1.1 本规程涵盖了位于活动堆芯附近的核反应堆容器支撑结构中铁素体材料所经历的中子辐射暴露监测程序。此做法包括以下方面的指导方针: 1.1.1 选择合适的剂量测量传感器组及其在反应堆腔中的正确安装。 1.1.2 进行适当的中子学计算以预测中子辐射暴露。 1.2 以国际单位制表示的数值应视为标准；非国际单位制的单位可以在术语中找到 170欧元 并且被视为标准。括号中的任何值仅供参考。 1.3 本规程适用于所有压水反应堆，其容器支架的寿命中子注量（E>1MeV）超过1 × 10 17 中子/cm 2. 或超过3.0 × 10 −4 dpa公司 ( 1. ) 。 2. （参见术语 170欧元 .） 1.4 伽马辐射对容器支撑结构的暴露不包括在本规范的范围内，但请参阅 3.2 。 1.5 本标准并非旨在解决与其使用相关的所有安全问题（如有）。 本标准的使用者有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 （例如， ( 2. ) .） 1.6 本国际标准是根据世界贸易组织技术性贸易壁垒委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认的标准化原则制定的。 ====意义和用途====== 3.1 长期以来，预测中子辐射对压力容器钢的影响一直是轻水反应堆发电厂设计和运行的一部分。两个联邦监管机构（参见 2.3 )和国家标准团体（参见 2.1 和 2.2 )已颁布法规和标准，以确保这些船只的安全操作。压水反应堆容器的支撑结构也可能受到类似的中子辐射效应 ( 1. ， 3个- 6. ) 。 2. 本规程的目的是为确定单个容器支架所经历的中子辐射暴露提供指南。 3.2 众所周知，高能光子也会产生位移损伤效应，这种效应可能与中子产生的效应相似。众所周知，在轻水反应堆压力容器的带线处，这些影响比中子引起的影响小得多。这一点尚未被证明适用于船舶支撑结构内的所有位置。 因此，应用耦合中子-光子输运方法和光子诱导位移截面来确定伽马诱导dpa是否超过3.0×10的屏蔽水平可能是谨慎的 –4 用于中子照射。（参见 1.3 .）

1.1 This practice covers procedures for monitoring the neutron radiation exposures experienced by ferritic materials in nuclear reactor vessel support structures located in the vicinity of the active core. This practice includes guidelines for: 1.1.1 Selecting appropriate dosimetric sensor sets and their proper installation in reactor cavities. 1.1.2 Making appropriate neutronics calculations to predict neutron radiation exposures. 1.2 The values stated in SI units are to be regarded as standard; units that are not SI can be found in Terminology E170 and are to be regarded as standard. Any values in parentheses are for information only. 1.3 This practice is applicable to all pressurized water reactors whose vessel supports will experience a lifetime neutron fluence (E > 1 MeV) that exceeds 1 × 10 17 neutrons/cm 2 or exceeds 3.0 × 10 −4 dpa ( 1 ) . 2 (See Terminology E170 .) 1.4 Exposure of vessel support structures by gamma radiation is not included in the scope of this practice, but see the brief discussion of this issue in 3.2 . 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. (For example, ( 2 ) .) 1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee. ====== Significance And Use ====== 3.1 Prediction of neutron radiation effects to pressure vessel steels has long been a part of the design and operation of light water reactor power plants. Both the federal regulatory agencies (see 2.3 ) and national standards groups (see 2.1 and 2.2 ) have promulgated regulations and standards to ensure safe operation of these vessels. The support structures for pressurized water reactor vessels may also be subject to similar neutron radiation effects ( 1 , 3- 6 ) . 2 The objective of this practice is to provide guidelines for determining the neutron radiation exposures experienced by individual vessel supports. 3.2 It is known that high-energy photons can also produce displacement damage effects that may be similar to those produced by neutrons. These effects are known to be much less at the belt line of a light water reactor pressure vessel than those induced by neutrons. The same has not been proven for all locations within vessel support structures. Therefore, it may be prudent to apply coupled neutron-photon transport methods and photon-induced displacement cross sections to determine whether gamma-induced dpa exceeds the screening level of 3.0 × 10 –4 used in this practice for neutron exposures. (See 1.3 .)