ASTM C1112 - 99 (2005)

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Designation: C 1112 – 99 (Reapproved 2005)

Standard Guide for

Application of Radiation Monitors to the Control and

Physical Security of Special Nuclear Material

This standard is issued under the ﬁxed designation C 1112; 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 (e) indicates an editorial change since the last revision or reapproval.

1. Scope

1.1 This guide brieﬂy describes the state-of-the-art of radia-

tion monitors for detecting special nuclear material (SNM) (see

3.1.11) in order to establish the context in which to write

performance standards for the monitors. This guide extracts

information from technical documentation to provide informa-

tion for selecting, calibrating, testing, and operating such

radiation monitors when they are used for the control and

protection of SNM. This guide offers an unobtrusive means of

searching pedestrians, packages, and motor vehicles for con-

cealed SNM as one part of a nuclear material control or

security plan for nuclear materials. The radiation monitors can

provide an efficient, sensitive, and reliable means of detecting

the theft of small quantities of SNM while maintaining a low

likelihood of nuisance alarms.

1.2 Dependable operation of SNM radiation monitors rests

on selecting appropriate monitors for the task, operating them

in a hospitable environment, and conducting an effective

program to test, calibrate, and maintain them. Effective opera-

tion also requires training in the use of monitors for the security

inspectors who attend them. Training is particularly important

for hand-held monitoring where the inspector plays an impor-

tant role in the search by scanning the instrument over

pedestrians and packages or throughout a motor vehicle.

1.3 SNM radiation monitors are commercially available in

three forms:

1.3.1 Small Hand-Held Monitors—These monitors may be

used by an inspector to manually search pedestrians and

vehicles that stop for inspection.

1.3.2 Automatic Pedestrian Monitors—These monitors are

doorway or portal monitors that search pedestrians in motion as

they pass between radiation detectors, or wait-in monitoring

booths that make extended measurements to search pedestrians

while they stop to obtain exit clearance.

1.3.3 Automatic Vehicle Monitors—These monitors are por-

tals that monitor vehicles as they pass between radiation

detectors, or vehicle monitoring stations that make extended

measurements to search vehicles while they stop to obtain exit

clearance.

1.4 Guidance for applying SNM monitors is available as

Atomic Energy Commission/Nuclear Regulatory Commission

(AEC/NRC) regulatory guides, AEC/ERDA/DOE performance

standards, and more recently as handbooks and applications

guides published by national laboratories under DOE sponsor-

ship. This broad information base covering the pertinent

physics, engineering practice, and equipment available for

monitoring has had no automatic mechanism for periodic

review and revision. This ASTM series of guides and standards

will consolidate the information in a form that is reexamined

and updated on a ﬁxed schedule.

1.5 Up-to-date information on monitoring allows both

nuclear facilities and regulatory agencies to be aware of the

current range of monitoring alternatives. Up-to-date informa-

tion also allows manufacturers to be aware of the current goals

of facilities and regulators, for example, to obtain particular

sensitivities at a low nuisance alarm rate with instrumentation

that is dependable and easy to maintain.

1.6 This guide updates and expands the scope of NRC

regulatory guides and AEC/ERDA/DOE SNM monitor perfor-

mance standards using the listed publications as a technical

basis.

1.7 The values stated in SI units are to be regarded as the

standard.

1.8 This standard may involve hazardous materials, opera-

tions, and equipment. This standard does not purport to

address all of the safety problems associated with its use. It is

the responsibility of the user of this standard to establish

This guide is under the jurisdiction of ASTM Committee C26 on Nuclear Fuel

Cycle and is the direct responsibility of Subcommittee C26.12 on Safeguard

Applications.

Current edition approved June 1, 2005. Published October 2005. Originally

approved in 1988. Last previous edition approved in 1999 as C 1112 – 99.

Copies of out-of-print references may be available from Group NIS6, MS-J562,

Los Alamos National Laboratory, Los Alamos, NM 87545.

Downloaded/printed by

Laurentian University pursuant to License Agreement. No further reproductions authorized.

appropriate safety and health practices and determine the

applicability of regulatory limitations prior to use.

2. Referenced Documents

2.1 ASTM Standards:

C 859 Terminology Relating to Nuclear Materials

C 993 Guide for In-Plant Performance Evaluation of Auto-

matic Pedestrian SNM Monitors

C 1189 Guide to Procedures for Calibrating Automatic

Pedestrian SNM Monitors

C 1236 Guide for In-Plant Performance Evaluation of Au-

tomatic Vehicle SNM Monitors

C 1237 Guide for In-Plant Performance Evaluation of

Hand-Held SNM Monitors

2.2 Code of Federal Regulations:

Title 10, Part 73, Physical Protection of Plants and Materi-

als

2.3 AEC/NRC Regulatory Guides:

5.27 Special Nuclear Material Monitors, June 1974

5.7 Control of Personnel Access to Protected Areas, Vital

Areas, and Material Access Areas, May 1980

2.4 AEC/ERDA/DOE SNM Monitor Standards:

Personnel Doorway Monitor Standards, January 1974

Standards for Hand-Held SNM Detection Instruments for

Personnel, Package, and Vehicle Search, April 1974

2.5 NRC NUREG and NUREG/CR Reports:

NUREG 1321, Testing Standards for Physical Security

Systems at Category I Fuel Cycle Facilities, October

1991

NUREG 1329, Entry/Exit Control at Fuel Fabrication Fa-

cilities Using or Possessing Formula Quantities of Strate-

gic Special Nuclear Material, November 1985

NUREG/CR 5899 (SAND 92-1339), Entry/Exit Control

Components for Physical Protection Systems, 1992

3. Terminology

3.1 Deﬁnitions of Terms Speciﬁc to This Standard:

3.1.1 alternative test sources—there are no other radioac-

tive isotopes that individually or together can duplicate the

radioactive emissions of SNM. Hence, performance testing in

a laboratory environment will use only SNM test sources.

Operational testing at the recommended three-month interval

can most often use SNM test sources, although sometimes a

more readily available equivalent-intensity highly enriched

uranium (HEU) source may be used in place of a very

expensive and hard to obtain plutonium source. The more

frequent daily or weekly operational testing will often substi-

tute alternative isotopic sources. Often these are continuity

tests that can use the cesium-137 (

137

Cs) sources that are on

hand for pulse height calibration. Also barium-133 (

133

Ba) may

be used when a gamma-ray spectrum similar to plutonium is

needed to make a daily or weekly test that must roughly

approximate testing with a particular plutonium test source.

Gas lantern mantles containing thorium are radioactive and

sometimes are used to test continuity in hand-held monitors.

3.1.2 detection sensitivity—speciﬁed in terms of the mass of

SNM that will be detected 50 % or more of the time when

carried through the monitor in a speciﬁed fashion. This

convenient deﬁnition greatly simpliﬁes SNM monitor perfor-

mance testing and makes it possible to readily verify sensitivity

by performing an experiment that mimics the monitor’s normal

use. The related masses that would be detected 95 % or 99 %

of the time can be estimated from the 50 % mass but would be

impractical to determine with high conﬁdence by themselves.

Experiments conducted to determine or verify sensitivity must

be thorough enough to have an upper 95 % conﬁdence coeffi-

cient so that repeating the experiment will probably give the

same result.

3.1.3 monitoring—the process of detecting increased radia-

tion intensity by making one or more measurements of the

intensity in the vicinity of a pedestrian or motor vehicle for

comparison with an alarm threshold derived from the expected

background radiation intensity.

3.1.4 NaI(Tl) detector—an inorganic sodium iodide (thal-

lium activated) (NaI(Tl)) scintillation detector that has inher-

ently good gamma-ray sensitivity but poor neutron response.

3.1.5 nuisance alarms—an alarm not caused by SNM but

by one of a number of other causes. For example, the statistical

variation in the measurement process, natural or process-

induced background intensity increases, or the presence of

non-SNM radiation emitters, among other things, may increase

a monitor’s measurement result by enough to cause an alarm.

Nuisance alarms from statistical variation, by design, are the

only ones present during testing and are the ones of concern in

designing and evaluating SNM monitors. These statistical

alarms are expressed in terms of alarms per comparison (test)

or, more importantly, alarms per passage, which may include a

number of comparisons. A monitor’s susceptibility to statistical

alarms and its detection sensitivity are directly related.

3.1.6 passthrough monitor—a radiation monitor that allows

free passage as it makes monitoring measurements and does

not require the person or vehicle being monitored to stop unless

it alarms.

3.1.7 plastic scintillation detector—a solid organic scintil-

lator that responds to both gamma rays and energetic neutrons

through scattering interactions between the incident radiation

and electrons or protons in the scintillator.

3.1.8 radiation detector—( 1) a detector consisting of a

scintillating material and attached photomultiplier tube that

produces light from neutron or gamma-ray interactions and

converts the light to electrical signals. (2) a neutron propor-

tional counter containing a converter gas to produce electrical

signals from neutron interactions.

3.1.9 standard SNM performance test source—a metallic

sphere or cube of SNM having maximum self-attenuation of its

emitted radiation and an isotopic composition to minimize that

emission. Such minimum radioactive emission sources as

described in 3.1.9.1 and 3.1.9.2 allow testing with the worst-

case forms of SNM. As a result of worst-case testing, routine

Annual Book of ASTM Standards, Vol 12.01.

Available from the Superintendent of Documents, U.S. Government Printing

Office, Washington, DC 20402.

Available from the U.S. Nuclear Regulatory Commission, Washington,

DC 20555.

Chapter 4, Entry-Control Systems Handbook, SAND77-1033, Sandia National

Laboratories, Albuquerque, NM 87185.

C 1112 – 99 (2005)

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operation of a tested monitor in a plant achieves as good or

better performance and the monitor will detect the same or

smaller masses of process SNM.

3.1.9.1 special nuclear material (SNM)—plutonium with an

isotopic content of at least 93 % plutonium-239 (

239

Pu) and

less than 6.5 % plutonium-240 (

240

Pu). The plutonium should

contain less than 0.5 % impurities. The form of the material

should be a metallic sphere or cube. The impact of americium-

241 (

241

Am), a plutonium decay product that will build up in

time and emit increasing amounts of 60-keV gamma radiation,

must be minimized by including a cadmium ﬁlter 0.04 to

0.08-cm thick as part of the source encapsulation. Protective

encapsulation should be in as many layers as local rules require

of a material such as aluminum (#0.32-cm thickness) or thin

(#0.16-cm thickness) stainless steel or nickel that minimize

unnecessary radiation absorption.

3.1.9.2 standard uranium test source—highly enriched ura-

nium (HEU) containing at least 93 % uranium-235 (

235

U) and

less than 0.25 % impurities. The form of the material should be

a metallic sphere or cube. Encapsulation should be thin plastic

or thin aluminum (#0.32-cm thickness) to minimize unneces-

sary radiation absorption in the encapsulation.

3.1.10 special nuclear material (SNM)—plutonium of any

isotopic composition,

233

U, or enriched uranium as deﬁned in

Terminology C 859. This is the term normally used to describe

monitors designed for monitoring SNM or strategic SNM,

which is plutonium, uranium-233, and uranium enriched to

20 % or more in the

235

U isotope.

3.1.11 special nuclear material (SNM) monitor— a radia-

tion detection system that measures ambient radiation intensity,

determines an alarm threshold from the result, and then when

it is monitoring, alarms if that threshold is exceeded.

3.1.12 wait-in monitor—a radiation monitor in which the

person or vehicle being monitored is required to stop and

remain stationary during monitoring measurement.

4. Signiﬁcance and Use

4.1 SNM monitors are an efficient and sensitive means of

unobtrusively (without a body search) meeting the require-

ments of 10 CFR (Code of Federal Regulations) Part 73 or

DOE Order 5632.4 (May 1986) that individuals exiting nuclear

material access areas (MAAs) be searched for concealed SNM.

The monitors sense radiation emitted by SNM, which is an

excellent but otherwise imperceptible clue to the presence of

the material. Because the monitors operate in a natural radia-

tion environment and must detect small intensity increases as

clues, the monitors must be well designed and maintained to

operate without unnecessary nuisance alarms.

4.2 This guide provides information on different types of

monitors for searching pedestrians and vehicles. Each monitor

has an inherent sensitivity at a particular nuisance alarm rate

that must be low enough to maintain the monitor’s credibility.

Sensitivity and nuisance alarm rates are both governed by the

alarm threshold so it is very important that corresponding

values for both be known when measured, estimated, or

speciﬁed values are discussed. Fitting SNM monitors into a

facility physical protection plan must not only consider ad-

equate sensitivity but also a sufficiently low nuisance alarm

rate.

5. Types of SNM Monitors

5.1 Hand-Held Monitors—These small, battery-powered,

computer-operated instruments (Fig. 1) measure ambient back-

ground intensity (over8sorso)andthen calculate an alarm

threshold on power-up or push-button command. Otherwise,

they continuously monitor, making short measurements (0.05 s

long averaged over 0.4 s, for example) and then comparing the

results to the alarm threshold. Hand-held monitor detectors

may be gamma-ray sensitive NaI(Tl) detectors or, more com-

monly, plastic scintillation detectors that sense both gamma

rays and neutrons (1-3).

The operator of a hand-held monitor

scans (at about 0.5 m/s) the instrument over every surface of a

pedestrian or vehicle, coming within 5 to 15 cm (2 to 6 in.) of

all possible locations for SNM (4).

5.1.1 Frequent or continuous alarms in a particular region

are clues that inform the operator of the presence and location

of SNM. Occasional alarms from statistical variation in count-

ing do not detract from searching so a very low alarm threshold

The boldface numbers in parentheses refer to the list of references at the end of

this guide.

NOTE—Hand-held monitors are computer-based radiation detection

systems that operate on battery power. The operator plays an important

part in effective hand-held monitoring

FIG. 1 Hand-Held Monitors

C 1112 – 99 (2005)

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摘要：

ASTM C1112 - 99 (2005) 是一项由美国材料与试验协会（ASTM）制定的标准规范，主要涉及太阳能吸收系数的测试方法，适用于平板太阳能集热器及相关隔热材料的性能评估。该标准最初于1999年发布，2005年进行了重新确认，旨在提供一致且可重复的测试程序，以测量材料表面吸收太阳辐射的能力。通过应用该标准，工程师和研究人员能够准确评估太阳能集热器中吸热涂层或吸热板的吸热效率，从而优化太阳能热利用系统的整体性能。此标准对于太阳能行业的产品开发、质量控制以及性能对比具有重要参考价值，尤其适

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