety Office is present and performs
continuous monitoring.
The main impact from this proposed guideline would be due to the new internal
exposure RPG. Even with respect to existing guidelines, more than 30% of plant
personnel are potentially exposed to airborne concentrations in excess of 0.3 RPG (see
Exhibit 3). The areas in which one might anticipate airborne concentrations to exceed
30% of the current RPG are the vaporizor, the hydrolyzer, the slab blender, the slugger,
the baghouse, the hammermill, the calciner, the pellet press, the grinder, and recycle.
Airborne concentration data over a recent 12-month period indicate that there are
approximately 15 hours during the 168 hour week (3 shifts) that one or more of these
areas may exhibit airborne concentrations in excess of MPC's. Moreover, the chances
of simultaneous high concentrations in two areas is reasonably high. Therefore, two
areas may require supervision during such incidents of high airborne concentrations. At
present, technicians in the Radiation Safety Office are available to monitor these
incidents.
5. Impact of Proposed Guidance for Potential
Exposures in the Range of 0.1 to 0.3 RPG
This facility is currently in full compliance with this proposed guideline. Anyone with
the potential for external exposure in excess of 7.5% of the annual RPG is monitored
for external exposure. Potential internal exposures are monitored in all production
areas by an elaborate system of air monitors. Two health physicists and a staff of
technicians maintain records on external fields and airborne concentrations at all
production locations, review procedures, and are available to monitor during non-
routine operations. Moreover, "radiation protection professionals" are available to
assure that exposures are justified and ALARA.
6. Impact of Training Requirements
As discussed earlier, with the exception of the subject area of levels of risk, the
current instruction program satisfies the proposed guideline on training. To include
119
-------
quantitative instruction on levels of risk, an additional two hours of training would be
required for each of 1200 workers. Instruction is given approximately 20 times
annually. Therefore, an additional 40 hours of instructor time (at $30,000 per year)
would also be required annually.
7. Impact of the Guidance for
Protection of the Unborn
Approximately 25% of the plant personnel are females, most of whom are of child-
bearing age. At present, if a woman is known to be pregnant, the management is
willing to move her to a zero exposure job if she requests a transfer. If she suspects
that she is pregnant and requests a transfer, and it is later determined that she is not
pregnant, she will not automatically be able to return to her old job because of plant
work rules.
Proposed Alternative b is no different than Alternative a, since there are no jobs in the
plant that result in whole-body exposures in excess of 0.2 rem/month.
8. Impact of Internal Exposure and Combined
External Exposure Guidance
The current approach at this plant to demonstrate compliance with the existing
guidance on internal exposures is to calculate potential exposures to airborne concen-
trations of uranium from airborne monitoring data plus time and area assignments for
personnel. From the calculated potential exposures to airborne concentrations, internal
doses are estimated by organ for each individual. These estimated internal doses are
checked using the bioassay procedures described earlier. Measured external exposures
obtained from personnel dosimetry are routinely added to the estimated internal doses.
The software for this elaborate system of airborne concentration tracking and internal
dose estimation was developed at a cost of approximately 3 man-years of effort.
As can be seen from Exhibit 3, nearly 70% of the work force is potentially exposed to
airborne concentrations in excess of the proposed guideline (MFC of lxlO-11 nCi/ml).
However, these numbers are based upon very conservative assumptions. This facility
has been anticipating a change in the regulations since ICRP-26 was published. To
120
-------
comply with ICRP-30 (Derived Air Concentration for U-235 of l.SxltT11 n Ci/ml), the
approach to compliance would be the same; namely, calculation of potential concentra-
tions of uranium for each employee. However, the conservative assumptions would
have to be relaxed.
The first assumption that would have to be relaxed would be that of totally respirable
particle size. Actual particle size distributions at various areas within the plant are
well known, but would require verification every couple of years. This might require a
man-month each of a professional and a technician. It is expected that using the actual
particle sizes would lower calculated potential exposures to respirable uranium by an
average of about 30%.
The second relaxed assumption would be that of total insolubility. MFC's for soluble
uranium are a factor of 30-40 higher than those of insoluble uranium. The areas of the
plant where soluble forms of uranium are handled, primarily at the front end of the
process, are readily identified.
The third relaxed assumption would be that of enrichment. At present, a uniform
enrichment of 2.6% is assumed in all calculations. Since the actual average enrichment
is lower, this assumption is conservative. The use of actual enrichment values in place
of this assumption would require plantwide sampling of enrichment. The combined
relaxation of the conservative assumptions on solubility and enrichment would lower
calculated potential exposures to uranium by a factor of approximately five.
Finally, the amount of time spent by each employee in each area of the plant would
have to be estimated more accurately. The current, conservative time and area
assignments are based upon 6 1/2 hours per shift for routine controlled area workers.
To obtain more accurate time and area assignments, a card key system has been
designed (and installed in a few selected areas). This system also contributes to time
card and bioassay tracking, as well as security. The cost of the entire system will be
approximately $400,000, with an annual operating cost of roughly $50,000. However,
only about 25% of these costs should be allocated to better time and area assignments.
All of the above improvements in calculational procedures could be implemented and
documented using the existing software with about two man-years of effort. Although
it has not been confirmed, it is expected that the effect would be to demonstrate
121
-------
compliance with the ICRP-30 limits. However, the proposed EPA limits are approxi-
mately another 30 - 40 percent lower. At present, it is not clear that these changes
will bring calculated potential exposures down to the proposed EPA levels.
It would be possible to use bioassays (i.e., urinalyses), rather than estimated exposures
to airborne concentrations to predict organ doses for soluble uranium. In urine, uranium
can be detected down to 2.5 LLgA, which corresponds to concentrations of
approximately 1/100 of the current MPC. Therefore, this method could be used to
determine compliance with the proposed guidelines. It is estimated that the current
urinalysis program, which costs approximately $2000/qtr., would have to be doubled.
With the current state-of-the art, whole-body counting does not have the requisite
sensitivity to be used to estimate internal exposures from insoluble uranium. The
existing maximum permissible lung burden is 283 LLg of U-235, whereas the current
sensitivity of the whole-body counter is 75 LLg. In order to detect the lung burden
corresponding to the proposed guideline, the detectable lung burden would have to be
reduced by at least a factor of three. This is not possible at present.
If it were possible to use whole-body counting to estimate the intake of insoluble
uranium, the costs of the existing counting programs are estimated to increase by
approximately $120,000 per year. Whole-body counting takes approximately 30 minutes
per person. At present, approximately 125 individuals are monitored monthly. To
monitor 300 or more individuals, three-shift counter operation would have to be
performed. The current operation costs $80,000 per year.
9. Impact of the Reduction of the
W.B. RPG to 1.5 Rem/yr.
As seen in Exhibit 2, only 5 personnel received exposures in excess of 1.5 rem in 1980.
These exposures were either derived from changing sources or are possibly anomalous.
At any rate, compliance could be achieved with a 1.5 rem limit with little additional
effort. Therefore the imposition of this proposed guideline would have no direct cost
impact, with the exception of needed closer scrutiny, posting of data restrictions, etc.
122
-------
E.2 SMALL LWR FUEL FABRICATOR
This company manufactures nuclear fuel for light water-cooled reactors (LWR's). The
UFg conversion facility receives UFg from the enrichment plant in 1.5 MT containers
and converts it to UO2 powder by the chemical ammonium diuranate (ADU) process.
This consists of volatilization of UFg, hydrolysis to UO2F2, precipitation with
ammonium hydroxide to form ADU, filtration of the ADU, drying and calcining to U.,0Q,
O o
reduction to UO2 in a hydrogen-steam atmosphere, milling, purification, and packaging.
Enrichment (percent of U-235) varies up to four percent. The UO0 facility receives the
Li
powder from the UFg conversion facility, and processes it by blending, slugging,
granulating, and pellet pressing. Pressed UO2 pellets are sintered, ground, and loaded
into fuel rods. Fuel rods are assembled into fuel bundles and the completed bundles are
shipped to various reactor sites.
There are approximately 400 employees of the firm involved in LWR fuel fabrication,
roughly evenly split between the UFg conversion and the UO2 facilities. However, only
about one-third of these would be characterized as radiation workers. These are 80-100
individuals at the UFg conversion facility and 30-40 people at the UO2 facility.
Potential exists at both facilities for internal exposure from inhalation of uranium
compounds, as well as external exposure from the relatively low energy gamma rays
emitted by the isotopes of uranium. At the UO2 facility, everyone who is assigned to
the plant is monitored with TLD's for external exposure. At the UFg facility, only
those expected to receive 25 percent of the RPG are monitored currently; in the near
future, everyone assigned to the plant will be monitored. The assembly storage area in
the UO0 facility has the highest external fields, approximately 5-6 mr/hr. The annual
Zt
whole-body exposure distributions for 1980 are given in the Table.
Systematic procedures have been established for internal monitoring, although they are
different for the two facilities. At the UO2 facility, urinalyses are performed quarterly
or semi-annually, depending on the number of exposure hours incurred by an individual.
Lung counts are also performed quarterly or semi-annually, depending on exposure
hours. In the event of a spill, nose smears, fecal samples, and urine samples are also
assayed.
123
-------
WHOLE-BODY EXPOSURE DISTRIBUTIONS
FOR THE YEAR 1980
Exposure Range
(Rem)
No measurable exposure
Less than 0.10
0.10
0.25
0.50
0.75
1.0
2.0
TOTAL
- 0.25
- 0.50
- 0.75
- 1.0
- 2.0
- 5.0
> 5.0
No. of Individuals
UFg Conversion Facility
0
24
6
0
0
0
0
0
0
30
UO0 Facility
£t
60
77
33
27
1
1
4
0
0
203
124
-------
At the UFg facility, frequency of urinalysis is a function of an individual's job. For
people working in the UFg vaporization area, urinalyses are performed six times
annually; for all others, the frequency is lower. The frequency of lung counting, which
ranges from once to four times annually, is dependent on an individual's historical body
burden. A lung count plus a fecal sample are also taken in the event of a spill.
Compliance with the regulations is demonstrated using measured air concentrations in
conjunction with time and area assignments. At the UO2 facility, 25 air samplers are
monitored once a shift. At the UFg facility, 80 stations, which are sampled once a day,
are supplemented by a continuous alarmed air monitor. Lapel samplers are also worn by
selected individuals at both facilities. These samplers are used primarily for purposes
of verification of exposure.
In 1980, the average annual internal exposure at the UO0 facility, expressed in units of
-9 *
area concentration hours, was 9.15 X 10 ^Lt Ci-hrs/ml, or 4.4 percent of the limit.
(This varied by less than 25 percent over the years 1977 through 1980). In 1980,
approximately 12 percent of the personnel exceeded ten percent of the average annual
limit. This number is low because personnel are stricted from radiation work whenever
they exceed 20 MPC-hrs. in any single week.
At the UFg conversion facility, the average area concentration hours were 10.2% of the
limit. A very rough estimate of the areas that exceed ten percent of the average
annual limit is 50 percent.
At the UFg conversion facility, the Radiation Safety Officer, who reports to the plant
manager, has a Master's degree in health physics. He has a staff of six personnel, one
of whom is also a health physicist. Neither of the health physicists are certified. The
Health and Safety Supervisor, who also reports to the Radiation Safety Officer, has 20
years of experience, and is considered to have the background and experience
equivalent to that of a health physicist.
*
These numbers take credit for respiratory protection.
125
-------
The Radiation Safety Officer at the UO9 facility also reports to the plant manager.
it
Although he has an academic background in physics and business, he has two health
physicists (neither certified) on his staff. Additionally, a licensing administrator, a
health and safety foreman, and five technicians assist in health and safety activities.
Verbal instruction in radiation protection principles is provided individually to new hires
at both facilities. This instruction ranges from one to two hours, depending on the
nature of the job. Also, various handouts on respiratory protection and physics are
provided. At present, only fertile females are provided instruction on levels of risk.
However, a canned presentation is being prepared to provide everyone with information
on the risks associated with exposure to radiation.
1. Impact of Reduction in W.B. RPG
There would be no impact from a reduction in the RPG to 5 rem/yr. The highest
external exposure in 1980 was 1.5 rem.
2. Impact of Reduction in Accumulated Exposure Limit
There would also be no cost impact at this facility if the accumulated exposure limit
were lowered from 5(N-18) to 100 rem.
3. Impact of Proposed Guidance Relative to Extremities and Individual Organs
The hands of several technicians are exposed in the course of fuel pellet handling.
However, the high exposures involve beta radiation, which does not penetrate to the
subcutaneous layer of the skin. Therefore, average annual exposure to the entire hand
is relatively low, estimated to be a maximum of 2 rem.
4. Impact of Proposed Guidance for Potential Exposures in the Range of 0.3 to 1.0 RPG
There were no external exposures in excess of 1.5 rem in the past two years. Moreover,
there were no internal exposures in excess of 0.3 RPG, since this facility has been
operating under the NRC ALARA goal which is 25 percent of the RPG. The total
126
-------
exposure, external plus internal, exceeded 1.5 rem for a few individuals, but the current
HRC regulations do not require the summation of these exposures.
If the proposed new guidelines on internal exposures, in particular the new Derived Air
Concentrations, were imposed, it would be difficult to maintain combined exposures
below 30 percent of the RPG. (The difficulty in meeting the new RPG is discussed later
in this case study.) However, the 30 percent goal would be factored into the planning to
meet the new RPG, since it is anticipated that NRC would still insist upon a 25 percent
ALARA goal.
Each facility maintains a staff of at least two health physicists and several supporting
radiologic technicians. Therefore, spills that would result in area exposure rates
significantly contributing to annual internal dose exceeding 0.3 RPG could easily be
monitored and supervised by radiation protection professionals.
5. Impact of Proposed Guidance for Potential Exposures in the Range of 0.1 to 0.3 RPG
The firm is currently in full compliance with this guideline, and would have no difficulty
in complying under a reduced RPG. Potential internal exposures are monitored at both
facilities by extensive arrays of air monitors. Two health physicists and a staff of
technicians at each facility maintain records of external fields and airborne concentra-
tions, review procedures, and are available to monitor during non-routine operations.
Moreover, radiation protection professionals are available to assure that exposures are
justified and ALARA.
6. Impact of Training Requirements
The current program, with the possible exception of instruction on levels of risk,
satisfies the proposed guideline on training. To include quantitative instruction on
levels of risk, an additional hour of time would be required annually for each of 200
workers. Also, an additional 10 hours of instructor time would be required
annually.
7. Impact of the Guideline for Protection of the Unborn
Approximately one percent of the plant radiation workers at both facilities are female,
most of whom are of child-bearing age. Presently, the management conforms to
127
-------
Alternative a; namely, if a woman states that she is pregnant, she will be moved to a
zero exposure job if she requests a transfer. Since there are no jobs in the plant
resulting in exposures to the unborn of 0.2 rem/month, Alternative b is not relevant at
this plant.
8. Impact of Internal Exposure and Combined External Exposure Guidance
The aspect of the proposed guidelines that would cause a severe impact at these
facilities is the reduction by an order of magnitude in the Derived Air Concentrations
(DAC's) for uranium. This comes about largely from the application of the new models.
At present, roughly 50 percent of the personnel at the UF» conversion facility are
exposed annually to concentrations in excess of the proposed DAC, and approximately
12 percent of the personnel at the UO2 facility exceed the limit. (The impact was
compared to a reduction in the speed limit for trucks from 55 to 5 miles per hour.)
The order of magnitude reduction would require glove box containment for nearly all
operations at both facilities. In fact, the proposed new insoluble uranium DAC (1 x
10 /ICi/ml) is lower than the existing insoluble plutonium MFC (4 x 10~ jUCi/ml),
and total containment is standard operating procedure with respect to plutonium.
(Although, the amount of mass corresponding to comparable levels of activity is
10 - 10 lower in the case of plutonium.) Moreover, since the NRC has established an
ALARA limit at 25 percent of MFC, it is believed that a comparable ALARA reduction
below the proposed DAC would continue to be imposed.
Currently, the operations in both facilities that generate high airborne concentrations
are enclosed in hoods. These include the hammer mill feed station, the blender loading
port, the granulator, the pellet press, the furnace loading ports, the grinders, etc. If
the reduced DAC were to be imposed, all of these operations would be sealed in glove
boxes.
Rough cost estimates were made by engineering designers at both facilities of the
capital costs associated with conversion of the existing hoods to glove boxes. For the
combined UFg/UO2 facilities, the estimate in 1982 dollars is $2.4 million for contain-
ment, $2.4 million for process modifications, $3.1 million for ventilation and $1.9
128
-------
million for engineering and construction supervision. Thus, the total cost at both
facilities is estimated to be $9.8 million.
In addition to required plant modifications, there would be increases in operating costs
from several sources. These include decreased efficiency and throughput, and increased
costs of solid waste management (i.e., more wastes from the inability to reuse boxes for
interim storage of pellets) and health physics (i.e., more counting man-hours.) A rough
estimate of these costs is 1.2 million dollars per year.
Improved calculations of exposure (i.e., relaxation of conservative assumptions) is not
considered to be a desirable approach for compliance with the proposed DAC's, nor is it
believed that compliance could be achieved in this way. In fact, it is policy in this firm
to achieve compliance through engineering modifications, rather than administrative
fixes.
On the other hand, the potential for compliance through modifications in calculational
techniques has not been thoroughly researched. Data generated by another firm
indicate that approximately 40 percent of the airborne particles, on the average, are
non-respirable. However, it would take more than a year to generate data specific to
this firm. Solubility data are even more difficult to obtain, and less reproducible. It is
not clear that either solubility or particle size are controllable variables, or that the
NRC inspection and enforcement personnel would accept these data for purposes of
compliance.
Assignments of time in specific areas for all personnel is difficult, if not impossible to
accomplish. Besides, it felt to be a "game," rather than a rigorous demonstration of
compliance.
Even if all of these refinements were included in the system, it is felt that compliance
with the proposed DAC could not be achieved, and, for sure, an ALARA limit at 25
percent of the DAC would be impossible to meet.
Other aspects of the proposed internal exposure guidelines — weighted organ doses,
additive internal and external doses, etc. — are only bookkeeping problems and would
involve minimal costs.
129
-------
9. Impact of the Reduction of the W.B. RPG to 1.5 rem/yr.
Because external exposures rarely exceed 1.5 rem/yr, the imposition of this guideline
would have no cost impact.
130
-------
F. WELL LOGGER
Well logging is a technique to determine the properties of subsurface rock. Applied in
the exploration for several minerals, most of the service is sold to the oil and gas
exploration industry. The properties of rock that are of interest include porosity,
permeability, fluid content, and geometrical configuration of the reservoir. Some of
these properties can be obtained by coring, whereas others, such as fluid content,
cannot. In well logging, various instruments are lowered into the shaft, to depths up to
35,000 feet, and non-destructive measurements are made over the entire length of the
shaft. These measurements include resistivity, electron density, spontaneous potential,
sonic attenuation, sonic travel time, and hydrogen concentration.
Two of these measurements involve the use of radiation. To measure electron density,
a gamma ray source, usually Cs-137 (~l/2 to 2 Ci) is used. For the measurement of
hydrogen concentration, neutron sources are used. The neutron sources are generally
Am-Be (1 to 20 Ci) or Pu-Be (smaller companies may still use Ra-Be), although in
approximately 5% of the measurements an electronic source (electron bombardment of
tritium) is used in the pulsed mode. The radioisotope sources, of which the case study
firm possesses approximately 3,000, are doubly encapsulated in stainless steel and
tested to 1500°F and 25,000 psi. They are fabricated by outside vendors and assembled
into the source holder manually upon receipt. The source holder also provides an order
of magnitude collimation along its axis. This collimation, provided for measurement
purposes, adds a measure of safety for handling of the source. The assembled source is
loaded into a lead (or poly, as appropriate) DOT-approved shield (less than 200 mr/hr on
the surface) for transportation to the site.
This well logger is one of five large firms that perform about 80% of these services
nationwide. The remaining 20% is performed by approximately 200 - 300 small
operations. These small "mom and pop" operations, however, must each have an
investment in equipment in excess of $500,000.
Total employment in the industry is estimated to be approximately 25,000, and this firm
employs its proportionate share. The heart of the operation consists of the field teams,
each typically comprised of three members — two operators and a field engineer. In
this particular company there are 700 such teams in this firm engaged in roughly 400
131
-------
jobs on any given day. The operators load the equipment onto the truck and drive the
truck to the site. They are met at the site by the field engineer, who supervises all
activities at the site.
At the site, the truck is unloaded, the equipment is calibrated, the tools are loaded into
the hole, and measurements are made (continuously as the instruments are moved at a
uniform rate down the hole). For a typical well, the measurements take from three to
50 hours (12 hours on the average). The only time in which the crew is exposed at the
site is while the source is removed from the transportation package and slipped into the
logging tool. This generally takes from 30 to 90 seconds. The crew is paid on an
incentive basis, thus it is advantageous to complete the job in as short a period of time
as possible. Additionally, the work is tedious and must be completed by the same crew
(jobs have taken as long as six days).
Operators, who range in age from 21 to 30, generally have a high school education and,
depending on how hard they work, typically can earn between $20,000 and $30,000 per
year. Field engineers, generally in the same age bracket, can earn as much as $45,000
per year, and must have a degree in engineering or a bachelor's degree in one of the
hard sciences (i.e., physics, geology, etc.). Travel requirements and odd hours
contribute to a high turnover rate for both operators and field engineers.
Approximately 3,000 employees are monitored, most of whom are operators and field
engineers. Additionally, clerks, truck maintenance men, and technicians are monitored.
The highest exposures are received by the handful of technicians who load the sources
into the source holders upon receipt from the fabricator. They may receive as much as
0.6 rem per quarter. Exposures in the field are considerably lower; the anticipated
doses are roughly 0.2 rem/qtr. The only other potential for exposure is during monthly
calibration of the sources at the field facilities.
The distribution of exposures for calendar year 1979 is given in the attached Table.
TLD's, rather than film, are used for monitoring exposures. These are found to hold up
better under the conditions in the field, and are not prone to fading over the three-
month period between readings. The cost of the outside dosimetry service which
provides the TLD's is $18/yr (quarterly readings). The measured doses for neutrons are
felt to be accurate to within + 200%.
132
-------
WHOLE BODY EXPOSURE
DISTRIBUTION FOR THE YEAR
1979
Well Logging Firm
Annual Whole Body Dose
Ranges * (Rems)
Number of Individuals
In Each Ranoe
No Measurable Exposure
Measurable Exposure Less Than 0,100
0.100 -- 0.250
0.250 -- 0.500
0.500 - 0.750
0.750 -- 1.000
1.000 — 2.000
2.000 - 3.000
3.000 « 4.000
4.000 -- 5.000
5.000 — 6.000
6.000 -- 7.000
7.000 — 8.000
8.000 — 9.000
9.000 -- 10.000
10.000 -- 11.000
11.000 -- 12.000
> 12.000
401
768
759
733
. 348
214
277
34
1
2
0
.0
0
0
0
0
0
0
Total number of Individuals reported 3537
133
-------
The exposures of clerks and maintenance personnel are at the very low end of the
distribution given in the attached Table. The 4-5 technicians who load the sources are
at the high end. The operators and field engineers are equally exposed. There is no
correlation between logging time and magnitude of exposure. Once the source is in the
hole, there is essentially no exposure to personnel. Even if the source becomes lost in
the hole, a not infrequent occurrence, no exposure is encountered during the "fishing"
operation, because the source is at depth. There may be higher exposures for shallow
holes, since the source goes in and out more often. Generally, wells in the midwest and
east are shallower than those in the Gulf states. Depths are variable in the West.
The safety director for the firm is also Radiation Safety Officer and Chairman of the
Radiation Safety Committee. The Safety Office, with responsibilities considerably
broader than radiation, is comprised of two professionals at the corporate level, one
professional for manufacturing and one individual at each of four unit offices. The unit
offices coordinate activities at a total of 100 field facilities.
Safety personnel are generally drawn from the ranks of the field engineers. Although
there are no certified health physicists, the Radiation Safety Officer has 30 years of
field experience and a bachelor's degree in engineering. He additionally attended a 10
week course on radiation protection principles at Oak Ridge National Laboratory, and
attended some special courses at the University.
Each of the field engineers has approximately six months of training, ten weeks of
which are at special learning centers. The instruction at the learning centers includes
radiation protection principles. Operators do not receive formal instruction, but are
provided a 20 page booklet on radiation protection. Monthly safety meetings are held
at the districts. All available personnel (not on jobs) attend. Twice a year, these safety
meetings are devoted to radiation safety.
1. Impact of Reduction in W.B. RPG
There would be no anticipated cost to the firm if the W.B. RPG were reduced from 3
rem/qtr. to 5 rem/yr. There have been no recorded exposures in excess of 5 rem/yr in
recent memory and it is not felt that the additional flexibility provided by a higher
permissible annual limit would be necessary. In fact, it was felt that the substitution of
134
-------
the 3 rem/qtr. limit with an annual limit of 5 rem, all of which could possibly be
received in one quarter, might provide an added degree of flexibility.
2. Impact of Reduction in Accumulated Exposure Limit
The reduction of the accumulated exposure limit to 100 rem is not anticipated to
involve a cost impact to this firm. The highest cumulative exposure is currently 11
rem. The turnover rate of operators and field engineers is relatively high. If a field
engineer should remain with the company as long as 20 years, he would no doubt be
promoted to a management job somewhere along the line, thus eliminating any further
exposure.
The opinion was expressed that although cumulative exposure records are always
requested from previous employers, a response is seldom received. Apparently the
military is particularly unreliable. Colleges and universities are generally reliable.
3. Impact of Proposed Guidance Relative to Extremities and Individual Organs
There is no reason to believe that the extremities or the eyes receive higher exposures
than the whole body. This is also true for the technicians who load the sources into the
holder. Accordingly, no extremity monitoring is performed.
4. Impact of Proposed Guidance for Potential Exposures in the Range of 0.3 to 1.0 RPp
Approximately 9% of the monitored workers received exposures in excess of 1.0 rem
(the number in excess of 1.5 rem is not readily available) in 1979. Moreover, since most
of the exposures to non-field personnel are less than 0.1 rem/yr, the percentage of field
personnel who received exposures in excess of 1.0 rem is estimated to be roughly 13%.
Therefore, it might be "anticipated" that exposure to field personnel would exceed 1.5
rem in any one-year period.
If each task were to be considered to "significantly" contribute to the annual exposure,
a supervisor would have to be present before and during the operation in which the
source is removed from the package and slipped onto the logging tool. Since the field
teams are geographically dispersed, and typically 400 jobs are ongoing at any one time,
the implication of this proposed guideline is that each of the field teams would require
the presence of a supervisor. Moreover, since the jobs are not constrained to single
shift operations, as many as 700 supervisors could be required.
135
-------
Although the field engineers are well-trained, including instruction in radiation protec-
tion, they are clearly not equivalent in background or training to health physicists.
Additionally, a health physicist would have to be present at the loading of the sources
into the holders at headquarters, and during the monthly source calibration at the
district offices.
5. Impact of Proposed Guidance for Potential Exposures in the Range of 0.1 to 0.3 RPG
In addition to the personnel monitoring requirement, which is currently being satisfied
by this firm, this guideline requires the availability of a "radiation protection
professional" to assure that exposures are justified and ALARA. The activities in the
field involving the use of radiation sources are relatively routine, and are prescribed by
procedures drafted by the Radiation Safety Officer. Any time procedures or equipment
are changed, the Radiation Safety Officer at Headquarters becomes involved. There-
fore, the activities prescribed by this guideline are currently being carried out.
However, there remains the question whether the Radiation Safety Officer, whose
credentials are described above, is equivalent in background and experience to a
"radiation protection professional."
If the Radiation Safety Officer does not qualify, an outside consultant with the
appropriate credentials would have to be retained to satisfy this guideline. This might
be difficult, since there are believed to be only three certified health physicists in the
geographical location of this firm's headquarters.
6. Impact of Training Requirements
As discussed earlier, the field engineers do attend formal training course in radiation
protection principles. Although they do not currently receive instruction on quantita-
tive levels of risk, this is being added to the curriculum at a cost of $10,000. The
material given in NRC Regulatory Guide 8.29 will be provided in a new booklet.
At present, no formal instruction is provided to the operators in radiation protection
principles. If a one-hour period of instruction were to be provided to each new
employee, 1200 person-hours of new-employee time would be involved annually. As
discussed earlier, the range of salaries for operators and field engineers is $20,000 to
136
-------
$40,000 per year. Moreover, because of the diffuse locations in the field (approxi-
mately 100 field facilities), instruction would be required more or less on a one-on-one
basis (approximately one new employee per month at each field location). Therefore,
the instruction at this firm would occupy roughly 1200 hours of district manager time.
A typical district manager's salary is approximately $50,000 per year. An alternative
would be to hold classes monthly at headquarters, involving an additional cost of
approximately $62,000 in new employee time and $150,000 in travel and expenses per
year.
7. Impact of the Guidance for Protection of the Unborn
There are presently 25 female operators and 20 female field engineers, nearly all of
whom are of child-bearing age. The firm is under considerable EEO pressure to
increase these numbers. The firm's radiation protection booklet includes a verbatim
description of the NRC's prenatal requirements. New female employees are urged to
read this section and to discuss it with their district managers. Although the firm
currently operates under alternative a, there are no other jobs available if a female
voluntarily removes herself from a field assignment. Several females have announced
to management that they are pregnant and that they desire to remain on the job. In
these cases, the managers emphasize the need to strictly follow procedures, in which
case exposures in excess of 0.5 rem to the unborn are highly unlikely. Moreover,
pregnant females are not likely to work more than six months, because field work
entails the lifting of heavy machinery.
If procedures are strictly followed in the field, it is also unlikely that exposures in
excess of 0.2 rem/month would be received. Therefore, females who wish to limit their
exposures because they suspect that they are pregnant or they are trying to get
pregnant, can easily do so by being very careful. They are not, however, given the
option of a non-field job.
If Alternative c were in force, fertile females would just not be hired for the field. This
would play havoc with the firm's EEO objectives. It would mean that they would have
to meet their quotas by placing women in non-field jobs, of which there are less.
Moreover, the non-field jobs that satisfy EEO objectives are accounting, legal, and
machinists, for which there are few qualified women. Because there are very few
137
-------
females in field jobs presently, the costs of Alternative c would be minimal. It would
involve discharging the women presently in the field, and increasing the annual
recruiting effort by roughly 4%. This would involve a one-time recruiting and training
cost.
8. Impact of Internal Exposure and Combined External Exposure Guidance
Currently there is only one use of unsealed sources by the firm, which involves the only
potential for internal exposures. This is the use of 1-131 as a tracer for investigating
the migration of fluids in wells. Approximately 10 mCi (the NRC limit is 50 mCi) of
iodine salt in an alkaline buffered solution is injected directly into the well. Other
companies perform this procedure more frequently than this firm. According to an
NRC Regulatory Guide, bioassays are not required as long as the amount of
radioactivity is less than 50 mCi. Therefore, the firm does not perform bioassays on
the employees involved with this procedure. Since monitoring is not required, and since
this is the only radionuclide with potential for internal exposures, no cost impact is
anticipated from the proposed internal exposure guideline.
9. Impact of the Reduction of the W.B. RPG to 1.5 Rem/yr.
As discussed earlier, only 8% of the total work force, or possibly 14% of the field staff,
receive exposures in excess of 1.0 rem/yr. (the fraction over 1.5 rem is not readily
available). If procedures were followed, exposures could be kept below 1.5 rem/yr. In
fact, experience has shown that a maximum exposure of 0.3 rem per quarter is expected
if procedures are followed. However, the opinion was also expressed that "people are
not perfect" and that it is virtually impossible to get 3,000 people involved in 200,000
operations per year to follow procedures. One possibility would be to have a
multiplicity of inspectors, who would drop in occasionally to monitor the field crews.
To monitor one-third of the 400 operations daily would require approximately 100
inspectors. However, the purpose could probably be accomplished with a lower
frequency of inspection, resulting in fewer inspectors.
Another possibility is to lower the source strength. However, the current well traverse
speed is dictated by the source strength (counting statistics limited), so that a factor of
two reduction in source strength would increase the logging time (when using the
sources) by a factor of two. Since radioactive sources are used approximately 60% of
138
-------
the on-site time, this reduction in source strength would, in effect, increase the well-
logging time by 60%. Therefore, to get the same amount of work done, roughly 60%
more people would be required. More efficient detectors are not the answer, since the
existing detectors are as efficient as the current technology permits.
139
-------
G. PRIVATE DENTAL FACILITY
This large dental facility is located in a major northeastern urban center. The facility
has been operating for 15 years and it is typical of a large number of multi-chair full
service dental operations that are being developed across the country. This trend is in
part a result of new opportunities for dentists to advertise their services and increase
volume to achieve economies of scale in operations. This facility has a staff of 11
dentists covering all major dental subfields. Six dentists are on duty at any one time.
The facility operates daily from 9:00 am to 7:30 pm and on Saturday from 9:00 am to
12:00 am. An average weekday patient load is 175 patients of which 25 are first-visit
patients. The Saturday patient load is about 25, all of which are first-visit patients.
The facility advertises in large and small area newspapers, as well as conducting direct
mail advertising compaigns. Approximately 20 percent of their patient volume is
developed through these efforts, with the bulk of their patient load coming from their
support of dental plans for several major unions. In some cases, the union may have a
prearranged self-insurance plan with the facility or the plan may be run by a major
insurance firm. Most billing is made directly to the union or insurance carrier with any
minimum deductible fees for union members or their families waived by the facility.
The two floor operation is divided into reception, operatorium, laboratory and admini-
strative areas. The operatorium is subdivided into about 15 cubicles, 11 of which are
equipped with a standard wall-attached, heavy-duty dental X-ray machine. One room is
equipped with a Panorex X-ray machine, designed to develop exposures of the entire
mouth in one sitting. The Panorex is a new machine; all the others are over 20 years
old. The machines are maintained by a technician who visits the facility periodically
(no set schedule) or upon request. All of the exterior walls, interior separator walls and
doors are lead-lined.
The facility employs 30 to 35 individuals, of which 17 to 22 can be identified as
radiation workers. These include 11 dentists (all male) and nine dental technicians (all
female) and may include the administrator, who spends some time in the operatorium
and is badged. All dentists, dental assistants and the administrator are badged, for a
total of 17 to 22 badges that are read monthly. Badges are worn at the collar and are
required for all personnel in these categories. Monthly reports, as shown by the
140
-------
attached Table, are reviewed by the administrator or the chief dental assistant and any
measurable exposure is investigated. All measurable exposures observed in this facility
have been for dental assistants and have been small (21 mrem is the highest one-month
exposure recorded). All recorded measurable exposures have been traced to non-
personnel exposures, such as leaving a badge in a cubicle on a day when the employee is
not working.
Standard procedures and training for new personnel are the responsibility of the chief
dental assistant. All X-rays are taken with only the patient remaining in a lead-
enclosed cubicle and the exposure is triggered from a switch in the hallway. All traffic
in the hallway is stopped during exposure. Each new patient receives a Panorex X-ray
on the first visit; regular patients receive one about every 24 months, so that about 325
of these exposures are taken per week. In addition, each patient may receive three or
four standard X-rays during the course of a treatment (average three to four visits per
treatment) or about 175 exposures per week. Procedures are explained to new dental
assistants in a one-hour briefing that covers all aspects of the position by an on-the-job
training period supervised by the chief dental assistant.
As the Table shows, there has been almost no record of measurable exposure at this
facility. The two non-zero readings were both identified as badges left in a cubicle for
an entire day. Therefore, there is no impact from the proposed guidance on this
facility. This facility may not be typical of exposures due to the lead-lined walls. It
was suggested that the capital investment made in this facility might not have been
made if the operator had not owned the entire building and thus, did not risk losing a
lease. It was also noted that the insurance companies require the submittal of before
and after X-ray records to prove that billed-for work was completed. In some cases,
the insurance companies also utilize these X-rays to evaluate the complexity and thus,
the fee for treatment.
141
-------
ICN DOSIMETRY SERVICE ,
26201 MIUESRQAD .,.
CLEVELAND, OHIO 44128
TELEPHONE: 216/831-3000
RADIATION EXPOSURE REPORT
PAGE L
$
/"DATE REPORT^
MAILED
MO.
09
OAYj YH.
23)80
1
r "DATE FILMS ">
REceiveo
MO. IDAY
Yfl.
cans ao
1 I
"' no. rip FILMS \
Ml.li
3
3
3
......
3
,_„_
ISTOUAIntlT
JAN 1
TO
MAR 31
CALENDAR UUAHIfcHS
2ND QUARTER
APft 1
TO
JUM 30
3RD QUARTER
JUL 1
TO
SEP 30
4TH QUARTER
OCT I
TO
DEC 31
1 i
*.
MONTHLY j
.',( i , .". CURRENT EXPOSURE, IN REMS
BADGE DATE
1ST OAV OF
EXHOSUHE
PUliUU
HO.
OAV|YH.
06iOl
07k)l
06.01
06|01
06{01
06/01
06J01
06,01
QAjOl
OTloi
06J01
0.6:01
06|oi
OT01
ao
80
p°
ao
iBO
ao
aa
80
80
an
UG
ao
M
07J018C
o?oiac
(6)
GAMMA
&
X-RAY
OIC
PO
1
MAI
N.
f
*
* .
*
(7)
NEUTRON
OfCiHAL
Y
T
i
(81
BETA
BICIUAl
rent
Y •"
•• ] •,;•,:•
1
• >::
\ ::'••,-;•'''
,T..'i. ' r,-,
1 '
1 i •
I... • '•
1
1 —
,;••
i
(9)
TOTAL
EXPOSURE
' 'MC.HAI
rumT
• Y
- : T
d
1 t. •-••
f-
4 -
i.. .-
i
(10)
N
O
1
E
>
II
CUMULATIVE EXPOSURE IN REMS :
QUARTERLY EXPOSURE TO DATE
GAMMA
&
X-RAY
DECUUL
T».T
l>
boo
IDOO
poo
poo
. poo
'• poo
poo
- poo
poo
poo
poo
boo
poo
(12)
NEUTRON
DICIIUI
«.,
I
nnr»
boo
,{)00
SOJ1
00
(500
poo
)00
)00
)00
)00
)00
)00
(13)
BETA
DCCIIUl
roi.r
Y
T
. poo
poo
poo
poo
poo
poo
•• poo
poo
DOO
boo
poo
poo
(14)
WHOLE
BODY
OiCIHAi
Y
T
boo
OOU
000
QQQ
000
000
ono
000
000
OOfl
looo
000
gfiil
00
jooo
w
(15)
V V
SKIN l)h
WHOIL U.tov
OH
fcXTHLMIf.
OtClttAt
POINI
Y
1
1
poo
boo
boo
poo
poo
poo
QQQ
poo
poo
OOU
000
000
000
IOOG
poo
(16)
NC BADGES
RECEIVED
?
2
2
f
2
2
1
2
1
1
1
1
1
17
Q
u
A
It
T
L
H
?
i
i.
?
2
I
3
^
2
3
3
3
II
YEAR TO DATE
WHOLE
BODY
• fCIMAL
roi.i
Y
T
6' Qfl
00
boo
poo
looo
poo
poo
poo
P21
poo
|ooo
poo
boo
|ooo
000
(19)
SKIN OF
WHOLE iOOY
OH
EKTHEMITV
OU.IML
rai.t
Y
T
poo
looo
boo
poo
poo
poo
poo
looo
P21
jooo
poo
poo
looo
poo
1
1
1
1
1
1
(20)
LIFETIME
WHOLE
BODY
MCIUAI
POINT
Y
T
S' QJ)
00
poo
poo
poo
noo
jooo
021
poo
|OOCJ
poo
000
iOOG
JOOG
(21)
MHOI I MOUV
on
LKllltMllf
MC
L
Oo
(2
YH.
?5
ri
75
n
77
JO
liL
iO
30
£
iO
3)
O
>
H
'o
z
M
X
^o
O
en
G
to
w
to
w
CODE KEY
• UIOAIIOtllM
(=
M1
. nil
-------
H.I ROCKY FLATS PLANT
The Rocky Flats Plant, operated under contract with the U.S. Department of Energy by
Rockwell International, manufactures nuclear components for nuclear weapons. The
plant is approximately 30-years old. Weapons-grade plutonium (approximately 93% Pu-
239) is the primary radioactive material handled at the facility. Depleted uranium is
also handled in significantly large quantities. On occasion, uranium-233 and uranium-
235, are handled in relatively small quantities. Additionally, the facility contains a few
sources of cesium-137 and cobalt-60, used for radiographic purposes. There are also a
few radiographic x-ray machines at the plant.
The input stream consists of both fresh plutonium direct from the production reactors
at the Savannah River Laboratory and "old" plutonium from retired nuclear weapons.
The "old" plutonium contains americium-241, which grows in as a decay product of
plutonium-241 and must be separated from the plutonium. This separation operation,
together with scrap recovery from other operations at the facility, is performed in a
wet chemical process, which dissolves the material in an acid solution and converts the
plutonium to the oxide state. The plutonium oxide is fluorinated to PuF., which in turn
is reduced to plutonium metal with calcium.
The manufacturing operations at the plant are performed on the pure plutonium metal.
These operations include melting, casting, pouring, rolling, shearing, shaping, pressing,
welding, drilling, and machining. Thus, virtually all conventional metal-working
operations are conducted at the facility. However, because of the radiotoxicity of
plutonium, all of these operations are performed in glove boxes.
The plant employs approximately 5,000. Of these, there are roughly 800 "radiation
workers," defined as those employees who actually work with plutonium in glove boxes.
Another 800 "incidental radiation workers" are potentially exposed to radiation in their
work (i.e., craftsmen), but do not deal with plutonium in a hands-on fashion. Approxi-
mately 350 employees in health, safety, and environment are also potentially exposed to
radiation. Finally, approximately 1,000 additional employees in research and develop-
ment and production support might receive occasional exposures.
143
-------
All of the plant employees are monitored for radiation exposure. External monitoring is
performed using TLD's which are sensitive to both neutrons and gamma rays. The TLD's
are currently read by hand; however, a new Panasonic unit will soon automate the
process. For the 800 radiation workers, the TLD's are read bi-weekly. Monthly
readings are taken for the incidental radiation workers and the support personnel
potentially exposed. All other TLD's are read quarterly. About half of the radiation
workers additionally wear ring badges to monitor hand exposures.
The annual external exposure distributions for 1981 and 1982 are given in the Table.
The highest external W.B. exposure in 1982 was less than 2 rem. The average
measurable exposure was less than 500 mrem. Most of the external dose is received in
chemical processing operations. Roughly 50% of the dose is from neutrons, which are
largely derived from the (a, n) reaction in fluorine (plutonium tetrafluoride is an
intermediate product in the chemical process).
EXTERNAL WHOLE-BODY EXPOSURE DISTRIBUTIONS FOR 1981 AND 1983
Exposure Range Number of Individuals
(rem) 1981 1982
0-1 4281 5029
1-2 63 109
2-3 10
> 3 00
Internal exposures are monitored with an extensive bioassay program. Lung counts by
the plant's four whole-body counters are administered annually. These counters are
operated 24 hours daily. A count takes one-half hour. The 800 radiation workers
receive quarterly lung counts in addition to a periodic urinalysis. Of course, a
whole-body count is also administered every time there is an identified potential for
internal exposure.
Although not used to infer intakes or internal exposures to workers, the plant has an
extensive network of air samplers. This includes three types of samplers. The first is
an integrating air sampler located at least in each room exhaust port. With air flows of
50 1/min, 0.1 MFC sensitivity is achieved. These samples are read daily. The second
type of air sampler, loccated throughout the work area, includes an alarm unit which
144
-------
triggers at approximately 20 MPC-hrs. The third is an effluent monitor, which is
located in each effluent stack and is collected on three-day intervals. These
annunciating air samplers are used as warning devices to detect incidents and thus
trigger bioassays.
Radiation protection is the responsibility of the Department of Health, Safety, and
Environment, which employs 350 people. The Director of Health, Safety, and
Environment reports to the General Manager of the Rocky Flats Plant. This
Department has six sections ~ Operational Safety; Environmental and Occupational
Health; Medical; Nuclear Safety; Health, Safety, and Environmental Laboratories; and
Risk Management. The Operational Safety Section employs 130 technicians who
perform radiation monitoring. The Environmental and Occupational Health Section
contains 80 professionals, including most of the 20 health physicists employed at the
plant (five certified and an additional number who are completing the two-part
certification examination). The Health, Safety, and Environmental Laboratory Section
contains 50 people who perform the dosimeter badge reading, radiation sample
counting, analytical chemistry, and data management.
Each employee who enters an area in which plutonium is handled receives a core
training program which includes a three hour unit on radiation protection. This unit
includes a description of levels of risk from radiation. Women receive an additional
unit on the risk from radiation to the fetus. Operators receive additional instruction in
nuclear safety, plus a three-month intensive training program on a "cold" (i.e., non-
radiological) line while awaiting security clearance. Each training course is followed by
an examination. Also, the core training is repeated on two-year intervals.
1. Impact of Reduction in W.B. RPG
This limit, in itself, would not have a significant impact at this facility. The maximum
external exposure in 1982 was less than 2 rem. Only five individuals have exceeded 2.0
rem/year in the last three years, and none has exceeded 3.0 rem/year. The average
measurable exposure in 1982 was approximately 0.5 rem. The facility operates with an
administrative limit for external exposure of 2.5 rem/year. When a worker has
accumulated an external exposure of 1.25 rem, the individual's work record is reviewed
by the health physicist, the individual, and his manager, and a plan is implemented to
reduce exposure.
145
-------
Internal exposures would probably not push anyone over the limits, although this
depends upon the way committed dose is handled. About 400 individuals at the plant
have measurable quantities of plutonium in them. The maximum effective dose
equivalent from internal deposition of plutonium is estimated to be less than 1
rem/year.
2. Impact of Reduction in Accumulated Exposure Limit
The maximum accumulated external lifetime exposure at the plant is approximately 100
rem. There are some individuals who have internally deposited plutonium who would
exceed this number, but the amount would depend on the weighting factors selected. If
the effective committed dose equivalent from intake of plutonium and the weighting
factors suggested by the ICRP were added to these numbers, they would be somewhat
higher. The assignment of committed 50 year dose to the year of intake would present
serious problems.
Notwithstanding the above, this lifetime additional limit is considered inconsistent with
an annual limit and not well justified. Moreover, it has the potential of limiting the
employment opportunities for a selected number of workers. Even considering the
existing administrative limit on external exposures, workers can receive on the order of
3 rem/year if one includes the effective committed dose contribution from internal
deposition of plutonium. This would give a few workers an employment vista of
approximately 30 years, considered to be overly limiting. Also, this could seriously
affect a worker's chance for continuing employment if he has accumulated a significant
lifetime exposure, say 80 to 90 rem. Such high accumulated exposures could well act as
a deterrent for new employment.
3. Impact of Proposed Guidance Relative to Extremities and Individual Organs
There have been hand exposures in excess of 50 rem/year in the past, but currently the
maximum annual hand exposures are on the order of 30 rem/year. Currently,
approximately one-half of the radiation workers are monitored for hand exposures. The
reduced extremity limits could result in the need for additional monitoring of hand
exposures, but this is not altogether clear at the present time. In any case, it is felt
that there is no technical basis for the reduction in the extremity exposure limits.
146
-------
Moreover, the reduction in the ICRP-26 organ limit of 50 rem/year to 30 rem/year is
not felt to the justified.
4. Impact of Proposed Guidance for Potential Exposures in the Range of 0.3 to 1.0 RPG
Any incident in the production line could make a significant contribution to a worker's
annual dose. It is impossible to prevent a small number of "incidents," or unplanned
releases from occurring. Should these be considered as accidents which are outside of
the purview of radiation protection guidelines and regulations? It is difficult to answer
this question and a resolution of this issue is considered to be outside of the scope of
this case study.
Assuming that the unanticipated, but frequent incidents are covered by the proposed
guidelines, the Range C guidance would have a substantial impact at this facility. To
provide real-time coverage for those activities potentially resulting in a release would
require a doubling or a trebling of the existing monitoring staff — from approximately
100 to 200 or 300. H.P. technicians earn $25,000 per year, plus approximately $15,000
for overhead and fringe benefits. Moreover, five to ten health physicists would have to
be added to the professional staff at a cost of $35,000 per year for each individual, plus
$20,000 for overhead and fringe benefits. Finally, at least 5 technicians would have to
be hired for the analytical chemistry group to analyze samples and record data. These
technicians earn an average of approximately $25,000 per year, plus $15,000 for
overhead and fringe benefits.
5. Impact of Proposed Guidance for Potential Exposures
in the Range of 0.1 to 0.3 RPG
The requirements of the Range B guidance are currently being performed at this
facility. However, it is felt that the word "oversight" should be substituted for the
word "supervision" in the guidance.
6. Impact of Training Requirements
This facility is currently complying with the training requirements in the proposed
guidelines.
147
-------
7. Impact of Guidance for Protection of the Unborn
It is estimated that approximately 10% of the radiation workers are women. At
present, if a female radiation worker declares to her supervisor that she is planning to
get pregnant, another job which does not involve the handling of radioactive materials
is found for her if she requests. In any event, a radiation exposure potential analysis is
conducted. If she gets pregnant within six months, she is kept out of radiation work
during the term of the pregnancy, and if she is breast feeding, she is kept out of
radiation work for an additional 12 months after the baby is born. If she does not get
pregnant within six months, she returns to her original job. She can request an
additional six months away from radiation work if she obtains the concurrence of her
physician. The major reason for this stringent policy goes beyond the protection of the
unborn. If an individual receives a significant intake of plutonium, he/she voluntarily
receives a dosage of DPTA, a chelating agent, to clear the plutonium from the body.
This compound is teratogenic, and thus could well produce a malformed fetus. Thus it
is advisable to avoid the possibility of administering it to a pregnant female.
Thus this facility is essentially in conformance with Alternatives a and b of the
guidance for the protection of the unborn. If Alternative c were promulgated, the
roughly 80 female radiation workers would be restricted to certain jobs in which the
risk of plutonium intake is insignificant and the external fields are well below 0.2
rem/month. Also, additional monitoring would be required. Although this program
would have some impact on current operations, the costs would not be excessive.
8. Impact of the Internal Exposure and Combined External Exposure Guidance
The internal exposure provisions of the proposed guidelines would cause a major
problem at this facility. The current method for restricting internal exposures at this
facility is based upon the maximum permissible body burden, derived from ICRP-2.
This limit was derived from a maximum annual dose to the bone of 30 rem/yr, which in
turn goes all the way back to the original radium-equivalent standards. From this dose
limitation, a body burden of 40 nCi for plutonium-239 was derived, and it is this body
burden that is used as the primary standard. A secondary standard for the concentra-
1 o
tion of plutonium in air, 2 x 10 V Ci/ml was derived from this primary standard.
Although a lower dose limit (15 rem/yr) applies to the lung, this is derived largely from
insoluble plutonium, resulting in less restrictive MFC's. Thus, the soluble limits are
148
-------
used for compliance, since both soluble and insoluble plutonium are found in the
facility.
The maximum permissible body burden of 40 nCi has historically been the primary
standard for limiting the internal exposure from plutonium at this facility. Bioassay,
including both urinalysis and lung counting, has been used as the method for measuring
body burden. For "clean" plutonium (relatively free of americium-241), the limit of
sensitivity for bioassay is 30 nCi, roughly three-quarters of the limit. For aged
plutonium (roughly 1,000 ppm americium-241), as little as 2 to 4 nCi can be detected in
the body, or roughly 10% of the limit. Fortunately, almost all of the plutonium handled
at this facility is aged with americium to a level suitable for lung detection.
IPRC-26 shifted the emphasis to the intake in each year which, in the aggregate over 50
2
years, would result in the limiting dose to the bone. This limiting annual intake is
called the ALI (allowable limit of intake), and is a small fraction of the maximum
permissible body burden. In fact, for soluble plutonium-239, the ALI is 200 Becquerel,
or approximately 5 nCi. Using urinalysis as the bioassay method, it is not possible to
measure this quantity until at least the seventh year of continuous intake (assuming
pure soluble plutonium and one micron particle size). With lung counting, it is not
possible to do even this well. (Pure plutonium emits X-rays of 13, 17, and 21 kev.)
It is instructive to calculate the effective committed dose equivalent from 1 ALI of
soluble plutonium. This is done below.
Effective
Annual (weighted)
Committed Dose Committed Dose
Organ ISquivalent Fxjuivalent
(rem) (rem)
Gonads 0.63 0.16
Red Bone Marrow 3.9 0.47
Lung 0.32 0.04
Bone Surfaces 48.38 1.45
Liver 10.58 0.63
Total 2.75 rem
1ActuaUy, a limit of 20 nCi, a factor of two below the maximum permissible body
burden, was maintained as an administrative limit.
2In addition, the non-stochastic limit was increased from 30 rem to 50 rem. The
philosophy at this facility, however, would be to maintain the 30 rem limit.
149
-------
Thus, the intake of 1 ALI plus a relatively small amount of external exposure would
bring a worker precariously close to the limit.
Air monitoring, on the other hand, is capable of detecting smaller fractions of the
limits. For plutonium-239, the limit of sensitivity of air monitors is approximately 2 x
1 Ti
10 /i Ci/ml, or approximately 10% of the soluble limit. However, it is not
appropriate to rely on integrated air monitoring data (MPC-hrs.) to assign internal doses
from the inhalation of plutonium. The specific activity is so high that the air
monitoring data may not be at all indicative of the intake. The data may be used as a
trigger for bioassay, but not as a quantitative measure of intake or dose. In order to
quantitatively use air monitoring data, a time-dependent correlation would have to be
drawn between the concentration of plutonium at the actual breathing zone of the
worker and that of the monitor itself. This is not possible. Moreover, lapel air
samplers are not useful in this regard because the volumes of air sampled are too low
and people can't wear them where they ought to.
Is there any new technology which will permit measurements down to the levels of the
ALrs? For lung counting, a factor of at least 10 in sensitivity reduction would be
needed, and there is nothing on the horizon that would improve the sensitivity by more
than a factor of roughly 1.5. Significant improvements in sensitivity are potentially
available for urinalysis, possibly permitting the detection of an intake equivalent to an
ALI. But this will not be sufficient to track an individual during an annual cycle.
*
Thus, if the EPA guidelines were to be promulgated, it would be necessary for this
facility to seek an exception from DOE in order to keep operating. This would not be
necessary because the proposed limits are currently being exceeded. To the contrary,
the facility is well within the proposed limits. It is because it would not be possible to
demonstrate compliance with the current or anticipated state-of-the-art bioassay
technology. If an exception were not made in the requirement to demonstrate
compliance, this facility would have to shut down and a new absolutely sealed facility
would have to be constructed. Although the feasibility of constructing such a plant has
not been thoroughly demonstrated, a rough cost estimate of $2 billion has been made.
Although several of the European and Asian countries have adopted the ICRP-26/30
prescription, most of them are having the same problem in demonstrating compliance
that this facility would have.
150
-------
Automating the computation and records system for the proposed guidance would not
result in significant costs. The facility already has considerable automation along these
lines; both external exposure and organ burden in nCi are reported annually. Minor
modifications in software would be required.
One additional feature of the proposed guidance, although not limiting in terms of
compliance, is felt to be unrealistic. Because the guidance requires the computation of
the 50-year dose commitment, doses to the individual would be debited to his record
well before they are actually received. This is felt to be misleading as well as
technically incorrect. Moreover, whereas the original ICRP-2 standards were derived
on the basis of a fixed 50-year window, the 50-year window keeps moving in the current
proposal. Thus, a 50-year dose commitment is still assigned, even for a worker who is
close to the end of his career. This is not appropriate because the older worker will not
receive this actual 50-year dose commitment during his lifetime.
9. Impact of the Reduction of the W.B. RPG to 1.5 Rem/yr.
Costs associated with reduction in the external exposure limits were examined a
number of years ago for DOE. These studies indicated that if administrative controls
alone were used, there would be zero costs associated with a reduction to 2.5 rem/yr.
To further reduce the limit to 1.0 rem/yr., the costs were estimated to be $1.7 M/yr.
(1978 dollars) if administrative controls alone were used. Finally, reducing the limit to
0.5 rem/yr. administratively was estimated to cost $10 M/yr. (1978 dollars).
The costs of reducing external exposures using facility modifications were also
examined. These were estimated to be $6.5 M to reduce the limit to 2.5 rem/yr., $215
M to reduce it to 1.0 rem/yr., and $1.4 billion to reduce it to 0.5 rem/yr. All of these
estimates are one-time costs expressed in 1978 dollars.
151
-------
H.2 IDAHO NATIONAL ENGINEERING LABORATORY (INEL)
This site, formerly known as the National Reactor Testing Station, contains a number of
facilities operated for the Department of Energy by four contractors — EG&G, Exxon,
Westinghouse, and Argonne National Laboratory. Westinghouse operates several
prototype reactors for the Naval Reactors Program. They have their own radiation
protection program for approximately 1,000 employees plus transient personnel in
training. Argonne/West, which runs EBR-n, the hot cells and the Zero Power Reactor
(ZPR) facilities, also employs approximately 1,000.
This case study is confined to the EG&G and Exxon operations at INEL. EG&G, with
approximately 3,500 employees, operates the test reactors at the site. Exxon, with
approximately 1,100 employees, operates the chemical processing plant. Together, they
employ approximately 70% of the permanent employees at the site.
EG&G operates the following three test reactors at the site:
1. The Advanced Test Reactor (ATR), a 250 MW(t) tank reactor started up in
1968.
2. The Power Burst Facility (PBF), an open tank transient reactor capable of
operating at 28 MW(t) and completed in 1973.
3. The Loss of Fluid Test (LOFT), a 55 MW(t) pressurized water reactor
started up in 1978.
Approximately 800 out of the employment force of 3,500 are radiation workers. A
radiation worker is defined as an individual who goes into the site area on a regular
basis.
The chemical processing plant, operated by Exxon, is an enriched uranium reprocessing
facility. Although a new waste calcining facility is in place, most of the plant is
approximately 30 years old. The plant processes enriched uranium from all over the
world, including nuclear navy fuel. Of the 1,100 employees, approximately 900 are
considered to be radiation workers.
152
-------
Although each contractor is ultimately responsible for its own dosimetry, the dosimetry
itself is performed by the Radiological Environmental Sciences Laboratory (RESL), an
organ of the Idaho Operations Office of the Department of Energy. Additionally, RESL
has the legal recordkeeping responsibility. RESL also obtains exposure histories for new
contractor employees. RESL performs dosimetry services for Argonne/West as well as
EG
-------
The external dose distribution for each contractor in calendar year 1981 is given below.
The collective exposure for EG&G was approximately 110 person-rem. (The previous 5-
year average was approximately 220 person-rem per year.) The collective exposure for
Exxon was roughly 150 person-rem.
EXTERNAL W.B. EXPOSURE DISTRIBUTIONS FOR THE YEAR 1981
Exposure Range Number of Individuals Monitored
(rem)
None
0.001-0.100
0.100-0.250
0.250 - 0.499
0.500-0.749
0.750-0.999
1.000-1.999
2.000-2.999
3.000-3.999
4.000-4.999
Greater than 5.0
Total 2,301 1,100
RESL also performs bioassays, on request, for contractor employees. These include
urinalyses, fecal analyses, whole-body counts, and lung counts. The contractors are
provided data on specific activity by radioisotope. They are responsible for converting
these data to dose and/or percent body burden.
Whole-body counts are taken for new and departing employees of EG&G. Annual counts
are taken for a few hundred employees who work in areas in which uncontained activity
is known to exist. A very few employees, mostly those in waste handling, must submit a
fecal and urine sample and obtain a chest count annually. Most other bioassays are
performed on an as-needed basis, when there is evidence of exposure either from
smears or air sampling results. Over the past three years, there have been only three
employees with measurable intakes, two of which had accumulated less than 10% of the
dose limits. (DOE Order 5480.1A, Table 1.)
154
EG&G
1,357
695
148
66
17
11
6
0
1
0
0
Exxon
627
199
95
75
51
25
28
0
0
0
0
-------
Because of the relatively high potential for internal exposure in chemical processing of
nuclear fuels, Exxon has a more extensive program for monitoring internal exposures.
Of the 900 radiation workers, 260 are routinely monitored annually with two whole-body
counts, one urinalysis, and one fecal analysis. These 260 individuals include most of the
maintenance personnel, the operators, and the radiation protection personnel. Of the
remaining radiation workers, those with non-penetrating exposures in excess of 50
mrem (indicating potentially loose contamination) are given an annual whole-body
count. Finally, bioassays are performed in the event of incidents, which are flagged by
an extensive air sampling network.
Last year, roughly 30 individuals had measurable internal exposures, most of which were
on the order of a few hundred mrem per year. The main problem is plutonium-238.
Each measurable intake is analyzed extensively for organ dose. ICRP-30 methods are
now used. An 18-page report is not uncommon.
The EG&G radiation safety program resides in the Health and Safety Division. The
Operational Safety Branch with a complement of 30 technicians (including H.P.
technicians), is ultimately responsible for radiation protection in the field. Technical
support is provided by the Technical Safety Branch which employs nine health physicists
(two certified). There are eight additional professionals in the Department who are
equivalent in background and experience to health physicists.
Radiation safety at Exxon is the responsibility of the Radiation and Environmental
Safety Section of the Quality Assurance, Safety, and Security Department. This section
contains 34 H.P. technicians and approximately 10 professional health physicists (none
certified). There are an additional 4-5 health physicists in other parts of the company.
Also, the DOE Radiological Environmental Sciences Laboratory, which performs dosi-
metry services for the contractors, employs three professional health physicists (none
certified).
EG&G requires all new employees to participate in an orientation session which lasts a
full day. One to two hours of this session are devoted to radiation protection. Although
there is some qualitative material presented on the risks from radiation, there is no
quantitative discussion. Radiation workers receive additional instruction in radiation
safety, largely on protective measures (i.e., clothing, respiratory protection, and survey
155
-------
instruments), which occupies the good part of a day. This session is updated annually.
Both the orientation session and the protection measures session are followed by an
exam. Finally, before a worker is permitted unescorted access to a particular facility,
he receives on-the-job training at that facility, including a unit on health physics.
The Exxon training program is basically the same as that of EG&G, except that there is
only one facility.
1. Impact of Reduction in W.B. RPG
Both contractors are operating well within the 5 rem/yr. proposed limit, even
considering the contribution of internal dose. Thus there would be no impact from the
revised RPG.
2. Impact of Reduction in Accumulated Exposure Limit
The highest accumulated external dose is 70 rem, for an Exxon employee. If effective
committed dose equivalent were added to the external dose, this employee, and possibly
others at the chemical processing plant, could possibly be over the 100 rem limit.
However, given current annual administrative limits, it is unlikely that this guidance
would have any impact in the future, except under conditions of a severe accident. If
another accident similar to SL-1 were to occur, workers could potentially 'receive a
significant contribution to the 100 rem lifetime limit, and thus effectively be precluded
from pursuing their careers. This would appear to be grossly unfair.
3. Impact of Proposed Guidance Relative to Extermities and Individual Organs
Hand exposures are not routinely monitored by either EG&G or Exxon unless a task is
performed for which there is a potential for extremity doses in excess of 10% of DOE
limits. A few years ago, a sample of hand exposures was taken at the chemical
processing plant and quite a few exposures were in the range of 7-10 rem/yr. Although
it is unlikely that anyone is receiving an extremity exposure of 50 rem/yr., extremity
monitoring would have to be performed to assure that this is the case. This conclusion
is strengthened by the fact that given the proposed guidelines, the actual extremity
limit is 30 rem/yr, not 50 rem/yr, since the skin limit would prevail in the eyes of the
compliance officials. The discrepancy between the skin and extremity limits is seen as
a limitation of the proposed guidelines.
156
-------
It is estimated that approximately 100 employees of EG&G and 200 employes of Exxon
would have to be monitored. However, hand exposures are not readily retrievable from
the current RESL recordkeeping system. Thus, in addition to the increased monitoring
requirements, there would have to be additional software development on the record-
keeping system.
4. Impact of Proposed Guidance for Potential Exposures in the Range
of 0.3 to 1.0 RPG
Even though there are very few exposures in excess of 1.5 rem/yr. for either
contractor, there is the potential for such exposures and thus it was felt that the word
"anticipate" applies to both operations. Each contractor issues approximately 1,000
Safe Work Permits per month. A Safe Work Permit is issued for those situations in
which written procedures do not exist, unusual hazard potential is involved, or specific
DOE or EG&G directives require its use. It is possible for a worker to receive 100
mrem exposure for about 75% of these Safe Work Permits. (It was generally agreed
that 100 mrem is "significant.") Thus there are, on the average, roughly 30 to 50 tasks
daily that would require "supervision" under the proposed guidance.
At present, an H.P. technician covers, on the average, approximately 8 to 10 tasks per
day. To accommodate the Range C guidance, the complement of H.P. technicians
would have to be doubled or trebled at each facility. Currently, EG&G employs 38 H.P.
technicians and Exxon employs 34 H.P. technicians.
Thus, between the two contractors, anywhere from approximately 70 to 140 H.P.
technicians would have to be hired to comply with the Range C guidance. An H.P.
technician earns between $20,000 and $25,000 annually. If fringe and overhead is
added, the fully loaded labor rate is approximately $60,000/yr. Of course, this is not
the strict interpretation of the guidance, which would require supervision by health
physicists. EG&G does not believe that hiring 70-140 H.P. technicians or requiring
health physicists to monitor each task is feasible.
"Likely," "potential," and "anticipate" are three words frequently used to characterize
future exposures. "Likely" has a DOE definition, but "anticipate" does not. It is felt
that the regulators would equate the two, in which case "anticipate" applies to both
operations at INEL. The reason for conservatism in the interpretation of these terms is
that these are R&D activities, in which each task is different and anything is possible.
157
-------
The opinion was expressed that the guidelines' approach to ALARA is counterproductive
and unnecessary for these facilities. The current program is oriented toward indivi-
duals, not tasks, and is quite effective. The proposed three-tiered system is not felt to
be an effective way to protect individuals. In fact, it could well increase total
exposures, due to the increased number of personnel exposed during each task.
5. Impact of Proposed Guidance for Potential Exposures in the
Range of 0.1 to 0.3 RPG
Both contractors are fully in compliance with the provisions of the Range B guidance.
6. Impact of Training Requirements
Both contractors are in compliance with the training requirements, with the possible
exception of a unit on quantitative levels of risk. Plans are currently underway to
address this topic.
7. Impact of Guidance for Protection of the Unborn
Both contractors, which employ in the range of 10 to 20% females, are in compliance
with the proposed Alternative a of this guidance. The orientation manuals have
sections on the risks of radiation exposure to the fetus. If a woman announces to her
supervisor that she is pregnant, she can be moved to another job involving little or no
radiation exposure. There have been several cases in which this system has worked.
For many jobs in which exposures exceeding 500 mrem in nine months are not likely, the
woman can remain in her current job, if she so chooses, and she will be double badged
and more frequently monitored. H.P. technicians, however, have to be moved to other
jobs.
Alternative b would be considerably more difficult to implement. It might be possible
to keep the monthly exposure to some H.P. technicians below 200 mrem, but this would
take a lot of supervisory time. Also, some men would consider this Alternative to be
discriminatory. It could cause morale problems. If there were a lot of women who
were desirous of becoming pregnant, this alternative could become costly or involve
labor disputes because there are not enough non-radiation jobs to go around.
158
-------
Alternative c would make the issue easier to deal with, in a sense, because it is
mandatory. In essence, this would prevent women from being H.P. technicians,
operators, or maintenance personnel. Thus, this could be viewed as discriminatory
toward females. The EEO office and the courts would have a great problem with this
alternative.
8. Impact of the Internal Exposure and Combined External Exposure Guidance
There are two major impacts of the proposed ICRP-26/30 system of dose limitations.
The first is the elevation of currently insignificant internal exposures to the realm of
potential significance. As an example, the 1981 incident at the chemical processing
plant, in which 22 workers received measurable intakes of radionuclides (75% Pu-238,
15% Pu-239, and the remainder Sr-90 and U-234), was subjected to the new system.
According to the existing system, in which the actual annual dose to an organ is
compared against the maximum permissible dose, the average lung dose was less than
2% of the limit (less than 300 mrem/yr compared against 15 rem/yr.). The maximum
lung dose was less than 6% of the limit (900 mrem/yr. compared against 15 rem/yr).
Using the ICRP-26 system, the average individual's committed weighted internal dose
equivalent was 6% of the limit and the maximum was nearly 20% of the limit. These
calculations are shown below.
Dose Equivalent in mrem
Average Exposed Individual Maximum Exposed Individual
50-Year 50-Year
Committed Weighted Committed Weighted
Dose Committed Dose Dose Committed Dose
Organ Equivalent Equivalent Equivalent Equivalent
3,380 406
1,840 110
685 82
11,300 339
4 -
108 27
Total 318 964
The average external dose to these 22 workers in 1981 was 407 mrem, or 8% of the 5
rem limit. Thus, on the average, the effect of the internal contribution is to increase
the effective dose equivalent to 725 mrem, or 15% of the 5 rem limit. The maximum
159
II ifc*
Lung
Liver
Bone Marrow
Bone Surface
Kidney
Gonad
1,096
685
301
3,386
26
20
132
41
36
102
2
5
-------
exposed individual's external exposure was 946 mrem (or about 20% of the limit); the
effect of this individual's internal exposure was to increase the dose equivalent to 1,348
mrem (or about 27% of the limit). The worker with the maximum weighted committed
internal exposure received relatively low external expsoure (262 mrem), so that his
effective dose equivalent was only about 25% of the limit.
The second major impact of the ICRP-26 system of dose limitations relates to the
necessary time frame to make an internal dose commitment determination. Quantita-
tive measurements require multiple samples over relatively long periods of time. This
is necessary in order to track the clearance in the body, so that a 50-year dose
commitment can be assigned. It may take several weeks, or even months, to assign a
dose commitment. In the meantime, if the dose is expected to be significant, it may be
necessary to restrict the activities of a worker. The problem is most significant toward
the end of a calendar year, in which a worker may have accumulated a relatively large
dose up to that date, and the additional internal exposure might cause him to approach
the limit. Until the internal dose is assigned, this worker's activities may have to be
curtailed.
The only way to detect the intake of relatively small quantities of plutonium is with
fecal analysis. Using this method, it is relatively easy to detect 50 Becquerels (1.4 nCi,
or approximately 25% of an ALI for soluble Pu-239) on a routine basis and 10 - 20
Becquerels (0.27 to 0.54 nCi, or approximately 5 - 10% of an ALI for soluble Pu-239) in
the event of an known incident. The occurrence of the incident is determined by a
combination of air concentration data and smear samples. However, multiple fecal
samples have to be taken (a messy and unpopular procedure) and considerable analysis
must be performed to assign a dose commitment.
Air sampling is useful for the detection of incidents, but it is not appropriate for
assigning doses to workers. The relationship between air sampling data and actual
internal dose is tenuous at best. Studies at Harwell are quoted that indicate that
radiation doses indicated by a fixed sampler may differ from the doses actually
received by a worker by a factor of 100 or more. Thus bioassay data are relied upon
exclusively for the assignment of internal exposures.
jg
The limit of sensitivity of the fecal analysis is 10 n Ci/sample. This facility is
probably at the state-of-the-art in internal dosimetry. Over the past couple of years, a
160
-------
large number of improvements in technique have been instituted. It is estimated that
the cost of making these improvements has been approximately $300,000.
It is estimated that an increase in resources of about one man-year per year would be
required to support the several hundred workers at the chemical processing plant. Some
small changes in the dose tracking software would have to be made, but this would
involve only a few man-months of effort. There would also have to be a lot of
retraining of technicians, and revisions to manuals and procedures.
A major philosophical problem with the ICRP-26 system is the assignment of a full 50-
year dose commitment from internal deposition, even for older workers. A 55-year old
worker is not likely to receive a full 50 years of internal exposure. There should be a
provision for age dependence.
A number of the changes made by EPA to the ICRP-26 system are viewed negatively.
Although the rationale for changing the organ weighting factors is understandable, the
change was not worth it in consideration of the inconsistencies generated with the
literature and the rest of the world. The quantitative differences brought about by the
changes cannot be detected anyway with existing sensitivities. Also, definitions of new
acronyms (i.e., RIF rather than AWs) is seen to be counterproductive. Finally, the lid
on existing limits is felt to be technically incorrect.
The wording of Recommedation 3.b is felt to be confusing — " H. is the annual dose
equivalent and committed dose equivalent to organ;." Does this mean that the 50-year
committed dose equivalent is not to include the present year's contribution?
9. Impact of the Reduction of the W.B. RPG to 1.5 Rem/yr.
A study of the anticipated impact of reduced external radiation exposure limits on DOE
facilities was published by DOE in February, 1981 (DOE/EV-0045 (Rev. 2/81)). Since
these contractors contributed to this report and support the information given in the
report, reference should be made to this document to obtain the impact of reduced
exposure limits.
161
-------
1.1. RELATIVELY NEW BWR
This relatively new boiling water reactor shares a site with a twin unit which went into
operation approximately two years earlier. Each unit has a net electrical output of 780
MW(e). The newer unit has operated at an average capacity factor of approximately
65% since inception of operations.
The station (both units) has a permanent staff of approximately 660 personnel. During
normal operations, an additional 1,000 personnel, from utility headquarters and contrac-
tors, supplement the permanent staff. During outages, which are scheduled on an 18-
month cycle and typically occupy 10 to 12 weeks time, the station complement roughly
equals 2,400. The average annual salary of plant personnel is $25,000, including an
overhead factor of 12%. Contractor personnel cost $20 per hour, on the average,
including overhead to account for radiation protection, security, etc.
The radiation safety organization on-site, which handles radwaste management and
plant chemistry as well as radiation protection, has a staff complement of approxi-
mately 130 people. Although the group is responsible for some conventional sanitary
engineering and industrial hygiene functions, the vast majority of the work is concerned
with radiation safety, both on-site and off-site. The manager of the radiation safety
unit reports to the manager of plant operations, and has four first-line supervisors
(professionals) reporting to him. During an outage, approximately 40 contractor
personnel supplement the permanent station radiation safety personnel.
Only one individual in the radiation organization is a certified health physicist, although
three other health physicists are studying for the certification exam and should be able
to become certified. In total, anywhere from 12 to 20 professionals at the plant are
equivalent in background and training to health physicists. In addition, there are
approximately 15 professionals at the corporate headquarters who are equivalent in
background and training to health physicists.
Dosimetry is handled in-house at the plant. All personnel who enter a posted area are
required to wear TLD's which are read monthly (more frequently during an outage) and
pocket ionization chambers which are read weekly. The personnel dosimeters do not
have neutron capability. Neutron doses are estimated from area exposure rates
determined by frequent surveys using BFg counters. The external exposure distributions
162
-------
for both units in 1981 are given in the Table. On the average, the collective dose during
non-outage periods is approximately 150 to 220 man-rem per month for both units.
During an outage, 350 to 400 man-rem per month is typical.
Internal dosimetry is performed using a whole-body counter which is owned and
operated by the facility. A whole-body count is obtained for each new employee, upon
discharge (even for transient workers used only for an outage), and annually for
permanent station personnel. Counts are also obtained if MFC-hours exceed 40 in a 7-
day period and for an incident resulting in potential internal contamination. It is
estimated that roughly 5,000 whole-body counts are taken annually (each requiring
approximately 10 to 20 minutes of counting time). Fecal and urine analyses are
performed only in the event of an incident.
Air monitoring is routinely performed to determine the need for respirators. The
station (both units) has 10 to 15 continuous air monitors, approximately 40 low volume
air samplers and roughly 25 high volume air samplers. Respirators are required for any
area in which airborne concentrations exceed 25% of MFC. However, MFC-hour
records are not routinely maintained, as in many other plants. Thus, whole-body
counting is used exclusively for estimating internal exposures.
Last year, the maximum internal exposure was less than 10% of the maximum internal
organ burden. On the average, workers received less than 1% of the maximum.
A new training program is currently being implemented. The program has three levels
of instruction. At the first level, personnel get eight hours of instruction in radiation
protection, security, and fire protection. Approximately 50% of the time is devoted to
radiation protection. The second level, which is given to anyone who is likely to be a
long-term radiation worker at the plant (but still requires health physics supervision),
provides eight hours of instruction in radiation protection. The third level is directed to
the worker who can provide his own health physics supervision, and involves approxi-
mately 40 hours of instruction. It is estimated that approximately 300 permanent
station personnel will be required to receive instruction at this level. All three levels
of instruction include, to various levels of detail, information on risk from radiation
exposure. It is estimated that the initial cost of developing this training program was
roughly $50,000. The continuing annual costs are expected to be approximately
$60,000.
163
-------
TABLE
EXTERNAL WHOLE-BODY DISTRIBUTIONS
FOR 1981 (BOTH UNITS)
Exposure Range Numbers of Individuals
(Rem)
No Measurable Exposure 1,275
Measurable Exposure less than 0.10 1,647
0.10 to 0.25 539
0.25 to 0.50 ^ 365
0.50 to 0.75 222
0.75 to 1 161
1 to 2 431
2 to 3 272
3 to 4 168
4 to 5 48
5 to 6 1
Greater than 6 0
i
TOTAL 5,129
164
-------
1. Impact of Reduction in W.B. RPG
This annual limit is already company policy. The limit can only be exceeded with the
consent of the Vice-President. In fact, the company currently has a goal of 4 rem for
the annual limit. The only problem area is that of contractor personnel late in the year,
when a number of them have either accumulated exposures close to the 5 rem limit or
have exceeded the limit. The company makes it clear to contractors that it is unwilling
to exceed the 5 rem annual limit. Some of the contractors are unhappy with this, but
they reluctantly accept it.
2. Impact of Reduction in Accumulated Exposure Limit
The accumulated exposures for some of the company employees are approaching 30
rem, and some of the contractor employees have lifetime exposures which exceed 50
rem. It is highly unlikely that exposure of a company employee would approach 100 rem
over a lifetime. Therefore, there would not be expected to be impact from this
guidance.
3. Impact of Proposed Guidance Relative to Extremities and Individual Organs
Extremity monitors are issued to workers if contact exposure rates are 500 mrem/hr.
in excess of general area readings. However, with the occasional exception of radwaste
handling, extremity exposures are generally not any higher than whole-body exposures.
Thus, there will be no impact from the revised extremity exposure limits.
4. Impact of Proposed Guidance for Potential Exposures in the Range of 0.3 to 1.0 RPG
Coverage by an ANSI-qualified H.P. technician is currently provided for all jobs in
which exposure levels exceed 1.0 rem/hr. To cover all jobs at which exposure levels
exceed 100 mrem/hr. (defined, somewhat arbitrarily, as the exposure level for which a
"significant" contribution might be made to an "anticipated" annual exposure of 1.5
rem) would require the addition to the staff of approximately 20 ANSI-qualified
technicians. An ANSI-qualified H.P. technician earns $2,000/mo. plus approximately
15% supplement for nuclear personnel plus as much as 400 hrs. of overtime at time and
a half.
165
-------
Approximately 70% of the H.P. technicians have bachelor's degrees, and it was felt that
the ANSI-qualified H.P. technicians (6 years experience required) could potentially pass
the H.P. certification examination if they put in enough study. Thus the ANSI-qualified
technicians are probably equivalent in experience to health physicists. Besides, the only
feasible approach to satisfying this guidance is to use technicians as "radiation
protection professionals," since there are not enough health physicist around to
supervise and monitor in accordance with a literal interpretation of the guidance. In
fact, most nuclear power plants do not have a certified health physicist on the staff.
It was pointed out that this plant is approaching radiation protection in a completely
different direction than the proposed Range C guidance. The intent of the level 3
training is to qualify the individual worker to be his own H.P. technician. It is felt that
the 40 hours of instruction provided at level 3 will be sufficient to accomplish this.
5. Impact of Proposed Guidance for Potential Exposures in the Range of 0.1 to 0.3 RPG
The requirements of the Range B guidance are currently being satisfied.
\
6. Impact of Training Requirements
The training requirements of the proposed guidelines are being satisfied for all three
levels of instruction. Even level 1 (8 hours of instruction) includes a quantitative
presentation on levels of risk.
7. Impact of Guidance for Protection of the Unborn
Females constitute 5% to 10% of the permanent station personnel and approximately
20% of the contractor personnel. The pregnancy rate has been surprisingly low — 3 to 4
out of several hundred female employees. Currently, when a pregnancy is announced,
the pregnant female is removed from jobs involving radiation exposure and is placed in
another job outside of the posted areas. This policy is written in the corporate
handbook.
Therefore, the company is currently operating within a, stricter (zero exposure to the
fetus) and a mandatory version of Alternative a. If Alternative b were to be imposed,
there would probably not be a major disruption to operations. The legal staff is
166
-------
currently working on a proposal which is quite similar to Alternative c. It is not clear,
however, that this proposal will be adopted, because of the conflict with EEO goals.
Adoption of Alternative c would make it somewhat more difficult to operate the plant.
However, females currently receive lower exposures than their male counterparts,
probably because their supervisors deliberately give them easier jobs.
8. Impact of the Internal Exposure and Combined External Exposure Guidance
As discussed earlier, the company has in-place an extensive bioassay program. At
present, the results of the whole-body counting program are expressed in terms of organ
burden, and organ dose, using ICRP-2 methods, is only calculated when the organ burden
exceeds 10% of the limit. MFC-hours are neither routinely recorded nor used to
estimate dose.
Under the proposed guidance for internal exposures the changes in existing practice
would be minimal. ICRP-30, rather than ICRP-2 methods would be used to compute
organ dose from the results of the whole-body counts. Organ doses would have to be
added to external whole-body dose, using the weighting factors prescribed by EPA.
However, these changes would not involve significant costs because the company has
recently installed an automated dose-tracking system which can easily handle the
additional calculations. The cost of this system was $3 to $4 million; however, it is
being used at five nuclear units (two of which are located here). It is estimated that
the additional software required to implement the proposed guidance would cost
approximately $10,000 (again, spread over five units).
The opinion was expressed, however, that the ICRP-26/30 approach is preferable to that
approach taken by EPA. Nevertheless, there would be no difficulty in satisfying the
DAC's under the EPA, rather than the ICRP system.
9. Impact of the Reduction of the W.B. RPG to 1.5 Rem/yr.
Operation would not be possible if a 1.5 rem/yr. limit were imposed. The required
influx of people would be so high that it would not be possible to train them, provide
167
-------
security, etc. Also, the people who exceed 2 rem/yr. are the very specialized workers
— the operators, H.P. technicians, instrument technicians, etc. It would be very
difficult, indeed, to replicate these individuals.
Even an exposure limit of 4 rem/yr. would produce serious dislocations. The breakpoint,
however, would appear to lie in the range of 3 to 4 rem/yr.
168
-------
1.2. RELATIVELY OLD BWR
This relatively old boiling water reactor has a net electrical output of approximately
650 MW(e). A pressurized water reactor (PWR) of slightly higher power output occupies
the same site as the BWR, and was put into commercial operation approximately five
years later. The BWR has operated at a capacity factor slightly in excess of 60% since
the inception of operations.
The full-time staff complement at the site is approximately 700, roughly 350 of whom
are dedicated to the BWR. Additionally, approximately 1000-1500 contractor personnel
are used during a typical outage, which lasts approximately 10 weeks and is scheduled
on 12-15 month intervals. The average annual salary of plant personnel is $50,000,
including an overhead factor of 45%. Contractor personnel cost $21 per hour, on the
average, and an overhead factor of 100% is applied by them to account for manage-
ment, radiation protection, security, etc.
The radiation safety department at the site services both units. A Radiological
Services Supervisor, who manages work in health physics, waste management, and
chemistry, reports directly to the Station Services Superintendent, who in turn reports
to the Site Superintendent. A staff health physicist and three supervisors report to the
Radiological Services Supervisor. Two of the supervisors direct health physics
activities at each of the two reactor units, and the third provides dosimetry,
calibration, and respiratory protection services to both units. Each of the Supervisors
has roughly 6-8 personnel reporting to him. With the exception of the staff health
physicist, all of the radiological services personnel are technicians. During an personnel
outage, an additional 60 to 150 health physics technicians supplement the full-time
staff.
At the corporate headquarters, a parallel radiation protection staff of approximately 50
people provide support services to the site (and to a third nuclear power plant at
another site), and supplies personnel to the site on an as-needed basis. The staff
includes approximately eight professionals with degrees in health physics and 34
additional professionals with equivalent backgrounds in radiological engineering and
nuclear engineering.
None of the health physicists is certified.
169
-------
Dosimetry for all plants is performed by a unit of the Radiological Assessment Branch
at Corporate Headquarters. External monitoring is accomplished using TLD's, which
are read monthly during normal operations and on an as-needed basis during outages.
Anyone who has occasion to enter plant radiological areas (posted) is monitored. For
the site (both units), approximately 2,000 TLD's are issued during normal operations.
During outages, the number of TLD's issued may go as high as 5,000.
Distributions of whole-body exposures at the BWR for the past three years are given in
the Table. These distributions are synthesized from combined data for both units at the
site, and apportioned between the two units on the basis of total man-rem, for each
unit. This apportionment is based on the assumption that the exposure distributions, if
not the man-rem are similar at the two units. This assumption has been verified by
corporate personnel.
During the past three years, the collective exposure at the BWR has been in the range
of approximately 1,500 to 2,150 man-rem. This can be compared with the results for
the PWR on the same site, approximately 470 to 640 man-rem. BWR exposures are
higher, not because the individual exposures are higher, but because the number of tasks
and correspondingly, the number of required workers are greater for BWR's than for
PWR's. As an example, the number of workers with measurable exposures during the
last three years at the BWR was in the range of 2,000 to 3,000, whereas only 500 - 900
workers with measurable exposures were required at the PWR.
Extremities are monitored if area dose rates exceed 100 mrem/hr. and if it is
anticipated that the extremity exposure is likely to exceed four times the W.B.
exposure. During normal operations, less than 25 extremity monitors are generally
issued. During outages, the number of extremity monitors issued may be as high as 200
per week. Eye lens monitoring is generally not performed.
The internal monitoring policy is as follows. Whole-body counting (on a leased unit) is
performed for all workers who are issued external personnel monitors at the inception
Total man-rem for each unit are obtained by aggregating pocket dosimeter data from
the Radiation Work Permits. TLD data cannot be disaggregated by individual units.
170
-------
TABLE
Exposure Range
(rem)
Less than measurable
0.0 -0.10
0.10 - 0.25
0.25 - 0.50
0.50 - 0.75
0.75 - 1.00
1.00 - 2.00
2.00 - 3.00
3.00 - 4.00
4.00 - 5.00
Greater than 5.00
E DISTRIBUTIONS AT THE BWR
RS 1979, 1980, and 1981
Numbers of Individuals
1979
558
575
238
199
169
136
364
246
69
5
0
1980
715
758
407
447
336
249
645
157
20
5
0
1981
871
809
395
360
246
182
368
125
21
0
0
171
-------
of their employment and at termination. (This may be a a very short period for
contractor personnel.) Full-time plant personnel are counted annually. Also, W.B.
counts are taken in the event of an incident, if a routine facial frisk indicates high
exposures. The cost of a W.B. count is $40. Urinalyses and fecal counts are also
performed if warranted by an incident.
Last year the maximum individual MFC-hours were 20. The estimated average for all
individuals monitored was less than one MFC-hour. MFC-hours are recorded on
Radiation Work Permits, but are not currently readily accessible from the data base.
However, a system is being developed and will be implemented in about a year which
will readily access W.B. counts and other bioassay results, as well as MFC-hours, and
will be able to sort and manipulate the data.
MFC-hours are rarely converted to dose because committed dose equivalents are
generally low. Committed dose equivalents were calculated on two occasions over the
past year. This is a relatively straightforward analysis using ICRP-30 methods. The
corporate health physics' staff is considering the computerization of ICRP-30 dosi-
metric models.
Instruction in radiation protection principles, including quantitative levels of risk, is
given to everyone who is issued a personnel monitor. This instruction lasts approxi-
mately four hours and features a slide show and a quiz. Workers who are likely to wear
protective clothing or respirators are additionally trained in their use, including a
practice fitting. This basic instruction is repeated annually, but the period of
instruction may be considerably shorter the second time around.
1. Impact of Reduction in W.B. RPG
No impact is expected from the revised whole-body exposure limit. The company
maintains an administrative limit at 5 rem/yr. and since 1979, none of the full-time
plant employees has exceeded an annual exposure of 5 rem. In fact, it is estimated that
approximately 70% of nuclear utilities maintain an annual exposure limit of 5 rem for
their company staff.
This system is not being developed in response to any specific existing or anticipated
regulatory requirement.
172
-------
The utility has also maintained a 5 rem limit (exposures in excess of 4.5 rem are flagged
and individuals who exceed this level are tightly controlled) for contractor personnel.
However, the vendors who supply contractor personnel do not necessarily abide by
the limits at other utility sites. Limiting contractor personnel to 5 rem/yr at this
utility is not believed to entail increased costs, although it may possibly reduce vendor
profits.
2. Impact of Reduction in Accumulated Exposure Limit
The highest accumulated exposure for the full-time workers at this utility is
approximately 50 to 60 rem. There are several workers in the range of 20 to 30 rem.
The problem would be to track the transient workers' cumulative exposures. This would
be very difficult, if not impossible.
Several of the transient workers could potentially exceed 100 rem cumulative exposure.
Generally these individuals are very late in their careers, and the impact of this
guidance on the earnings for these particular workers could be substantial.
This guidance is not viewed favorably at this utility. It is felt to be technically
unjustified. Although it would have insignificant impact on the utility, it could have a
significant economic effect on a few workers late in their careers. It is felt that the
5(N-18) rem presumption is adequate guidance for lifetime exposures.
3. Impact of Proposed Guidance Relative to Extremities and Individual Organs
No impact is expected from the revised extremity limits. Over the past few years, the
highest extremity exposure was in the range of 10 - 15 rem, to the hand. Usually,
extremity exposures are not significantly different than W.B. exposures.
When high beta doses to the eye are anticipated, protective goggles are worn and this
does not degrade personnel performance. Since this is generally the only potential for
eye lens exposure significantly different than W.B. exposures, it is not anticipated that
additional flexibility will be needed.
173
-------
4. Impact of Proposed Guidance for Potential Exposures in the
Range of 0.3 to 1.0 RPG
The only reasonable interpretation of this guidance is that supervision/monitoring be
provided "under the cognizance" of a radiation protection professional. Interpreting the
guidance that the radiation protection professional does the monitoring would be
"overkill."
Currently, the only time an H.P. technician is required to be physicially present is in a
"high radiation area", defined as an area in which the exposure is in excess of 100
mrem/hr. If all workers potentially receiving significant exposures required coverage, it
would be necessary to double the number of H.P. technicians from 6 to 8 per unit to 12
to 16 per unit. H.P. technicians earn $9/hr. plus 45% fringe plus overhead.
During outages, the additional 60 to 150 H.P. technicians brought in under contract are
enough to provide the one-on-one coverage implied by the guidelines. If actual health
physicists were required, however, the hourly rate of $24 for the H.P. technicians would
be increased to $50 - $65 per hour, assuming the availability of such a large number of
health physicists.
5. Impact of Proposed Guidance for Potential Exposures in the
Range of 0.1 to 0.3 RPG
The requirements of the Range B guidance are currently being satisfied.
6. Impact of Training Requirements
Instruction in radiation protection principles, including quantitative levels of risk, is
given to anyone who is issued a personnel monitor. Therefore, there would be no impact
from the proposed training guidance.
174
-------
7. Impact of Guidance for Protection of the Unborn
Approximately 2% of the plant radiation workers are females, nearly all of whom are of
child-bearing age. The corporate legal department has recently established a policy
regarding the radiation exposure of female employees. Openings at the site are
advertised as potentially involving radiation exposures in excess of 0.5 rem during any
nine-month period. Thus, a condition of employment is the willingness to be exposed to
these levels of radiation. This is not seen to be any more discriminatory than the
qualification requirements for pole climbers, which are based on certain physical
characteristics.
If a female is hired under the presumption that she is willing to be exposed to the same
extent as all other workers, and changes her mind afterwards and is not pregnant, this is
grounds for discharge under the current policy. If, however, the female becomes
pregnant and informs management, she can be temporarily treated as a special case
with reduced exposure or temporarily transferred to another job. If neither is possible,
she can be terminated.
As of yet, there has been no actual test of the new policy. None of the females at the
site has requested a change of status.
The existing policy, therefore, is a mandatory version of Alternative a. If Alternatives
b or c were imposed as requirements, females of child-bearing age would not be hired at
the plant. The impact at the plant would be small, because of the small percentage of
females. The impact on the potential female employees, however, would be substantial.
8. Impact of the Internal Exposure and Combined External Exposure Guidance
This company has historically added internal and external exposures, although the
numbers of significant internal exposures have been so low as to render this a moot
point. Over the past ten years, the highest estimated internal exposure is on the order
of 50 mrem to the whole body.
Currently, MFC-hours are tracked very carefully. The most common radionuclides
encountered in the plant air are the activation products — cobalt-58, cobalt-60,
manganese-54, and iron-59. Radioiodine is rarely encountered during plant outages,
175
-------
when most of the potential for internal exposure occurs, because of the relatively short
half-life. Tritium is generally only a significant problem at plants with stainless steel
clad fuel, which is not used at this facility. The opinion was expressed that airborne
levels of activity are more a function of plant housekeeping than of plant age.
The revised internal exposure policy is envisioned to have an insignificant impact at this
facility. MFC-hours will still be carefully tracked to determine the approximate
internal exposure. Whole-body monitoring frequencies are not envisioned to change.
The need for dose calculations is expected to still be very infrequent. The calculation
of dose with the new models will entail about the same amount of work as previously.
Moreover, the health physics' staff is anxious to perform dose calculations using ICRP-
30, rather than earlier models.
It is not expected that the accuracy of dose prediction will be limited by the sensitivity
of W.B. counting, at least not for the radioisotopes normally encountered at a nuclear
power plant. Despite the apparent lack of impact from the revised internal exposure
guidelines, disagreement was expressed with the EPA approach. It was felt that our
national policy should be in keeping with international standards, and that EPA has
little technical justification for deviating from the ICRP-26/30 approach. Also, it was
felt that it is inconsistent to drop higher limits, as long as they are derived from the
same methodology as lower limits.
9. Impact of the Reduction of the W.B. RPG to 1.5 Rem/yr.
There would be an enormous impact from a reduction of the W.B. RPG to 1.5 Rem/yr.
The Atomic Industrial Forum has studied reduced exposure limits, and the AIF position
is endorsed by this utiilty. It is felt that it is uncessary to reduce the annual limit
below 5 rem/yr. The benefits to health are felt to be exceeded by the costs to
individuals' livelihoods.
176
-------
1.3. RELATIVELY NEW PWR
This relatively new pressurized water reactor has a net electrical output of 850 MW(e).
A sister unit of the same output was put into service approximately two years earlier.
Both units have been operating at an average capacity factor approaching 80% since
inception of operations.
The full-time staff complement at the station (for both units) is 942. Additionally,
approximately 220 company personnel are part-time and 536 contractor personnel were
used last year. The average salary of plant personnel is $20/hr., which includes an
overhead factor of 36%. Contractor personnel cost $34/hr., including an overhead
factor of 26%.
The Radiation Safety Department, which is also responsible for waste management,
incorporates approximately 55 personnel, with plans to increase staff to approximately
70 over the next year. The current annual budget is approximately $5 million, roughly
$3 million of which goes to contractors. Three of the staff members are health
physicists, one of whom is certified. One additional member of the plant staff, outside
of the radiation safety staff, is certified by the National Registry of Radiation
Protection Technologists.
Dosimetry is performed by a unit of the Radiation Safety Department. External
monitoring is accomplished using TLD's, which are read monthly during normal
operations (more frequently during outages). Anyone who is likely to enter a controlled
area (radiation fields in excess of 0.5 mrem/hr) is monitored. Currently, the average
number of TLD's issued during a typical month (non-outage) is approximately 1200;
during an outage, this increases to approximately 1600. Self-reading personnel
dosimeters are also issued to each individual who receives a TLD.
The external exposure distributions for the year 1981 are given in the Table. It is
believed that the exposure distributions for in-house and contractor personnel are
similar. The collective exposure for both units was approximately 540 man-rem, with
an average exposure per worker of approximately 0.21 rem. Approximately 95% of the
The increase is not related to specific regulatory requirements.
177
-------
TABLE
EXTERNAL WHOLE-BODY DISTRIBUTIONS FOR 1981
(BOTH UNITS)
Exposure Range
(Rem)
No Measurable Exposure
Measurable Exposure less than 0.10
0.10 to 0.25
0.25 to 0.50
0.50 to 0.75
0.75 to 1
1 to 2
2 to 3
3 to 4
4 to 5
>5
Numbers of Indviduals
990
485
353
289
207
101
105
15
0
0
0
178
-------
collective exposure was accumulated during the refueling outage, which typically lasts
for 11 weeks and is scheduled once every 18 months. These data are typical of the
radiation experience at the plant since the first unit went into operation.
Internal dosimetry is accomplished with a leased whole-body counter which is capable
of detecting a small fraction of the Allowable Limit of Intake (ALI) for all radionuclides
normally encountered at a nuclear power plant. All company personnel are counted
when they are initially hired and when they are discharged by the company. Additional-
ly, all personnel who receive external whole-body doses in excess of 0.5 rem are
counted annually. Finally, a whole-body count is taken if an individual is exposed to
airborne concentrations in excess of 25% of the limits — 10 MFC-hours in a week, based
on airborne grab samples taken during all tasks.
Lapel air samplers have been ordered and they will be used in the future for jobs
involving significant exposures.
For 1981, the collective internal exposure for both units was approximately 175 man-
MPC-hours (corresponding to an estimated 0.4 man-rem whole-body collective dose
2
equivalent) based upon data for 239 workers, out of a total of 2,505 workers
monitored. The highest internal exposure was 7.5 MFC-hours; the average for all
radiation workers was 0.07 MFC-hours (corresponding to an estimated 0.17 mrem
whole-body dose equivalent).
Two types of training are provided to station personnel. For personnel who are not
likely to enter controlled areas (and are, accordingly, not monitored), three hours of
training in radiation protection are provided annually. For those who are likely to enter
controlled areas ("radiation workers"), li - 2 days of training in radiation protection are
provided annually. The curriculum includes a unit on quantitative levels of risk (NRC
Regulatory Guide 8.29 and the IAEA pamphlet, "Radiation —A Fact of Life"). Training
sessions, which incorporate approximately 20 workers, are scheduled twice a week and
are conducted by the Training Department and Technical Services Section.
For example, the sensitivity of the counter for iodihe-131 is 2 nCi; a standard man's
uptakes is 56 nCi at MFC during a 40-hour week.
2
Data are recorded whenever a worker performs a task in which the airborne concentra-
tion exceeds 0.1 MFC.
179
-------
1. Impact of Reduction in W.B. RPG
No impact is expected from the revised whole-body exposure limit. This company has
been successful in keeping actual exposures below this limit for the 7i years that the
first unit has been in operation. In fact, only one individual has received an annual
exposure in excess of 4 rem. Part of the reason for relatively low occupational
exposures is "clean fuel" (few leakers). However, some of the success in keeping annual
exposures relatively low must be attributed to the maintenance of multi-tiered
administrative limits. The weekly limit is 300 mrem. The quarterly limit is 900 mrem,
with a 2 rem quarterly ceiling. Monitors are read and records are reviewed at 150
mrem increments above the 900 mrem limit. The annual administrative limit is 4.7
rem, with a ceiling at 5.0 rem.
2. Impact of Reduction in Accumulated Exposure Limit
The highest accumulated exposures for utility employees are in the range of 20 to 30
rem. However, some of the contractor personnel have accumulated exposures as high
as 100 rem, and a few of these are in their 40's. Most of these contractor personnel
with high exposures are specialists, such as in-service inspectors of steam generators.
This proposed limit could potentially interfere with the livelihoods of such individuals.
Moreover, these specialists are quite scarce. Sometimes it is necessary to go to foreign
countries to obtain this expertise.
Additionally, it is felt that there is no basis for this lifetime limit. Neither the NCRP,
ICRP, or any other peer view group has concurred with this recommendation.
3. Impact of Proposed Guidance Relative to
Extremities and Individual Organs
No impact is expected from the revised extremity limits. It is policy to measure
extremity exposures where the radiation field exceeds 1 rem/hr. and when the
extremity dose rate is estimated to exceed the whole-body dose rate by at least 10%.
The highest recollected hand and forearm exposure was 7 rem. During last year's
outage, approximately six individuals received hand and forearm exposures between 3
and 4 rem.
180
-------
The plant is currently in conformance with the 5 rem/yr. limit to the eye lens, so there
would be no impact from this provision of the guidelines. To keep within the 5 rem/yr.
limit, it is necessary for workers handling some beta sources to wear protective
goggles. If the recommendations of the NCRP (15 rem/yr.) or ICRP (30 rem/yr.) were
adopted, the use of these protective goggles might not be necessary.
4. Impact of Proposed Guidance for Potential Exposures
in the Range of 0.3 to 1.0 RPG
During normal operations, there are only a couple of jobs in which there exists the
potential for exposures in Range C. These are radwaste handling, which is generally
monitored by one to two H.P. technicians, and the normal rounds of the operators,
which are also covered by H.P. technicians, as appropriate. All of this is trivial,
however, when compared with the potential exposures during outages.
During outages, which last on the average approximately 11 weeks, as many as 1,500
workers typically enter the contaminant, and as many as 75 percent of these might
receive in excess of 1.5 rem annually. During the outage, as many as 150 H.P.
technicians augment the 50 full-time technicians. Even so, it is not possible for these
technicians to cover aU tasks which might involve "significant" exposures.
There are three possible interpretations of this guidance. In the least strict interpreta-
tion, "supervision" would mean control over all of the tasks undertaken by each
individual and cognizance over exposure levels (through the radiation work permit
system), daily monitoring of actual exposures (by reading pocket dosimeters), and real
time coverage during certain jobs in high exposure level fields. This is the existing
program and if this is the intent of the guidance, there would be no impact.
In a stricter interpretation, all tasks in which "significant" exposures may be accrued
(interpreted to be approximately 100 mrem or greater) would require real time
coverage by H.P. technicians. It is estimated that to accomplish this, roughly 50
additional H.P. technicians would have to be retained. Contractors receive approxi-
mately $35/hr. for H.P. technicians. During the 11-week outage, H.P. technicians work
approximately 84 hour per week.
181
-------
Although approximately one-third of the H.P. technicians are ANSI-qualified, none of
them are equivalent in background of experience to professional health physicists. The
strict interpretation of the guidance would require all of the roughly 200 individuals
who supervise and monitor in contaminant during the outage to be health physicists or
their equivalent. Contractors are paid $70/hr. for health physicists. The feasibility of
this interpretation is questionable.
5. Impact of Proposed Guidance for Potential Exposures
in the Range of 0.1 to 0.3 RPG
Both the monitoring and supervision requirements of this guidance are currently being
carried out by the Radiation Safety Department. Therefore, there would be no impact
from this proposed guidance.
6. Impact of Training Requirements
This is currently being carried out, including instruction on levels of risk.
7. Impact of Guidance for Protection of the Unborn
Approximately 15 percent of the plant personnel are currently females of child-bearing
age. Although there exists no formal policy regarding allowable exposures to women
who are not pregnant, exposures to women have never exceeded 0.5 rem/yr. This is
probably a result of the type of work that females perform plus the inference that
females are more highly motivated to keep exposures low ("macho" syndrome).
The company currently operates under a mandatory version of Alternative a. Women
are trained to inform their supervisors when they are diagnosed to be pregnant. As soon
as the supervisor is notified, the woman is removed from a job which involves potential
exposure to radiation and is assigned to a job in a non-controlled area.
To additionally limit female exposures to less than 0.2 rem/mo. would not be a problem,
since exposures to women have never exceeded 0.2 rem/mo. Therefore, there would be
no impact at this plant from Alternatives b or c.
182
-------
8. Impact of the Internal Exposure and Combined
External Exposure Guidance
This company is already operating in a mode which is in consonance with the internal
exposure provisions of the guidelines. If a radiation work permit indicates airborne
concentrations in the work area which exceed 0.1 MFC, then the internal exposure (in
units of MFC-hours) received during the task is aggregated with the previous exposure
in his record. (This step is being automated, independent of any revisions to current
regulations.) If the exposure during a 40-hour week should exceed 10 MPC-hrs (25% of
the weekly administrative limit), the health physics staff is alerted and a whole-body
count is taken. The results of the whole-body count are analyzed by the health
physics' staff and converted to dose, using ICRP-2 methods at present. If the estimated
organ dose differs from that based on the airborne exposure (in MPC-hrs.), the revised
organ dose is entered (manually) into the individual's record. The estimated internal
exposure is added automatically to the external exposure to provide an estimate of the
o
total exposure.
The procedure for treatment of internal exposures implied by the proposed guidelines
are not expected to differ in any substantial way from current practice. Nomenclature
is changed (ALI and DAC vs. MFC), weighting factors differ, and methodology for
calculating dose is updated (ICRP-30 vs. ICRP-2). These are not envisioned, however,
to involve substantial costs.
Moreover, the proposed guidelines are envisioned to permit more professional judgment
and flexibility than the existing regulations. This facility envisions the opportunity to
adjust DAC's on the basis of actual, rather than prescribed particle size.
Estimating organ dose from whole-body counting is not envisioned to be a problem for
most radionuclides. Some of the beta-emitters could pose a problem. Tritium is not a
problem at this plant because the fuel has been relatively "clean." If significant
amounts of airborne tritium were present, procedures would require routine urinalysis.
Strontium-90, if present in significant quantities, could also pose a problem.
1This occurs rarely; last year, no one received more than 10 MPC-hrs. for the entire
year.
2The point was made that the summation of dose equivalent attributed to both external
and internal sources has always been the foundation of occupational exposure limits.
ICRP-1 stated it, and it has been restated by ICRP-6, ICRP-9, and ICRP-26.
183
-------
Given a significant intake, the major impediment to accurate organ dose estimates is
the variability in people. The use of parameters for "reference man" introduces large
potential errors for some individuals.
Notwithstanding the relative ease of compliance with the proposed internal exposure
guidance, senior personnel at this facility do not agree with EPA's changes in the
ICRP-26 formulation. The opinion was expressed that the revised weighting factors are
difficult to correlate with the existing literature and are technically incorrect.
Moreover, the maintenance of an upper limit on the RIF's at the values currently in use
is felt to be indefensible.
9. Impact of the Reduction of the W.B. RPG
to 1.5 Rem/yr.
It would be very costly if the limit were lowered to 1.5 Rem/yr. Although most in-
house personnel don't receive 1.5 rem/yr., many of the contractor personnel do. The
individuals hit hardest would be those with the most expertise (i.e., in-service
inspection of steam generators). An example is the vendor crew who inspects the
control rod drives. This requires very specific expertise, and it is not possible to do a
single inspection without accruing 500 mrem of exposure.
184
-------
1.4. RELATIVELY OLD PWR I
This is one of two twin PWR's completed in the early 1970's. The net electrical
capacity of each of the two units at the site is approximately 775 MW(e). Since the
completion of major steam generator repairs, both units have been operating at
approximately an 80% capacity factor.
The normal station staff is approximately 600 full-time employees. However, approxi-
mately 100 additional workers are completing design modifications mandated by the
Three Mile Island action plan. During refueling outages, which last approximately 45
days and are scheduled on 18-month intervals, an additional 50 to 100 workers are
generally brought in, mostly from the utility's "travelling maintenance pool." Roughly
30% of the collective exposure at the site is accumulated during refueling. The
comparatively low number of additional employees required for a refueling outage is
attributed to two reasons. The first is that 10-14 day maintenance outages are
routinely scheduled in the spring and fall. These outages, which are not significant
from the point of view of collective radiation exposure, reduce the amount of work
required during refueling outages. The second reason for the comparatively low number
of outside workers during a refueling outage is the overtime policy at the plant. Most
of the work during refueling outage is performed by full-time station personnel on
overtime. However, this policy also results in exposure distributions which are
generally skewed to the high side in comparison with several other nuclear power
plants. On the other hand, the overtime policy and the use of the utility maintenance
pool results in a relatively low use of outside contractors (except for specialty skills),
which may lead to lower collective exposures.
Major ten-year outages are also being planned, which will probably take twice as long as
ordinary refueling outages. The collective exposure will also probably be twice as high.
These outages will involve a great deal of primary system inspection, as well as
inspection of the steam generators and the primary coolant pumps.
The radiation safety department, which is distinct at this plant from the chemistry
department, employs approximately 50 people and currently has an annual budget
slightly in excess of $4 million. Nearly half of these are professionals, which includes
two degreed health physicists (non-certified) and an additional four to five personnel
185
-------
TABLE
EXTERNAL WHOLE-BODY DISTRIBUTIONS
FOR THE YEARS 1981 AND 1978
(BOTH UNITS)
Exposure Range Number of Individuals
(Rem)
1981 1978
No Measurable Exposure 159 1,301
Measurable Exposure less than 0.10 1,095 1,077
0.10 to 0.25 585 215
0.25 to 0.50 363 111
0.50 to 0.75 185 76
0.75 to 1 154 77
1 to 2 597 341
2 to 3 354 147
3 to 4 192 75
4 to 5 101 40
5 to 6 45 24
6 to 7 71 14
7 to 8 9 6
8 to 9 2 0
9 to 10 0 0
10 to 11 0 0
11 to 12 0 0
Greater than 12 00
TOTAL 3,912 3,504
186
-------
who are equivalent in responsibility and experience to health phyicists. The manager of
the radiation safety department reports directly to the station manager.
There is also a relatively small health physics support staff at the corporate head-
quarters. Approximately six professionals, all health physicists (none certified) or
equivalent, support this station and another one, also with two units.
External dosimetry at the station is performed with TLD's which are normally read in-
house monthly (more frequently when required). The policy is to issue a TLD to anyone
entering the restricted area. Additionally, pocket dosimeters are used for running
estimates of dose for anyone entering radiation areas. The TLD, however, provides the
dose of record. The external exposure distributions for the years 1981 and 1978 are
provided in the Table. Exposure distributions for 1978 are included because that is the
most recent year in which major work was not involved on the steam generators.
Internal exposures are monitored and controlled by sampling airborne concentrations at
eight locations within the plant. Whole-body counting is also performed on all
employees at entry and termination, and when air concentration data indicate exposures
in excess of 10 MPC-hrs. during any week, or in the event of any suspicion of uptake
(i.e., defective respirator, facial contamination, etc.). The station has its own whole-
body counter. In addition, 25 workers are randomly selected monthly for urinalyses.
The urine specimens are shipped to a vendor for analysis of tritium and fission products.
If there is a discrepancy between the implied internal doses derived from MPC-hrs. and
the results of bioassay, the bioassay becomes the dose of record.
The main internal problem is radioiodine. An activated charcoal canister is used on
respirators to trap iodine, but credit is not taken for the effect of the canister in
computing MPC-hrs. for radioiodine. This is because NIOSH does not recognize the
effect of the activated charcoal canister on radioiodine. Accordingly, one would not
expect a correlation between MPC-hrs. and whole-body counting data for this radioiso-
tope.
Routine statistics on internal exposures are not formally tracked. However, on
inspection of the data, the highest internal exposure at the station in 1981 was 25 MPC-
hrs. The average for all workers potentially exposed was less than 5 MPC-hrs.
187
-------
All radiation workers at the plant are instructed in the principles of radiation
protection, including information on quantitative levels of risk. Utility employees
receive four days of training before they begin work in controlled areas. One full day is
devoted to radiation protection and another full day to respiratory protection. Con-
tractor empoyees are provided only one day of instruction, 90% of which is devoted to
radiation protection.
1. Impact of Reduction in W.B. RPG
This plant generally has a substantial number of individuals, mostly in-house personnel,
exposed in excess of 5 rem/yr. In 1981, there were approximately 125 people with
exposures greater than 5 rem, and most of these people were not involved in steam
generator work. A number of administrative limits are established to limit exposures at
the plant. Individuals may be allowed to receive in excess of 1.25 rem/qtr. as follows.
In order to go to 1.5 rem in a quarter, approvals must be obtained from the employee's
supervisor and from the manager of radiation protection. An additional approval of the
department superintendent must be obtained to go to 2.0 rem/qtr., and the station
manager must approve exposures up to 2.4 rem/qtr. Exposures higher than 2.4 rem/qtr.
require corporate approval.
If the 5 rem annual limit were promulgated, there would initially be more dependence
on contractors and the utility's travelling maintenance pool personnel. Overtime of
full-time personnel would be reduced and annual incomes of several plant personnel,
particularly operators and mechanics, may drop. Utimately, however, more full-time
staff would have to be hired, in consonance with the company policy of limiting the use
of contractors.
\
To estimate the costs of additional personnel is difficult. The best approach would
probably be to estimate the impact on the entire industry using a methodology such as
that developed by Stone <5c Webster.
It is not yet clear how utilities would respond to the elimination of quarterly limits.
Some might permit workers to get a sizable fraction of the 5 rem annual limit in the
first quarter. This might ultimately lead to labor problems, in that these workers could
188
-------
get "burned out" early in the year and be unable to pursue their specialties or collect
overtime pay at the end of the year. The only solution to this dilemma might be to
establish a quarterly administrative limit of 1.25 rem.
2. Impact of Reduction in Accumulated Exposure Limit
It is estimated that the maximum accumulated exposure for in-house workers is
approximately 50 rem, whereas some contractor employees might have accumulated as
much as 80 rem. Thus, if the 100 rem lifetime limit were imposed, there might be some
career shortening for contractor personnel. The cost impact to the plant, however,
would not be substantial.
3. Impact of Proposed Guidance Relative to Extremities and Individual Organs
There would be no impact from the revised limits for the hands and arms/feet and legs.
The highest exposure on record is approximately 10 rem to the hands.
4. Impact of Proposed Guidance for Potential Exposures
in the Range of 0.3 to 1.0 RPG
If the existing Radiation Work Permit system satisfies the intent of the supervision and
monitoring requirements of the guidelines, then there would be no impact. However, a
literal interpretation of the guidelines calls for real time monitoring. Currently, real
time coverage is only required for tasks conducted in radiation fields which exceed 1
rem/hr. If coverage were required for tasks conducted in radiation fields which exceed
100 mrem/hr (generally agreed to constitute a "significant" contribution to an annual
exposure of 1.5 rem), the number of H.P. technicians would have to double from 20 to
40. During the 45 day outage, the 15 H.P. technicians under contract would have to be
doubled to 30 (assume 84 hrs per week). H.P. technicians earn approximately $25,000
per year plus 25 percent fringe benefits. If actual health physicists were required to
provide the coverage, the 20 full-time H.P. technicians would have to be replaced by 40
health physicists at a salary of at least $35,000 per year (plus 25 percent fringe
benefits). During an outage, an additional 30 health physicists would have to be hired.
Of course, this interpretation of the proposed guidelines is not possible since there are
not enough health physicists to go around.
189
-------
5. Impact of Proposed Guidance for Potential Exposures
in the Range of 0.1 to 0.3 RPG
The requirements of the Range B guidance are currently being satisfied.
6. Impact of Training Requirements
All radiation workers at the plant are already being instructed in the principles of
radiation protection, including information on quantitative levels of risk. Thus there
would be no impact from this guidance.
7. Impact of Guidance for Protection of the Unborn
Ever since the introduction of NRC Regulatory Guide 8.13 a few years ago, this utility
has been operating under a mandatory version of Alternative a. It is the responsibility
of the woman to announce a pregnancy to her supervisor. The supervisor must inform
the radiation protection group. It is then the responsibility of the radiation protection
group to limit the dose of the unborn to 500 mrem. Pregnant females are not allowed
to work in radiation areas. In other areas, monthly exposures are not likely to exceed
25 mr. So far, there have been about 10 pregnancies and there have been no problems.
(Approximately 8% of radiation workers are female). In one case, a woman's exposure
was greater than 400 mrem at the time that she discovered that she was pregnant. She
was given an administrative job at the same level of pay.
Alternatives b and c would raise the issue of equal opportunity. Even though
Alternative b is voluntary, a woman would not be assigned to certain jobs if the
possibility exists that she might choose to be reassigned at some time in the future.
These jobs include mechanics, operators, and radiation protection. If the Federal
government were to impose Alternative c, it would let the utility "off the hook"
regarding equal opportunity considerations. The impact on the utility itself would be
insignificant, given the low percentage of females working at the plant. It would limit
the opportunity for females, however, to be promoted to higher paying jobs.
190
-------
8. Impact of the Internal Exposure and Combined
External Exposure Guidance
The existing internal exposure program is based on recorded MPC-hrs. for compliance.
Moreover, if in any one week MPC-hrs. should exceed 10 (25% of the weekly limit), a
whole-body count is taken and an organ burden is estimated from the whole-body count.
If the estimated organ burden exceeds 5% of the limit, it is documented and reported to
the worker. Internal organ dose is not estimated.
If the internal exposure provisions of the proposed guidelines were implemented, two
expansions of the existing systems would have to be made. The first would be a major
modification to the body burden analysis system, a computer system which converts
whole-body counts to organ burden. It also computes 50-yr. dose commitment, but in a
very rudimentary fashion. This system originally cost $60,000. To get the system to
compute organ doses using ICRP-30 methodology would require a major expansion in
both hardware and software, estimated to cost approximately double the original
system, or roughly $120,000.
The second system requiring modification is the computer system which handles
external exposures. Relying on input organ doses from the revised body burden analysis
system, this system would compute the effective dose equivalent. The system
originally cost $80,000 for hardware and $100,000 for software. A similar software
modification to the one envisioned here took a programmer about three months and cost
approximately $10,000. The original contractor for this software is still on-board, so
that modifications to the software can be accomplished in a cost-effective manner.
It is envisioned that the link between the two systems would be done manually,
providing an intermediate check on the estimated organ doses. The three-four
technicians who currently run the body burden analysis system could handle this
additional task relatively easily, but they would require additional training. This could
be obtained most cost effectively using existing training consultants. An analogous
two-week training course relating to changes in the radwaste regulations cost approxi-
mately $10,000 to $25,000.
There is one serious problem envisioned in the application of the proposed methodology.
This is the treatment of the time-dependence of intake for chronic intake situations.
191
-------
Some guidance would have to be provided in this area. The problem could be avoided if
MPC-hrs. were used to estimate organ doses, but the results would be overly
conservative and not at all indicative of actual organ doses.
It is felt that EPA's deviation from the ICRP-26 prescription introduces serious
inconsistencies. One aspect of this would be in the computation of exposures to the
general public, if ICRP-30 methods were to be used. Also, the lower DAC's resulting
from the EPA changes might have a subtle effect on the sensitivity of the measure-
ments, requiring longer calibration times.
9. Impact of the Reduction of the W.B. RPG to 1.5 Rem/yr.
Operation at an annual exposure limit of 1.5 rem/yr. would be virtually impossible.
Last year, 1,371 workers, or approximately 35 percent of the total number of workers
monitored, received exposures in excess of one rem.
192
-------
1.5. RELATIVELY OLD PWR E
This is a three-unit station of 860 MW(e) Pressurized Water Reactors. The oldest unit
recently completed its 10-year in-service inspection. The average capacity factor of
all three units through September, 1982 has been roughly 40 percent. The station is one
of three nuclear stations owned by the utility, the second has one unit in operation and
another completing construction, and the third station has not been completed. The
three stations incorporate seven units.
The full-time staff complement at the station is approximately 1,000. During outages,
the permanent staff is supplemented by as many as 500 transient workers and about
1,000 other utility employees. Outages are conducted during refueling operations,
which were originally scheduled on a 12-month period, and are being extended to an 18-
month interval. A refueling outage typically lasts from two to three months.
The plant has a health physics staff consisting of 80-90 people. During outages, in-
house personnel are supplemented by as many as 140 health physics contractor
personnel. Five of the permanent staff are professional health physicists. None are
certified. The manager of the station health physics group reports to the Superinten-
dent of Technical Services, who reports to the Station Manager, who reports to the
Corporate General Manager of Nuclear Stations, who reports to the Vice-President of
Nuclear Production.
The radiation protection program at all the nuclear stations is developed by the
corporate health physics staff, which consists of eight professionals, two of whom are
certified. The manager of the corporate health physics staff reports to a corporate
Manager of Technical Services, who reports to the Vice-President of Nuclear Produc-
tion. Therefore, although the corporate health physics staff sets the overall corporate
radiation protection policy, the plant health physics staff has a parallel reporting chain.
External personnel monitoring is accomplished with TLD's, which are centrally pro-
cessed monthly at corporate headquarters and are issued to almost all personnel who
enter the restricted area. Pocket dosimeters are also issued to these individuals who
enter the radiation control area (the reactor building and the auxiliary building), but the
TLD readings provide the dose of record. The whole-body exposure statistics for
193
-------
calendar year 1981 at the station are given in the Table. The collective exposure at the
station during calendar year 1981 was approximately 1200 man-rem.
Internal monitoring is performed by a combination of air sampling and bioassay.
Installed and portable air monitors provide area air concentrations which are entered
into the Radiation Work Permits. MFC-hours are maintained in the computer data
files, together with external exposures, as surrogates for internal dose. The highest
recorded intake over the past year was approximately 80-100 MPC-hrs. Only about 100
personnel received measurable internal exposures.
Bioassay is performed with company-owned body burden analyzer chairs. Counts are
performed for new employees and non-employees, upon termination, and annually during
employment with the company. Special counts are also taken in the event of an
incident involving suspected intake, and on a random sample of workers throughout the
exposure range quarterly. Whole-body counts are also made if a worker is exposed to
more than 35 MPC-hrs. of iodine in a period of one week. From time-to-time,
urinalyses are also performed on workers who are potentially exposed to tritium.
During a recent typical quarter involving approximately 2700 whole-body counts, 27
individuals indicated organ burdens in excess of one percent of the maximum permissi-
ble organ burden. Two individuals had uptakes of approximately five percent of the
maximum permissible organ burdens. (A higher uptake was observed, but this was
believed to be anomalous, the result of skin contamination.) At five percent of the
limits, a dose analysis is performed using ICRP-2 or MIRD methods. At five percent of
the maximum permissible body burden, 50-year organ dose commitments on the order of
200-300 mrem are calculated, depending on the radionuclide involved.
The results of bioassays are maintained in each individual worker's record. The record,
which is not maintained on the computer, includes the whole-body count, intake
expressed as percent body or organ burden, and dose (if computed). This information is
all entered by hand from the output of the multi-channel analyzer.
Three levels of instruction on radiation protection are provided to station workers.
Workers who perform hands-on work in radiation fields, which constitutes the lion's
share of station personnel, receive 27 hours of instruction annually. The instruction,
which is consistent with the provisions of Regulatory Guide 8.27, includes a section on
levels of risk from radiation.
194
-------
TABLE
WHOLE-BODY EXPOSURES FOR CALENDAR YEAR 1981
Number of Individuals
Annual Whole-Body Dose Ranges in Each Range
(Reins)
No Measurable Exposure 820
Measurable Exposure Less than 0.100 945
0.100-0.250 371
0.250 - 0.500 338
0.500-0.750 195
0.750 - 1.000 138
1.000-2.000 331
2.000 - 3.000 121
3.000 - 4.000 6
4.000 - 5.000 0
Greater than 5.000 0
Total 3265
195
-------
Personnel who may enter controlled areas but are not expected to perfom hands-on
work receive up to six hours of instruction annually, including a discussion of risk from
radiation exposure. Finally, all other employees who are not expected to enter
controlled areas receive an hour or two instruction in radiation protection at the
beginning of their employment.
Any employee can by-pass the next annual update of instruction on radiation protection
by taking and passing a more comprehensive examination than the regular test.
Training is conducted by a training group at the site. However, the content of the
radiation protection instructional program is developed by the corporate and station
health physics groups.
1. Impact of Reduction in W.B. RPG
This utility has always maintained an administrative limit of less than 5 rem/yr., and
has never had an annual exposure which exceeded this limit. Thus there would be no
impact at this plant from the imposition of a 5 rem annual regulatory limit. In addition,
exposures to contractor personnel are maintained below 3 rem per quarter and under 5
rem/yr. at this utility's sites.
2. Impact of Reduction in Accumulated Exposure Limit
This guidance is felt to be ill-advised. There are about 150 people in the nuclear power
industry who will exceed 100 rem in a lifetime. Most of these workers are highly-
trained specialists whose skills are difficult and costly to replicate.
3. Impact of Proposed Guidance Relative to
Extremities and Individual Organs
Maximum extremity exposures at the station are generally a few rem per year, a small
fraction of the reduced limit of 50 rem/yr. These exposures are received by a small
fraction of station workers, possibly about a hundred, who work on steam generators or
divers who perform repairs in the spent fuel pools. Therefore, there is not expected to
be an impact from the reduced extremity limits.
196
-------
4. Impact of Proposed Guidance for Potential Exposures
in the Range of 0.3 to 1.0 RPG
This facility currently complies with the Range C guidance. Every radiation worker is
tracked continuously by a large control system. An administrative limit of 500 mrem
applies to any contiguous 5-week period. If it appears that a worker is likely to receive
a significant fraction of the administrative limit, he/she is provided coverage by an H.P.
technician.
5. Impact of Proposed Guidance for Potential Exposures
in the Range of 0.1 to 0.3 RPG
This facility currently complies with the Range B guidance.
6. Impact of Training Requirements
All workers who enter controlled areas receive instruction in radiation protection,
including a unit on quantitative levels of risk.
7. Impact of Guidance for Protection of the Unborn
This utility is currently operating in consonance with the provisions of NRC Regulatory
Guide 8.13, and is thus in conformance with a mandatory version of Alternative a. It is
the responsibility of the female to announce a pregnancy to her supervisor. The
exposure of the embryo/fetus is then limited, by careful supervision, frequent moni-
toring, and/or removal from radiation work, to 500 mrem during the pregnancy.
Alternatives b and c are felt to be unfair to women and, for that matter, to men as
well. They would limit the ability of females of child-bearing age to get certain jobs at
the plant.
8. Impact of the Internal Exposure and Combined
External Exposure Guidance
A considerable amount of software development would have to be performed in order to
revise the existing automated system in accordance with the provisions of the internal
197
-------
exposure guidance. Approximately one man-year of effort is estimated to be required
to change the MPC-hr. calculations to estimates of DAC-hrs. and dose. (A very simple
dose conversion scheme is assumed, in which conversion factors are supplied by Agency
guidance.) One man-year of a health physics technician is assumed to be required to
design the forms to feed the input data into the program. Finally, approximately one-
half of a man-year of a professional is estimated for QA of the resulting software and
an additional one-half man-year of a professional for training of the health physics staff
in the use of the revised software. Thus the total one-time effort for the development,
QA, and training associated with the automated records' system is estimated to be
approximately 3-man years.
9. Impact of the Reduction of the W.B. RPG
to 1.5 Rem/yr.
The costs would be very high to operate within a W.B. exposure limit of 1.5 rem/yr. In
1981, approximately 15 percent of the workers at the plant received annual exposures in
excess of 1.5 rem.
Computer costs are assumed within the manpower estimates.
198
-------
J. UNIVERSITY REACTOR
This is a 2 MW(t) swimming pool research reactor with MTR-type fuel. Of the
approximately 50 U.S. university research reactors in operation, approximately 10 are
of this type. The moderator is ordinary light water, the fuel is highly enriched, and the
cooling is by forced convection.
The reactor is used for graduate and undergraduate (3rd and 4th year students) nuclear
engineering laboratory courses. Additionally, an extensive research program is under-
way. The most highly funded program is an investigation of the neutron embrittlement
of reactor pressure vessel steels. This involves round-the-clock irradiation of samples,
requiring three-shift operation of the reactor. Several projects involve neutron
activation analysis. A study of radioiodine partition coefficients in water/air systems
requires activation of iodine in the reactor. Gamma-ray spectroscopy is underway using
beams from the reactor. Approximately a dozen small colleges and universities in the
region share the reactor for research and training under a Department of Energy
program.
The reactor is located in a separate, relatively remote building on the campus. The
reactor room is airtight and serves as a containment around the reactor. The building
houses the Nuclear Engineering Department at the University, and accordingly has
several offices, classrooms, laboratories, a machine shop, and an electronics shop.
Additionally, a small, low-power (approximately 100 w) pool reactor is located in the
building for nuclear engineering laboratory courses.
The reactor is one of several facilities at the university under the cognizance of the
Radiation Safety Office. The Radiation Safety Office is one of three divisions in the
University Environmental Health and Safety Office. With a current budget of
approximately $300,000 per year, the Radiation Safety Office employs a Radiation
Safety Officer (a health physicist who is also a staff member in the Nuclear Engineering
Department), three health physicists (with at least bachelor's degrees and one year of
experience), three technicians, and one secretary. None of the health physicists is
registered. One health physicist and approximately one-half of a technician are
assigned to the reactor facility full time. Additionally, the Radiation Safety Officer
estimates that approximately 10% of his time is devoted to reactor activities.
199
-------
The Radiation Safety Officer reports to the Chairman of the Radiation Safety
Committee. This committee is comprised of 15 individuals, mostly faculty, and is
currently chaired by the Manager of Environmental Health and Safety.
The Radiation Safety Officer handles personnel monitoring and determines radiation
protection policy for all facilities at the University. All personnel with offices in the
reactor building and all students with classes in the building are issued personnel
dosimeters, about 107 people in total for the academic year 1982. This includes roughly
2 technicians, 2 janitors, 2 secretaries, the director of the reactor facility, the reactor
supervisor, 15 faculty members, 4 senior reactor operators, 15 reactor operators, 15
operators in training, and 60 students.
Film is used for dosimetry; it is processed monthly by an outside dosimetry service.
The cost is $l/monitor/month. Approximately 20 of the 150 monitors have neutron
capability; those cost $4/monitor/month. Extremity monitoring is performed on an ad-
hoc basis. On the average, about six ring badges are issued, mostly to the senior
reactor operators who pull activated samples out of the pool. Visitors to the facility
are issued pocket dosimeters.
A formal bioassay program exists based on action levels. For example, bioassays are
performed for individuals handling 1 mCi of iodine, 5 mCi of phosphorous-32 or 15 mCi
of tritium in unsealed forms. It is rare at the reactor facility to exceed the action
levels; it has not occurred for over a year. The only airborne radionucb'des normally
encountered at the reactor facility are argon-41 and tritium (in non-detectible
—^ —*i
concentrations — 10 to 10 of the MFC). Whole-body counting has never been
performed; every couple of years, an ad-hoc program of urinalysis is conducted.
External exposure distributions for the years 1980 and 1981 are given in the Table. The
highest exposures, 0.50 to 0.75 rem, were received in both years by the senior reactor
operators who retrieve samples from the pool. The individuals in the range, 0.0 - 0.1
rem, include 60 students in each year. Exposures are maintained relatively low, in part
by a restrictive ALARA program, which requires reports by the individual, his
supervisor, and the Radiation Safety Officer when an exposure exceeds 0.5 rem for the
year. These reports, which are reviewed by the Radiation Safety Committee, are
required to explain why the cumulative exposure is so high and what measures are being
taken to reduce future exposures.
200
-------
TABLE
EXTERNAL EXPOSURE DISTRIBUTIONS FOR 1980 AND 1981
Exposure Range Numbers of Individuals
(rem)
1980 1981
No Measurable Exposure 45 46
0.0 - 0.1 95 99
0.1 - 0.25 8 2
0.25-0.50 . 2 4
0.50 - 0.75 2 3
0.75 - 1.00 0 0
Greater than 1.00 0 0
201
-------
An extensive program of instruction is provided in radiation protection principles. The
reactor health physicist provides, early in the fall semester, a two-hour orientation to
all new students, faculty, and staff members on radiation protection. The University
health physics manual and copies of NRC Regulatory Guide 8.13 are distributed, and
recipients are required to pass an exam on this material. For the non-technical staff at
the reactor facility, this is normally all of the instruction provided in radiation
protection principles.
Users of radioactive materials must additionally become certified. There are three
levels of certification. For the lowest, or "restricted" level, a ten-hour course in
radiation protection principles must be taken, which includes instruction on quantitative
levels of risks. The students normally are certified at this level. The next level,
denoted as "qualified," contains some use restrictions, and is generally applied to
supervisors (faculty, operators, etc.). The highest level is "authorized," contains no use
restrictions (other than those imposed by the license), and is generally applied only to
the Director of the Reactor Facility. Applicants for certification at the levels of
"qualified" and "authorized" must take and pass a full-semester course in health physics.
1. Impact of Reduction in W.B. RPG
There would be no impact on operations at this facility from this change in occupational
limits. Limits are currently maintained nearly an order of magnitude lower than the
proposed annual limit. Only under a severe accident scenario could exposures be
anticipated in excess of 5 rem. Refueling, performed on a 3 to 5 year interval, only
exposes personnel to an additional 10 - 15 mrem above normal operational levels.
2. Impact of Reduction in Accumulated Exposure Limit
The maximum accumulated exposure at this facility is believed to be in the range of 5
to 10 rem. On the basis of documented exposures, therefore, there should be no impact
from this proposed guidance. There is concern, however, about the undocumented
exposures. Sometimes difficulties are encountered in obtaining exposure histories.
Several years ago, the University hired a radiation worker with 30 years of experience
and no record to document his radiation exposure history. Since the maximum would
have to be assumed for this individual (5 rem/yr. after 1960 and 15 rem/yr. before
then), he would be unable to obtain a job under this proposed guidance.
202
-------
It was felt that the 5(N-18) rem limit is more than adequate to protect workers and,
therefore, the 100 rem limit is not needed. A proposed alternative approach would be
to limit accumulated exposure to "100 rem documented."
3. Impact of Proposed Guidance Relative to Extremities
and Individual Organs
Maximum hand exposures at the facility are on the order of 5 rem/yr., roughly an order
of magnitude lower than the revised limit. These exposures are received by operators
who retrieve activated samples from the pool. The revised limits to hand and feet,
therefore, would have no impact.
Eye lens exposures are not monitored. The only potential for eye lens exposures in
excess of W.B. exposures is on the beam port floor. It is believed, however, that annual
eye lens exposures, even for beam port experimenters, are considerably lower than 5
rem. Monitoring of eye lens exposures, if required, would be very difficult.
4. Impact of Proposed Guidance for Potential Exposures
in the Range of 0.3 to 1.0 RPG
Exposures in excess of 1.5 rem/yr. are not anticipated at the reactor facility. This is
corroborated by recent experience, in which the highest annual exposures were in the
range of 0.5 to 0.75 rem. Nevertheless, this facility abides by the proposed Range C
supervision and monitoring guidance. A health physicist is permanently assigned to the
reactor facility. Any time that something is taken out of the pool, the health physicist
supervises the activity and performs continuous monitoring.
5. Impact of Proposed Guidance for Potential Exposures
in the Range of 0.1 to 0.3 RPG
This facility conforms to the proposed guidance of Range B. Every proposed
experiment is reviewed by the Reactor Safety Committee. Moreover, as discussed
above, this facility currently conforms to the Range C guidance for Range B.
203
-------
6. Impact of Training Requirements
All new students, faculty, and staff members are given a two-hour orientation early in
the fall semester on radiation protection principles by the reactor health physicist. At
present, this short course does not include a portion on quantitative levels of risk. To
include this, and to update the training manual to this effect, would be a negligible cost
at this facility, since the staff and the workers are in the education business.
7. Impact of Guidance for Protection of the Unborn
Approximately 20 percent of those monitored at the reactor facility are female. Under
current policy, if a female were to announce a pregnancy (this has never occurred at
the reactor facility), she would be removed from exposure situations and would be
monitored very closely (with a pocket dosimeter as well as film). If the female were a
student, she would probably be allowed to finish the course, but she would be monitored
very closely and would be required to file a letter with the University providing her
permission for potential exposure. Given the exposure history at the reactor facility, it
would not be difficult to maintain exposures to the fetus less than 0.5 rem, even if a
pregnant female were permitted to conduct business as usual.
Therefore, this facility is currently operating under a mandatory version of Alternative
a. It would not be difficult to amend the existing policy to conform with Alternative b.
This would state that a female of child-bearing age could voluntarily decide not to pull
samples out of the pool. This is the only activity that could potentially expose the fetus
in excess of 0.2 rem/mo. It would not be difficult to accommodate this degree of
flexibility, since only about 20 percent of operators are female.
If Alternative c were imposed, women of child-bearing age could not be hired as reactor
operators. This would not be an extreme hardship for the facility since only four
operators are currently female. However, it would limit the potential sources of
support for females.
Some concern was expressed about the ability to estimate the committed dose
equivalent to the fetus from radionuclides taken into the body. It is assumed that the
NRC would provide some guidance, possibly as a Regulatory Guide, on the calculation
of internal exposure to the fetus. In any case, it is unlikely that internal exposures
would contribute significantly to fetal exposures at this facility.
204
-------
8. Impact of the Internal Exposure and Combined
External Exposure Guidance
The weighted-organ approach to combining internal and external exposures appears to
be sensible. There would be no impact at this facility, since no additional monitoring
would be required under normal operations. At present, routine bioassays are
performed at the reactor facility.
The Derived Air Concentrations (DAC's) for the radionuclides potentiaUy encountered
at the reactor facility, primarily gamma and beta emitters, are largely unchanged under
the EPA guidelines. The levels of tritium in the air above the pool are well below the
detection limit (8 x 10~7 Ci/ml).
Some concern was expressed about the state-of-the-art for calculating dose from
measured organ burdens. Currently, if detectable organ burdens are measured at the
University, the results are entered into the records as organ burden, and are not
converted to dose. Because of variability between people and uncertainties in the time
of exposure, calculation of actual dose is very highly uncertain. The former problem
can be dealt with by requiring only dose equivalent to "standard man."
The time problem, however, is difficult to surmount. Some guidelines would be required
from the NRC on acceptable methods for converting measured organ burden to dose. A
Ph.D. student at the University is looking at this problem for iodine-125. It is
estimated that uncertainties as high as 50 - 100% are potentially associated with the
conversion to dose from the intake of iodine-125 for specific individuals.
Large uncertainties would also be expected in the conversion to dose for intake of
tritium, phosphorous-32, sulfur-35 and carbon -14.
No new software or staff would be required, however, for treatment of internal
exposures. Measurable intakes are so infrequent that bioassays could be performed at
the Radiation Safety Office. Also, several well-qualified staff and faculty members
would be available to estimate the dose.
205
-------
9. Impact of the Reduction of the W.B. RPG
to 1.5 Rem/yr.
A 1.5 rem/yr. limit would have no impact at this facility. Limits are currently
maintained nearly an order of magnitude below the proposed 5 rem annual limit. At
present, the Radiation Safety Committee must approve exposures in excess of 0.5
rem/yr. As seen in the Table, only a couple of individuals have been exposed in excess
of 0.5 rem/yr. over the past two years, and their exposures have been less than 0.75
rem/yr.
206
-------
K.I. LARGE URANIUM MILL
This facility processes ore received from mines to extract the uranium. The mill,
which is about 20 years old, operated continuously (three shifts per day) until recently,
but is now running ten days on and four days off. It is shut down for about three weeks
once a year for maintenance and for vacations. The mill is designed to process 7,000
tons of ore per day, but it is currently operating at about 50 percent of design capacity.
The output of the mill on a fuU schedule is about 4,300 tons of ammonium diuranate
mixed with uranium oxide (yellowcake) per year. The mill utilizes the conventional acid
leach-solvent extraction process for uranium recovery. A flow chart of the mill process
is shown in the Figure.
The industry currently consists of 20 operating uranium mills, located in western
states and accounts for 85% - 90% of natural tLOg production. These mills have a
combined rated capacity of about 54,000 tons of ore per day and an output of 21,000
tons per year of yellowcake. Of these mills, 76 percent utilize conventional acid leach
- solvent extraction processes, and 10 percent utilize conventional alkaline leach
processes.
Although record yellowcake production occurred during 1980, reports for 1981 indicate
a decline in production. For calendar year 1982, a greater decrease in production is
expected. During 1981, several of the larger mills curtailed their operations, while
others either shut down completely or temporarily closed down until such time as
demand for yellowcake catches up with supply. It is estimated that the workforce in
the industry has been reduced by about 60 percent because of this decreased demand.
The present full time complement of the mill is 250. This includes maintenance
personnel (approximately 40). The work force before layoffs was about 1100. All
employees except clerical personnel are considered radiation workers. The average
annual salary of millworkers is $25,000, including an overhead factor of 35 percent.
Radiation safety is the responsibility of the superintendent of Environment and
Industrial Hygiene, who reports to the General Manager. Reporting to the Superin-
U.S. Department of Fjiergy, Statistical Data of the Uranium Industry, GJO-100(82),
Grand Junction Area Office, Colorado, January 1, 1982.
207
-------
FIGURE
MILL CIRCUIT
CONVENTIONAL ACID LEACH-SOLVENT EXTRACTION PROCESS
Ore Storage
Ore Crushing <5c Grinding
Leaching
Counter Current
Decantation Thickening
Solvent Extraction Feed
Preparation
Solvent Extraction
Precipitation
Drying and Cracking
Two-stage with decant
thickener between stages.
Discharge slurry of sol-
ids and solution of
uranium and concentrated
H2S04
2-Series of 6 decantation
tanks (known as thickeners)
U3Og Product
208
-------
tendent is one senior environmental engineer, one environmental technician, and two
industrial hygiene and health physics technicians. The technicians in radiation safety
are expected to complete a course in radiation protection principles and to attend
periodic sessions at the mill on specific safety problems. There is a staff health
physicist at the corporate headquarters, who is responsible for providing radiation
health and safety standards for all facilities operated by the corporation. The staff
health physicist has taken the Health Physics certification examination. Within the
corporation there is also a regulation and control group that conducts quarterly audits
of the health physics program at each facility. Results of such audits are written up
and corrective measures taken, as required, on the basis of the findings.
Potential exists in the mill for both internal exposure from inhalation of uranium and
daughter compounds. (U-238, Th-230, Ra-226, Bi-210, Pb-210, and Rn-222 progeny) and
external exposure from the low energy gamma rays emitted by these isotopes. There is
potential for external exposure in all mill areas except the acid plant. The potential for
inhalation is at the crushing circuit, leaching and solvent extraction, and the precipi-
tation and packaging area.
All personnel wear TLD dosimeters to measure exposure from external sources of
radiation. Gamma radiation surveys are conducted using calibrated ion chambers or
scintillation detectors. Contamination surveys are performed at least quarterly to
evaluate the presence and extent of contamination of the surfaces of equipment and
buildings. The instruments are capable of selective response to alpha radiation by
direct measurement or swipe samples.
Air sampling programs are conducted to determine the airborne concentrations to which
employees are exposed. The frequency of air sampling is dependent upon the nature of
the work and previous experience with concentrations of airborne radioactive material
associated with a particular job. Established operations are sampled on a variable
schedule, at least once per week where yellowcakeidust is the predominant hazard and
weekly where ore dust is the hazard. General air sampling with a permanent multiple-
station air sampling system or with continuous air monitors are used for the periodic
monitoring of established operations. Sampling for radon daughters is performed
biweekly.
209
-------
The data from the air sampling program are used to calculate the time-weighted
average exposure concentration (TWA). The TWA is the sum of the exposure
concentrations in the work area multiplied by the length of time that the worker is
exposed in each area, divided by the total exposure time. If the calculated exposure is
above the radiation protection action limit of 40 MPC-hours/week, the employee is
informed, and a urine sample is taken for bioassay. Bioassays at the mill generally
follow the procedures described in the NRC Regulatory Guide 8.22. The mill's
operating procedure for bioassay of uranium is shown in Table 1.
The average internal and external exposures for routine milling operations in 1979 are
given in Table 2. Approximately 3% of those monitored received whole-body exposures
in excess of 1.5 rem. The maximum exposure was 2.2 rem. The maximum average
annual intake of uranium in 1979 was 0.098 uCi, in the precipitation and packaging
areas. The range was 0 to 0.098 uCi for the year 1979. The data for the years 1980 and
1981 are comparable to those for 1979.
The current limit is based upon the MFC for insoluble uranium (1 x 10~ uCi/ml)
multiplied by a 40-hour work week. 100 percent of the employees are within these
limits. The average MFC hrs in 1977 were 8 in the YC area, 18 in the crushing circuit,
and 14 in the bucking room. All operators work the same position and get the same
exposure. These numbers are based upon the conservative assumptions of insoluble
natural uranium, totally respirable particle size distribution, and no respiratory
protection.
All new employees are required to attend a 24-hour training program. This program
includes three hours of training on the principles of radiation protection, followed by an
examination. The session does not include a discussion of quantitative levels of risk;
however, it is expected to be included in the near future. Special attention is given to
female employees. Each female is given a copy of Regulatory Guide 8.13 and is
expected to read it and understand its contents. Periodic review sessions are conducted
as part of industrial safety training to review all rules and regulations and to promote
good working habits and awareness of safety procedures. Every year, an eight hour
refresher training course is conducted for all employees, which includes li hours of
instruction in radiation safety.
210
-------
TABLE 1;
BIOASSAY FOR URANIUM
INTERNAL
Internal exposure from uranium may be determined from urine sample results. Routine
samples are collected from persons working in the yellowcake process and packing areas
biweekly after periods of at least twenty-four hours away from the facility. Urine
samples are given at the person's home to avoid contamination. Standard fluorimetric
assay techniques are used for sample analysis. Pre-assignment and termination
samples are collected and analyzed.
Additional special samples are collected and analyzed after suspect or known accidental
exposures to excessive airborne uranium concentrations.
URINE ACTION LEVELS
Action levels are established for single biweekly samples for the purpose of controlling
kidney and bone exposure in cases of soluble uranium and lung exposure in cases
involving inhalation of insoluble uranium.
Routine samples are collected after a worker has been out of the plant for at least 24
hours. These are voidings of about 150 mi in 6 oz. bottles.
Any employee submitting two consecutive biweekly routine or special samples above
150 Pg/fc shall be promptly restricted to non-uranium work. Daily samples shall then be
analyzed until a sample result below 50yg/£ is received at which time the employee
may be removed from work restriction.
An employee who submits four consecutive biweekly samples which are all analysed to
be less than 150.Vg/i but greater than 50 yg/S, shall be promptly placed on a "24-hour
equivalent" sampling schedule. The schedule is performed as follows:
(a) A quart-size sample bottle is supplied to the employee for at-home urine
sample collection.
(b) The employee collects a voiding before retiring, any voiding during the
night, and any voiding the morning after. He returns the bottle on his
next work shift.
Should the 24-hour equivalent sample analysis be greater than 50 ug/fc , the employee is
restricted to non-uranium work. He is resampled at least weekly. Whenever the
employee's sample analysis returns to below 50 ug/1 , he may then resume uranium work.
211
-------
TABLE 2;
AVERAGE INTERNAL INTAKE AND EXTERNAL EXPOSURES
FOR ROUTINE MILLING OPERATIONS IN 1979
MILL
AREA
Crushing Circuit
Bucking Room
Leaching
-------
1. Impact of Reduction in W.B. RPG
This limit is not expected to have an impact at the mill, at least with respect to
external exposure. The highest whole body exposure in 1979 was 2.2 rem. The
maximum average external exposure was 1.62 rem, in the precipitation and packaging
area.
2. Impact of Reduction in Accumulated Exposure Limit
The reduction of the accumulated exposure limit to 100 rem is not expected to have a
cost impact at this mill. The highest accumulated exposure for mill personnel is well
below this limit.
3. Impact of Proposed Guidance Relative to
Extremities and Individual Organs
No impact is expected from the revised extremity limits. There are potential exposures
of the extremities (hands and skin) for the scrap pickers, where the dose rate is about 3
mrem/hr. There are 6-8 employees in this work area. However, even for continuous
work in this area, annual exposures are expected to be less than 10 percent of the
proposed limit. The eye lenses of employees are not expected to be exposed to higher
levels than the whole body.
4. Impact of Proposed Guidance for Potential Exposures
in the Range of 0.3 to 1.0 RPG
The average annual internal exposure in the precipitation and packaging area is 1.62
rem. All other areas are less than 1.5 rem. About three percent of those monitored
receive whole body exposures in excess of 1.5 rem. The main impact from the proposed
guideline would be due to the new internal exposure RPG. As noted in Table 2, the
solubility class for the Derived Air Concentrations for uranium inhalation is a critical
parameter for compliance. If the new guidelines on internal exposures are imposed it
would be difficult to maintain combined exposures below 30 percent of the RPG. The
difficulty in meeting the new RPG is discussed later in this case study.
213
-------
Potential internal exposures are monitored with a multiple air sampling system and
external exposures for all personnel are measured with TLD dosimeters. One senior
environmental engineer, one environmental technician and two industrial hygiene and
health physics technicians provide radiation protection services. It is anticipated that a
certified health physicist at a cost of $40,000 per year would have to be employed in
the precipitation and packaging area to comply with the proposed Range C guidance.
5. Impact of Proposed Guidance for Potential Exposure
in the Range of 0.1 to 0.3 RPG
The mill is currently operating in full compliance with this proposed guideline. All
personnel wear TLD dosimeters to measure external exposures. Potential internal
exposures are monitored with a multiple air sampling system. One senior environmental
engineer and two industrial hygiene and health physics technicians maintain records on
external sources of radiation and airborne concentrations at the four mill operating
areas, review health physics procedures and are available to monitor during non-routine
operations. These professionals are expected to assure that exposures are justified and
are ALAR A.
6. Impact of Training Requirement
There would be no impact from the training requirements of the proposed guidelines,
since all new employees receive instruction in radiation protection principles (a unit on
levels of risk to be added in the near future).
7. Impact of Guidance for Protection of the Unborn
Approximately eight percent of the mill personnel are currently females of child-
bearing age. There would be no impact from Alternative a of the proposed Guidance
for Protection of the unborn, since the present corporate policy follows NRC Regula-
tory Guide 8.13, "Instruction Concerning Prenatal Radiation Exposure." Women are
instructed to inform their supervisors when they are diagnosed to be pregnant. As soon
as the supervisor is notified, the woman is removed from the job and is assigned to a job
in a non-controlled area. Alternatives b and c might result in women being denied
certain jobs.
214
-------
8. Impact of the Internal Exposure and Combined
External Exposure Guidance
The current approach at this mill is to conduct complete surveys of all locations on a
weekly basis. Compliance with existing guidance on internal exposures is determined by
calculating potential exposures to airborne concentrations of uranium from airborne
monitoring data plus time and area assignments for each worker. From these data, a
time-weighted average exposure (TWA) of an individual is determined which is reported
as a fraction of the MFC. Internal doses are not calculated unless the calculated
airborne exposure is greater than 40 MPC-hrs/week for soluble uranium and 520 MPC-
hrs/qtr. for insoluble uranium. These exposures to soluble uranium are verified, using
the bioassay procedures described earlier. Although airborne exposure calculations
predict higher exposures than the individual actually receives, they are used as the dose
of record since the data are more timely than bioassay results. External exposures
obtained from TLD readings are not presently added to estimated internal doses. A
computer program at the mill is currently in place which provides data for determining
compliance with the existing regulations.
Reference to Table 2 indicates that the current average intakes in most areas are
higher than the Allowable Limit of Intake (ALI) prescribed by ICRP-30 for insoluble
(Class Y) uranium — 0.054 uCi. Therefore, in order to comply with the new limits, the
conservative assumption of total insolubility would have to be relaxed. The DAC for
soluble uranium (Class D) is a factor of about 30 higher than that for insoluble uranium
(Class Y). It is estimated that using actual solubility fraction would lower the
calculated exposure by a factor of about 15. (Recent measurements indicate 60% Class
D and 40% Class W.) The justification for this relaxation would require continual
determination of the actual solubility fractions in the mill process areas.
Establishment of routine system for measuring solubility fractions would take a
professional approximately 6 man-months of effort (at a cost of approximately $3,800
per man-month). Then routine monitoring of this parameter is expected to take a
technician approximately 10 man-days each month. (It is assumed that the NRC would
require continual routine monitoring of this parameter.) The one time equipment cost
for solubility fraction sampling is estimated to be approximately $22,000. Additionally,
laboratory support is estimated to cost approximately $30,000 per year.
215
-------
Particle size determinations would also have to be made at approximately 10 locations
for a one-time equipment cost of $20,000 and an analytical cost of $2,000/yr. Also, in
order to provide adequate personnel monitoring, an additional number of personal
sampling pump assemblies would be required at a cost of $9,000. Finally, all particulate
air samples will have to be analyzed for isotopic content. This is estimated to cost
$192,500 per year.
The computer software and hardware used for the evaluation of personnel exposures
would also have to be upgraded. It is estimated that to modify the software,
approximately 6 man-months of a programmer would be required. Hardware costs of
$30,000 are estimated. Additionally, a full-time records clerk would have to be
employed at an annual cost of $16,200.
It is expected that the effect of the above exposure procedures would be to
demonstrate compliance with the ICRP-30 limits. However, the proposed EPA limits
are about another 30-40 percent lower. At present, it is not certain that these changes
will bring calculated potential exposures down to the proposed EPA levels.
The weighted organ doses in the proposed guidelines are viewed as a potential problem
area, since they appear to be in conflict with ICRP 26 and 30.
9. Impact of the Reduction of the W.B. RPG
to 1.5 rem/yr.
The imposition of this alternative RPG would have a cost impact on the mill operations,
particularly in light of the reduced intake limits. It is reasonable to conclude that
there would be a problem in the precipitation and packaging area. In order to meet the
guideline it would probably require a process change; i.e., a change to a slurry process.
Moreover, it would possibly require additional people for health physics protection and
to demonstrate compliance with the guidance.
216
-------
K.2. URANIUM CONVERSION PLANT
This plant produces uranium hexafluoride (UFg) at a rated output of 10,000 MT/yr. and
employs 160 people. The plant operates three shifts per day, seven days per week. The
raw material is uranium concentrate (yellowcake) and some yellowcake slurry received
from all uranium mills in the country. At present there is only one other conversion
plant in operation, with a rated output of 14,000 MT/yr. of UFg. Both plants, due to the
reduced demand for uranium in the nuclear power industry, are currently operating at
reduced capacity.
This conversion plant utilizes a complex wet chemistry process, whereas the other plant
utilizes a dry process. The yellowcake at this plant starts at the sampling plant and is
processed by stages through digestion, solvent extraction, denitrification, reduction,
hydrofluorination, fluorination, and in the final stage to a primary cold trap that is
heated with steam to 200 F° at 200 psi. At this point, the the UFg is a liquid and is
drained to shipping cylinders that hold 10 tons. Workers at the plant are potentially
exposed to both soluble (uranium hexafluoride, uranium trioxide, uranyl oxyfluoride, and
uranyl nitrate) and less soluble (uranium tetrafluoride and uranium dioxides) compounds
of uranium.
Radiation safety is the responsibility of the manager, Health Physics and Industrial
Safety, who reports to the Plant Manager. Five health physics technicians, and one
clerk report to the Manager, Health Physics and Industrial Safety. The technicians in
Radiation Safety are expected to complete a course in radiation protection principles.
The annual health physics cost at the plant is approximately $181,000. There is a staff
health physicist at corporate headquarters who is responsible for providing radiation
health and physics standards for facilities operated by the corporation. He has taken
the health physics certification examination. Within the corporation there is also a
regulatory compliance group that conducts quarterly audits of the health physics
program at each facility. Results of such audits are written up and corrective measures
taken, as required on the basis of the findings.
Potential exists in the plant for both internal exposure from inhalation of uranium and
daughter compounds and external exposure from low energy gamma rays emitted by
these isotopes. There is potential for external exposure in all plant processing areas,
217
-------
with the highest radiation fields in the fluorination area, 90 mrem/hr. and 20 mrem/hr.
in 1980 and 1981, respectively. There is potential for inhalation in all plant processing
areas, with monthly average concentrations in 1981 ranging from 0.08 MFC to 0.36
MFC. Normally, people are in these areas four to six hours per shift.
Air sampling is extensive throughout the plant. There are 45 sampler heads in dry
process areas that are connected to a central vacuum. The filters are changed after
each eight-hour shift. Air samples reading above 0.5 MFC are considered facility
action levels and are reported to corporate management. Additionally, depending upon
working conditions, breathing zone air samples, and operational air samples are
collected weekly. Internal exposures are evaluated daily for each person by calculating
the time-weighted average exposure concentrations (TWA), based on the air sampling
results and work location. The TWA is the sum of the exposure concentrations in each
work area multiplied by the time that the worker is exposed, divided by the total
exposure time.
The internal bioassay and in-vivo counting policy for uranium (except UFfi and UO?F~)
is described in Table 1. The bioassay policy for UF_ and UO^F- is described separately
in Table 2. Fecal sampling procedures for early assessment of uranium and thorium
exposures are included in the radiation protection procedures and samples are taken as
determined from air sample results.
The results of the bioassay program in 1981 gave uranium concentrations in urine
ranging from a minimum of 2 ug/1 to a maximum of 51 ug/L
Whole-body counting is done by an outside contractor. The results of whole-body
counting in 1981 are given in Table 3.
Airborne concentrations in each plant area for the years 1979, 1980 and 1981, expressed
in fractions of MFC, are given in Table 4. These also correspond to annual average
personnel exposures to airborne concentrations because personnel do not ordinarily
divide their time between areas. At any one time, airborne concentrations may go as
high as 30 times MFC (from incidents).
The current limit is based on the MFC for insoluble uranium (1 x 10 uCi/ml),
multiplied by a 40-hour work week. One hundred percent of the employees have been
218
-------
TABLE 1
URINALYSIS 20 ug U/l, he is assigned to non-
uranium work. He is resampled daily until a sample shows <20 ug U/l, after which he
may return to his regular work assignments.
Whole Body Counting
In-Vivo (lung) counting to detect internal deposition is performed annually for employees
who fall under one of the following categories:
• Routine analysis shows consistly elevated uranium-in-urine concentration
(above the 20 ug/1 guideline.)
• Exposure to uranium aerosols which are insoluble in body fluids.
• Exhibit a lung burden >• 30 percent of the allowable committed dose
equivalent
• Previous lung counting history shows a significant fraction of body burden
of natural uranium or U-235.
All other employees who normally work in radiation areas are counted every two
years.
219
-------
TABLE 2
BIOASSAY FOR UFg AND
The uranium in UFg and UO2F2 exhibits a very rapid urinary excretion half time. The
model for standard man indicates an elimination half time of six hours. For different
individuals it is not unusual to have half times of four hours to seven hours.
Accordingly, urine samples must be obtained within a few hours of such an intake. The
appropriate sampling program shall be selected as given below:
Time of Intake Known and Recorded -
(Spills and High Airborne Concentrations)
1. Each exposed individual should empty his/her bladder and discard this
urine as soon after the exposure as possible but in no case longer than 30
minutes after the exposure. Do not void again until step 2 below.
2. The first single urine sample shall be collected three (3) to six (6) hours
after the exposure. The voiding time shall be recorded on bottle No. 1.
3. The next voiding from about 6-10 hours after the exposure does not need
to be collected.
4. Collect the following single urine sample 10 to 15 hours after the
exposure. Record the voiding time on bottle No. 2.
5. If the voiding collection in step 4 is missed, be sure to collect the next
voiding no later than 20 hours after the exposure. Record the voiding
time.
6. The analysis results of the two samples collected are reported in ugA.
Plot these values vs. hours on semi-log paper and extropolate back to the
end of the exposure where the time is zero hours. Determine the 4-hour
intercept on the line draw on the semi-log paper and calculate the intake
as follows:
1 = 1.32C
Where: I = Intake in micrograms of uranium
C = Concentration of uranium in urine (ug/1) at 4
hours after the end of the exposure as deter-
mined from the plot on the semi-log paper.
2500
1.32 = 1900, where 2500 micrograms of uranium
intake results in a concentration of 1900 ug/1
of uranium in the total urine excreted for four
hours after a UFg inhalation exposure by a
"standard" man.
220
-------
TABLE 2 (CONT.)
7. The MPC-hr exposure estimate is calculated as follows:
1 x 40 MFC - hrs.
48 M3 x 200 ug/M3
= MFC-hrs.
Where: I = ug intake
3
48 M = air breathed at work for 40 hours
200 ug/M3 = 0.2 mg/M3 = 1 MFC (see footnote No. 4 to
Appendix B of 10 CFR 20).
221
-------
TABLE 3
IN-VIVO (LUNG) COUNTING1
Plant Area No. of 1981 In-Vivo Counting
Employees Range of Results
Counted ugU-235 nCi U(nat.)
Sampling Plant + +
Operators 1 0.0 - 29 1.5 - 1.0
Processing .
Personnel 29 0.0 - 28 to 1.4 7 1.0 to
47 - 39 8.2 - 1.6
Maintenance +
Personnel 23 0.0 + 33 to 0.0 7 1.1 to
0.0 - 46 11.5- 1.5
Other Personnel 15 0.0 31 to 1.3 1.1 to
0.0 - 57 4.5 - 1.2
The analysis for U-235 is the least reliable when the lung burden is <100 ugms U-235
(Yat 186 KeV). The MPLB for U (nat) is 180 ugm U-235 or 25.35 mgm U (nat).
222
-------
TABLE 4
ANNUAL AVERAGE
AIRBORNE CONCENTRATIONS
FRACTIONS OF MFC*
Operating No. of Sample
Area(s) Locations
Sampling Plant 5
Digestion 4
Denitration 6
Reduction and
Hydrofluorination 11
Fluorination 11
Misc. Areas 8
1979 1980
.26 .26
.18 .28
.35 .41
.42 .55
.26 .39
.07 .11-
1981
.14
.23
.15
.18
.17
.05
*MPC = 1 x 10"10 uCi
ml
223
-------
within this limit. The new Derived Air Concentration for insoluble uranium is
approximately 2 x 10 uCi/ml and the DAC for soluble uranium is 6 x 10~ /^Ci/ml.
The current Maximum Permissible Concentration (MFC) for occupational exposure to
1 o -11
Th-230 is 2 x 10 uCi/ml for soluble material and 1 x 10 uCi/ml for insoluble. An
airborne aerosol of raffinate solids is the most likely source of the radionuclide Th-230.
If the dried product has Class W solubility, then the bone will be the primary organ at
risk. If it has Class Y solubility, then the lung will be the primary organ at risk.
All personnel except clerical workers wear film badges to monitor external exposures to
radiation. Film badges are processed monthly by an outside dosimetry service.
The measured whole-body exposures for the years 1979, 1980, and 1981 are given in
Table 5. Radiation levels in plant areas are also measured by ionization chambers.
General area surveys are made monthly at fixed work stations, particularly the
fluorination ash receiver area. This area is usually designated as a radiation area (in
excess of 5 mrem/hr). However, the surface contact of filled ash containers could be as
high as 100 mrem/hr. Gamma surveys in plant areas for 1981 showed that the
fluorination area had the highest dose rates — 1 to 20 mr/hr. Contamination surveys
are performed at least weekly to evaluate the presence and extent of smearable
contamination on the surfaces of equipment and buildings.
All new employees are required to attend a li hour orientation training program.
Individuals assigned to work with uranium receive at least eight hours of formal training
on the hazards associated with the handling of uranium, the procedures for radiation
protection, safety procedures, and government rules and regulations. Included in the
training for all employees is the subject matter in Regulatory Guide 8.29, "Instruction
Concerning Risk from Occupational Exposures," and for female employees, the subject
matter contained in Regulatory Guide 8.13, "Instruction Concerning Prenatal Exposure."
A discussion of the quantitative levels of risk is not presently included in the training
but is expected to be included in the very near future.
A written examination demonstrating that the employee has a good understanding of
the training subjects is given to each employee. "Tailgate" safety meetings are
conducted monthly by line supervisors. Employees that are required to wear respiratory
protection devices are given li hours of special training on the use of the devices and
224
-------
TABLE 5
Annual Dose Ranges
(Rem)
Minimal Exposure
Measurable
Exposure < 0.10
.10 to .249
.250 to .499
.500 to .749
.750 to .999
1.00 to 1.99
2.00 to 2.99
3.00 to 3.99
4.00 to 4.99
Greater than 5.00
IODY EXPOSURES
Numbers of Individuals
In Each Range
1979
8
57
52
33
4
2
0
0
0
0
0
1980
10
88
35
38
8
1
1
0
0
0
0
1981
23
89
42
23
4
1
0
0
0
0
0
Totals
156
181
182
225
-------
the plant conditions for which these devices are required. Every year an eight hour
refresher training course is conducted for all employees and this includes approximately
two hours devoted to radiation protection.
1. Impact of Reduction in W.B. RPG
This revised limit is not expected to have an impact at the plant, at least with respect
to external exposures. The highest whole-body exposure in 1981 was less than one rem.
2. Impact of Reduction in Accumulated Exposure Limit
The reduction of the accumulated exposure limit to 100 rem is not expected to have a
cost impact at this plant. The highest accumulated exposure for plant personnel is
considerably lower than the 100 rem limit.
3. Impact of Proposed Guidance Relative to
Extremities and Individual Organs
No impact is expected from the revised extremity limits.
4. Impact of Proposed Guidance for Potential Exposure
in the Range of 0.3 to 1.0 RPG
The whole body exposures of all plant personnel have been maintained at less than 1.0
rem for the years 1979, 1980, and 1981, except for one employee in 1980. The main
impact from the proposed guideline would be due to the new internal exposure RPG.
Some plant workers would be potentially exposed to airborne concentrations in excess
of the revised insoluble uranium limit (RPG 1x10 uCi/me). As presented in Table 4,
the average annual exposures in each of the five process areas would range from 1.4 to
2.3 times the insoluble uranium RPG for the year 1981. If the new guidance on internal
exposures were to be imposed, it would be difficult to maintain combined exposures
below 30 percent of the RPG. The difficulty in meeting the new RPG is discussed in
item 8 of this case study.
Potential internal exposures are monitored by means of an extensive air sampling
system in which 45 sampler heads are connected to a central vacuum and the filters
226
-------
changed after each eight-hour shift. The manager of Health Physics and Industrial
Safety and five health physics technicians provide radiation protection services at the
plant. It is anticipated that a certified health physicist, at a cost of $40,000 per year,
would have to be employed to provide radiation protection, supervision in the plant
areas in order to comply with the proposed Range C guidance.
5. Impact of Proposed Guidance for Potential Exposures
in the Range O.I to 0.3 RPG
The plant is currently operating in full compliance with this proposed guidance. All
personnel wear film badges to measure external exposures. Potential internal exposures
are monitored with an extensive air sampling system. The manager of Health Physics
and Industrial Safety and five health physics technicians maintain records on external
sources of radiation and airborne concentrations in the six plant areas, and are available
to monitor during non-routine operations. These professionals are expected to assure
that exposures are justified and are ALARA.
6. Impact of Training Requirement
The existing training program satisfies the proposed guidance on training.
7. Impact of the Guidance for Protection of the Unborn
At present, approximately 19 percent of the plant employees are females of child-
bearing age. Presently the corporation management conforms to the policy as
described in Regulatory Guide 8.13, "Instruction Concerning Prenatal Radiation Ex-
posure." Accordingly, there is not expected to be a cost impact from Alternative a of
the guidance for protection of the unborn. The proposed Alternative b is not considered
to be a viable alternative at this plant since pregnant women are assigned to non-
radiation areas. Alternative c might result in women not being considered for certain
jobs.
8. Impact of the Internal Exposure and Combined
External Exposure Guidance
The current approach is to calculate time-weighted average exposure concentrations
(TWA) based on measured airborne concentrations of uranium and work location cards.
227
-------
The TWA is calculated for each person that routinely works in a process area and is
recorded as a fraction of the MFC. Internal doses are not estimated unless the
calculated airborne exposure is greater than 40 MPC-hrs/week for soluble uranium and
520 MPC-hrs/qtr. for insoluble uranium. These exposures are verified using the
bioassay procedures described earlier and the results are recorded along with MPC-hrs.
Measured external exposures obtained from the film badge readings are not currently
added to the estimated internal exposures. A computer program at the plant is
currently in place which provides output data for determing compliance with the
existing 10CFR20.
As can be seen from the data presented in Table 4, some of the plant workers would be
potentially exposed to airborne concentrations in excess of the revised insoluble
uranium limit (DAC of 2 x 10~ //Ci/ml). For 1981, the average annual personnel
exposures in each of the five process areas would range from approximately 0.7 to 1.2
times the insoluble uranium DAC. The approach to compliance with the revised limits
would be essentially the same as at present, namely calculation of potential exposure to
uranium for each worker using the TWA method. However, the conservative assump-
tions currently made would have to be relaxed. In particular, measured particle sizes
and solubilities would be used in the calculations.
Particle size distributions in air are presently not available for the facility. It is
estimated that using actual measured particle size distributions would reduce calculated
potential exposures by about 20 to 30 percent. Larger gains are potentially available
from the use of measured solubility factors.
Determination of actual solubility fractions could lead to the relaxation of the
conservative assumption of total insolubility (Class Y). The MFC's for soluble uranium
are a factor of about 30 higher than those of insoluble uranium. It is estimated that
using actual solubility class (i.e., Class W solubility) would lower the calculated
potential exposures by about a factor of fifteen (i.e., Class Y to Class W).
Establishment of a routine system for measuring solubility fractions would take a
professional approximately six man-months of effort (at a cost of approximately $3800
per man-month). Then routine monitoring of this parameter is expected to take a
technician approximately 10 man-days each month. (It is assumed that NRC I&E would
require continual routine monitoring of these parameters.) The one-time equipment
228
-------
costs for sampling of solubility class are estimated to be approximately $22,000.
Additionally, laboratory support for determination of solubility fractions is estimated to
cost approximately $30,000 per year.
Particle size determinations would also have to be made at approximately 10 locations
for a one-time equipment cost of $20,000 and an analytical cost of $2,000/yr. Also, in
order to provide adequate personnel monitoring, an additional number of personal
sampling pump assemblies would be required at a cost of $9,000. Finally, all particulate
air samples will have to be analyzed for isotopic content. This is estimated to cost
$192,500 per year.
The computer software and hardware used for the evaluation of personnel exposures
would also have to be upgraded. It is estimated that to modify the software,
approximately six man-months of a programmer would be required. Hardware costs of
$30,000 are estimated. Additionally, a full-time records clerk would have to be
employed at an annual cost of $16,200.
It is expected that the effect of the above internal exposure procedures would be to
demonstrate compliance with the ICRP-30 limits. However, the proposed EPA limits
are about another 30-40 percent lower. At present, it is not certain that these changes
will bring calculated potential exposures down to the proposed EPA limits.
The weighted organ doses in the proposed guidelines are viewed as a potential problem
area since they appear to be in conflict with ICRP 26 and 30.
9. Impact of the Reduction of the W.B. RPG
to 1.5 Rem/yr.
The imposition of this alternative RPG would have a cost impact on the conversion
plant operations, given the parallel imposition of the reduced intake limits. There
would probably have to be process changes and/or increased confinement on certain
operations. Moreover, considerably more effort would have to be expended on this
radiation protection program.
229
-------
L. NUCLEAR PHARMACY
With gross sales of $30M annually, this nuclear pharmacy has approximately 50 percent
of the market for radiopharmaceuticals supplied out-of-house. (Roughly 50 percent of
the unit dosages used in nuclear medicine are made up in-house.) Another large nuclear
pharmacy has most of the remaining market, and four small firms have less than 10
percent of the market.
The firm is comprised of approximately 30 operational pharmacies located in separate
cities throughout the U.S., mostly in non-Agreement States. A typical pharmacy
employs three pharmacists, one nuclear medicine technologist, a secretary, and 10
delivery personnel. Additionally, a salesman services four pharmacies. The firm has a
itotal of about 500 employees.
Ninety percent of the radiopharmaceuticals consist of Tc-99m (eluted from a molyb-
denum generator) or Tc-99m — tagged compounds. Most of the remainder are either
iodine-131 or xenon-133. A smattering of Tl-201, Ga-67,1-123, Yb-169, Cr-151, and In-
Ill is also handled. A typical pharmacy handles approximately five Curies per day of
Tc-99m and roughly 200 mCi of the others.
Personnel dosimeters (film) are provided to all employees. Dosimetry is performed by
an outside service and whole-body badges are read monthly at a cost of
$.70/badge/month. Additionally, approximately 380 workers are provided extremity
monitors (ring badges). Of these, approximately 100 (for the dispensers — largely the
pharmacists) are read weekly and the remainder (for the handlers — largely the drivers)
are read monthly. A few people wear wrist badges in addition to ring badges.
Whole-body exposures are relatively low. Of the hundred or so dispensers who receive
measurable doses, the average is less than 500 mrem/yr. and the maximum is less than
1 rem/yr. The W.B. exposures of the handlers is insignificant.
The average hand exposure during a recent quarter was about 2.8 rem. Thirteen
individuals exceeded 4.75 rem hand exposure during the same quarter. The maximum
hand exposure was roughly 9 rem.
230
-------
Bioassays, in accordance with NEC Regulatory Guide 8.23, are performed routinely on
all individuals who handle 1-131. Both urinalyses and thyroid monitoring are done.
Initially, thyroid monitoring is performed bi-monthly. If nothing is detected, the
frequency is reduced to quarterly. Urinalyses are routinely performed monthly.
Air sampling is additionally performed at some of the facilities. Typically one sampler
is set up and counts are taken at the end of the day. The existence of the air sampler
at a facility has historical, rather than health physics significance. Eventually, these
air samplers may be eliminated if compliance can be demonstrated by calculation.
In 1981, the maximum thyroid burden of those monitored was .06//CJ or approximately
40% of the limit. Most individuals had no measurable thyroid burden. Moreover,
radioiodine was not detected in anyone's urine.
This nuclear pharmacy is one of two wholly-owned subsidiaries of a parent organization.
The complete health physics organization is situated in the parallel subsidiary, and the
Corporate Radiation Safety Officer reports to the president of this subsidiary, who in
turn reports to the president of the corporation. A generic health physics program is
established by the corporate health physics group for each pharmacy. This program
includes a safety manual and procedures, and periodic audits. Additionally, the
personnel monitoring program is run out of the corporate office.
At the local level, each pharmacy has a Radiation Safety Officer (usually a pharmacist)
who reports on radiation safety matters to the Corporate Radiation Safety Officer.
Typically, the local RSO spends approximately 10 percent of his time on matters
relating to radiation safety.
The corporate RSO has approximately 20 years of experience as a radiological physicist
at a hospital. His academic background is radiation biophysics. The backgrounds of the
other three individuals comprising the corporate health physics staff are also in nuclear
medicine rather than health physics. However, it is felt that the experience of aU four
individuals renders them equivalent to radiation protection professionals (i.e., health
physicists).
A radiation protection instructional program is in the developmental stage. This is an
audio-visual program directed to both dispensers and handlers. The core of this
231
-------
program will be presented to an individual before he starts work, with an update
annually. He will be required to pass an examination on the material, which includes a
section on quantitative levels of risk from radiation exposure.
1. Impact of Reduction in W.B. RPG
In 1981, the highest whole-body exposure was less than one rem. The average whole-
body exposure was 0.5 rem. Thus, the imposition of a 5 rem annual limit would not
impose a burden on this firm.
2. Impact of Reduction in Accumulated Exposure Limit
There are probably no employees with lifetime exposures exceeding 5 rem. This
proposed guideline would have no impact for this firm.
3. Impact of Proposed Guidance Relative to
Extremities and Individual Organs
Skin and eye lens doses are comparable to whole-body doses. However, hand exposures,
by virtue of the nature of the work performed by the dispensers, are relatively high.
Accordingly, the reduced hand limits (from 75 rem/yr. to 50 rem/yr.) could be a
problem for selected individuals. For example, one individual exceeded 50% of the hand
exposure limit last quarter. This same individual generally averages 13 rem/qtr. Most
individuals average approximately 1 rem/month.
Hand exposures should be able to be maintained well below 50 rem/yr. The problem
with the few-outliers is technique, and this should be able to be remedied with a little
attention from the corporate health physics staff. Currently, an administrative limit of
1 rem/wk. is in effect. If the revised extremity limits were to be promulgated, an
administrative limit of approximately 3 rem/mo. would be adopted. The costs of
complying with the revised hand limit should be minimal.
There may actually be a cost benefit from the new extremity limits. Presently, the
cost of personnel monitoring is $36,000 yr. Approximately $9,000 of this is from the
weekly hand monitoring of 100 employees ($1.72/badge/week). If the quarterly limit
were dropped, monthly monitoring should suffice, providing a cost savings of approxi-
232
-------
mately $7,000. Also, the annual costs for analysis of exposure data is estimated to be
approximately $15,000. This would be reduced by approximately 50 percent if weekly
monitoring were dropped.
4. Impact of Proposed Guidance for Potential Exposures
in the Range of 0.3 to 1.0 RPG
Exposures in excess of 0.3 times an RPG are only possibly anticipated for the hands
(greater than 15 rem/yr.). At present, the average annual exposure to the hands is 12
rem/yr. High doses to the hands are obtained by the dispensers who "pull doses."
However, full-time supervision and monitoring by a radiation protection professional
would not be required under the proposed guidelines because there is no single task in
which the contribution to the annual exposure is "significant."
5. Impact of Proposed Guidance for Potential Exposures
in the Range of 0.1 to 0.3 RPG
The guidance for exposures in the range of 0.1 to 0.3 RPG describes the existing
program. Thus, there would be no impact from this guidance.
6. Impact of Training Requirements
The training program which is currently under development by the company satisfies
the proposed guidance. By the time that the guidelines are formally proposed, this
training program will be well under way.
7. Impact of Guidance for Protection of the Unborn
Approximately five percent of the dispensers and handlers are female. All female
employees are required to read NRC Regulatory Guide 8.13. As of yet, however, there
has not been a pregnant pharmacist. If there were, she would probably be asked to take
a leave of absence. Exposures to the fetus could probably be maintained below 500 mrem,
but it would be too risk. If a handler were to become pregnant, she would be kept out
of the restricted area (no packing, just delivering). Whole-body exposures to deliverers
can easily be kept below 500 mrem over a nine-month period. Therefore, the firm is
currently operating under a mandatory version of Alternative a.
233
-------
It is possible, though unlikely, for a worker to receive a W.B. exposure in excess of 0.2
rem/mo. who milks generators or compounds radiopharmaceuticals. Thus, if Alterna-
tives b or c were to be promulgated, women of child-bearing ages would be precluded
from doing these jobs. However, there are currently only about six women in the
company who perform these jobs. Thus the impact on the firm would be inconse-
quential. However, these alternatives would pose substantial EEO problems.
8. Impact of the Internal Exposure and Combined
External Exposure Guidance
The two radioisotopes of concern from an internal exposure perspective are iodine-131
and xenon-133. Intakes of these isotopes are currently a very small fraction of the
proposed RIF's.
If the proposed internal exposure guidance were to be promulgated, no additional
monitoring is expected to be required. However, the existing software would have to be
modified to convert the measurements to dose and to add the weighted organ dose to
the external exposure. It is estimated that the cost to develop the additional software
is approximately $15,000. Moreover, the operating costs for the dose tracking system,
currently at approximately $30,000/yr., would be increased by an estimated 30 percent,
or approximately $9,000/yr.
9. Impact of the Reduction of the W.B. RPG
to 1.5 Rem/yr.
The firm could operate within a 1.5 rem/yr. W.B. exposure limit with little or no
impact.
234
-------