ASTM C1237-99(2005)

Standard Guide to In-Plant Performance Evaluation of Hand-Held SNM Monitors (Withdrawn 2014)

SIGNIFICANCE AND USE
Hand-held SNM monitors are an effective and unobtrusive means to search pedestrians or vehicles for concealed SNM when automatic SNM monitors are not available or have sounded an alarm. Facility security plans apply SNM monitors as one means to prevent theft or unauthorized removal of SNM from designated areas. Functional testing of monitors on a daily basis with radioactive sources can assure they are in good working order. The significance of a less frequent, in-plant evaluation of an SNM monitor is to verify that the monitor achieves an expected probability of detection for an SNM or alternative test source.
The evaluation verifies acceptable performance or discloses faults in hardware or calibration.
The evaluation uses test sources shielded only by normal source encapsulation. However, shielded SNM test sources could be used as well.
The evaluation, when applied as a routine operational evaluation, provides evidence for continued compliance with the performance goals of security plans or regulatory guidance.
Note 1—It is the responsibility of the users of this guide to coordinate its application with the appropriate regulatory authority so that mutually agreeable choices for evaluation frequency, test sources, detection criteria (whether a single or multiple alarms constitute detection), minimum distance for first detection, number of trials, and reporting procedures are used. Regulatory concurrence should be formally documented.
SCOPE
1.1 This guide is one of a series on the application and evaluation of special nuclear material (SNM) monitors. Other guides in the series are listed in Section 2, and the relationship of in-plant performance evaluation to other procedures described in the series is illustrated in Fig. 1. Hand-held SNM monitors are described in of Guide C1112, and performance criteria illustrating their capabilities can be found in Appendix X1.
1.2 The purpose of this guide to in-plant performance evaluation is to provide a comparatively rapid procedure to verify that a hand-held SNM monitor performs as expected for detecting SNM or alternative test sources or to disclose the need for repair. The procedure can be used as a routine operational evaluation or it can be used to verify performance after a monitor is calibrated.
1.3 In-plant performance evaluations are more comprehensive than daily functional tests. They take place less often, at intervals ranging from weekly to once every three months, and derive their result from multiple trials.
1.4 Note that the performance of both the hand-held monitor and its operator are important for effective monitoring. Operator training is discussed in Appendix X2.
1.5 The values stated in SI units are to be regarded as standard.
1.6 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.  
Note—The procedures shown “above” the user provide the user with information before acquiring a monitor, and those “below” assist the user to obtain continuing acceptable performance from the monitor.
WITHDRAWN RATIONALE
This guide is one of a series on the application and evaluation of special nuclear material (SNM) monitors.
Formerly under the jurisdiction of Committee C26 on Nuclear Fuel Cycle, this practice was withdrawn in January 2014 in accordance with section 10.6.3.1 of the Regulations Governing ASTM Technical Committees, which requires that standards shall be updated by the end of the eighth year since the last approval date.

General Information

• Status: Withdrawn
• Publication Date: 31-May-2005
• Withdrawal Date: 15-Jan-2014
• ICS: 17.240 - Radiation measurements
• Technical Committee: C26 - Nuclear Fuel Cycle

Relations

• Replaces: ASTM C1237-99 - Standard Guide to In-Plant Performance Evaluation of Hand-Held SNM Monitors
• Effective Date: 01-Jun-2005

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: C1237 − 99 (Reapproved2005)
Standard Guide to
In-Plant Performance Evaluation of Hand-Held SNM
Monitors
This standard is issued under the fixed designation C1237; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 2. Referenced Documents
1.1 This guide is one of a series on the application and 2.1 The guide is based on ASTM standards that describe
evaluation of special nuclear material (SNM) monitors. Other application and evaluation of SNM monitors, as well as
guides in the series are listed in Section 2, and the relationship technical publications that describe aspects of SNM monitor-
of in-plant performance evaluation to other procedures de- ing.
scribed in the series is illustrated in Fig. 1. Hand-held SNM 2
2.2 ASTM Standards:
monitors are described in of Guide C1112, and performance
C859 Terminology Relating to Nuclear Materials
criteria illustrating their capabilities can be found in Appendix
C1112 Guide for Application of Radiation Monitors to the
X1.
Control and Physical Security of Special Nuclear Material
1.2 The purpose of this guide to in-plant performance C1189 Guide to Procedures for Calibrating Automatic Pe-
evaluation is to provide a comparatively rapid procedure to destrian SNM Monitors
verify that a hand-held SNM monitor performs as expected for
3. Terminology
detecting SNM or alternative test sources or to disclose the
need for repair. The procedure can be used as a routine
3.1 Definitions:
operational evaluation or it can be used to verify performance
3.1.1 alarm—the audible sound made by a hand-held SNM
after a monitor is calibrated.
monitor to indicate that it has detected radiation intensity at or
above the alarm threshold.
1.3 In-plant performance evaluations are more comprehen-
3.1.1.1 Discussion—One or more closely spaced alarms
sive than daily functional tests. They take place less often, at
may be chosen to signify detection of SNM.
intervals ranging from weekly to once every three months, and
derive their result from multiple trials.
3.1.2 alternative test source—Although no other radioactive
materials individually or collectively duplicate the radioactive
1.4 Notethattheperformanceofboththehand-heldmonitor
emissions of uranium or plutonium, some materials have
and its operator are important for effective monitoring. Opera-
similar attributes and are sometimes used as alternative test
tor training is discussed in Appendix X2.
sources.
1.5 The values stated in SI units are to be regarded as
3.1.2.1 alternative gamma-ray test sources—Examples of
standard.
alternative gamma-ray sources are highly enriched uranium
1.6 This standard does not purport to address all of the
(HEU) or Ba used in place of plutonium when a plutonium
safety problems, if any, associated with its use. It is the
source is not readily available or is prohibited.
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica- 3.1.2.2 Discussion—Table 1 tabulates amounts of HEU
mass, plutonium mass, and Ba source activity that produce
bility of regulatory limitations prior to use.
equal response in two different types of monitor.
This guide is under the jurisdiction ofASTM Committee C26 on Nuclear Fuel
Cycleand is the direct responsibility of Subcommittee C26.12 on Safeguard
Applications. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved June 1, 2005. Published November 2005. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 1999. Last previous edition approved in 1999 as C1237 – 99. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/C1237-99R05. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C1237 − 99 (2005)
3.1.5 detection—one or more alarm sounds from a hand-
held SNM monitor may constitute detection of SNM.
3.1.5.1 Discussion—Nuisance alarms are more likely to
occur in hand-held monitors than in other types of SNM
monitors for several reasons. Repeated alarms are most often
used to indicate detection of SNM.
3.1.6 detection probability—for hand-held monitors, ex-
pressed as the proportion of trials with a particular test source
for which the monitor is expected to detect the source.
3.1.6.1 Discussion—Although probabilities are properly ex-
pressedasproportions,performancerequirementsfordetection
probability in regulatory guidance have sometimes been ex-
pressed in percentage. In that case, the detection probability as
a proportion can be obtained by dividing the percentage by
100.
3.1.7 hand-held SNM monitor—ahand-heldradiationdetec-
tion system that measures ambient radiation intensity, deter-
mines an alarm threshold from the result, and then when it is
used for monitoring, sounds an alarm whenever its measured
radiation intensity exceeds the threshold.
3.1.8 nuisance alarm—a monitoring alarm not caused by
SNM but by other causes, that may be a statistical variation in
the measurement process, a background intensity variation, or
an equipment malfunction.
NOTE 1—The procedures shown “above” the user provide the user with
information before acquiring a monitor, and those “below” assist the user
3.1.9 operator—an individual who uses a hand-held SNM
to obtain continuing acceptable performance from the monitor.
monitor to search pedestrians, packages, or vehicles to detect
FIG. 1 The Relationship of In-plant Evaluation to Other Proce-
the presence of SNM.
dures Described in Guides for SNM Monitors
3.1.10 process-SNM test source—an SNM test source fab-
A
ricated by a facility from process material that differs in
TABLE 1 Alternative Test Source Equivalent Amounts
physical or isotopic form from the material recommended in
Monitor Ba (µCi) Required in:
NaI(Tl) Plastic
3.1.12 for standard test sources.
Plutonium, g Uranium, g
Category Description Scintillator Scintillator
3.1.10.1 Discussion—This type of source is used when it
Monitors Monitors
meetsplantoperatororregulatoryagencyperformancerequire-
I Plutonium 1 64 2.5 3.2
II Uranium 0.29 10 0.9 1.4
ments and a standard source is not appropriate or readily
A
This table combines information from Tables II and V of the report referenced in
available. Encapsulation and filtering should follow that rec-
Footnote 5. Note that the term “category” refers to an SNM monitor performance
ommended in 3.1.12.
category used in that report and not to an SNM accountability category. Also note
that the Ba source strengths depend on individual differences in how the
3.1.11 SNM (special nuclear material)—plutonium of any
scintillators respond to radiation from the barium isotope and plutonium.
isotopic composition, U, or enriched uranium as defined in
Terminology C859.
3.1.11.1 Discussion—Thistermisusedheretodescribeboth
3.1.2.3 alternative neutron test source—Acommon alterna-
SNM and strategic SNM, which is plutonium, U, and
tive neutron source used in place of plutonium is Cf, which
uranium enriched to 20 % or more in the U isotope.
emits neutrons from spontaneous fission as does plutonium.
3.1.12 standard SNM test source—a metallic sphere or cube
3.1.2.4 Discussion—Alternative test sources may have short of SNM having maximum self attenuation of its emitted
radiation and an isotopic composition listed below that mini-
decay half-lives in comparison to SNM isotopes, for example
133 252
the half-life of Ba is 10.7 years and Cf 2.64 years. Larger mizes the intensity of its radiation emission. Encapsulation and
filteringalsoaffectradiationintensity,andparticulardetailsare
source activities than initially needed are often purchased to
obtain a longer working lifetime for the source. listed for each source. This type of test source is used in
laboratory evaluation but, if suitable and readily available, also
3.1.3 confidence coeffıcient—the approximate percentage of
may be used for in-plant evaluation.
confidence intervals from a large number of repetitions of an
evaluation that would contain the true result.
3.1.12.1 standard uranium SNM test source—a metallic
3.1.3.1 Discussion—Forexample,aconfidencecoefficientis
sphere or cube of HEU containing at least 93 % U and less
being referred to by the words “with 95 % confidence.”
than0.25 %impurities.Protectiveencapsulationshouldbethin
3.1.4 confidence interval—a range that contains the (true) plastic or thin aluminum (≤0.32 cm thick) to reduce unneces-
detection probability for an evaluation situation with a stated sary radiation absorption in the encapsulation. No additional
confidence. filter is needed.
C1237 − 99 (2005)
3.1.12.2 standard plutonium SNM test source—a metallic 4.1.2.3 Use the evaluation procedure (see Section 8)ina
sphere or cube of low-burnup plutonium containing at least series of trials to check for nuisance alarms. Record the results,
239 240
93 % Pu, less than 6.5 % Pu, and less than 0.5 % alarm or no alarm for each trial.
impurities. 4.1.2.4 Use the evaluation procedure again in a series of
trials, this time to estimate whether the detection probability of
3.1.12.3 Discussion—A cadmium filter can reduce the im-
the hand-held monitor meets a minimum requirement. Record
pact of Am, a plutonium decay product that will slowly
the results, detect or miss for each trial.
build up in time and emit increasing amounts of 60-keV
4.1.2.5 End the testing when the preselected total number of
radiation. Begin use of a 0.04-cm thick cadmium filter when
trials is reached.
three or more years have elapsed since separation of plutonium
4.1.2.6 Analyze the results (see Section 9) to determine
decay products. If ten or more years have elapsed since
whether the hand-held monitor achieves a minimum require-
separation, use a 0.08 cm thick cadmium filter. The protective
ment.
encapsulation should be in as many layers as local rules
4.1.2.7 Report the results (see Section 10).
require. A nonradioactive encapsulating material, such as
aluminum (≤0.32-cm thick) or thin (≤0.16-cm thick) stainless
5. Significance and Use
steel or nickel, should be used to reduce unnecessary radiation
5.1 Hand-held SNM monitors are an effective and unobtru-
absorption.
sive means to search pedestrians or vehicles for concealed
3.2 Definitions of Terms Specific to This Standard:
SNM when automatic SNM monitors are not available or have
3.2.1 post-calibration evaluation—verifies the performance
sounded an alarm. Facility security plans apply SNM monitors
of a hand-held monitor immediately after calibration,
as one means to prevent theft or unauthorized removal of SNM
recalibration, or repair and calibration. The hand-held monitor
from designated areas. Functional testing of monitors on a
is prepared for best performance.
dailybasiswithradioactivesourcescanassuretheyareingood
working order. The significance of a less frequent, in-plant
3.2.2 routine-operational evaluation—verifies the routine
evaluation of an SNM monitor is to verify that the monitor
performanceofahand-heldmonitor.Themonitorisbeingused
achieves an expected probability of detection for an SNM or
in routine operation.
alternative test source.
3.2.3 saturation—an undesirable condition in which a hand-
5.2 The evaluation verifies acceptable performance or dis-
held SNM monitor exposed to intense radiation ceases to
closes faults in hardware or calibration.
function, falls silent, and does not indicate that SNM or intense
radiation is present.
5.3 The evaluation uses test sources shielded only by
normal source encapsulation. However, shielded SNM test
4. Summary of Guide
sources could be used as well.
4.1 Each evaluation, routine-operational or post-calibration, 5.4 The evaluation, when applied as a routine operational
is carried out using a predetermined test source, number of evaluation, provides evidence for continued compliance with
trials, and alarm criteria. The evaluation is summarized as theperformancegoalsofsecurityplansorregulatoryguidance.
follows:
NOTE 1—It is the responsibility of the users of this guide to coordinate
4.1.1 Steps for Routine-Operational Evaluation:
its application with the appropriate regulatory authority so that mutually
agreeable choices for evaluation frequency, test sources, detection criteria
4.1.1.1 Put the monitor into operation and check for satu-
(whether a single or multiple alarms constitute detection), minimum
ration.
distance for first detection, number of trials, and reporting procedures are
4.1.1.2 Use the evaluation procedure (see Section 8)ina
used. Regulatory concurrence should be formally documented.
series of trials to check for nuisance alarms. Record the results,
6. Apparatus
alarm or no alarm for each trial.
4.1.1.3 Use the evaluation procedure again in a series of 6.1 Besides a hand-held monitor to evaluate, the following
list of apparatus and supplies are needed.
trials, this time to estimate the detection probability of a
hand-held monitor in routine operation. Record the results, 6.1.1 Metre Stick, Tape Measure, or Other Means for
Measuring Distance.
detect or miss for each trial.
6.1.2 Means of Support, for the test source and hand-held
4.1.1.4 End the testing when the preselected total number of
monitor during the evaluation. For example, the test source
trials is reached.
could be supported on a table or shelf and the monitor moved
4.1.1.5 Analyze the results (see Section 9) to determine
towards it by a person holding the monitor and moving slowly
whether the hand-held monitor achieves a minimum require-
towards the source. A better example would be to use a long
ment.
wooden,orsimilar,plank(testplank)withamarkedtestsource
4.1.1.6 Report the results (see Section 10).
position and marked minimum distance for first detection. The
4.1.2 Steps for Post-Calibration Evaluation:
plank could be supported with sawhorses. The person could
4.1.2.1 Calibrate the monitor according to procedures sug-
then slowly move the monitor along the plank towards the test
gested by the manufacturer or other standard practice.
source in a more reproducible manner.
4.1.2.2 Put the monitor into operation and check for satu- 6.1.3 Evaluation Report Forms and Some Means to Record
ration. Evaluation Results.
C1237 − 99 (2005)
7. Test Materials serve to evaluate all monitors in all circumstances. Different
locations may require different test sources.
7.1 The materials ne
...