辐射防护 密封放射源 一般要求和分级

[中文适用范围]： 本标准建立了以试验性能为基础的密封放射源分类体系，规定了一般要求、性能试验、生产试验、标志和认证。 它提供了一系列测试，密封放射源的制造商可以通过这些测试来评估其产品在使用中的安全性，并且此类源的用户可以选择适合所需应用的类型，特别是在防止放射性物质释放的情况下，从而导致暴露于电离辐射，是值得关注的。 本国际标准还可作为监管机构的指南。 这些测试分为几组，包括暴露于异常高温和低温以及各种机械测试。 每个测试都可以按不同的严重程度进行应用。 通过或失败的标准取决于密封放射源内容物的泄漏。 注：ISO 9978 中给出了泄漏测试方法。 尽管本国际标准通过各种测试对密封源进行了分类，但这并不意味着密封源在额定分类下连续使用时将保持其完整性。 例如，在 600 °C 下测试 1 小时的密封源如果在 600 °C 下连续使用，可能会也可能不会保持其完整性。 表 3 列出了密封放射源的主要典型应用，以及每种应用的建议测试时间表。 这些测试构成了与最广泛意义上的应用相对应的最低要求。4.2 列出了在特别恶劣条件下应用时应考虑的因素。 本国际标准并未尝试根据发射的辐射对源的设计、构造方法或校准进行分类。 本国际标准不涵盖核反应堆内的放射性材料，包括密封源和燃料元件。 [外文原描述]： ISO 2919:2012 establishes a classification system for sealed radioactive sources that is based on test performance and specifies general requirements, performance tests, production tests, marking and certification. It provides a set of tests by which manufacturers of sealed radioactive sources can evaluate the safety of their products in use and users of such sources can select types which are suitable for the required application, especially where protection against the release of radioactive material, with consequent exposure to ionizing radiation, is concerned. ISO 2919:2012 can also serve as guidance to regulating authorities. The tests fall into several groups, including, for example, exposure to abnormally high and low temperatures and a variety of mechanical tests. Each test can be applied in several degrees of severity. The criterion of pass or fail depends on leakage of the contents of the sealed radioactive source. Although ISO 2919:2012 classifies sealed sources by a variety of tests, it does not imply that a sealed source will maintain its integrity if used continuously at the rated classification. For example, a sealed source tested for 1 h at 600 °C might, or might not, maintain its integrity if used continuously at 600 °C. A list of the main typical applications of sealed radioactive sources, with a suggested test schedule for each application, is given in Table 3. The tests constitute minimum requirements corresponding to the applications in the broadest sense. Factors to be considered for applications in especially severe conditions are listed in 4.2. ISO 2919:2012 makes no attempt to classify the design of sources, their method of construction or their calibration in terms of the radiation emitted. Radioactive materials inside a nuclear reactor, including sealed sources and fuel elements, are not covered by ISO 2919:2012.