1.1本指南简要介绍了用于检测特殊核材料（SNM）的辐射监测器的最新技术（见3.1.11），以建立编写监测器性能标准的背景。本指南从技术文件中提取信息，以提供选择、校准、测试和操作用于SNM控制和保护的辐射监测器的信息。作为核材料控制或核材料安全计划的一部分，本指南提供了一种不引人注目的方法，用于搜索行人、包裹和机动车辆中隐藏的SNM。辐射监测器可以提供高效、灵敏和可靠的方法来检测少量SNM的盗窃，同时保持低滋扰警报的可能性。 1.2 SNM辐射监测器的可靠运行取决于为任务选择合适的监测器，在适宜的环境中操作它们，并执行有效的程序来测试、校准和维护它们。有效的操作还需要为参加监控的安全检查员提供使用监控器的培训。培训对于手持式监控尤其重要，其中检查员通过扫描行人和包裹或整个机动车的仪器，在搜索中发挥重要作用。 1.3商用SNM辐射监测器有三种形式: 1.3.1 小型手持式监视器 — 检查员可以使用这些监视器手动搜索停车接受检查的行人和车辆。 1.3.2 自动行人监测器 — 这些监测器是门口或入口监测器，用于在行人通过辐射探测器时对其进行搜索，或在监测亭内等待，在行人停车以获得出口许可时进行扩展测量以搜索行人。 1.3.3 自动车辆监测器 — 这些监测器是在车辆通过辐射探测器时对其进行监控的入口，或者是在车辆停车以获得出口许可时进行扩展测量以搜索车辆的车辆监控站。 1.4 SNM监测器的应用指南可通过原子能委员会/核管理委员会（AEC/NRC）管理指南、AEC/ERDA/DOE性能标准以及最近由DOE赞助的国家实验室出版的手册和应用指南获得。 这一涵盖相关物理、工程实践和可用于监测的设备的广泛信息库没有定期审查和修订的自动机制。本ASTM系列指南和标准将以固定时间表重新检查和更新的形式整合信息。 1.5有关监测的最新信息使核设施和监管机构能够了解当前的监测替代方案范围。最新信息还允许制造商了解设施和监管机构的当前目标，例如，使用可靠且易于维护的仪器以低干扰报警率获得特定灵敏度。 1.6本指南以所列出版物为技术基础，更新并扩大了NRC管理指南和AEC/ERDA/DOE SNM监测器性能标准的范围。 1.7以国际单位制表示的数值应视为标准。 1.8 本标准可能涉及危险材料、操作和设备。本标准并非旨在解决与其使用相关的所有安全问题。本标准的用户有责任在使用前制定适当的安全和健康实践，并确定监管限制的适用性。 ====意义和用途====== SNM监测器是一种高效、灵敏的方法，可以不受干扰地（无需搜身）满足10 CFR（联邦法规）第73部分或DOE第5632号令的要求。 4（1986年5月），对离开核材料进入区（MAA）的个人进行搜查，以寻找隐藏的SNM。监测仪感应SNM发出的辐射，这是一个很好的但在其他方面无法察觉的材料存在的线索。由于监测器在自然辐射环境中运行，必须检测到轻微的强度增加作为线索，因此监测器必须经过良好的设计和维护，以在没有不必要的干扰警报的情况下运行。 本指南提供了用于搜索行人和车辆的不同类型监视器的信息。每个监视器在特定的干扰报警率下具有固有的灵敏度，该报警率必须足够低，以保持监视器的可信度。 灵敏度和干扰报警率均受报警阈值的控制，因此在讨论测量、估计或指定值时，必须知道两者的相应值。将SNM监测器安装到设施实物保护计划中不仅必须考虑足够的灵敏度，还必须考虑足够低的干扰报警率。

1.1 This guide briefly describes the state-of-the-art of radiation 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 information 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 concealed 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 operation 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 important 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 portals 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 sponsorship. 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 information 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 performance 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, operations, 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 appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. ====== Significance And Use ====== SNM monitors are an efficient and sensitive means of unobtrusively (without a body search) meeting the requirements 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 radiation environment and must detect small intensity increases as clues, the monitors must be well designed and maintained to operate without unnecessary nuisance alarms. 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’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 adequate sensitivity but also a sufficiently low nuisance alarm rate.