EPA-600/4-76-053
October 1976
RADIOACTIVITY STANDARDS DISTRIBUTION PROGRAM
FY 1977
by
Lee H. Ziegler
Monitoring Systems Research and Development Division
Environmental Monitoring and Support Laboratory
Las Vegas, Nevada 89114
U.S.ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF RESEARCH AND DEVELOPMENT
ENVIRONMENTAL MONITORING AND SUPPORT LABORATORY
LAS VEGAS, NEVADA 89114
,;.!. PRCTECTiCfi
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DISCLAIMER
This report has been reviewed by the Environmental Monitoring and Support
Laboratory-Las Vegas, U.S. Environmental Protection Agency, and approved for
publication. Mention of trade names or commercial products does not constitute
endorsement or recommendation for use.
11
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PREFACE
Quality assurance is an integral part of any viable environmental moni-
toring activity. The primary goals of the U.S. Environmental Protection
Agency's (EPA) quality assurance program are to improve and document the
credibility of environmental measurements. To achieve these goals, quality
assurance is needed in nearly all segments of monitoring activities and should
cover personnel, methods selection, equipment, and data handling procedures.
Five major functions, each essential to an effective quality assurance
effort, comprise EPA's quality assurance program.
Promulgation of standardized methods of
measurement
Distribution of standard reference materials
Issuance of guidelines and procedures
Training and technical assistance
Evaluation and certification of monitoring
activities
This manual has been prepared to assist laboratories involved with en-
vironmental radiation measurements in developing and maintaining a quality
control program and documenting the precision and accuracy of their data.
All EPA monitoring programs are requested to make use of this document in
planning their own radiation measurements and in assisting the States in
carrying out radiation monitoring activities.
Comments concerning the utility of this document, along with any sug-
gestions for possible changes and revisions, are welcomed. Questions on
matters related to quality assurance of environmental measurements in various
fields should be directed to the following person(s):
Air Pollution
Mr. Thomas Clark
Quality Assurance Branch
Environmental Monitoring and Support Laboratory
Research Triangle Park, North Carolina 27711
111
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Pesticides
Mr. Jack Thompson, Chief
Analytical Chemistry Branch
Environmental Toxicology Division
Health Effects Research Laboratory
Research Triangle Park, North Carolina 27711
Radiation
Mr. Arthur N. Jarvis, Chief
Quality Assurance Branch
Monitoring Systems Research and Development Division
Environmental Monitoring and Support Laboratory
Las Vegas, Nevada 89114
Water
Mr. John Winter, Chief
Quality Assurance Branch
Environmental Monitoring and Support Laboratory
Cincinnati, Ohio 45268
Periodically, manuals and documents will be issued which provide guide-
lines to be followed in all phases of monitoring activities. Use of these
guidelines throughout the Agency will enable a uniform approach to be estab-
lished within EPA which ultimately can be implemented at the State level.
This should permit a significant improvement in the validity and reliability
of environmental data collected throughout the Nation.
The implementation of a total and meaningful national environmental
quality assurance effort cannot succeed without the full support of all moni-
toring programs. Your cooperation is appreciated.
IV
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CONTENTS
Page
Preface iii
Program Objectives 1
Preparation and Calibration of Samples 1
Availability of Calibrated Samples 2
Participation in Calibrated Sample Distribution Program 10
Figures
1. Calibration certificate 3
2. Net pulse-height spectrum of sodium-22 measured
with 4-inch 4-inch Nal(Tl) crystal 6
3. Ratio of EPA values of activity to NBS values of
activity from EPA-NBS traceability studies 7
v
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PROGRAM OBJECTIVES
Environmental measurements are made daily by many different Federal,
State, local and private agencies. The data from these measurements are used
for a wide variety of purposes including assessment of health effects, estab-
lishment of standards and guides, and for enforcement activities. It is
therefore imperative that the precision and accuracy of the data be assured
in order that policy decisions concerning environmental quality be based on
valid and comparable data.
The quality assurance program of the U.S. Environmental Protection
Agency (EPA) is designed to encourage the development and implementation of
quality control procedures at all levels of sample collection, analysis, data
handling, and reporting. Quality control responsibilities, in the radiation
area, have been assigned to the Quality Assurance Branch at the EPA's Environ-
mental Monitoring and Support Laboratory in Las Vegas. This Branch, as an
integral part of its overall quality assurance effort, prepares and distri-
butes a variety of calibrated low-level radioactive samples for use in the
laboratories of Federal, State, and local agencies.
The major objective of this program is to encourage the development of
intralaboratory and interlaboratory quality control procedures and thus
ensure that environmental radiation data are valid. Providing accurately
calibrated samples assists laboratories in calibrating new instruments,
implementing and maintaining routine instrument calibration programs, evalu-
ating analytical procedures, and developing and revising data processing
programs.
The following pages briefly describe standard preparation procedures,
list the radionuclides available, and indicate how a laboratory may request
standards.
If your laboratory does not currently make use of the services provided
by the Quality Assurance Branch at the EMSL-LV, it is encouraged to do so.
PREPARATION AND CALIBRATION OF SAMPLES
The radionuclides used in preparing calibrated samples are obtained from
the National Bureau of Standards, the Laboratorie de Metrologie des Rayonne-
ments lonisants (France), Amersham/Searle, or from other reliable commercial
sources. The uncertainty in the known activity of individual sources ranges
from 0.5 to 5 percent. Activity of radionuclide impurities, excluding
daughters, is documented and typically is less than 1 percent of the activity
of the principal radionuclide at the time of sample preparation.
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Upon receipt, a radionuclide is checked for its activity and for the
presence of radioactive contaminants. The sample is then diluted to the
desired activity level (500-6,600,000 dpm/gm) with a carrier of the same
chemical composition and concentration as used by the supplier. In certain
cases the addition of a stabilizer is required. The accuracy of the dilution
is carefully checked and the solution flame sealed in 5-ml ampuls.
Accompanying each calibrated sample is a certificate listing pertinent
information concerning the sample and its calibration including an estimate
of the errors associated with the value of the activity (Figure 1). For
gamma emitters, a net plot of the pulse height spectrum is also included
(Figure 2).
To further assure the precision and accuracy of the calibrated samples,
the Quality Assurance Branch participates in on-going intercomparison studies
with the National Bureau of Standards (NBS). These studies involve the
measurement of unknown samples supplied by the NBS, and the measurement by
NBS of EPA-prepared samples. Results of this program are shown in Figure 3.
More complete details of the intercomparison studies with the NBS are de-
scribed elsewhere.*
AVAILABILITY OF CALIBRATED SAMPLES
The Quality Assurance Branch recommends use of the half lives listed in
this document. The primary sources of these half lives are "Nuclear Decay
Data for Selected Radionuclides," edited by M. J. Martin (ORNL-5114, VC -
34c - Nuclear Physics, Oak Ridge National Laboratory) and Nuclear Data
Tables, Volume A8, Numbers 1,2, edited by Katherine Way. Half lives of
those radionuclides not listed in either of these publications were taken
from selected volumes of the Nuclear Data Sheets, edited by the Nuclear Data
Group.
AQUEOUS CALIBRATED SAMPLES
The inventory of calibrated samples at the beginning of Fiscal Year
1977 consists of some 30 calibrated radionuclide solutions. Every effort is
made to keep this inventory supplied for immediate delivery with the exception
of iodine-131 and barium-140. Iodine-131 is prepared bimonthly and distri-
buted to requestors of record. Barium-140 is prepared approximately every 4
months and supplied to requestors of record. While the types of calibrated
samples in the inventory vary during the year, every effort will be made to
keep the following calibrated solution samples in stock and available for
distribution at any time.
* Quality Assurance Branch, Radiation Quality Assurance Intercomparison
Studies 1974-1975, Environmental Monitoring and Support Laboratory,
EPA-600/4-75-014, October 1975, Las Vegas, Nevada.
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U S. ENVIRONMENTAL PROTECTION AGENCY
ENVIRONMENTAL MONITORING AND SUPPORT LABORATORY-LAS VEGAS
QUALITY ASSURANCE BRANCH
Calibration Certificate
Description Principal radionuchde
Nominal activity
Nominal volume
Half-life
ml in ampoule/bottle number
Supplied to
Request
Measurement Activity of principal radionuchde
Activity per gram of this solution
curies of I
at O4OO hours PST on
Activity of daughter radionuclide
The principal activity was accompanied at the quoted time by
curies per gram
of the daughter nuclide
TOTAL MASS OF THIS SOLUTION
TOTAL PRINCIPAL ACTIVITY PER
GRAM AT THE QUOTED TIME
Figure 1. Calibration certificate
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Method of measurement
Useful Life
This radionuclide has decayed through
half lives since it was obtained by EMSL-LV
We recommend that this solution should not be used after
Purity
The manufacturer states that activities other than that of the principal nuclide
and of its daughter nuclides, if any, were estimated/known to be
less than
equal to
0)
(2)
(3)
less than
equal to
less than
equal to
% of the principal activity
%| of the principal activity
of the principal activity
The activity of impurity (1) is not (2) is not (3) is not included in the
quoted figures of the principal activity
It is estimated that we have added the following impurities
CO
(2)
(3)
less than
less than
curies/gram
curies/gram
curies/gram
Figure 1 (continued). Calibration certificate
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Random Errors
The repeatability of this standardization (dilutions, source preparations, counting statistics,
mass determinations, etc) was such that the certified value of the radioactive concentration
of the principle activity had a standard error (a) not greater than
(The 997% confidence limits are given by + 3 o )
The total systematic error (sum of estimated maximum residual systematic errors due to
dispensing, counting losses, counting corrections known uncertainty of standard) of the
certified radioactive concentrations of the principle activity has been estimated not to
exceed
% (5')
The overall limits of error calculated on the basis of +(3(7+5) or -(3 a + 5 ) are
% of the quoted radioactive concentration
The effective standard deviation is defined as 1/6th of the range between the overall limits
+(3fr+ <5) and -(3 a + Ł') and is therefore j % I
Schemes This standardization is based on the following assumptions of the principle nuclide, its
daughter nuchdes and impurities (no allowance for error m these assumptions or the
assumption of quoted half-life have been included in the statement of accuracy above)
Chemical Carrier content per gram of solution
Composition
of Solution
Preservative
Other components
Remarks
Date Certificate Prepared
Approval Signature
Figure 1 (continued). Calibration certificate
5
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10*
10 3
102
NET
CRN
10
10
1,64
80 120
CHANNEL NUMBER
16O
200
Figure 2.
Net pulse height spectrum of sodium-22 measured
with 4-inch x 4-inch Nal(Tl) crystal
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CALIBRATED RADIONUCLIDE SAMPLES KEPT IN INVENTORY
Isotope
3H
14C
22Na
46Sc
5kHn
57 Co
60Co
65Zn
75Se
88y
89Sr
90Sr
106Ru
Type
Emission
3"
3"
3+,Y
3~,Y
Y
Y
3~,Y
3+,Y
Y
3+,Y
3'
3-
3-,Y
Half -Life
12.35 y
5730 y
2.602 y
83.80 d
312.5 d
270.9 d
5.271 y
244.1 d
120 d
107 d
50.5 d
28.5 y
369 d
Isotope
109Cd
l l Om^n
125Sb
1 31j
133Ba
13 "Cs
137Cs
11(0Ba
ltt4Ce
226Ra
239Pu
241Am
Type
Emission Half -Life
Y 453 d
3~,y 250.8 d
3~,y 2.77 y
3~,y 8.04 d
Y 10.5 y
3~,Y 2.062 y
3~,Y 30.0 y
3~,Y 12.8 d
3~,Y 284 d
a,Y 160° y
a 2.439 x 101*
a 433 y
Throughout the year other radionuclide solutions are calibrated and made
available for distribution. In order to service the user efficiently, the
Quality Assurance Branch will obtain, calibrate, and distribute the following
radionuclides, as time and resources permit, after we have received 10 or more
requests for them. The user is reminded, however, that these are prepared as
time permits, and as the Branch is able to maintain the above inventory.
Isotope
7Be
51Cr
56Co
58CO
59Fe
85Sr
95Zr
95Nb
103Ru_103mRh
Type
Emission
Y
Y
3+,Y
3+,Y
3~,Y
Y
3~,Y
3-,Y
3~,Y
Half-Life
53.3 d
27.704 d
77.3 d
70.8 d
44.6 d
64.85 d
65.5 d
35.5 d
39.35 d
Isotope
12"sb
139Ce
^lCe
195Au
203Hg
230Th
232Th
235U
2380
Type
Emission
3~,Y
Y
3-,Y
Y
3~,Y
a
a
a
a
Half -Life
60.20 d
137.65 d
32.50 d
183 d
46.59 d
7.7 x 104 y
1.40 x lo10 y
7.1 x 108 y
4.49 x 109 y
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On occasion a few selected radionuclide solutions, not listed above, are
calibrated. Letters will be sent to known requestors of low-level radio-
nuclide solutions to efficiently allocate the distribution of these solutions.
A solution standard of radium-228, a beta emitter, is being prepared
under contract for distribution by EPA. These calibrated radium-228 samples
should be available for distribution to users in early 1977.
RADIOACTIVE GAS SAMPLES
Mixtures of radioactive gases in air are available for distribution.
These samples are contained in refillable propane bottles similar to those
supplied commercially for propane lamps, stoves, or gas torches. Currently
only krypton-85 is available. Krypton-85, with a half-life of 10.72 years,
emits both beta particles and gamma rays.
SOIL SAMPLES
Several soil samples have been prepared and analyzed under contract for
distribution by EPA. These soil samples have been dried, ground to pass a
170-mesh or a 200-mesh screen, and carefully blended. Reports of calibration
will accompany the samples. The samples will be packaged in plastic con-
tainers and will contain sufficient material to enable users to perform ex-
pected analytical methods in triplicate. Soils available are:
1. Standard Pitchblend Ore
Principal radionuclides 238U, 235U
Principal daughter products 210Pb, 210Po, 231*U, 230Th,
231Pa, 226Ra, 227Ac, 227Th,
211+Pb
2. Diluted Pitchblend
This is approximately a 10:1 dilution of material 1
with low-activity soil used for dilution.
3. Standard Monazite Ore
Principal radionuclides analyzed - 232Th, 230Th, 228Th,
228Ra
4. Diluted Monazite Ore
This is approximately a 10:1 dilution of material 3
with low-activity soil used as diluent.
5. Mill Tailings (1)
Principal radionuclides analyzed - 230Th, 226Ra, 210Pb
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6. Mill Tailings (2)
A composite mixture from 16 different mills.
Principal radionuclides analyzed - 230Th, 226Ra, 210Pb
7. Diluted Mill Tailings
A 7:1 dilution of Sample 6 with low-activity soil
used as a diluent.
8. Mancos Shale
For delivery in early 1977. This sample will be
certified for 226Ra activity.
COMPOSITE MIXTURES
A low-level solution sample containing tritium, strontium-go-yttrium-go,
cesium-134 and radium-226 is being prepared. The activity levels, when
diluted to a 4-liter sample, will be approximately 50 times the nominal lower
limit of detection as defined in the HASL Procedures Manual* at the 95 per-
cent confidence level. These solutions are expected to be available for
distribution in December 1976.
PARTICIPATION IN CALIBRATED SAMPLE DISTRIBUTION PROGRAM
Any Federal, State, local or private laboratory involved in, or concerned
with, environmental radiation monitoring and surveillance may participate in
the calibrated sample distribution program. To request samples, complete one
of the request forms included in this publication and return it to:
U.S. Environmental Protection Agency
Environmental Monitoring and Support Laboratory
Quality Assurance Branch (MSQ)
P.O. Box 15027
Las Vegas, NV 89114
All requests for calibrated samples should be submitted at least 3 weeks
in advance in order to ensure delivery on the date required. Should addition-
al forms be required, they may be requested from the same address.
* HASL Procedures Manual, HASL-300, Health and Safety Laboratory, ERDA, New
York, New York. John H. Harley, ed. pp D-08-d,02,03. Rev. August 1974.
10
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RADIONUCLIDE REQUEST FORM
TO: U.S. Environmental Protection Agency
Environmental Monitoring and Support Laboratory
Quality Assurance Branch
P.O. Box 15027
Las Vegas, NV 89114
Please ship the calibrated samples listed below to:
Contact Person
Title
Laboratory
Address
Telephone
AEC License
and/or Type(s)
State License Number(s)
NOTE: If either by-products (in quantities greater than exempt quanti-
ties) or special nuclear materials are requested, a copy of the
NRC license(s) should accompany the first request.
Radionuclide Samples Desired:
I certify that the calibrated sample(s) requested are to be used
only in this laboratory by qualified personnel for the purpose of de-
veloping or checking analytical procedures and/or for the calibration
of instrumentation.
I further certify that I am authorized to receive the above listed
radionuclides under the license number(s) listed above or that this
laboratory is exempt from licensing regulations.
Date Signature
Title
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-600/4-76-053
3. RECIPIENT'S ACCESSION-NO.
4. TITLE AND SUBTITLE
RADIOACTIVITY STANDARDS DISTRIBUTION PROGRAM FY 1977
5. REPORT DATE
October 1976
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
Lee H. Ziegler, Quality Assurance Branch
Monitoring Systems Research and Development Division
8. PERFORMING ORGANIZATION REPORT NO
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Environmental Monitoring and Support Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Las Vegas, Nevada 89114
10. PROGRAM ELEMENT NO.
1HD621
11. CONTRACT/GRANT NO.
12. SPONSORING AGENCY NAME AND ADDRESS
Same as above
13. TYPE OF REPORT AND PERIOD COVERED
interim (FY 1977)
14. SPONSORING AGENCY CODE
EPA-ORD, Office of Monitorirjg
and Technical Support
15. SUPPLEMENTARY NOTES
16. ABSTRACT
A program for the distribution of calibrated radioactive samples, as one function
of EPA's quality assurance program for environmental radiation measurements, is
described. Included is a discussion of the objectives of the distribution program
and a description of the preparation, availability, and distribution of calibrated
radioactive samples. Instructions and application forms are included for labora-
tories desiring to participate in the program.
This document is not a research report. It is designed for use by personnel of
laboratories participating or desiring to participate in the Radioactivity Standards
Distribution Program which is a part of the U.S. Environmental Protection Agency's
quality assurance program.
7.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS C. COSATI Field/Group
quality assurance
quality control
r ad ioact iv ity
quantitative analysis
calibrating
standards
07 B
14 B, D
18 H
8. DISTRIBUTION STATEMENT
RELEASE TO PUBLIC
19. SECURITY CLASS (ThisReport)
UNCLASSIFIED
21. NO. OF PAGES
20
20. SECURITY CLASS (Thispage)
UNCLASSIFIED
22. PRICE
EPA Form 2220-1 (9-73)
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