vVVATffiaS 7-.'>;
vV;v?_;.Y;'''ttV^
^r^S^.^i
3j?i'V *-yi..\V $#*
^K^KSSS
.•«%" ft*- -.V"',- "• ^
^i'^S
KRYPTON 85
A REVIEW of the LITERATURE
and
an ANALYSIS of
RADIATION HAZARDS
-------
ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF RESEARCH AND MONITORING
TWINBROOK RESEARCH LABORATORY
The technical publications issued by the Twinbrook Research
Laboratory report results of intramural and contractor pro-
jects. A limited number of the reports are distributed to
regional, state, and local radiological health agencies, to
universities and libraries, to other government and private
agencies, and to interested individuals.
Twinbrook Research Laboratory technical reports are generally
available from the National Technical Information Service,
Springfield, Virginia 22151. Microfiche copies are $0.95 and
paper copies are $3.00 unless otherwise noted.
-------
KRYPTON 85
A REVIEW of tke LITERATURE
ana
an ANALYSIS of
RADIATION HAZARDS
William P. Kirk
Eastern Environmental Radiation Laboratory
P.O. Box 61
Montgomery, Alabama 36101
->
ENVIRONMENTAL PROTECTION AGENCY
Office of Research ana Monitoring
Washington, D.C. 20460
-------
FOREWORD
Krypton-85 is a long-lived, fission-product, noble gas which
is released to the atmosphere in large quantities by the nu-
clear industry, primarily by reactor fuel reprocessing plants.
Although development of the technology needed to collect the
krypton-85 at reprocessing facilities is nearing fruition, the
atmospheric build-up of krypton-85 is expected to continue for
some time due to the rapid growth of the nuclear power industry.
The present atmospheric inventory of about 60 megacuries is
more than twice the inventory of a decade ago and is increasing
rapidly. The distribution of 85Kr is essentially global once
it is released, with radioactive decay (T]/2 = 10.76 yr) being
the only important removal mechanism.
The current permissible 85Kr concentration values are based on
calculations and extrapolations rather than on the results of
di; set experimental investigation of the effects of 85Kr on liv-
ing animals. Thorough investigation of the physiological beha-
vior and effects of °5Kr in living animals is, therefore, im-
perative. This report summarizes the background information up-
on which studies of this type, being undertaken at the Eastern
Environmental Radiation Laboratory, Montgomery, Alabama, are
based. Additional information is sought on a continuing basis,
and the interest and comments of all those concerned with radio-
logical and environmental health are solicited.
William A. Mills, Ph.D.
Director
Twinbrook Research Laboratory
^^•^
-------
TABLE OF CONTENTS
Foreword
Abstract
Acknowledgments
INTRODUCTION ........................... 1
BACKGROUND INFORMATION ...................... 1
Characteristics ........................ 1
Chemical ........................... 1
Physical Data ........................ 2
Radiological Data ...................... 3
Source Information ....................... 3
Present (MPC)a and Rationale .................. 4
85KR AS AN ENVIRONMENTAL CONTAMINANT ............... 5
How and When 8%r is Released to the Environment ........ 5
Distribution of 85Kr ...................... 7
Worldwide Concentration and Dose Estimates .......... 7
8^Kr Concentrations and Doses Near Reprocessing Facilities . . 10
Removal of 85Kr from Process Streams Before Release to the
Atmosphere ........................ 11
USES OF KRYPTON 85 ........................ 13
Medicine and Closely Allied Areas ............... 13
Non-medical Uses of 85Kr .................... 14
RADIATION HAZARDS ASSOCIATED WITH 85KR .............. 15
Skin Dose ........................... 15
Dose in the Body ........................ 16
Dose from 85Kr Outside the Body ............... 16
Dose from 85Kr Contained in the Body ............. 16
Doses to Skin, Whole Body, and Male Gonads at
Unrestricted (MPC)a .................... 17
Skin ............................. 17
Gonads (Male) ........................ 17
Whole Body .......................... 17
Other Dose Calculations .................... 18
Comparison of Doses Delivered at the Unrestricted (MPC)a
With Permitted Doses ................... 19
Unexplained Phenomena Involving Noble Gases .......... 21
-------
SAMPLING AND ANALYSIS OF 85KR 22
Detection and Counting 22
General ,22
Detectors Used 22
GM Counters 22
Internal lonization and Proportional Counters 23
Scintillation Counters 23
Gamma Scintillation 23
Beta Scintillation 23
Semi-Conductor Detectors 25
Calibration and Standardization 26
Sampling and Sample Preparation 26
SUMMARY 27
REFERENCES 29
TABLES
1. Annual Dose from Immersion in Air with a Concentration
3 x 10"7 yCi/cm3 18
2. Summary of Dose Limits for Individuals 19
3. Minimum Detectable 85Kr Concentrations for Calibrated
External Beta Counters 24
4. Minimum Detectable Concentrations of ^Kr in lonization
Chambers - 25
A-l. Solubility Coefficients for °%r in Various Solvents .... SO
FIGURES
1. Scheme of Hydroquinone Clathrate 2
2. Estimated Krypton-85 Concentrations in Air, 1970-2060 .... 6
3. Estimated Annual Doses from Krypton-85, 1970-2060 7
4. Comparison of Estimated 8%r Concentration in Air
1970-2060, with Measurements through 1970 8
5. Krypton-85 Concentration in Air 9
6. Estimations of Annual Dose Rates from 8%r 10
7. Comparison of Estimations of Annual Dose Rates from 8~"Kr . . 20
A-l. Hypothetical 85Kr Saturation and Desaturation Curves for
Standard Man 55
A-2. Experimental 85Kr Desaturation Curves in Rat Short
Exposure 56
A-3. Experimental °->Kr Desaturation Curves in Rat Long
Exposure 55
APPENDIX A
Absorption of Kr into the Body 47
Appendix Reference 57
vi
-------
ABSTRACT
This review summarizes most of the existing information on °%r.
Major subject areas covered are (1) physical, chemical and radiological
data, (2) maximum permissible concentration in air (MPC)a and its
rationale, (3) source data, (4) atmospheric concentrations and dose
estimates near reprocessing facilities and worldwide, (5) proposed
control methods, (6) uses in science, especially medicine, and industry,
(7) calculations of dose to various organs and their relationship to
the (MPC)a, (8) unexplained noble gas phenomena, and (9) methods of
sampling and analysis.
The in vivo internal behavior of °%r is discussed in detail in
appendix A and preliminary desaturation curves obtained with rats are
presented. The review includes 280 references.
v^^
-------
ACKNOWLEDGMENTS
This report was written as part of the Ph.D. dissertation
in the Department of Radiation Biology, School of Medicine and
Dentistry, University of Rochester, Rochester, New York.
The author wishes to especially thank his faculty advisor,
Donald A. Morken, Ph.D., for his support and assistance in its
evolution and a host of University Librarians for their assistance
in collecting the mass of reference material used.
-------
INTRODUCTION
Krypton 85 is one of the most important gaseous contaminants produced
in nuclear fission. Public health concern has centered on its release to
the atmosphere during reactor operations and especially during fuel repro-
cessing. Rapid expansion of the medical, scientific and industrial uses
of 85Kr have made it of practical importance to the health physicist. The
literature on ^%r is singularly parochial and is spread through many dis-
ciplines with little cross-referencing. This report reviews much of this
literature and provides general information and references regarding 85Kr.
The reference list is not complete, particularly with respect to some
government reports from this country and abroad which are difficult to
locate and obtain, and to the rapidly proliferating field of medical uses.
This report specifically attempts to:
1. Furnish physical, chemical, and radiological data on Kr
2. Review sources, yields, and amounts released in different
operations
3. Review the current maximum permissible concentrations in air
(MPC)a values and their rationale
4. Review the status of 85£r as an environmental contaminant
and proposed methods of control
5. Enumerate a number of uses for 85](r £n science, especially
medicine and industry
6. Evaluate the radiation hazard associated with ^Kr and
relate it to existing limits
7. Review methods that have been successfully used to collect,
prepare and analyze ^Kr.
BACKGROUND INFORMATION
CHARACTERISTICS
CHEMICAL
The family of noble gases that includes krypton has been traditionally
regarded as chemically inert. Modern studies have revealed, however, that
the more polarizable members can participate in ionic or covalent bonding,
under appropriate conditions, with highly1 reactive elements such as fluo-
rine and oxygen (1,2) and that clathrates can be formed with water
A clathrate is a solid that incorporates a gas into voids in its
crystal structure. See figure 1.
-------
(hydrates) and a number of organic solvents (1,3,4,5). Most of these
compounds dissociate at physiological temperatures but some of the organic
clathrates, including hydroquinones, are relatively stable at normal tem-
peratures (4,5). The structure of hydroquinone clathrate is shown in
figure 1. Several authors have postulated clathrate formation involving
side chains on body proteins to explain the observed narcotic effects of
xenon, the most reactive noble gas, and other gases that produce similar
reactions (3,6,7,8). The noble gases are highly soluble in non-polar
solvents, including body lipids, with solubility decreasing in order of
radon, xenon, krypton, argon, neon, and helium (9). Solubility is dis-
cussed in more detail in Appendix A.
BENZENE RINGS
Figure 1. Scheme of hydroquinone clathrate, after Balek (5)
PHYSICAL DATA
Cryogenic Reference Data (10) and the Radiological Health Handbook
(11) give the following information concerning krypton:
-------
Atomic weight (naturally occurring) =83.9
Melting point = -157.2° C (-250.9° F)
Boiling point = -153.3° C (-244° F)
Triple point = -157.2° C, 548.2 mm Hg (-251° F and 10.6 PSIA)
Critical point = -63.8° C (-82.8° F) and 41,165 mm Hg (796" PSIA)
One kg of natural krypton occupies a volume of 287.45 liters at NTP
(20° C, 760 mm Hg) or 266.79 liters at STP ( 0°C 760 mm Hg).
The naturally occurring isotopes of krypton and their percentages
of natural abundance are 78Kr (0.35%), 80Kr (2.27%), 82Kr (11.56%), 83Kr
(11.551), 84Kr (56.9%) and 86Kr (17.37%). Radioactive isotopes of
krypton include 74-77, 79, 79m, 81, 81m, 83m, 85, 85m, 87-95, and 97.
RADIOLOGICAL DATA
The following data are given by the Radiological Health Handbook (11)
or the National Bureau of Standards (12) for 85Kr:
Half life = 10.76 years
Emissions: Beta; E^^ = 0.672 MeV, E = 0.249 MeV, frequency =
99.59% (11) or 99.56% (12). A 0.16 MeV Emax beta, which is
usually ignored in calculations, is associated with the 0.514
MeV gamma.
Gamma; E = 0.514 MeV, Branching ratio = 0.41% (11) or
0.443% (12).
Revisions in the published values have occurred and are the cause of
most differences in doses or dose rates calculated by different authors.
SOURCE INFORMATION
o r
The amount of Kr formed depends on a number of factors including
the specific heavy nuclei being fissioned, the neutron flux, the neutron
energy spectrum, and the irradiation time. The amount present at anal
ysis will be determined by the foregoing factors and the time that has
elapsed between irradiaton and analysis, or cooling time. The general
expression for the amount of 8%r present in a reactor or fuel element is:
C = 8.4 x 105 PiYi (1 e-^T) e^ (13)
where: C = curies of 85j(r present
Pi = total nuclear power supplied by reactor system i, MW
Yj_ = fission yield of system for 85Kr
^ = decay constant for 8^Kr = 1.76 x 10~4 days~l
T = irradiation time (days)
t = cooling time (days)
-------
Various estimates of Y^ in the literature include:
Yi (235U, thermal neutrons) = 0.00293 (14); 0.00273 (15); 0.00306 (16)
Yi (235[j, fission neutrons) = 0.00310 (16)
Yi (239pu5 thermal neutrons) = 0.00099 (15); 0.0012 (16)
Yi (239pu, fission neutrons) = 0.001446 (16)
YJL (239pu5 fast neutrons) = 0.00076 (17)
Yi (233u, thermal neutrons) = 0.0058 (14)
An estimate of average S^Rr production is 0.2 kCi per megawatt of energy-
produced (1 year operation, 1 day cooling) (18) .
PRESENT (MPC)a VALUES AND RATIONALE
The presently accepted maximum permissible concentrations in air for
85Kr, as established by the AEC (19), NCRP (20), and ICRP (21) , are 3 x
10"7 p,Ci/cm3 (3 x 105 pCi/m3) for unrestricted areas, 10"5 ^Ci/cm^
(10 7 pCi/m3) for occupational exposure for 40 hours weekly, and 3 x 10-6
jj-Ci/on3 (3 x lo6pCi/m->) for occupational exposure for a 168 -hour week.
The (MPC)a values and the estimated doses in most published pro-
jections are based on calculations of the external dose received by a
person standing in an infinite hemispheric cloud of the radioactive
gas. This is standard procedure for noble gases.2 Internal absorption
or concentration is not considered. The occupational (MPC)a for a 40 -hour
week is calculated from the formula:
(MPC) = ^ Pa (Pa/Pt> l-iCi/cm3
a
where: R = dose permitted in one week (rem)
pa = density of air (0.00129 g/cm3)
Pa/pt = stopping power of air relative to tissue
( = 1/1.13 for beta and secondary electrons produced by x or y
radiation)
2(E) = effective energy per disintegration (MeV)
Two sub-categories are recognized. If the radiation emitted is gamma
radiation or beta radiation with maximum energy equal to or greater than
0.1 MeV, the critical organ is taken to be the whole body and R is set
at 0.1 rem/week. If the emissions are alpha particles or beta particles
with maximum energy less than 0.1 MeV, the critical organ is considered
to be to the skin of the whole body and R is taken to be 0.6 rem/week.
Krypton 85 falls in the former group and is considered to deliver its
dose to the whole body even though the deposition of energy from exter-
nally incident 0.672 MeV beta particles will be deposited within about
a 2 mm depth in tissue (11,22) with the average penetration being slightly
greater than 0.2 mm (22). The overall effect is to overestimate the dose
2The lung is used as the critical organ for radon in equilibrium with
its daughters.
-------
actually delivered to the whole body. This will be discussed in detail
later. It has been recognized that the MFC values in use are conserva-
tive (23,24), and the next issue of the ICRP Recommendations is expected
to increase them by a factor of about 5 (24).
85KR AS AN ENVIRONMENTAL CONTAMINANT
HOW AND WHEN 85KR IS RELEASED TO THE ENVIRONMENT
Krypton 85 is produced by nuclear explosions and continuously
during reactor operations. It has been concluded (25,26), from consider-
ations of experimentally determined air concentrations versus total weap-
ons yield, that most of the 85](r in the air, even during a period of
active atmospheric weapons testing, is due to reprocessing of reactor
fuel. This conclusion is strongly supported by evaluation of the data
of Logsdon and Chissler (27) and Kahn e±. a£. (28) which shows that about
0.02% of the 8%r formed in reactor operations from 1959 through 1968
was released to the air at the reactor.3 The °~*Kr produced in reactor
fuels is not released, in the absence of cladding failure or "tramp"
uranium,4 until the fuel elements are cut apart in the reprocessing plant
and the fuel is dissolved preparatory to chemical separations. Goode (29)
reported that 99-99.5% of the release occurs in the dissolution phase with
acid treatment of Th02-U02 fuel in the laboratory. This estimate is con-
firmed for full scale processing by data of Cochran e± ql. (30) who report
that all but about 20-50 curies of the approximately 5,000 curies of 8%r
released per batch processed at the Nuclear Fuel Services plant are
released during dissolution. Other radioactive gases released during
reprocessing include 131I, 129I, 131jnXe, 133Xe and 3H. Krypton 85 is
the only gas, other than 3H, released in sufficient quantity and having
a half life long enough to produce significant widespread concentrations
in the air. Whipple (50) estimates that ^5Kr emission will limit U.S.
nuclear power to about 150,000 MW(e) .5
3Assuming 0.2 kCi of 85j(r produced/MW-year, all beta-gamma activity
released to air by PWR/HTGR was 85Kr and 0.001% of total fission gas re-
lease from BWR was 8%r (Estimated from isotope composition data in 27,28)
4 According to Kahn et at.(28), the principal sources of fission
products in reactor coolant are holes or cracks in cladding or fission of
uranium in the coolant that has escaped from failed fuel elements. Tramp
uranium and direct diffusion through intact cladding are minor sources.
5The release limit by the U.S. power industry was determined to be
1010Ci/year assuming (a) (MPC)a of 3 x 10-7 jiCi/cm3 reduced by 1/3 for
individual variations and 1/10 for summing of dose from several isotopes,
(b) half the ^Kr released is from explosion (U.S.), (c) all °5Kr produced
is released, and (d) the U.S. uses 0.06 of world capacity (fair share
based on population).
-------
Small amounts of ^Kr have been released by venting of cavity gas
from certain Plowshare projects such as Gasbuggy and Rulison. Gasbuggy
produced an estimated 350 Ci of 85Kr which resulted in a cavity gas con-
centration of 2.8 jj,Ci/ft3 (31,32). The 85Kr concentration in the cavity
decreased exponentially as gas was removed (32-35). The amount of bbKr
released by these tests is minor in comparison to total 8bKr releases,
but is of the same magnitude as the amount of yhKr released at reactor
sites through 1968.
100.00
10.00 -z
.00 -
0.10 -
;> o.oi -
8
0.001
/
i
A
i
A
— MEDIAN ESTIMATE
^ RANGE OF VALUES FOR DILUTION
IN ENTIRE ATMOSPHERE
15551 UPPER RANGE FOR 75% RELEASE
IN NORTHERN HEMISPHERE
A AVERAGE FROM REFERENCE 25
1940 I960 1980 2000 2020 2040 2060
YEAR
Figure 2. Estimated krypton-85 concentrations in air, 1970-2060.
-------
DISTRIBUTION OF 85KR
WORLDWIDE CONCENTRATION AND DOSE ESTIMATES
Colemen and Liberace (13) estimated future world °%r levels, and
radiation doses resulting therefrom, based on projected world energy
requirements and that part expected to be met with nuclear power. Their
estimates, shown in figures 2 and 3, assume that all ^^Kr produced is
released and that the (MFC) actually delivers the permitted dose. Their
estimates of air concentrations, published data from a number of labor-
atories (25,26,36-45), and estimates of the United Kingdom contribution
100.00
10.00 -=
1.00 -
§ 0.10
0.01 -
MEDIAN ESTIMATE
RANGE OF VALUES FOR DILUTION
IN ENTIRE ATMOSPHERE
UPPER RANGE FOR 75'/.RELEASE
IN NORTHERN HEMISPHERE
0.001
1940 1960 1980 2000 2020 2040 2060
YEAR
Figure 3. Estimated annual dose from krypton-85, 1970-2060.
-------
(24) were converted to a common unit and are shown in figure 4.6 Data
from Shuping et al. (44,45) are shown in figure 5 with the time scale
expanded. The °5Kr levels appear to be increasing at a rate near or
slightly greater than the predictions. The predictions were not claimed
to be accurate in the 1965-1980 period mainly because of uncertainty in
the time delays from irradiation to reprocessing.
105-
io4-
O
10J-
I
10' -:
REFERENCE
+ (37)
A (38)
O (46)
D (36)
* (25)
(26)
(39)
(40)
(44,45)
(13)
COLEMAN & LIBERACE
PREDICTIONS
UK CONTRIBUTION
ESTIMATED BY
DUNSTER & WARNER (24)
1940 1960 1980 2000 2020 2040 2060
YEAR
Figure 4. Comparison of estimated 85Kr concentration in air,
1970-2060 with measurements through 1970.
In coverting the U.K. data, the cumulative
21
was assumed to be
diluted into the total atmosphere of 5.14 x 1021 g at 0.001293 g/cm3
(3.97 x IQlS m3) which yields a conversion factor of MCi/3.97 = pCi/m3.
-------
IO
16-
0^
N I*-
c
^ 12-
> 10-
^\
V
^'V^ O
^
^^i
^* ^EHHALT
^ HEIDELBERG, GERMANY
1962 1964
D
• ^
0 0 • A
• 0 0° A
O
O
0
AFTER SHUPING et.al. (44, 45~)
1966 1968 1970
MIDPOINT OF COLLECTION PERIOD
Figure 5. Krypton-85 concentration in air, including data from
Ehhalt et al. (25) .
The data from figure 3 have been replotted in figure 6 for compari
son with similar estimates from Dunster and Warner (24) , Cowser et al.
(46,47) and Csongor (38). The U.K. estimates (24) are based on de novo
dose calculations while the others assume that a dose of 0.5 rem is de-
livered when the average concentration is 3 x 10~? jj,Ci/cm3 for one year.
The calculations involved are discussed in the section on hazard
evaluation.
Krypton 85 in commercial krypton supplies began causing problems as
early as 1963 when Ostroski and Jelen (43) reported background problems
with krypton-filled ionization chambers. Lasseart and Kellershohn (48)
reported similar problems with self-triggering spark chambers in 1965.
Dunster and Warner (24) warn of the possibility of personnel hazards asso-
ciated with handling commercial krypton supplies long before atmospheric
concentrations present a significant problem.
For comparison, the cumulative whole-body radiation dose from all
nuclear testing conducted through 1962 (end of large scale atmospheric
tests) is estimated to be 110 mrem in 30 years (49), which is itself
about 1/30 of the dose received from natural sources over the same period
(peak dose rates from fallout are greater).
-------
10
100.00 -q
10.00 -
1.00 -
^ 0.10 -=
^^
0.01 -
0.001
REFERENCE
O (47,48)
D (38)
A (24)UK FROM WORLD TOTAL
+ (24)UK FROM UK
SKIN A
(13)
COLEMAN & LIBERACE
AGONADS
.^+
SKIN
^r
'GONADS
1940 1960 1980 2000 2020 2040 2060
YEAR
Figure 6. Estimations of annual dose rates from 85Kr.
85KR CONCENTRATIONS AND DOSES NEAR REPROCESSING FACILITIES
Personnel of the Northeastern Radiological Health Laboratory of the
Bureau of Radiological Health, PHS, DHEW, have investigated the °5Kr con-
centrations in the vicinity of the Nuclear Fuel Services reprocessing
plant at West Valley, New York, which is the only operating commercial
fuel processing facility. These data are reported in references (30)
and (51). Concentrations were monitored, as near to the periphery of
the NFS property as access roads permitted, during the dissolution of
several batches of fuel (about 1 ton/batch). Using data collected in
-------
11
1968 and early 1969, Shleien (51) reported that the average annual 85Kr
concentration at the plant boundary (1.5 km from the stack) would be 2.3
x 10 "11 |j.Ci/cm3 and that the maximum annual concentration would be 1.3
x 10~10 [iCi/cm^. These values, derived from plume measurements using
wind data gxg diffusion equations, correspond to annual doses of 0.05
i-Ytrem and oj^/nrem respectively, if the ICRP values are used to convert
the concentrations to doses. In a later report, Cochran et al. (30)
reported that the 85](r concentrations in the plume ranged from 1.7 x
10 ° to 7.65 x 10~7 ^Ci/cm^ average for a 3-hour dissolution cycle;
the peak values during the same time were 1.3 x 10~7 to 9.3 x 10"6 ^Ci/cm3-
They calculated that the highest annual concentration, 1.7 x 10"1° jj,Ci/cm3,
would occur at the property line in the north octant. The maximum 24-hour
off-property concentration was estimated to be 6.8 x 10~? uCi/cm3. Sax
et &1. (36) reported a concentration of 5.6 x 10 p,Ci/cm^ about 5 miles
from the plant on one occasion in February 1968.
Dunster and Warner (24) estimate that the dose to individuals in the
vicinity of United Kingdom reprocessing facilities in 2000 AD will be
about 45 mrad/year to the skin and 0.38 mrad/year to the gonads.
REMOVAL OF 85KR FROM PROCESS STREAMS
BEFORE RELEASE TO THE ATMOSPHERE
It seems improbable that overall atmospheric 8%r concentrations
will require corrective or preventive action on purely radiological
safety grounds before sometime in the next century (13,24). However,
the anticipated growth in size of reprocessing facilities, coupled with
increasing cost of enough land to permit MPC to be reached by diffusion
before the plume crosses the property line, will probably lead to instal-
lation of equipment to remove the 8%r from the process stream before it
leaves the stack. Blomeke and Perona (52) and Perona et al.(53) estimate
that this point will be reached when more than 5 tons/day of 150-day aged
fuel or 0.5 ton/day of 30-day fuel is reprocessed.7 East Germany re-
quires facilities for storing 85j(r originating in reprocessing plants (54)
Concern with removal of 85Kr dates to the late 1950's (13,55-57). A
number of techniques have been investigated including:
1. Adsorption onto activated charcoal at cryogenic temperatures
(24,58-61 and many others)
2. Solvent extraction (24,42,55,56,62-64)
3. Condensation in liquid nitrogen followed by fractional distil-
lation (65)
4. Selective permeating through cellulose acetate or silicone
rubber membranes (66,67).
7Their analysis included contribution from all noble fission gases,
but only 85Kr is important 150 days after cooling.
-------
12
Three of these techniques have been developed to the operating stage.
The solvent extraction method developed at the Oak Ridge Gaseous Dif-
fusion Plant over the past several years (63,64) was recently reported
to be commercially available (62). A plant using the LN-, condensation-
redistillation technique is in use at the Idaho Chemical Processing
Plant (NRTS) (65). Air and Water News (62) also reports that one com-
mercial reactor supplier is using a charcoal bed removal system.
The most practical disposition for recovered °5Kr appears to be
long-term storage in high pressure steel cylinders (24,52,53). Incor-
poration of 8%r into glasses, resins, clathrates, molecular sieves, and
pressurized steel or glass bulbs in an epoxy matrix have been considered
for secondary containment of the °%r inside the steel cylinders (68).
Serious attention has been given to the possibility of pumping ^^>Kr into
underground storage areas, such as abandoned gas or oil wells or similar
formations (52,69,70). This method requires a porous storage formation
with an essentially non-porous cap formation that is free of vertical
channels. This requirement is too restrictive to permit generalized
use at reprocessing plant sites.
One comprehensive proposal, made by Blomeke and Perona (52,53),
calls for separating the 8:>Kr from the process stream, alone or with
xenon, by solvent extraction or cryogenic distillation. Processing
2600 tons/year of LWR8 fuel is estimated to yield 28 cylinders, each
containing 50 liters or 106 Ci of 85Kr (heat production 5,800 BlU/hour),
or 160 cylinders each containing 50 liters of mixed Kr/Xe (180,000 Ci
85Kr, heat production 1000 BTU/hour). The cylinders would be temporarily
stored underwater on site and then shipped, in special water-cooled casks,
to underground salt mines and stored above the floor in sealed rooms.
The storage space requirement for one year's production is one quarter
acre and is determined by heat production. The cost of disposal of 8%r
by this technique, including (1) filling, testing, and on-site storage
of the cylinders, (2) shipment to a salt mine, and (3) permanent storage
in the salt mine, is estimated to be $190,000-220,000/year for a 2600 ton-
year plant. This amounts to 0.0003-0.00035 mills/kW-hr of electricity
generated by the reprocessed fuel. This is about 0.001% of the residen-
tial electric rate in Rochester, New York in 1971.
Dunster and Warner (24) make basically similar proposals except that
they consider solvent extraction or adsorption on activated charcoal to
concentrate the 85Kr and evaluated several different types of storage
tanks.
8The fuel considered is from a light water reactor (LWR) exposed
to 33,000 MWd/ton at 30 MW/ton. An equivalent amount of fuel from a
liquid metal fast breeder reactor (mixed core and blanket) with an aver-
age exposure of 33,000 MWd/ton at 58 MW/ton will yield about 10% less
volume of noble gases.
-------
13
USES OF KRYPTON 85
MEDICINE AND CLOSELY ALLIED AREAS
Krypton 85 has found important clinical use in the past 15 years.
Its physiological characteristics of low blood solubility, high lipid
solubility, and rapid diffusion, together with versatility of detection,
facilitate differential diagnosis. Specific applications have included:
1. Determination of total body fat (71-75)
2. Circulatory studies
a. General (72, 76-86)
b. Rate of blood flow
(1) Brain
(a) Whole and regional (87-116)
(b) Partition coefficients (100, 117, 118)
(c) Detection of lesions (87, 102, 119)
(2) Heart
(a) Output (120-125)
(b) Myocardial flow (126-132)
(3) Lungs and perfusion (133-140)
(4) Kidneys (108, 141-146)
(5) Skin (147-149)
(6) Gastric mucosa (150-152)
(7) Intestines (153-155)
(8) Liver (156,157)
(9) Eyes (158, 159)
(10) Muscle (106, 160)
(11) Testis (161)
(12) Tumors (162)
(13) Fresh grafts (163)
c. Circulatory shunts
(1) Left- to-right, including atrial septal defects,
ventricle septal defects, and patent ductus
(164-173)
(2) Right to left (pulmonary) (168, 174-179)
(3) Hepatic -pulmonary (177)
(4) Hepatic to vena cava (180)
(5) A-V aneurisms in brain (117)
3. Lung function studies - emphysema, cysts, cancer etc.
(133-140, 181-183)
4. Structure of teeth (crystalline) (184)
5. Determination of surface area of elastin (185)
The quantities of ^^Kr used in these studies have usually been in the
range.
-------
14
NON -MEDICAL USES OF 85KR
The non-medical uses of Kr can be divided into two areas: (1)
those that use 85j(r as the gas and (2) those that incorporate it into
solids prior to use. Examples of the first category are:
1. Replacement of radium bromide as an ionization source in cold
cathode gas discharge tubes (186)
2. Location of carbon monoxide leak into aircraft cabins in
flight (187)
3. Measurement of stream aeration (188)
4. Determination of surface area of atmospheric particulates (189)
5. Measurement of gas flow in piping systems (190)
6. Tests of gaseous diffusion theory in solids (68, 69, 191)
7. Measurement of stack gas dispersion and diffusion (31, 192-197)
8. Study of interhemi spheric atmospheric mixing (39)
9. Study of other atmospheric gases (40, 41)
Krypton 85 has been incorporated into or onto solids using techniques
recently reviewed by Balek (5) and by Eddy (198). Methods include: (1)
fission recoil, (2) bombardment of surfaces with high-energy °^Kr ions,
(3) diffusion into crystal lattices at high temperatures and pressures
(successful with over 150 materials) , (4) crystallization of solids from
melt or by sublimation in an S%r atmosphere and (5) by adsorption onto
outgassed surfaces. All but the last method yield more or less stable
products which are called kryptonates if surface labeled, as by the first
three methods, or clathrates if the °%r is incorporated throughout the
material as by the fourth method.
The distribution of 85.Kr can be determined by autoradiography, or
its electronic equivalent, and used to study structural features of solid
materials including surface phenomena, lattice structure, or channeling
(5, 199-201). Cracks and imperfections in machinery components, such as
turbine blades, can be detetected after either kryptonation or adsorptive
labeling. Autoradiography is the only technique sensitive enough to use
with the.Joyptonated materials while either autoradiography or electronic
imaging works well with the adsorptive technique.
Another potentially extensive use of kryptonates and krypton clath-
rates lies in the field of chemistry (4, 5, 202). Krypton 85 can be incor-
porated into one of the reactants, catalysts, or incidental materials, and
the release of the gas from the solid used to detect the beginning of
a reaction or to measure its rate. Reaction end points, such as in titra-
tions, can be objectively determined by including in the solution a kryp-
tonated solid that will not react until an excess of titrant is present.
The amount of 85Kr involved in non -medical uses is rarely mentioned;
however, some of the counting data presented and description of the pro-
cedures suggest that some procedures may use curie quantities.
-------
15
RADIATION HAZARDS ASSOCIATED WITH §5KR
SKIN DOSE
o r
The dose to the skin from a cloud of Kr is the sum of doses from
beta particles, gamma rays and Bremsstrahlung from the surrounding atmos
phere and from the 85j^r that has been absorbed into the body. In the cir
cumstances postulated in deriving the (MPC)a, only the contribution from
outside the body is significant; the internal contribution will be 1-2
orders of magnitude less than the external gamma/Bremsstrahlung component
and 4-5 orders of magnitude less than the dose delivered to the skin by
external beta radiation.
The surface beta dose in an infinite cloud of a beta-emitting gas
such as °%r is given by:
D = 1.07 x 10-6 CaE K rad/hour (24)
where: C^ = pCi Kr/gram of air
E = average beta energy in MeV = 0.249 MeV9 (11)
K = ratio of stopping power in tissue to stopping
power in air =1.15 (24)
This reduces to:
D = 3.064 x 10"7 Ca rad/hour = 2.68 x 10~3 Ca rad/year
or
D = 2.07 Ca rad/year where Ca = pCi 85Kr/cm3 air10
This equation represents 50% of the point dose at the center of an infi-
nite cloud of 85Kr or the dose at the surface of an infinite slab of
multiplied in either case by the stopping power ratio.
The expression for the dose to the surface of the body from gamma
radiation and Bremsstrahlung was derived by N. Adams in Appendix 1 to
reference (24). This dose is given by the expression:
D = 2.42 x 10"9 Ca rad/hour = 2.12 x 10'5 Ca rad/year
or
D = 1.64 x 10"2 Ca rad/year
where C = pCi 85Kr/gram of air and Ca = pCi 85Kr/cm3 of air as above,
3.
9Reference (24) uses 0.234 MeV. Results differ accordingly.
10Using 1 cm3 air = 0.001293 gram air.
-------
16
DOSE IN THE BODY
DOSE FROM 85M OUTSIDE THE BODY
The average dose to the total body from gamma radiation and
Bremsstrahlung from 85Kr outside the body (infinite cloud) is given by
(24 -Appendix 1) :
D = 1.97 x 10-9 ca rad/hour = 1.73 x 10'S Ca rad/year
or
D = 1.38 x 10" 2 C^ rad/year
DOSE FROM 85KR CONTAINED IN THE BODY
To calculate the dose of &$Kr in the body that results from a given
concentration of the isotope in the surrounding air, the fraction of the
air concentration that will ultimately be found in the body, or a specific
part thereof, must be known. This faction is the partition coefficient
which is usually designated as ^.
o r
The internal behavior of Kr is discussed in detail in Appendix A,
including gas solubility, partition coefficients, and kinetic parameters.
The partition coefficient for the body or a particular tissue is largely
dependent on its fat content and for °$~K.r is closely approximated by:
\ tissue: air =0.06 (9Vf + Vrj = (0.48Vf/Vtj + .06
Vt
where: V-j- = total tissue volume, V^ = Y£ + Vr
Vf = volume of fat in tissue
Vr = volume of rest of tissue
Thus the partition coefficients from body tissue to air ranges from 0.06
to 0.54. The average partition coefficient for standard man is 0.163
To calculate the tissue concentration of ^r at equilibrium, the
air concentration is multiplied by the partition coefficient. If tissue
density is unity, the result is in pCi/gram.
The dose which results from the gamma and Bremsstrahlung component
of 85](r in the body is given by (24, Appendix 1) :
D = 1.43 x 10-9 Ctrad/hour = 1.25 x lO'5 Ctrad/year
where Ct = pCi ^%r/gram of tissue (Ct = C^ x \)
The beta component of internal dose is given by:
-------
17
D = CtpCi/g x 2.22 disintegrations/pCi-min x 0.9959 beta/dis-
integration x 0.249 MeV/beta x 1.6021 x 10"6 ergs/MeV x
rad-g/100 ergs x 60 min/hour
= 5.29 x 10-7 Ctrad/hour = 4.62 x 10~3 Ctrad/year
I£ X air:tissue = 0.06; D = 2.77 x 10"4 C' rad/year
X air:tissue = 0.163; D = 7.58 x 10~4 Ca rad/year
X air:tissue = 0.54; D = 2.50 x 10'3 Ca rad/year
where C^ = pCi 85Kr/cm3 in the surrounding air.
DOSES TO SKIN, WHOLE BODY AND MALE GONADS AT UNRESTRICTED (MPC)a
An individual continuously submerged in an infinite cloud of ^%r at
a concentration of 3 x 10"7 yCi/cm3 (C' = 0.3 pCi/on3, with an air density
of 0.001293 g/on3 C& = 232.56 pCi/g air) receives the following annual
doses.
SKIN (SURFACE)
External beta dose = 2.073 Ca rad/year = 0.623 rad
Gamma and Bremsstrahlung dose = 1.64 x 10"2 Ca rad/yeatf a O.QQ493 rad
Total = 0.628rad
GONADS (MALE)
Gamma and Bremsstrahlung dose at surface =
1.64 x 10'2 C^ rad/year = 4.93 x 10'3 rad
Gamma and Bremsstrahlung dose from 8%r inside the body (X = .06) =
1.25 x 10"5 Ct rad/year = 7.5 x 10"7 C£ rad/year = 2.25 x 10"7 rad
Internal beta dose (X = .06) =
2.77 x 10"4 C' rad/year = 8.33 x 10"5 rad
Total 5.01 x ID'3 rad
WHOLE BODY (X = 0.163)
Gamma and Bremsstrahlung dose from 85^r outside the body =
= 1.38 x 1Q-2 C^ rad/year = 4.02 x 10"3 rad
-------
18
o r
Gamma and Bremsstrahlung dose from Kr inside the body =
1.25 x 10 ~5 Ct rad/year =
2.04 x 10-6 ca rad/year = 6.12 x 10"7 rad
Internal beta dose =
4.62 x 10~3 Ct rad/year =
7.58 x 10'4 C^ rad/year = 2.27 x 1Q-4 rad
Total 4.25 x 10~3 rad
OTHER DOSE CALCULATIONS
Depth-dose calculations presented by Hendrickson (203, 204) illus-
trate the discrepancies between the surface dose and the actual dose in
several critical tissues (ignoring contributions from 8bKr in the body).
The results of these calculations, which include contributions from beta
gamma, and Bremsstrahlung, for an 85Kr concentration of 3 x 10~7
are given in table 1.
TABLE l.a ANNUAL DOSE FROM IMMERSION IN AIR
WITH A CONCENTRATION OF 3 x 10-7 jjCi(85Kr)/Cm3
Tissue
Whole Body
Gonads
Gonads
Surface of Skin
(or clothing)
Skin
(shallowest layer
Lens of Eye
Lung
Tissue
Depth
(mm)
50
10
2
0.0
0.07
of live skin)
2
(Internal Sur-
face of Lung)
3
Radiation
(rem/yr)
Nil
Nil
4 x 10"7
0.5
0.3
4 x 10~7
0.005b
x and y
Radiation
(rem/yr)
0.007
0.007
0.007
0.007
0.007
0.007
0.007
aFrom Hendrickson (203).
blnternal exposure to surface lung tissue from 8^Kr in the lung.
-------
19
Detailed calculations of doses resulting from immersion in infinite
clouds of the various reactor-produced noble gases, including ^Kr, using
the MIRD11 methodology are nearing completion and will be published in the
near future (205) .
Relationships for calculating doses to various organs resulting from
inhalation or injection of 85Kr during the medical diagnostic procedures
previously mentioned have been derived by Lassen (206) who estimates that
the following doses would result from breathing 85^r a^ a concentration
of 1 i^Ci/cm3 for 1 minute:
Tracheal mucosa 71.9 mrad
Lungs - 27.3 mrad
Adipose tissue 4.2 mrad
Other (incl. gonads) 0.5 mrad
These values would change relative to each other as exposure time increases
The original paper should be consulted for details.
COMPARISON OF DOSES DELIVERED AT (MPC)a WITH PERMITTED DOSES
ICRP 9 (207) summarizes dose limits for occupational exposure and
exposure to members of the public as shown in ta.ble 2. An additional
limit is the recommended whole population genetic limit of 5 rems/30 years
(0.167 rem/year).
TABLE 2a. SUMMARY OF DOSE LIMITS FOR INDIVIDUALS
Maximum Permissible Doses.
Organ or Tissue for Adults Exposed in Dose Limits for
the Course of Their Work Members of the Public
(rems in a year) (rems in a year)
Gonads, red bone 5 0.5
marrow, whole body
Skin, bone, thyroid 30 3
Hands and forearms, 75 7.5
feet and ankles
Other single organs 15 1.5
aprom ICRP-9 (208).
1-1 Medical Internal Radiation Dose Committee of the Society of Nuclear
Medicine.
-------
20
Figure 7 shows the fractions of applicable limits delivered by °%r
at a concentration of 3 x 10~? p,Ci/cm3, to the skin, gonads, and whole
body. The full bar in each case represents the fraction given in an infi-
nite cloud with exposure time long with respect to body saturation time.
The shaded area of the bar represents the fraction delivered without the
external gamma/firemsstrahlung component. The numbers in parentheses are
the factor by which the (MPC)a is conservative for each case. It appears
that the (MPC)a is conservative by a factor of at least 4.8 and, when
shielding effects of clothing and buildings are considered, probably by a
much larger factor. Modifying factors of particular importance in the
occupational situation are heavy clothing, such as lab coats, and the
absence of an infinite cloud with respect to gamma radiation. For example,
if 50 mg/on^ of clothing is worn reasonably close to the body, the skin
10 -q
id!
102-
I
^
V:
NFINITE CLOUD VALUES
EXTERNAL GAMMA COMPONENT
1
I
"NT
.c\j.
I
-X -X
?3"—i I—&>'
Figure 7. Comparison of estimations of annual dose rates from 85Kr,
-------
21
beta dose would be 181 of the unclothed dose so the total skin dose/year
at 3 x 10'7 yCi/cm3 would be 0.112 rad beta + 0.005 rad gamma or 0.117
rad/year.12 This is conservative by a factor of 25.6. The controlling
dose would then be the extremity dose which is conservative by a factor
of 7.5/0.628 = 12.
An increase in the unrestricted (MPC)a by a factor of 5 and the occu-
pational (MPC)a by a factor of 10-12 would appear justifiable if the only
consideration is meeting existing dose limits, but may not be desirable
when other things are considered.
UNEXPLAINED PHENOMENA INVOLVING "INERT" GASES
A number of inert gas phenomena, reported in the literature, have
not been satisfactorily explained. These have all occurred at pressures
many times greater than those considered in radiation protection, but
may be applicable to the physiological behavior of °%r and must be con-
sidered. The relative mangitude of effects found with members of the helium
series usually have been in order of polarizability or oil solubility which
is Xe > Kr > A > Ne > He.
The growth of Neurospora crassa was inhibited by 50% with 0.8 atm.
of Xe, 1.6 atm. of Kr, 3.8 atm. of A, 35 atm. of Ne and 300 atm. of He
(208) ; the inhibition of growth at 650 mm pressure was found to be pro-
portional to the square root of the atomic weight of the gas.
High pressures of xenon (225 psi) led to cessation of motion, a
decrease in contractile vacuole activity, increase in cell volume and
surface area and cytoloysis in paramecia (209). Krypton produced a de-
crease in contractile vacuole activity at 915 psi.
Reversible inhibition of Na+ transport across frog skin was found at
200 psi xenon or 950-1000 psi krypton (210). Similar pressures caused
reversible blockage of frog sciatic nerve transmission. In similar frog
nerve-muscle preparations, 100 psi xenon caused a decrease in muscle con-
traction and nerve conduction and 200 psi krypton decreased muscle con-
traction (211).
Radioprotection by inert gases is reported for animals (212) and
besn sprouts (8) although krypton had no protective effect on mice at 2
atmospheres pressure (213). Markoe et al. (214) reported potentiation of
killing of HeLa cells by x rays which was proportional to the partial pre-
sure of Xe or Kr present at irradiation.
12Since the limits for members of the public are each 1/10 of the
corresponding occupational limit, the degree of conservativeness calculated
for one applies to the other.
-------
22
Possibly the most interesting mystery is the demonstrated anesthetic
action of xenon (6) in humans. Surgical procedures (orchidectomy and
Fallopian tube ligation) have been performed using an 80% Xe:20% 02 mix-
ture (1 atm. total pressure) for anesthesia. Higher partial pressures of
Xe are required to anesthetise animals. The narcotic potency of the
helium series seems to follow the order previously stated (215) although
narcotic effects of krypton are equivocal at atmospheric pressures (6).
Another observation that has not been accounted for is the uptake of
1 1/2 2 times as much inert gas by the adrenal as by any other tissues
(8).
The foregoing phenomena are not understood at this time although
they have been widely debated (3, 7, 8). The most popular postulates,
particularly for anesthesia, are membrane effects involving lipid solu-
bility or stabilization of the formation of hydrate microcrystals in the
nervous system to block electrical conduction.
SAMPLING AND ANALYSIS OF 85RR
DETECTION AND COUNTING
GENERAL
Krypton 85 has been successfully detected and counted by virtually
every conventional beta or gamma detection technique, and some unconven-
tional ones, when sampling methods and counting techniques have been
properly matched with the amount and concentration of isotope to be ana-
lyzed and its physical form or configuration.
DETECTORS USED
GM Counters: CM counting has been used extensively in the medical
studies cited. End window GM detectors were used to count the beta radi-
ation emitted from the surface of organs, thin-windowed sample containers,
or flowing gas mixtures. Internal GM counters have been used to analyze
environmental samples (43).
The detection efficiency of end-window GM tubes is determined by
many factors and may approach 50% with good geometry and thin windows.
Martin (192) showed that commercial GM tubes with 30 mg/cnr walls will
detect 5 x 10"7 |o,Ci/cm3 of 85](r in ^ infinite cloud geometry. Ludwick
et at. (194), using a very sensitive tube with a 3.5 mg/cm2 window 50 mm
in diameter, were able to detect the passage of a cloud with a concen-
tration of 10~7 jj,Ci/cm3. GM tubes coupled to ordinary survey meters
have been successfully used to assay the concentration of &^~Kr in
-------
23
pressurized steel cylinders (216). Most recently, Smith et al. (217)
report calibration of several types of GM detectors to 85Kr in a known
fraction of an infinite cloud. Their results are shown in table 3.
GM tubes are commonly used as stack monitors by placing them in a
tank large enough to provide an appreciable fraction of an infinite cloud
(for beta) and drawing part of the stack flow through the tank (30, 217).
Internal lonization Counters and Proportional Counters: The standard
technique of counting radioactive gases in internal proportional counters
or ionization chambers has been used by several authors to analyze 85xr
in environmental samples (25, 31, 217-219) and is the method used in
standardization. Gas flow proportional counting was used in conjunction
with gas-phase chromatography by Dupuis et al. (220). Calibration data
reported by Smith et al. (217) for various sized ionization chambers is
shown in table 4. These same chambers were equipped with needle valves
and flowmeters and used to obtain and count integrated atmospheric samples
near the Nuclear Fuel Services plant by Cochran et al. (30). Cold trap-
ping of xenon and radon was required.
lonization -chambers may be used in the flow-through mode as well as
a static mode. This method was used in characterizing the ^Kr concen-
tration used in calibrating GM tubes to infinite cloud geometry (217).
Scintillation Counters: Gamma Scintillation Next to GM counting,
gamma scintillation counting using Nal(Tl) crystals is used most to assay
^5Kr. The 0.514 MeV gamma photon emitted in about 0.431 of the 85Kr dis-
integrations penetrates tissue or sample containers easily and can be
detected with the Nal(Tl) crystal. This has been the technique used in
most of the papers reporting whole-body or whole-organ saturation or
desaturation data and in laboratory analyses if the activity was high
enough. The technique avoids the sample self absorption problems encoun-
tered with GM counting and the preparation problems involved with most
of the following techniques. However, the low detection efficiency of
the Nal combined with the low gamma emission rate of the °%r results
in very low efficiency.
Beta Scintillation Both liquid and solid beta scintillation tech-
niques have been used with 8%r. Liquid scintillation has become an
increasingly popular method of counting 85j(r and takes advantage of the
high solubility of Kr in toluene based scintillation cocktails (44, 45,
221, 222). Very low specific activity samples may require concentration
by cryogenic techniques before counting. According to Shuping et al.
(44f 45), the lowest concentration that can be analyzed without precon-
centration is about 3 pCi/ml. Counting efficiency is 92-1001 and 0.014
pCi of °%r can be counted with good precision. The limiting problem
with air mixtures is the poor solubility of the air in the scintillator.
The undissolved air forms a pocket and part of the Kr goes out of solu-
tion into the air.
-------
24
TABLE 3. MINIMUM DETECTABLE 85KR CONCENTRATIONS FOR CALIBRATED
EXTERNAL p DETECTORS [after Smith et al. (217)]
Count Time
Background/Sample
Detector
Type (Model)
Laboratory MDC (pCi/on5) Field MDC (pCi/cm3)
Long Count3- Short Count^ Long Countc Short Count^
0.5/4 hr 10/10 min 0.5/4 hr 10/10 min
2 window pancake GM
(Eon 8008H)
1 window pancake GM
.007
.012
.020
.012
(Amperex 18546)
(Eon 8001T)
Cylindrical Probe
(LND 719)
(Eon 5108E)
p Scintillator
(Pilot B)
.011
.014
.011
.013
.016
.024
.025
.024
.024
.029
.042
.040
.043
.046
.045
.027
.025
.024
.028
.029
Notes on counting conditions:
(1) All values assume the MDC = 2s/Cor where s = the standard
deviation of the measurement (CPMJ and C0r = the calibration
*z o o
factor for the detector (CPM/ (pCi/cnv3)) .
(2) Total instrument errors are assumed to be negligible in each case
(3) The magnitude of the relative background variations (2syb/B,
where B = background CPM and sy^ = standard deviation due to
background level fluctuations) assumptions for the four count-
ing interval combinations used are denoted by the following:
Superscript
a
b
c
d
Relative background variations (2svbJ
4.8%
9.8%
27.4%
11.8%
(4) 0.3 pCi/cm3(MPC)a for individuals in the general population,
10CFR20 (19).
-------
25
TABLE 4. MINIMUM DETECTABLE CONCENTRATIONS FOR 85KR
IN IONIZATION CHAMBERS3>b
MDC «i>Kr MDC
Chamber volume Chamber Unshielded Chamber/2" Pb Shields
(liters) (pCi/cm3) (pCi/cm3)
0.5
1.0
2.8
4.3
1.3 x 10-1
1.9 x 10"1
3.9 x 10~2
3.9 x ID'2
1.5 x 10-1
1.5 x 10'1
3.1 x 10'2
2.3 x 10~2
aCary-Tolbert design (Applied Physics Corp.).
bAfter Smith et aX.(217).
An ingenious counting technique, reported by Sax et al. (2g3) for
environmental samples, employs cryogenic preconcentration by 5 A molecular
sieves at liquid nitrogen temperatures and counting tubes full of plastic
scintillator shavings. The shavings are outgassed under vacuum and the
concentrated sample is drawn into the tube by vacuum. The tubes are
reusable after outgassing.
Smith et al. (217) also tested Pilot B scintillator for uses similar
to those of CM tubes and found that it was less sensitive than the CM
detectors (see table 3).
A pressurized scintillation chamber is described by Voice (224).
Semi-conductor' Detectors: Semiconductor detectors of both the lith-
ium-drifted pi-n (108) and the silicon p-n (225) types have been used in
inert catheters for in vivo monitoring of 85}(r concentrations in the heart
and lungs.
Integrating Dosimeters: Thermoluminescent dosimeters and film badges
have both been used for monitoring 85](r (226) . The major drawback with
both is difficulty in characterizing the exposure as to radiation type and
energy to properly assess dose.
-------
26
CALIBRATION AND STANDARDIZATION
Krypton 85 gamma or beta calibration standards are available from
the National Bureau of Standards or other suppliers. Secondary 85Kr
standards can be prepared by comparison. Gamma calibration has been done
with 85Sr sources, an adequate procedure when only the 0.514 MeV photo-
peak is used. The Bremsstrahlung spectrum from S^Kr overwhelms the
Compton shelf at lower energies and precludes using °5Sr without a lower
discriminator. Also ^Au ^as been used as a counting standard (227) but
is not recommended. GM tubes were calibrated to measure 85Kr beta radi-
ation by immersion in a 204T1 soiution (228). Data comparing the response
to 8%r in air and calibration factors are given.
SAMPLING AND SAMPLE PREPARATION
The gaseous nature and relative chemical inertness of Kr preclude
using the normal concentration techniques of drawing air through a filter
or an activated charcoal cartridge at ambient temperature. With suffi-
cient specific activity, an appropriate sample container can be filled
and counted by any of the mentioned techniques, or a flow-through sampling
and counting technique can be used with ionization or proportional counters
For samples of very low specific activity such as those collected in the
environment at large, or samples containing other radioactive inert gases,
concentration and/or separation by cryogenic techniques are the usual pro-
cedures. Molecular sieves (223, 229), activated charcoal (227, 229, 230),
silica gel, vermiculite and alumina (229) have been successfully used as
collectors with liquid nitrogen cooling. Copper wool was used success-
fully in a LN2 cooled cold trap to collect Xe (231) and was suggested for
collection of Kr. Gas chromatography is becoming popular for analysis of
85Kr in the presence of other noble fission gases (220, 232-234). Direct
condensation in LN2 or LOX, followed by redistillation has been used suc-
cessfully (26, 64).
In theory, any of the separation techniques discussed under removing
85Kr from the air can be used. The ones not mentioned in this section
have practical drawbacks such as bulk or less than 100% recovery. All of
the adsorbing media have a finite capacity. The quantity of media used
and the operating temperature must be matched to the flow rate and the
sample size required, and the system must be tested in its designed ser-
vice before field use is attempted.
-------
27
SUMMARY
Krypton 85 is an environmental contaminant for which progress in
development of monitoring and control methodology appears to have out-
stripped knowledge and understanding of its biologic effects. Monitoring
methods presently available, while subject to improvement, are adequate
for routine use and several reasonable techniques for removing ^%r from
effluent gas streams have been demonstrated on at least pilot plant scale.
On the other hand, the value judgments regarding the necessity for and
stringency of control of release have been and are being based on calcu-
lations and extrapolations rather than on experimental data obtained with
living systems. Data on the effects of both acute and chronic exposure
of several animal species to ^~Kx are needed to confirm these extrapola-
tions .
Until the behavior and effects of radioactive noble gases in living
systems are better understood, the basis for release regulations will
continue to be founded entirely on radiation dose calculations. These
calculations should be subjected to the scrutiny of in vivo experimenta-
tion. In the interim, control of the major source of 85xr release, fuel
reprocessing plants, to the lowest practical emission level is desirable.
It may be appropriate, especially if the (MPC)a for unrestricted areas is
relaxed, to require these plants and any other major source that may
develop to control their release to levels much lower than necessary to
reach the (MFC)a at plant boundaries.
Relaxation of the occupational (MPC)a, albeit justifiable by cal-
culations, is subject to the same reservations. It appears more desirable
to grant exceptions or modifications in individual cases for variations
in exposure conditions, such as wearing of heavy clothing or absence of
an infinite cloud, than to change the standard at this time.
-------
29
REFERENCES
1. Chernick, C.L. The chemistry of the noble gases. United States
Atomic Energy Commission, Division of Technical Information, Library
of Congress Catalog Card Number: 67-62972, (1967).
2. Streng, A.G. and A.V. Grosse. Acid of krypton and its barium salt.
Science 143:242-243 (1964).
3. Featherstone, R.M. The molecular pharmacology of anesthesia. Fed.
Proc. 27:870-871 (1968).
4. Lindquist, K.O. and .W.S. Diethorn. Kinetics of rare gas release from
hydroquinone clathrates. Int. J. Appl. Radiat. Isot. 19:333-344
(1968) .
5. Balek, V. Radioactive inert gases tool for analysis. Anal. Chem.
42:16A-18; 20A; 22A-3; 25A-6; 28A; 30A-1 (August 1970).
6. Cullen, S.C. and E.G. Gross. The anesthetic properties of xenon in
animals and human beings, with additional observations on krypton.
Science 113:580-582 (1951).
7. Pauling, L. A molecular theory of general anesthesia. Science
134:15-21 (1961).
8. Featherstone, R.M. and C.A. Muehlbaecher. The current role of inert
gases in the search for anesthesia mechanisms. Pharmacol. Rev.
15:97-121 (1962).
9. Nussbaum, E. Radon solubility in body tissues and in fatty acids.
Ph.D. Thesis, University of Rochester, Dept. of Radiation Biology
(1957).
10. Cryogenic Reference Data. Union Carbide Corp., Linde Division (1967).
11. Radiological Health Handbook (Rev,). Bureau of Radiological Health
and the Training Institute, Environmental Control Administration,
U.S. Dept. of Health, Education and Welfare, Public Health Service,
Consumer Protection and Environmental Health Service, Rockville,
Md. 20852 (January 1970).
12. National Bureau of Standards. Certificate (Provisional), Standard
Reference Material 4235, Radioactivity Standards Krypton-85.
Washington, D.C. 20234, (October 1969).
13. Coleman, J.R. and R. Liberace. Nuclear power production and estimated
krypton-85 levels. Radiol. Health Data Rep. 7:615-621 (1966).
14. Katcoff, S. Fission-product yields from neutron-induced fusion.
Nucleonics 18:203 (November 1960).
-------
30
15. Katcoff, S. and W. Rubinson. Yields of ^5Kr in thermal neutron fis-
sion of 235U and 239pu. j. inorg. Nucl. Chem. 27:1447-50 (July 1965).
16. Meek, M.E. and B.F. Rider. Summary of fission product yields for
U-235, U-238, Pu-239, and Pu-241 at thermal, fission spectrum and
14 MeV neutron energies. APED-5398-A, General Electric Co. (Oct.
1968).
17. Burris, L.J. and I.G. Dillon. Estimation of fission product spectra
in discharged fuel from fast reactors. ANL-5742, U.S. AEG, Washington,
D.C. 20545 (July 1957).
18. Weaver, C.L. and E.D. Harward. Surveillance of nuclear power reactors.
Public Health Rep. 82(10) :899-912 October 1967).
19. Standards for Protection Against Radiation. 10 CFR 20.
20. National Committee on Radiation Protection, Recommendations "Maximum
Permissible Body Burdens and Maximum Permissible Concentrations o£
Radionuclides in Air and in Water for Occupational Exposure."
National Bureau of Standards, Handbook 69 (1959).
21. International Commission on Radiological Protection, Recommendations.
"Report of Committee II on Permissible Dose for Internal Radiation
(1959)." Pergamon Press, (1960).
» .
22. Loevinger, R., E.M. Japha and G.L. Brownell. "Discrete Radioisotope
Sources." in Radiation Dosimetry, G.J. Hine and G.L. Brownell, Ed.
Academic Press, New York (1956). Chapt. 16, pp. 693-799.
23. Goussev, N.G., O.A. Kochetkov, L.M. Mikhailov, A.D. Tourkin, E.G.
Trukhmanova and V.P. Filipovitch. Contribution to the setting up
of standards for inert radioactive gases. Health Phys. 12:1836
(1966). (Abstract of paper given at 1st IRPA meeting-1966).
24. Dunster, H.J., and B.F. Warner. The disposal of noble gas fission
products from the reprocessing of nuclear fuel. U.K. Atomic Energy
Authority, Authority Health and Safety Branch Report. AHSB(RP)R
101, Conf. 691039-1 (1970).
25. Ehhalt, D., K.O Munnich, W. Roether, J. Scholch and W. Stich.
Krypton-85 in the atmosphere. Proc. 3rd Int. Conf. Peaceful Uses
Atomic Energy. Vol. 14 pp. 45-47 (1964).
26. Kigoshi, K. Krypton-85 in the atmosphere. Bull. Chem. Soc. Japan
35:1014-1016 (1962).
27. Logsdon, J.E. and R.I. Chissler. Radioactive waste discharges to
the environment from nuclear power facilities. BRH/DER 70-2
Division of Environmental Radiation, HIS, BRH, Rockville, Md. 20852
(March 1970).
-------
31
28. Kahn, B., R.L. Blanchard, H.L. Krieger, H.E. Kolde, D.B. Smith, A.
Martin, S. Gold, W.J. Averett, W.L. Brinck, and G.J. Karches. Radio-
logical surveillance studies at a boiling water nuclear power reactor.
BRH/DER 70-1. EHS, BRH, Radiological Engineering Laboratory, Divi-
son o£ Environmental Radiation, 5555 Ridge Avenue, Cincinnati, Ohio
45213 (March 1970).
29. Goode, J.H. The release of tritium and krypton-85 to the atmosphere
during processing of Th02-U0? reactor fuel. Trans. Am. Nucl. Soc.
9:21-22 (June 1966).
30. Cochran, J.A., D.G. Smith, P.J. Magno and B. Shleien. An investi-
gation of airborne radioactive effluent from an operating nuclear
fuel reprocessing plant. BRH/NERHL 70-3. EHS, BRH, Northeastern
Radiological Health Laboratory, 109 Holton Street, Winchester, Mass.
01890 (July 1970).
31. Smith, C.F. and F.F. Momyer. Studies of chemical and radiochemical
composition of natural gas from the cavity produced by the Project
Gasbuggy nuclear shot. Radiol. Health Data Rep. 10:281-288 (July
1969) .
32. Smith, C.F. Gas quality analysis and evaluation program for Project
Gasbuggy. UCRL-72153, Lawrence Radiation Laboratory, University of
California, Livermore, (December 19, 1969).
33. Jacobs, D.G. and M.J. Kelly. Fifth quarterly progress report on the
theoretical evaluation of consumer products from nuclearly stimulated
gas wells. ORNL-TM-2862, Oak Ridge National Laboratory (Feb. 1970),
AEC Contract W-7405-eng-26.
34. Jacobs, D.G., M.J. Kelly, K.E. Cowser, S.V. Kaye, P.S. Rohwer, E.G.
Struxness and W.S. Snyder. Dose estimation related to peaceful uses
of nuclear explosives. In:ORNL-4446, Health Physics Division Annual
Progress Report for Period Ending July 31, 1969. Oak Ridge National
Laboratory (Oct. 1969), pp. 26-39, AEC Contract W-7405-eng-26.
35. Smith, C.F. Jr. Project Gasbuggy gas quality analysis and evaluation
program tabulation of radiochemical and chemical analytical results.
UCRL-50635, Lawrence Radiation Laboratory, Univ. of California, Liver-
more, (17 Nov. 1969).
36. Sax, N.I., R.R. Reeves and J.D. Denny. Surveillance for krypton-85 in
the atmosphere. Radiol. Health Data Rep. 10:99-101 (March 1969).
37. Delibrias, G. and C. Jehanno. Activite de 1'atmosphere due au krypton
85 (activity of the atmosphere caused by krypton-85). Bull. Inform.
Sci. Tech (Paris) 30:14-15 (1959).
-------
32
38. Csongor, E. Radioactivity of the atmosphere. Fiz. Szemle 20:36-41
(1970). Abstract NSA 24-27244 (July 31, 1970).
39. Bannetier, R. Original use of the radioactive tracer gas krypton-85
to study the meridian atmospheric flow. J. Geophys. Res. 75:2985-2989
(May 20, 1970).
40. Haines, A.E. Isotopic studies of atmospheric methane, ethane and
krypton. TID 25284, Arkansas University, Fayetteville (1968), Con-
tract AT(40-1)-3192.
41. Shearer, E.G. Relationships among atmospheric formaldehyde, methane
and krypton. TID-25286, Arkansas University, Fayetteville (1969).
42. Steinberg, M. and B. Manowitz. Recovery of fission product noble
gases. Ind. Eng. Chem. 51(1):47-50 (January 1959).
43. Ostroski, K.W. and K. Jelen. On the contamination of atmospheric
krypton by °%r from fission products. Nukleonika 10:61-62 (1965).
44. Shuping, R.E., C.R. Phillips and A.A. Moghissi. Low-level counting
of environmental krypton-85 by liquid scintillation. SERHL 69-09,
BRH Southeastern Radiological Health Laboratory, P.O. Box 61,
Montgomery, Alabama 36101 (1969).
45. Shuping, R.E., C.R. Phillips and A.A. Moghissi. Low-level counting
of environmental krypton-85 by liquid scintillation. Anal. Chem.
41:2082-2083 (Dec. 1969).
46. Cowser, K.E., J. Tadmor, D.G. Jacobs, F.L. Parker, W.J. Boegley,
G.H. Llewellyn and D.A. Dyslin. Engineering, economic and safety
evaluations. In: ORNL 4168. Health Physics Division annual
progress report for period ending July 31, 1967, Oak Ridge National
Laboratory. (Oct. 1967) pp. 39-48.
47. Cows«r, K.E., J. Tadmor, D.G. Jacobs and W.J, Bpegley, Jr Evalua-
tion of environmental hazards from release of 85Kr and % in an
^^?ing ™clear fuel reprocessing industry. Health Phys. 13:943
(1967). (Abstract of paper at 13th Health Physics Society meeting).
48. Lasseart, A.H. and C. Kellershohn. Spark chambers in nuclear
medicine. Nucleonics 24:56 (March 1966).
49. Federal Radiation Council. Report No. 4. "Estimates and Evaluation
2a" °(1963) Unlted StateS fr°m NuClear WeaP°ns Testing through
-------
33
50. Whipple, G.H. Approaches to the calculation of limitations of
nuclear detonations for peaceful purposes. In: Proceedings for
the Symposium on Public Health Aspects of Peaceful Uses of Nuclear
Explosives, April 7-11, 1969. SWRHL-82, CPEHS, EGA, BRH, South-
western Radiological Health Laboratory, Las Vegas, Nevada. (1970).
pp. 684-696.
51. Shleien, B. An estimate of radiation doses received by individuals
living in the vicinity of a nuclear fuel reprocessing plant in 1968.
BRH/NERHL 70-1. EHS, BRH, Northeastern Radiological Health Labor-
atory, 109 Holton Street, Winchester, Mass. 01890 (May 1970).
52. Blomeke, J.O. and J.J. Perona. Management of noble-gas fission-
product wastes from reprocessing spent fuels. ORNL-1M-2677,
Chemical Technology Div., Oak Ridge National Laboratory (21 Nov.1969)
Contract W-7405-eng-26.
53. Perona, J.J., J.O. Blomeke and W.C.T. Stoddart. Management of noble-
gas fission product wastes from reprocessing spent fuels. Trans.
Am. Nucl. Soc. 12:449-50 (Nov. 1969).
54. Zindler, H. Some problems of the discharge of radioactive gases and
aerosols from nuclear installations into the atmosphere. SZS-16/69
Staatliche Zentrale fuer Strahlenschutz, Berlin (East Germany)
(December 1969) Abstract-NSA 24-25252 (July 15, 1970).
55. Steinberg, M. and B. Manowitz. An absorption process for recovery of
fission product noble gases. BNL 493 (T-115), Brookhaven National
Laboratory (Feb. 1958).
56. Mclllroy, R.W., E. Glueckauf, H. J. de Nordwall and F.C.W. Pummery.
The recovery of radiokrypton from dissolved waste gases by fractional
extraction into solvents. Pvoc. 2nd Int. Conf. Peaceful Uses of
Atomic Energy. Vol. 18, United Nations, Geneva (1958) pp. 190-199.
57. Glueckauf, E. Long-term aspect of fission product disposal. In: Proc.
1st Int. Conf. Peaceful Uses of Atomic Energy, Geneva 1966, Vol. 9,
p. 3, United Nations, New York (1956).
58. Werner, L. Dynamic behavior of gaseous fission products in charcoal
adsorber columns. DP-Report-290, Project Dragon, Atomic Energy
Establishment, Winfrith, England (March 1965).
59. Kovach, J.L. Krypton-xenon adsorption on NACAR carbons. NACAR 010004,
Research and Development Dept., North American Carbon, Inc., Columbus,
Ohio. (December 28, 1969).
60. Underbill, D.W. An experimental analysis of fission-gas holdup beds,
Nucl. Applic. Technol. 8:255-260 (March 1970).
-------
34
61. Thorny, A. and X. Duval. Adsorption of simple molecules on graphite.
II. Variation of the adsorption potential as a function of the number
of adsorbed layers. J. Chim. Phys. 67:286-90 (Feb. 1970). Abstract
NSA 24-36976 (September 30, 1970).
62. Anonymous. Inexpensive, effective radioactive-gas trapper. Air and
Water News (October 19, 1970).
63. Merriman, J.R., J.H. Pashley and S.H. Smiley. Engineering develop-
ment of an absorption process for the concentration and collection
of krypton and xenon. Summary of progress through July 1, 1967.
Rept. K-1725. Oak Ridge Gaseous Diffusion Plant (Dec. 1967). Con-
tract W-7405-eng-26.
64. Merriman, J.R. and J.H. Pashley. Engineering development of an
absorption process for the concentration and collection of krypton
and xenon. Fourth summary progress report, July through December
1968. Rept. K-1786, Oak Ridge Gaseous Diffusion Plant. (April 1,
1970). Contract W-7405-eng-26.
65. Bendixsen, C.L., G.F. Offutt, and B.R. Wheeler. Rare-gas recovery
facility at the ICPP. Trans. Am. Nucl. Soc. 12:497-498 (Nov. 1969).
66. Stern, S.A. Separation of krypton and xenon from reactor atmospheres
by selective permeation. NYO-4057-1, Department of Chemical Engi-
neering and Metallurgy, Syracuse University (1969). Contract AT
(30-1)-4057.
67. Ferguson, D.E., K.B. Brown, R.G. Wymer, R.E. Blanco, M.E. Whatley,
H.E. Goeller and R.E. Brookshank. Annual Progress Report for period
ending May 31, 1969. ORNL-4422. Chemical Technology Division, Oak
Ridge National Laboratory, October 1969. Part 4. Waste Treatment
and Disposal.
68. Clark, W.E. and R.E. Blanco. Encapsulation of noble fission product
gases in solid media prior to transportation and storage. ORNL-4473.
Oak Ridge National Laboratory, (Feb. 1970). Contract W-7405-eng-26.
69. Reist, P.C. The disposal of radioactive krypton-85 in porous media.
NYO 841-7, D. Sc. Thesis Harvard University (October 29, 1965).
70. Reist, P.C. Steady-state measurement of krypton-85-air diffusion
coefficients in porous media. Environ. Sci. Technol. 1:566-569
(1967) .
71. Davidsson, D., I. Maclntyre, A. Rapaport and J.E.S. Bradley. Deter-
mination of total fat in vivo using ^5Kr. Biochem. J. 62:34 (1956).
72. Lesser, G.T. and G. Zak. Measurement of total body fat in man by
the simultaneous absorption of two inert gases. Ann. N.Y. Acad. Sci.
110:40-54 (1963).
-------
35
73. Hytten, F.E. Measurement of the total body fat in man with
Proc. Nutr. Soc. 23:xxi (1964).
74. Hytten, F.E., K. Taylor, and N. Taggart. Measurement of total body
fat in man. Clin. Sci. 31 (1):111-119 (1966).
75. Lesser, G.T., W. Perl, and J.M. Steele. Determination of total body
fat by absorption of an inert gas; measurements and results in normal
human subjects. J. Clin. Invest. 39:1791-1806 (1960).
76. Kety, S.S. The theory and applications of the exchange of inert gas
at the lungs and tissues. Pharmacol. Rev. 3:1-41 (1951).
77. Kety, S.S. Theory of blood-tissue exchange and its application to
measurement of blood flow. Methods Med. Res. 8:223-227 (1960).
78. Sanders, R.J. and R.C. Sullivan. A method for continuous blood flow
measurements using krypton-85. Surg. Forum 13:132-133 (1962).
79. Sanders, R.J. and R.C. Sullivan. Continuous regional blood flow
determinations with radioactive krypton-85. J. Surg. Res. 3:185-188
(1963).
80. Hutten, H. The influence of diffusion of inert gases on the deter-
mination of blood flow by the clearance method. Scand. J. Clin. Lab.
Invest. 22:Suppl. 102:II-c (1968).
81. Zierler, K.L. Basic aspects of kinetic theory as applied to tracer-
distribution studies. In: Dynamic Clinical Studies with Radioisotopes
R.M. Kniseley and W.N. Tauxe, Ed., U.S. AEC, Div. of Technical Infor-
mation. (June 1964) pp. 55-79.
82. Zierler, K.L. Equations for measuring blood flow by external monitor-
ing of radioisotopes. Circ. Res. 16:309-321 (1965).
83. Wagner, H.N., Jr. Regional blood-flow measurements with krypton-85
and xenon-133. In: Dynamic Clinical Studies with Radioisotopes.
R.M. Kniseley and W.N. Tauxe, Ed., U.S. AEC, Div. of Technical Infor-
mation. (June 1964) pp. 189-212.
84. Robertson, J.S. Theory and use of tracers in determining transfer
rates in biological systems. Physiol. Rev. 37:133-153 (April 1957).
85. Rees, J.R. Radio-Isotopes and regional blood flow. Br. Heart J.
32:137-41 (March 1970).
86. Harper, A.M. Measurement of blood flow through organs and tissues
with inert gases. Ann. R. Coll. Surg. Eng. 46:126-127 (March 1970).
-------
36
87. Ingvar, D.H. and N.A. Lassen. Regional blood flow of the cerebral
cortex determined by krypton^. Acta. Physiol. Scand. 54:325-338
(1962).
88. McHenry, L.C., Jr. Quantitative cerebral blood flow determination.
Application of a krypton-85 desaturation technique in man. Neurology
14:785-793 (1964).
89. Alexander, S.C., H. Wollman, P.J. Cohen, P.E. Chase, E. Melman, and
M. Behar. Krypton 85 and nitrous oxide uptake of the human brain
during anesthesia. Anesthesiology 25:37-42 (1964).
90. Lassen, N.A. Blood flow of the cerebral cortex calculated from
"-'krypton beta-clearance recorded over the exposed surface; evidence
of inhomogeneity of flow. Acta. Neurol. Scand 41:Suppl 14:24-28
(1965) .
91. Nilsson, N.J. Observations on the clearance rate of p radiation
from krypton"^ dissolved in saline and injected in microliter
amounts into the grey and white matter of the brain. Acta. Neurol.
Scand. 41:Suppl. 14:53-57 (1965).
92. Lassen, N.A. and A. Klee. Cerebral blood flow determined by satura-
tion and desaturation with krypton . an evaluation of the validity
of the inert gas method of Kety and Schmidt. Circ. Res. 16:26-32
(1965) .
93. Ingvar, D.H., S. Cronquist, R. Ekberg, J. Riseberg and K. Hoedt-
Rasmussen. Normal values of regional cerebral blood flow in man,
including flow and weight estimates of gray and white matter. Acta.
Neurol. Scand. 41:Suppl. 14:72-78 (1965).
94. Kety, S.S. Measurement of local circulation within the brain by
means of inert, diffusible tracers; examination of the theory,
assumptions and possible sources of error. Acta. Neurol. Scand.
41:Suppl 14:20-23 (1965).
95. Haggendal, E., and B. Johansson. Effects of arterial carbon dioxide
tension and oxygen saturation on cerebral blood flow autoregulation
in dogs. Acta. Physiol. Scan. 66:Suppl. 258:27-53 (1965).
96. Haggendal, E. Effects of some vasoactive drugs on the vessels of
cerebral gray matter in the dog. Acta. Physiol. Scand. 66: Suppl.
258:55-79 (1965).
97. Kety, S.S., W.L. Landau, W.H. Freygang, Jr. L.P. Rowland, and L.
Sokoloff. Estimation of regional circulation in the brain by
uptake of an inert gas. Fed. Proc. 14:85 (1955).
-------
37
98. Lewis, B.M., L. Sokoloff, W.B. Wentz, R.L. Wechsler, and S.S. Kety.
Determination of cerebral blood flow using radioactive krypton. Fed.
Proc. 14:92 (1955).
99. Lassen, N.A. and 0. Munck. The cerebral blood flow in man determined
by the use of radioactive krypton. Acta. Physiol. Scand. 33:30-49
(1955) .
100. Lassen, N.A. and 0. Munck. Cerebral blood flow in arteriovenous
anomalies of the brain determined by the use of radioactive krypton-85.
Acta. Physchiat. Neurol. Scand. 31:71-80 (1956).
101. Albert, S.N., C.A. Albert and J.F. Fazekas. A rapid and simple method
for measuring the rate of cerebral blood flow in humans with krypton"
J. Lab. Clin. Med. 56:473-482 (1960).
102. Glass, H.I., A.M. Harper and M.M. Glover. The measurement of local
cortical blood flow in the brain by the analysis of the clearance
curve of krypton-85. Phys. Med. Biol. 6:65-71 (1961).
103. Harper, A.M., H.I. Glass and M.M. Glover. Measurement of blood flow
in the cerebral cortex of dogs by the clearance of krypton-85. Scott.
Med. J. 6:12-17 (1961).
104. Lassen, N.A. and D.H. Ingvar. The blood flow of the cerebral cortex
determined by radioactive krypton. Experientia 17:42-3 (15 Jan 1961).
105. Ingvar, D.H. and N.A. Lassen. Quantitative determination of regional
cerebral blood flow in man. Lancet 2:806-807 (1961).
106. Haggendal, E., N.J. Nilsson, and B. Norback. On the components of
Kr55 clearance curves from the brain of the dog. Acta. Physiol.
Scand. 66:Suppl 258:5-25.
107. Hoedt-Rasmussen, K. Regional cerebral blood flow in man measured
externally following intra-arterial administration of ^%r or 133xe
dissolved in saline. Acta. Neurol. Scand. 41:Suppl. 14:65-68 (1965).
108. Appelgren, K.L., D.H. Lewis and E. Haggendal. A solid state needle
detector for the determination of regional blood flow in the brain
and the kidney by the Kr-85 clearance method. Scand. J. Clin. Lab.
Invest. 17:511-512 (1965).
109. Fieschi, C., A. Agnoli, N. Battistini and L. Bozzao. Relationships
between cerebral transit time of nondiffusible indicators and
cerebral blood flow. A comparative study with krypton-85 and radio-
albumin. Experientia 22:189-190 (1966).
110. Fieschi, C., A. Agnoli, N. Battistini and L. Bozzao. Mean transit
time of a nondiffusible indicator as an index of regional cerebral
blood flow. Trans. Am. Neurol. Assoc. 91:224-226 (1966).
-------
38
111. Brock, M., D.H. Ingvar, and C.W. Sem Jacobsen. Regional blood
flow in deep structures of the brain measured in acute cat experi-
ments by means of a new beta-sensitive semiconductor needle detector.
Exp. Brain. Res. 4:126-137 (1967).
112. Michenfelder, J.D., J.M. Messick, Jr. and R.A. Theye. Simultaneous
cerebral blood flow measured by direct and indirect methods. J.
Surg. Res. 8:475-481 (October 1968).
113. Wollman, H., S.C. Alexander, P.J. Cohen, G.W. Stephen and L.S.
Zeigler. Two-compartment analysis of the blood flow in the human
brain. Acta. Neurol. Scand. 41:Suppl 14:79-82 (1965).
114. Sokoloff, L. Cerebral blood flow measured with radioisotopes. In:
Dynamic Clinical Studies with Radioisotopes. R.M. Kniseley and
W.N. Tauxe, Ed. U.S. AEC, Div. of Technical Information. (June 1964)
pp. 153-169.
115. Saito, H. Radioisotopic diagnostics. Rinsho Byori 17:781-89
(October 1969). Abstract NSA 24-27629 (July 31, 1970).
116. Lewis, B.M., L. Sokoloff, R.L. Wechsler, W.B. Wentz, and S.S. Kety.
A method for the continuous measurement of cerebral blood flow in
man by means of radioactive krypton (Kr'7^). J. Clin. Invest 39:
707-716 (1960).
117. Haggendal, E., D.H. Ingvar, N.A. Lassen, J. Nilsson, G. Norlen,
I. Wickbom and N. Zwetnow. Pre- and postoperative measurements
of regional cerebral blood flow in three cases of intracranial
arteriovenous aneurysms. J. Neurosurg. 22:1-6 (1965).
118. Lassen, N.A., K. Hoedt-Rasmussen, S.C. Sorensen, E. Skinhoj , S.
Cronquist, B. Bodforss, and D.H. Ingvar. Regional cerebral blood
flow in man determined by krypton85. Neurology 13:719-727 (1963).
119. Glass, H.I. and A.M. Harper. The measurement of the partition
coefficient of krypton between the brain cortex and blood by a
double isotope method. Phys. Med. Biol. 7:335-339 (1962).
120. Chidsey, C.A. Ill, H.W. Fritts, Jr., A. Hardewig, D.W. Richards,
and A. Cournand. Fate of radioactive krypton (Kr-85) introduced
intravenously in man. J. Appl. Physiol. 14:63-66 (1959).
121. Cornell, W.P., E. Braunwald and E.G. Brockenbrough. Use of krypton85
for the measurement of cardiac output by the single-injection indi-
cator dilution technique. Circ. Res. 9:984-988 (1961).
122. Rochester, D.F., J. Durand, J.O. Parker, H.W. Fritts, Jr. and R.M.
Harvey. Estimation of right ventricular output in man using radio-
active krypton (Kr85). J. Clin. Invest. 40:643-648 (1961).
-------
39
123. Markason, C.R., H. Smulyan, J.F. Keighley, R.P. Cuddy and R.H. Eich.
Estimation of pulmonary blood flow with the use of krypton8^. J.
Lab. Clin. Med. 60:714-722 (1962).
124. Sanders, R.J and R.G. Sullivan. Cardiac output determination with
radioactive "krypton. J. Surg. Res. 8:522-527 (November 1968).
125. Prys-Roberts, C. The measurement of cardiac output. Br. J. Anesth.
41:751-60 (Sept. 1969) .
126. Hansen, A.T., B.F. Haxholdt, E. Husfeldt, N.A. Lassen,. 0. Munck,
H.R. Sorensen and K. Winkler. Measurement of coronary blood flow
and cardiac efficiency in hypothermia by use of radioactive kryp-
ton-85. Scand. J. Clin. Lab. Invest. 8:182-188 (1956).
127. Herd, J.A., M. Hollenberg, G.D. Thorburn, H.H. Kopald and A.C.
Barger. Myocardial blood flow determined with krypton-85 in unan-
esthetized dogs. Am. J. Physiol. 203:122-124(1962)
128. Cohen, L.S., W.C. Elliott and R. Goblin. Measurement of mycardial
blood flow using krypton-85. Am. J. Physiol. 206:997-999 (1964).
129. Johansson, B., E. Linder and T. Seeman. Collateral blood flow in
the myocardium of dogs measured with krypton-85. Acta. Physiol.
Scand. 62:263-270 (1964).
130. Ross, R.S., K. Ueda, P.R. Lichtlen and J.R. Rees. Measurement of
myocardial blood flow in animals and man by selective injection
of radioactive inert gas into the coronary arteries. Circ. Res.
15:28-41 (1964).
131. Linder, E. Measurements of normal and collateral coronary blood
flow by close-arterial and intramyocardial injection of krypton-85
and xenon-133. Acta. Physiol. Scand. 68:Suppl 272:5-31 (1966).
132. Norman, J.C., V.H. Covelli and S. Aronow. Krypton-85 and xenon-133
myocardial flow measurements in chronically cannulated internal
mammary transplants. Surg. Forum 18:110-111 (1967).
133. Briscoe, W.A., A. Hardewig, G. Emmanuel, P. Gurtner, D. Rochester
and A. Cournand. The distribution of blood perfusion to the lung
in emphysema. Fed. Proc. 18:59 (1959).
134. Gurtner, H.P-, W.A. Briscoe and A. Cournand. Studies of the venti-
lation-perfusion relationships in the lungs of subjects with chronic
pulmonary emphysema following a single intravenous injection of
radioactive krypton (Kr-85). I. Presentation and validation of
a theoretical model. J. Clin. Invest. 39:1080-1090 (1960).
135. Arborelius, M. Jr. Kr8^ in the study of pulmonary circulation
during bronchospirometry. Scand. J. Clin. Lab. Invest. 17:253-256
(1965).
-------
40
136. Arborelius, M. Jr. Kr^ in the study of pulmonary circulation and
ventilation during unilateral hypoxia. Scand. J. Resp. Dis. Suppl.
62:105-111 (1966).
137. Rochester, D.F., R.A. Brown, Jr., W.A. Wichern, Jr., and H.W. Fritts,
Jr. Comparison of alveolar and arterial concentrations of °%r and
133xe infused intravenously in man. J. Appl. Physiol. 22:423-430
(March 1967).
138. Cellerino, A.F., A. Gaetini, F. Rosso and C. Banaudi. Uneveness of
blood and air distribution to the lungs studied by a combined radio-
krypton and helium method. J. Nucl. Biol. Med. 11:32-39 (1967).
139. Mellemgaard, K. The alveolar-arterial oxygen difference in chronic
obstructive lung disease. Scand. J. Resp. Dis. 48:23-39 (1967).
140. Ranson-Bitker, B., M. Leroy Ladurie and J. Durand. Measurement of
blood flow distribution of the right and left lungs by bronchospiro-
metry and excretion of a radioactive isotope of krypton (Kr^S),
Respiration 25:395-404 (1968).
141. Brun, C., C. Crone, H.G. Davidson, J. Fabricus, A.T. Hansen, N.A.
Lassen and 0. Munck. Renal blood flow in anuric human subject
determined by use of radioactive krypton-85. Proc. Soc. Exp. Biol.
Med. 89:687-690 (1955).
142. Thorburn, G.D., H.H. Kopald, J.A. Herd, M. Hollenberg, C.C.C.
O'Morchoe and A.C. Barger. Intrarenal distribution of nutrient
blood flow determined with krypton-85 in the unanesthetized dog.
Circ. Res. 13:290-307 (1963).
143. Bell, G., and A.M. Harper. Measurement of local blood flow in the
renal cortex from the clearance of krypton-85. J. Surg. Res.
5:382-386 (1965).
144. Cosgrove, M.D. The effect of arterial hypoxia on the blood-flow
through the renal cortex. Br. J. Surg. 52:613-617 (1965).
145. Ladefoged, J. and F. Pedersen. Renal blood flow in isolated
kidneys measured with an electromagnetic flowmeter and by xenon-133
and krypton-85 wash-out techniques. Pfluegers Arch. 299:30-37 (1968).
146. MacDonald, A.G. The effect of halothane on renal cortical blood
flow in normotensive and hypotensive dogs. Br. J. Anaesth. 41:644-
655 (1969).
147. Bell, G. and A.M. Harper. Measurement of regional blood flow
through the skin from the clearance of Kr85. Nature (London)
202:704-705 (May 1964).
-------
41
148. Sejrsen, P. Diffusion processes invalidating the intra-arterial 85-
Kr beta particle clearance method for measurement of skin blood
flow in man. Circ. Res. 21:281-295 (1967).
149. Sejrsen, P. Cutaneous blood flow in man studied by freely diffusible
radioactive indicators. Scand. J. Clin. Lab. Invest. 19:Suppl 99:
52-59 (1967).
150. Jansson, G., M. Kampp, 0. Lundgren and J. Martinson. Studies on
the circulation of the stomach. Acta. Physiol. Scand. 68:Suppl
277:91 (1966).
151. Bell, P.R.F. and T. Shelley. Gastric mucosal blood flow and acid
secretion in conscious animals measured by heat clearance. Am. J.
Dig. Dis. 13:685:696 (1968).
152. Bell, P.R.F., and C. Battersby. Effect of vasopressin (Pitressin)
on gastic mucosal blood flow measured by clearance of krypton .
Surgery 66:510-514 (September 1969).
153. Lundgren, 0. and M. Kampp. The washout of intraarterially injected
krypton" from the intestine of the cat. Experientia 22:268-270
(1966) .
154. Kampp, M., 0. Lundgren and J. Sjostrand. On the components of the
Kr^-" washout curves from the small intestine of the cat. Acta.
Physiol. Scand. 72:282-297 (1968).
155. Kampp, M., and 0. Lundgren. Blood flow and flow distribution in
the small intestine of the cat as analyzed by the Kr°~" wash-out
technique. Acta. Physiol. Scand. 72:282-297 (1968).
156. Hollenberg, M. and J. Dougherty. Liver blood flow measured by
portal venous and hepatic arterial routes with Kr° . Am. J. Physiol.
210:926-932 (1966).
157. Birtch, A.G., B.H. Casey, and R.M. Zakheim. Hepatic blood flow
measured by the krypton-85 clearance technique. Surgery 62:174-180
(July 1967).
158. Friedman, E., H.H. Kopald, and T.R. Smith. Retinal and choroidal
blood flow determined with krypton-85 in anesthetized animals.
Invest. Ophthalmol. 3:539-546 (1964).
159. Friedman, E. and T.R. Smith. Estimation of retinal blood flow in
animals. Invest. Ophthalmol. 4:1122-1128 (1965).
160. Holzman, G.B., H.N. Wagner, M. Ho, D. Rabinowitz and K.I. Zierler.
Measurement of muscle blood flow in the human forearm with radio-
active krypton and xenon. Circulation 30:27-34 (1964).
-------
42
161. Setchell, B.P., G.M.H. Waites and G.D. Thorburn. Blood flow in
the testis of the conscious ram measured with krypton85: effects
of heat, catecholamines and acetylcholine. Circ. Res. 18:755-765
(1966) .
162. Gump, F.E. and R.L. White. Determination of regional tumor blood
flow by krypton-85. Cancer 21:871-875 (May 1968).
163. Rosen, R.G., C.E. Silver, J.C. Dougherty and M.L. Som. The pattern
of rejection of dog laryngeal grafts. Surg. Forum 20:479-482 (1969).
164. Sanders, R.J. Use of a radioactive gas (Kr85) in diagnosis of
cardiac shunts. Proc. Soc. Exp. Biol. Med. 97:1-4 (1958).
165. Sanders, R.J. and A.G. Morrow. The localization of circulatory
shunts with inhaled krypton. A preliminary clinical report. Bull.
Johns Hopkins Hosp. 103:27-31 (1958).
166. Long, R.T.L. and W.P. Cornell. Experimental detection of left-to-
right circulatory shunts with injections of krypton . Soc. Exp.
Biol. Med. 101:836-838 (1959).
167. Sanders, R.J. and A.G. Morrow. The identification and quantifica-
tion of left-to-right circulatory shunts. Am. J. Med. 26:508-516
(1959).
168. Long, R.T.L., E. Braunwald and A.G. Morrow. Intracardiac injection
of radioactive krypton. Clinical applications of new methods for
characterization of circulatory shunts. Circulation 21:1126-1133
(1960).
169. Braunwald, E., A. Goldblatt, R.T.L. Long and A.G. Morrow. The
krypton85 inhalation test for the detection of left-to-right shunts.
Br. Heart J. 24:47-54 (1962).
170. Selzer, A., R.W. Popper and F. Mintz. Evaluation of left-to-right
cardiac shunts. J. Cardiovasc. Surg. 5:285-291 (1964)
171. Weitzman, D., J. McAlister and A. Houlder. Localization of left-to-
right shunts by radioactive krypton. Br. Heart J. 26:577-583 (1964).
172. Singleton, R.T., D.H. Dembo and L. Scherlis. Krypton-85 in the
detection of intracardiac left-to-right-shunts. Circulation 32:
134-137 (1965).
173. Bekheit, S., J.G. Murtagh, E. Fletcher and P.P. Binnion. Comparison
between oximetry and 85krypton studies in left-to-right cardiac
shunts. Ir. J. Med. Sci. 8:169-176 (1969).
-------
43
174. Long, R.T.L., J.A. Waldhausen, W.P. Cornell and R.J. Sanders.
Detection of right-to-left shunts: A new method utilizing injec-
tions of krypton85. Proc. Soc. Exp. Biol. Med. 102:456-458 (1959).
175. Fritts, H.W. Jr., A. Hardewig, D.F. Rochester, J. Durand and A.
Cournand. Estimation of pulmonary arteriovenous shunt-flow using
intravenous injections of T-1824 dye and Kr . J. Clin. Invest.
39:1841-1850 (1960).
176. Mellemgaard, K., N.A. Lassen and J. Georg. Right-to-left shunt
in normal man determined by the use of tritium and krypton-85.
J. Appl. Physiol. 17:778-782 (1962).
177. Zaky, H.A., A.R. El-Heneidy and M. Khalil. Use of krypton-85 in
the study of hypoxia in porto-pulmonary bilharziasis
(Shistosomiasis). Br. Med. J. 5389:1021-1024 (1964).
178. Cleempoel, H., P. Mercenier, R. Bernard, M. Lebedelle and J.
Lequime. The krypton-85 method in the detection of pulmonary
arterio-venous shunts. Cardiologia 51:55-63 (1967).
179. Sanders, R.J. and L.J. Hellerstein. The diagnosis of right-to-left
shunts with krypton-85. J. Surg. Res. 9:441-448 (July 1969).
180. Long, R.T.L., C.R. Lombardo and E. Braunwald. Use of radioactive
krypton and cardio-green dilution curves in the detection of
experimental portal-systemic venous shunts. Ann. Surg. 151:146-
152 (1960).
181. Cellerino, A.F. and R. Catolla-Cavalcanti. The slow radioactive
krypton method using a breath-by-breath counting system in measure-
ment of blood and gas distribution in separated lungs. Panminerva
Med. 7:427-433 (1965).
182. Byun, H.H., G. Albrecht, G.W. Holmes and R.S. Landauer. Pulmonary
function test using krypton-85. J. Nucl. Med. 4:345-358 (1963).
n83. West, J.B. The use of radioactive materials in the study of lung
function. Medical Monograph No. 1, Radiochemical Centre, Amersham
England (1967).
184. Dibdin, G.H. The internal surface and pore structure of teeth. J.
Dent. Res. 48:771-776 (Sept.-Oct. 1969).
185. Robert, L., B. Robert, J. Medema and J.P.W. Houtman, Surface areas
of elastin samples determined by krypton-85 adsorption. Biochim.
Biophys. Acta 214:235-237 (1970).
186. Geller, E.I., F.X. Worden, G. Cassidy, and C.Y. Bartholomew. Per-
sonnel protection program for industrial use of krypton-85. Am.
Ind. Hyg. Assoc. J. 22:403-408 (1961).
-------
44
187. Ellis, W.R. and B.W. Seatonberry. A radioisotope method for
locating points of entry of carbon monoxide into the cabin of an
aircraft. Int. J. Appl. Radiat. Isot. 17:81-84 (1966).
188. Tsivoglou, E.G., J.B. Cohen, S.D. Shearer and P.J. Godsil. Tracer
measurement of stream aeration. J. Water Pollut. Contr. Fed.
40:285-305.
189. Corn, M. and T.L. Montgomery. Atmospheric particulates: specific
surface areas and densities. Science 159:1350-1351 (1968).
190. Fries, B.A. Flow rate measurements of condensable gases by the
carrier-gas method. Int. J. Appl. Radiat. Isot. 19:39-42 (1968).
191. Robertson, J.B. Diffusion from a gaseous source in a porous medium
a field and theoretical investigation. U.S. Geol. Surv., Prof.
Pap. 650-0:265-273 (1969).
192. Martin, J.E. The correlation of wind tunnel and field measurements
of gas diffusion using krypton-85 as a tracer. Ph.D. Thesis, Univer-
sity of Michigan, 1965.
193. Martin, J.E. Methods of using 85j(r as a tracer to study gas emission
from nuclear facilities. Health Phys. 15:175 (Aug. 1968). Abstract
of paper given at 1968 Health Physics Society meeting.
194. Ludwick, J.D., J.J. Lashock, R.E. Connaly and P.W. Nickola. Automatic
real time air monitoring of ^5Kr utilizing the 4096 memory of a multi-
parameter analyzer. Rev. Sci. Instrum. 39:853-859 (June 1968).
195. Nikola, P.W., J.V. Ramsdell, Jr., and J.D. Ludwick. Detailed time-
histories of concentrations resulting from puff and short-period
releases of an inert radioactive gas: a volume of atmospheric dif-
fusion data. BNWL-1272. Battelle-Northwest, Richland, Wash. Pacific
Northwest Lab., (Feb. 1970). Contract AT-(45-1)-1830.
196. Nikola, P.W., J.V. Ramsdell and J.D. Ludwick. Real time histories
of diffusing plumes and puffs determined from use of an inert gas
tracer system. BNWL 1307 (pt. 1), pp. 6-10, Battelle-Northwest,
Richland, Wash. Pacific Northwest Lab. (1970).
197. Nikola, P.W. Measurements of the transport speed and physical dimen-
sions of a diffusing puff of a gaseous tracer in the atmosphere.
BNWL-1307 (pt. 1) pp. 10-14, Battelle-Northwest, Richland, Washington,
Pacific Northwest Lab. (1970).
198. Eddy, W.J. Jr. Evaluation of cracks in turbine-blade leading edge
by use of 85Kr gas. Isotop. Radiat. Technol. 7:277-285 (Spring 1970).
-------
45
199. Jech, C. An autoradiographic technique for observing channeled
penetration of low energy ions. Appl. Phys. Lett. 15:248-50
(Oct. 15, 1969).
200. Jech, C. and R. Kelly. Studies on bombardment -induced disorder.
II. Formation of ion-bombardment-induced disorder in zircon,
corundum, and diamond. J. Phys. Chem. Solids 31:41-8 (Jan. 1970).
Abstract NSA 24-21861 (June 15, 1970).
201. Lukac, P. Device for preparing radioactive kryptonates by ion
bombardment. Radiochem. Radioanal. Lett. 3:121-127 (12 March 1970)
Abstract NSA 24-21861 (June 15, 1970).
202. Toelgyessy, J. , V. Jesenak, and E. Koval. Possible uses of radio-
active kryptonates of silver in chemical analysis. J. Radioanal.
Chem. 4:13-19 (Jan. 1970) (In German) . Abstract NSA 24-16417,
May 15, 1970.
203. Hendrickson, M.M. The dose from Kr released to the earth's
atmosphere. BNWL-SA-3233A. Battelle Memorial Institute, Pacific
Northwest Laboratory, Richland, Washington 99352. (July 1970).
n r
204. Hendrickson, M.M. The eventual whole body exposure rate from Kr
released to the atmosphere. Battelle Memorial Institute, Pacific
Northwest Laboratory, Richland, Washington 99352. (July 13, 1970).
205. Russell, J.L. and F.L. Galpin. Estimated doses to the whole body
and to the lungs from radioactive noble gases using the MIRD
methodology. EPA, Office of Radiation Programs, Division of Techno-
logy Assessment, Rockville, Maryland 20852. (In draft - July 1971).
206. Lassen, N.A. Assessment of tissue radiation dose in clinical use
of radioactive inert gases , with examples of absorbed doses from
3H2, 85Kr and 133Xe. Minerva Nucleare 8:211-217 (Jul.-Aug. 1964).
207. ICRP Publication 9. Recommendations of the International Commission
on Radiological Protection (Adopted Sept. 17, 1965). Pergamon Press
(1966) .
208. Bucheit, R.G., H.R. Schreiner and G.F. Doebbler. Growth responses of
Neurospora erassa to increased partial pressures of the noble gases
and nitrogen. J. Bacteriol. 21:622-627 (1966).
209. Sears, D.F- and S.M. Gittleson. Cellular narcosis of Parameciwn
multimicronucleatim by xenon and other chemically inert gases. J.
Protozool. 11:538-546 (1964).
210. Gottlieb, S.F., A. Cymerman and A.V. Metz. Effect of xenon, krypton
and nitrous oxide on sodium active transport through frog skin with
additional observations on sciatic nerve conduction. Aerosp. Med.
39:449-453 (May 1968).
-------
46
211. Gottlieb, S.F. and J.M. Weatherly. Physiological effects of the
noble gases on frog sciatic nerve and gastrocnemius muscle. Am. J.
Physiol. 208:407-411, (1965).
212. Schreiner, H.R. General biological significance of metabolically
inert gases. Int. Anesthesiol. Clin. 1:919-926 (1963).
213. Evans, J.C., T.W. Roberts and L.R. Orkin. Modification of radio-
sensitivity of mice by inert gases and nitrous oxide. Radiat. Res.
21:243-255 (1964).
214. Markoe, A.M., R. Anigstein and R.J. Schulz. Effects of inert gases
and nitrous oxide on the radiation sensitivity of HeLa cells. Phys.
Med. Biol. 15:200 (Jan. 1970).
215. Schreiner, H.R. General biological effects of the helium-xenon
series of elements. Fed. Proc. 27:872-878 (1968).
216. Williams, K.D. A rapid determination of the specific activity of
krypton-85 in pressurized cylinders. J. Nucl. Med. 5:913-919 (1964).
217. Smith, D.G., J.A. Cochran and B. Shleien. Calibration and initial
field testing of ^Kr detectors for environmental monitoring around
a nuclear fuel reprocessing facility. BRH/NERHL 70-4, EHS, BRH,
Northeastern Radiological Health Laboratory, 109 Holton Street,
Winchester, Mass. 01890 (November 1970).
218. Anonymous. Continuous sampler monitor (CMS). Cape-1985, Idaho
Nuclear Corp., Idaho Falls (10 Sept. 1969). Abstract NSA 24-25169
(July 15, 1970).
219. Tolbert, B.M. lonization chamber assay of radioactive gases. UCRL
3499, University of California, Radiation Laboratory, Berkeley
California, (March 5, 1956).
220. Dupuis, M.C., G. Charrier, C. Alba and D. Massimino. Possibilities
of gas-phase radiochromatography application to permanent gas
analysis. CEA-R-3879. Commissariat a 1'Energie Atomique, Bruyeres-
le-Chatel (France) Centre d'Etudes. (Jan 1970) (French). Abstract
NSA 24-38744 (Oct. 15, 1970).
221. Horrocks, D.L. and M.H. Studier. Determination of radioactive noble
gases with a liquid scintillator. Anal. Chem. 36:2077-2079 (1964).
222. Curtis, M.L., S.L. Ness and L.L. Bentz. Simple technique for rapid
analysis of radioactive gases by liquid scintillation counting.
Anal. Chem. 38:636-637 (1966).
223. Sax, N.I., J.D. Denny and R.R. Reeves. Modified scintillation
counting technique for determination of low level krypton-85. Anal
Chem. 40:1915-1916 (1968).
-------
47
224. Voice, E.H. A low-level measurement of 85xr. DP-Report-109,
Project Dragon, Atomic Energy Establishment, Winfrith, England
(Aug. 1962).
225. Ueda, H., Y. Sasaki, M. lio, S. Kaihara and I. Ito. Catheter semi-
conductor radiation detector for continuous measurement of caridac
output. J. Nucl. Med. 10:713-721 (Dec. 1969).
226. Terrill, J.G. Jr., C.L. Weaver, E.D. Harward and D.R. Smith. Envi-
ronmental surveillance of nuclear facilities. Nucl. Safety 9:143-
149 (Mar.-Apr, 1968) .
227. Sheibley, D.W. A simple method for determination of fission gases
trapped in irradiated fuel forms. Anal. Chem. 42:142-3 (Jan. 1970).
228. P,§vis> M.A. and J. Shapiro. Calibration of a CM detector to measure
"Kr in air by immersion in a standardized 204ji solution. Health
Phys. 13:907-910 (1967).
229. Jennison, E. Fission gas collection and trace gas analysis. Progr.
Nucl. Energy, Ser. IX; 10:225-54 (1970).
230. Flygare, J.K., G. Wehmann, A.R. Harbertson and C.W. Sill. A method
for the collection and identification of radioactive xenon and
krypton. TID 7593, Health and Safety Division, AEC, Idaho Falls,
(Oct. 1960) p. 18-25.
231. Mantel, J., K.J. Cook and K.E. Corrigan. Radioactive krypton and
xenon trapping by cryogenic technics. Radiology 90:590-591 (1968).
232. Lengweiler, H. Experiments on separation procedure for krypton
and xenon in connection with pluto Loop radiochemical sampling.
DP-Report-89. Project Dragon, Atomic Energy Establishment, Winfrith,
England (Apr. 1962). Abstract NSA 24-36166 (Sept. 30, 1970).
233. Charrier, G. Separation and determination of krypton and xenon by
gas phase radiochromatography. CEA-R-3889, Commissariat a 1'Energie
Atomique,Bruyeres-le-Chatel (France). Centre d'Etudes. (March 1970)
Abstract NSA 24-26994, (July 31, 1970).
234. Aubeau, R., L. Champeix and (Mme) J. Reiss. Separation et dosage du
krypton et du xenon par chromatographie en phase gazeuse. Applica-
tion aux gaz de fussion. J. Chromatog. 6:209-219 (1961).
-------
49
APPENDIX A
ABSORPTION OF KR INTO THE BODY
I. SOLUBILITY OF 85KR IN VARIOUS MATERIALS: PARTITION COEFFICIENTS
(General references 1,2)
Gas solubility data in the literature are frequently expressed in
terras' of either the Bunsen solubility coefficient (a) or the Ostwald
solubility coefficient (L). In component units:
= Vo(aJ Po
Q V P
where: Vo(a) = volume of gas absorbed
V = volume of absorbing fluid
Po = 760 mm Hg
P = partial pressure of the gas being
absorbed in mm Hg
and L = a T/To
where: To = 273° K
T = 273° K + temperature at which gas is
absorbed in °C
The Ostwald coefficient, L, is also commonly called the partition
coefficient and is sometimes designated as A.. As commonly used, a parti-
tion coefficient will be written as A. medium l:medium 2 (example \ blood:
air) and is the ratio of the volume concentration in medium 1 to the
volume concentration in medium 2 at equilibrium. If A. blood:air = 0.06,
and the air concentration is 1 uCi/cm3, the blood concentration will be
3 x 0.06 = 0.06
The solubility of Kr has been determined in vitro, usually with
degassed solvents, for a number of solvents and solutions. These data
are summarized in Table A-l.
2. IN VIVO PARTITION COEFFICIENTS
The tissue:air partition coefficient (A, ) for an organ or system is
given by:
where: A tissue:air = I (A-:tissue:blood x £-.) A blood:air
A. = tissue:blood partition coefficient for component i
f. = the fraction of the organ or system made up of component i
-------
50
TABLE A-l. SOLUBILITY COEFFICIENTS FOR 85KR IN VARIOUS SOLVENTSa
Solvent
Olive oil
Water
Saline soln.
/8- albumin
Hemoglobin
soln. (15.4?
Blood
Muscle
homogenate
Brain
homogenate
Temp(oC)
45
37
30
25
22
45
45
37
30
25
22
45
37
30
25
37
30
25
37
^)
37
37
30
25
37
30
25
Bunsen Coefficient
0.3844
0.4031
0.43
0.44
0.4225
0.4376
0.44
0.0441
0.0441
0.0481
0.045 (37
0.0539
0.0581
0.059
0.0411
0.0444
0.0499
0.0542
0.0195
0.0412
0.0624
0.0247
0.0455
0.0439
0.0501
0.0549
0.0454
0.0517
0.0572
(ref)
(13)
(13)
(35)
(36)
(13)
(13)
(35)
(14)
(14)
(14)
,35)
(14)
(14)
(35)
(14)
(14)
(14)
(14)
(12)
(12)
(12)
(12)
(12)
(12)
(12)
(12)
(12)
(12)
(12)
Ostwald Coefficient
0.4477 (13)
0.4581 (13)
0.4688 (13)
0.4746 (13)
0.0499 (38)
0.0517 (12)
0.06 (39)
-------
51
Solvent Temp (UC)
Human fat
Dog fat
Rat fat
Toluene base
liquid scint.
cocktail
45
37
30
25
45
37
30
25
45
37
30
25
-15
Bunsen Coefficient (ref)
0.3878
0..3875
0.4071
0.4062
0.420
0.414
0.4258
0.4247
0.4412
0.4404
0.3853
0.4031
0.4225
0.4364
0.3847
0.4037
0.4219
0.4363
0.9
(13)
(13)
(13)
(13)
(36)
(36)
(13)
(13)
(13)
(13)
(13)
(13)
(13)
(13)
(13)
(13)
(13)
(13)
(40)
Ostwald Coefficient
0.4516
0.4513
0.4626
0.4617
0.425
0.4725
0.4713
0.4816
0.4807
0.4426
0.4581
0.4721
0.4764
0.4481
0.4588
0.4755
0.4762
(13)
(13)
(13)
(13)
(41)
(13)
(13)
(13)
(13)
(13)
(13)
(13)
(13)
(13)
(13)
(13)
(13)
aAddtional 85Kr solubility data in a wide variety of chemicals may be
found in references (2, 42-46).
-------
52
If the tissue components, their relative fractions, and their Ostwald
coefficients are known, the tissue:air coefficient can be calculated. In
practice this is rarely the case and the coefficient is either determined
for the tissue by a dual isotope method such as that of Glass and Harper
(3), or, in many cases, estimated to be the same as that for blood. A
partial listing of the experimentally determined tissue:air or tissue:
blood partition coefficients for ^^>Kr follows:
Part
Cortex
White
Cortex
Medulla
Tissue
Brain
Kidney
Fat
Liver
Eye Retina
Skeletal
muscle
Testis
Blood
Tissue:Blood
0.92 (Hc=50)
1.26 (Hc=50)
1.0
0.96
1.0
9
5
1.06
1.04
1.0
1.0
0.85
Tissue:Air
0.54
0.05-0.06
Reference
4,5
4,5
6
7
6
6
8
5
9
5
5
5
5,10
Various
Because the coefficients are so similar, Lassen (8), one of the pioneers
in this work, normally uses a tissue:air coefficient of 0.06 for all tis-
sues except fat for which he uses 0.54 (9 x 0.06). The only significant
variable, for most purposes, is the fat content of the tissue or body
being studied. Lassen (8) uses a whole-body tissue:air coefficient of
0.11 for lean people, 0.20 for normal weight people, and 0.30 for obese
people. The calculated coefficient for standard man is 0.163.
Whole-body partition coefficients and kinetic parameters for female
Rochester Wistar rats, weighing about 250 grams, were experimentally deter-
mined by saturating the animals with ^5^r in a closed exposure system for
12 1/2 or 33 1/2 hours, then whole-body counting in a 3- x 5-inch Nal well
crystal until the count reached background (about 12 hours). The average
seven determinations on four animals was 0.0921 (S. D. = 0.0188). The
coefficient for one animal that died during the 12 1/2 hour run, deter-
mined by counting component pieces, was 0.0958. The value predicted for
rats of 320 grams, using the tissue composition data of Caster, et aZ.(ll),
and the solubility data of Yeh and Peterson (12, 13, 14) was 0.076. Using
Lassen's coefficients (8) and the Caster fat fraction of 0.0708 of the
body weight, a value of 0.094 would be predicted.
-------
3. KINETICS OF 85KR ABSORPTION AND DESORPTION IN THE BODY
The rate of absorption of 85Kr into the tissues of the body during
exposure and desorption after exposure or Injection of the isotope is a
complex function of the tissue :blood partition coefficients and, partic-
ularly, the blood circulation in the tissue in question. The curves
obtained will have as many exponential components as there are differently
perfused elements in the tissue being studied. Kety (1) has discussed the
kinetics involved in detail. For a single tissue, with the concentration
in alveolar air considered constant and blood-tissue diffusion time con-
sidered negligible (actually less than 1 sec.), the following equations
apply:
Saturation: Ci = A-jC^l e~kt)
Desaturation: C-j_ = C- /• ^e'^t
where: C^ = concentration in tissue i at time t, yd/cm3
\i = tissue: air partition coefficient
C^ = concentration in air, yCi/cm^
k = F^/Vi where Fj_ = blood flow rate in tissue i, and V^ = volume
of tissue i
The quantity of gas in the tissue (q^) = ViCi or Qi = V^C^l e~kt)
in saturation. Q-; roo~) ~ VjA-C' . F°r the whole body, or a multiple compartment
tissue, Q - Q1(a0(l e-klt) + 0^(1 e^ + . . . ^^ (1 e-knt) in
saturation and similarly for desaturation:
Q = Qe~klt
Most investigators have found at least 2-4 components in their satu-
ration and desaturation curves with 8%r . The exceptions have been when a
GM counter was being used to count the beta emissions from a homogenous
surface layer thicker than the maximum beta range such as the cerebral
cortex or renal cortex. Wherever Nal detectors were used or heterogenous
tissues were counted, monoexponential curves were rarely found (15-32).
Experimental observations in dogs, cats, and humans (4, 6, 7, 10, 15-32)
indicate that there are three or four groups of similarly perfused tissues
that can be treated as compartments for purposes of whole -body analyses.
There is a fast component, with T 1/2 from 0.04-0.8 min, which may be due
to arterial blood content. Three slower compartments are usually seen with
average half times of about 2.5 minutes, 7.5 minutes, and 20-30 minutes
(range of 1-5, 5-10 and 11-180 minutes). Anything that changes blood flow
rate can radiaally change the observed compartmental half-times in satura-
tion or desaturation and can even cause an apparent change in the number
of compartments observed.
-------
54
Lesser and Zak (33) proposed a three-compartment parallel model con-
sisting of:
1. Rapidly perfused lean tissues such as the heart, brain,
kidneys, etc.
2. More slowly perfused lean tissues such as resting muscle,
skin, connective tissue, etc.
3. Adipose tissue.
While this is obviously an oversimplification, it will suffice for the
purpose of this discussion.
The relative contribution of the various compartments to the whole-
body burden at full saturation (Q-J is determined by the size of the com-
partment, V^, the tissue:air partition coefficient, A-, and the gas concen-
tration in air provided the factors are known. Hypothetical saturation
and desaturation curves for standard man are shown in Figure A-l.
Experimental saturation/desaturation data are usually plotted on
semilog paper and resolved into components graphically- Computer curve
stripping techniques have been reported (34).
Desaturation data obtained with female rats in the experiments pre-
viously mentioned were resolved by a stripping technique. The original
curve and three components for a rat saturated in an B^Kr mixture for
12 1/2 hours are shown in Figure A-2. The component half times were 3.75
minutes, 22.6 minutes, and 94.2 minutes and the corresponding fractions
of total activity were 0.248, 0.647 and 0.105. A second experiment,
using the same animal and saturation time of 33 1/2 hours, resulted in the
two-compartment curves shown in Figure A-3 with halftimes and fractional
activities of 15.7 minutes: 0.89, and 85 min: 0.11, respectively. The.
cause of the differences in curves obtained is not known but may be stress
from prolonged exposure to radiation ( ~ 3000 rad) and chamber dryness
resulting in increased respiration and circulation which increased the
rate of gas exchange from the tissue to air. Another possibility is
greater loss of stored fat in the longer experiment. A greater weight
loss was noted; but, since no food or water balance was kept, the loss
could not be unequivocally attributed to fat loss.
-------
55
1
MINUTES AFTER BEGINNING OF EXPOSURE
DESATURATION
CURVE
}
2
3
4
5
COMPONENT
WHOLE BODY
ADIPOSE TISSUE
OTHER LEAN TISSUE
HIGHLY PERFUSED
LEAN TISSUE
BLOOD
Q-CO/Ca'
11400
8100
2499
471
330
k(min')
0.0277
0.092
0.277
2.77
. i / - i
t j'(min)
25
7.5
2.5
0.25
CONDITIONS
1. TISSUE DENSITY 1.0
2.C£ = /aG85Kr/cm3AIR
3. PARTITION COEFF:
BLOOD:AIR =0.06
FAT:BLOOD=9.0
OTHER
TISSUES
:BLOOD = 1
Figure A-l.
10 20 30 40 60 80100 120140160180 200
MINUTES AFTER END OF EXPOSURE
o c
Hypothetical Kr saturation and desaturation curves
for standard man.
-------
en
o(total)
U J4
RAT 1 , RUN 1
10,000-
1000^
100^
O = ORIGINAL DATA
A = LONGEST COMPONENT STRIPPED
D = 2 LONG COMPONENTS STRIPPED
CURVE
1
2
3
A0(CPM)
1,870
11,532
4,432
fi(min)
94.2
22.6
3.75
Mmm'1)
.0074.
.37
.185
HOURS POST EXPOSURE
Figure A-2. Experimental S5j(r desaturation
curves in rat - short exposure.
10,000
O= ORIGINAL DATA
A= LONG COMPONENT STRIPPED
6 8 10 12
HOURS POST EXPOSURE
Figure A-3. Experimental &$Kr desaturation
curves in rat - long exposure.
-------
57
APPENDIX REFERENCES
1. Kety, S.S. The theory and applications of the exchange of inert gas
at the lungs and tissues. Pharmacol. Rev. 3:1-41 (1951).
2. Steinberg, M. and B. Manowitz. An absorption process for recovery
of fission product noble gases. BNL 493(1-115). Brookhaven National
Lobaratory (Feb. 1958).
3. Glass, H.I. and A.M. Harper. The measurement of the partition coef-
ficient of krypton between the brain cortex and blood by a double
isotope method. Phys. Med. Biol. 7:335-339 (1962).
4. Ingvar, D.H. and N.A. Lassen. Regional blood flow of the cerebral
cortex determined by krypton^5. Acta Physiol. Scand. 54:325-338
(1962).
5. Kampp, M. and 0. Bundgren. Blood flow and flow distribution in the
small intestine of the cat as analyzed by the Kr^5 wash-out technique.
Acta Physiol. Scand. 72:282-297 (1968).
6. Thorburn, G.D., H.H. Kopald, J.A. Herd, M. Hollenberg, C.C.C. O'Morchoe
and A.C. Barger. Intrarenal distribution of nutrient blood flow deter-
mined with krypton^5 in the unanesthetized dog. Circ. Res. 13:290-307
(1965).
7. Bell, G. and A.M. Harper. Measurement of local blood flow in the
renal cortex from the clearance of krypton"-1, j. Surg. Res. 5:
382-386 (1965).
8. Lassen, N.A. Assessment of tissue radiation dose in clinical use of
, with examples of absorbed doses froi
Nucleare 8:211-217 (Jul.-Aug. 1964).
___ .-. ^^ _ -—- - __. *^ ^ ~--- -— .-.''- __
radioactive inert gases, with examples of absorbed doses from
°%r and-^Xe. Minerva I
9. Hollenberg, M. and J. Dougherty. Liver blood flow measured by portal
venous and hepatic arterial routes with Kr°^. Am. J. Physiol. 210:
926-932 (1966).
10. Setchell, B.P., G.M.H. Waites and G.D. Thorburn. Blodd flow in the
testis of the conscious ram measured with krypton 85: effects of
Iheat, catecholamines and acetylcholine. Circ. Res. 18:755-765 (1966).
11. Caster, W.O., J. Poncelet, A.B. Simon and W.D. Armstrong. Tissue
weights of the rat. I. Normal values determined by dissection and
chemical methods II. Changes following 700 r total body X-irradiation
Proc. Soc. Exp. Biol. Med. 91:122-129 (1956).
12. Yeh, S.Y. and R.F. Peterson. Solubility of krypton and xenon in
blood, protein solutions and tissue homogenates. J. Appl. Physiol.
20:1041-1047 (1965).
-------
58
13. Yeh, S.Y. and R.F. Peterson. Solubility of carbon dioxide, krypton
and xenon in lipids. J. Pharm. Sci. 52:433-458 (1963).
14. Yeh, S.Y. and R.F. Peterson. Solubility of carbon dioxide, krypton,
and xenon in aqueous solution. J. Pharm. Sci. 53:822-824 (1964).
15. Glass, H.I., A.M. Harper, and M.M. Glover. The measurement of local
cortical blood flow in the brain by the analysis of the clearance
curve of krypton-85. Phys. Med. Biol. 6:65-71 (1961).
16. Lassen, N.A. Blood flow of the cerebral cortex calculated from
85krypton-beta-clearance recorded over the exposed surface; evidence
of inhomogeneity of flow. Acta Neurol. Scand. 41:24-28 (1965).
17- Haggendal, E. and B. Johansson. Effects of arterial carbon dioxide
tension and oxygen saturation on cerebral blood flow autoregulation
in dogs. Acta Physiol. Scand. 66:Suppl. 258:27-53 (1965).
18. Haggendal, E. Effects of some vasoactive drugs on the vessels of
cerebral grey matter in the dog. Acta Physiol. Scand. 66:Suppl-
258:55-79 (1965).
19. Haggendal, E., N.J. Nilsson and B. Norback. On the components of
Kr" clearance curves from the brain of the dog. Acta Physiol.
Scand. 258:5-25 (1965).
20. Brock, M., D.H. Ingvar and C.W. Sem Jacobsen. Regional blood flow
in deep structures of the brain measured in acute cat experiments
by means of a new beta-sensitive semiconductor needle detector. Exp.
Brain. Res. 4:126-137 (1967).
21. Herd, J.A., M. Hollenberg, G.D. Thorburn, H.H. Kopald and A.C. Barger.
Myocardial blood flow determined with krypton 85 in unanesthetized
dogs. Am. J. Physiol. 203:122-124 (1962).
22. Cohen, L.S., W.C. Elliott and R. Goblin. Measurement of myocardial
blood flow using krypton 85. Am. J. Physiol. 206:997-999 (1964).
23. Ross, R.S., K. Ueda, P.R. Lichtlen and J.R. Rees. Measurement of myo-
cardial blood flow in animals and man by selective injection of radio-
active inert gas into the coronary arteries. Circ. Res. 15:28-41
(1964).
24. Cosgrove, M.D. The effect of arterial hypoxia on the blood-flow
through the renal cortex. Br. J. Surg. 52:613-617 (1965).
25. MacDonald, A.G. The effect of halothane on renal cortical blood flow
in normotensive and hypotensive dogs. Br. J. Anaesth. 41:704-705
(1964).
-------
59
26. Bell, G. and A.M. Harper. Measurement of regional blood flow through
the skin from the clearance of krypton-85. Nature (Lond) 202:704-705
(1964).
27. Jansson, G., M. Kampp, 0. Lundgren and J. Martinson. Studies on the
circulation of the stomach. Acta Physiol. Scand. 68:Suppl 277:91
(1966).
28. Lundgren, 0. and M. Kampp. The washout of intraarterially injected
krypton85 from the intestine of the cat. Experientia 22:268-270
(1966).
29. Birtch, A.G., B.H. Casey and R.M. Zakheim. Hepatic blood flow
measured by the krypton-85 clearance technique. Surgery 62:174-180
(July 1967) .
30. Friedman, E., H.H. Kopald and T.R. Smith. Retinal and chroidal
blood flow determined with krypton-85 in anesthetized anijnals.
Invest. Ophthalmol. 3:539-546 (1964).
31. Holzman, G.B., H.N. Wagner, M. lio, D. Rabinowitz and K.I. Zierler.
Measurement of muscle blood flow in the human forearm with radio-
active krypton and xenon. Circulation 30:27-34 (1964).
32. Tobias, C.A., H.B. Jones, J.H. Lawrence and J.G. Hamilton. The
uptake and elimination of krypton and other inert gases by the human
body. J. Clin. Invest. 28:1375-1385 (1949).
33. Lesser, G.T. and G. Zak. Measurement of total body fat in man by the
simultaneous absorption of two inert gases. Ann. N.Y. Acad. Sci.
110:40-54 (1963).
34. Sveinsdottir, E. Clearance curves of Kr85 or Xel33 considered as a
sum of mono-exponential outwash functions. Description of a computer
program for the simple case of only two compartments. Acta Neurol.
Scand. 41:Suppl. 14:69-71 (1965).
35. Lawrence, J.H., W.F. Loomis, C.A. Tobias, and F.H. Turpin. Prelimi-
nary observations on the narcotic effect of xenon with a review of
values for solubilities of gases in water and oils. J. Physiol.
105:197-204 (1946).
36. Masson, M.B.R. and K. Taylor. Solubility of krypton-85 in olive oil
and human fat. Phys. Med. Biol. 12:93-98 (1967).
37. Lawrie, J.A., H.R. Schreiner and C.W. Cowley. Controlled atmosphere
incubator for physiological studies involving the rare gases. J. Appl
Physiol. 19:330-332 (1964).
-------
60
38. Hardewig, A., D.F. Rochester and W.A. Briscoe. Measurement of
solubility coefficients of krypton in water, plasma, and human blood,
using radioactive Kr85. J. Appl. Physiol.. 15:723-725 (1960).
39. Morrison, T.J. and N.B. Johnson. Solubilities of the inert gases in
water. J. Chem. Soc. 1954:3441-3446 (1954).
40. Horrocks, D.L. and M.H. Studier. Determination of radioactive noble
gases with a liquid scintillator. Anal. Chem. 36:2077-2079 (1964).
41. Hytten, F.E., K. Taylor and N. Taggart. Measurement of total body
fat in man by absorption of S^Kr. Clin. Sci. 31:111-119 (1966).
42. Clever, H.L. The solubility of argon and krypton in p-xylene and p-
xylene-p-dihalobenzene mixtures at 30°. J. Phys. Chem. 61:1082-1083
(1957).
43. Clever, H.L., J.H. Saylor and P.M. Gross. The solubility of helium,
neon, argon, krypton and xenon in methylcyclohexane and perfluoro-
methylcyclohexane . J. Phys. Chem. 62:89-91 (1958).
44. Clever, H.L., R. Battino, J.H. Saylor and P.M. Gross. The solubility
of helium, neon, argon and krypton in some hydrocarbon solvents.
J. Phys. Chem. 61:1078-1082) (1957).
45. Reed, E.L. and J.J. Droher. Solubility and diffusivity of inert gases
in liquid sodium, potassium, and NaK. LMEC-69-36, Atomics Interna*-
tional, Canoga Park, Calif. Liquid Metal Engineering Center, (31 Jan.
1970), (Contract AT(04-3) -700).
46. Yamamoto, Y. and H. Takeda. Solubility of 8%r in some organic sol
vents. Tokyo Daigaku Kogakubu Kiyo, A; 7:44-5 (Dec. 1969). (In
Japanese). Abstract NSA 24-27214. (July 31, 1970).
U. S. GOVERNMENT PRINTING OFFICE : 1 972--U8^-U82A6
-------
ENVIRONMENTAL PROTECTION AGENCY
Office of Research and Monitoring
12720 Twinbrook Parkway
Rockville, Maryland 20853
March 1, 1972
ERRATA SHEET:
Please make the following corrections on page 11,
lines 5 and 6 of the report: "Krypton 85, A Review of the
Literature and an Analysis of Radiation Hazards."
".... annual doses of 0.05 rem and 0.03 rem
respectively, ..." should read "....annual
doses of 0.05 mrem and 0.3 mrem respectively.,.'
Donald M. Hodge
Chief, Technical Reports Office
------- |