1.1本试验方法涵盖了使用 252 Cf shuffler。Shuffler测量已应用于高达100L的容器中的各种基质材料。对基质材料的影响进行了校正。该测试方法的应用包括用于保障、责任、TRU和U废物分离、处置和过程控制目的的测量 (1, 2, 3) . 1.1.1本试验方法使用被动中子符合计数 (4) 测量 240 Pu有效质量。它已用于测定总钚含量在0.03 g至1000 g之间的项目。它可用于测量其他自发裂变同位素，如Cm和Cf。它具体描述了移位寄存器电子设备使用的方法；然而，它可以适用于其他电子产品。 1.1.2本试验方法使用带有可移动Cf源的中子辐照，并对诱发裂变产生的延迟中子进行计数，以测量 235 U当量裂变质量。它已用于检测具有以下特征的项目: 235 铀含量在0.1克至1000克之间。它可用于测定其他裂变和可裂变同位素。 1.2本试验方法要求了解相对同位素组成（见试验方法C 1030） )根据可测量的量来确定不同元素的质量。 1.3以国际单位制表示的数值应视为标准值。本标准不包括其他计量单位。 1.4本试验方法中所述的技术适用于除废料和废物以外的材料。本试验方法中未涉及这些其他应用。 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。 第8节给出了具体的预防说明。 ====意义和用途====== 本试验方法用于测定容器中废料和废物的U和Pu含量。主动测量时间通常为100至1000秒。被动测量时间通常为400秒至数小时。根据具体的矩阵、校准材料、临界安全或计数设备考虑，可以进一步限制以下限制。 被动测量已应用于208 L桶中的良性基质，Pu含量在30 mg至1 kg之间。 主动测量已应用于带有 235 铀含量范围约为100 mg至1 kg。 该测试方法可用于证明符合保障、废物、处置和环境法规中规定的放射性水平（例如，见NRC管理导则5）。 11、5.53、DOE订单5820.2a和10CFR61第61.55节和第61.56节、40CFR191和DOE/WIPP-069）。 该试验方法可用于检测使用屏蔽封装核材料的转移尝试。 测量结果的偏差与项目大小和密度、基质的均匀性和成分以及核材料的数量和分布有关。测量结果的精度与核材料的数量和测量的计数时间有关。 对于特定于基体的方法和基体校正方法，该方法假设校准材料与待测量项目相匹配，涉及基体的均匀性和成分、中子慢化剂和吸收体含量以及核材料的数量，其影响测量的程度。 建议在将废料和废物装入大型容器之前，对其进行测量。 可能需要特殊安排，以在大空腔通用脱毛器中对小容器进行分析，以达到最佳效果。 建议在内容物均匀的容器上进行测量。一般来说，核材料、中子慢化剂和中子吸收剂分布的不均匀性有可能导致有偏差的结果。 本试验方法要求已知贡献元素的相对同位素组成。 本试验方法假设当基质影响中子传输时，作用同位素在整个容器中的分布是均匀的。 本试验方法假设肿块影响不重要 — 也就是说，大量特殊核材料并没有集中在容器的一小部分中。 为了从本试验方法的应用中获得最佳结果，需要对物品进行适当的包装。 应为测量前包装废料和废物的人员提供适当的培训（例如，见ANSI 15.20，指南C 1009 ，指南C 1490 ，和指南C 1068 用于培训指导）。有时，现场特定条件和要求可能具有更大的影响。

1.1 This test method covers the nondestructive assay of scrap and waste items for U, Pu, or both, using a 252 Cf shuffler. Shuffler measurements have been applied to a variety of matrix materials in containers of up to several 100 L. Corrections are made for the effects of matrix material. Applications of this test method include measurements for safeguards, accountability, TRU, and U waste segregation, disposal, and process control purposes (1, 2, 3) . 1.1.1 This test method uses passive neutron coincidence counting (4) to measure the 240 Pu-effective mass. It has been used to assay items with total Pu contents between 0.03 g and 1000 g. It could be used to measure other spontaneously fissioning isotopes such as Cm and Cf. It specifically describes the approach used with shift register electronics; however, it can be adapted to other electronics. 1.1.2 This test method uses neutron irradiation with a moveable Cf source and counting of the delayed neutrons from the induced fissions to measure the 235 U equivalent fissile mass. It has been used to assay items with 235 U contents between 0.1 g and 1000 g. It could be used to assay other fissile and fissionable isotopes. 1.2 This test method requires knowledge of the relative isotopic composition (See Test Method C 1030 ) of the special nuclear material to determine the mass of the different elements from the measurable quantities. 1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.4 The techniques described in this test method have been applied to materials other than scrap and waste. These other applications are not addressed in this test method. 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 and health practices and determine the applicability of regulatory limitations prior to use. Specific precautionary statements are given in Section 8. ====== Significance And Use ====== This test method is used to determine the U and Pu content of scrap and waste in containers. Active measurement times have typically been 100 to 1000 s. Passive measurement times have typically been 400 s to several hours. The following limits may be further restricted depending upon specific matrix, calibration material, criticality safety, or counting equipment considerations. The passive measurement has been applied to benign matrices in 208 L drums with Pu content ranging from 30 mg to 1 kg. The active measurement has been applied to waste drums with 235 U content ranging from about 100 mg to 1 kg. This test method can be used to demonstrate compliance with the radioactivity levels specified in safeguards, waste, disposal, and environmental regulations (for example, see NRC regulatory guides 5.11, 5.53, DOE Order 5820.2a, and 10CFR61 sections 61.55 and sections 61.56, 40CFR191, and DOE/WIPP-069). This test method could be used to detect diversion attempts that use shielding to encapsulate nuclear material. The bias of the measurement results is related to the item size and density, the homogeneity and composition of the matrix, and the quantity and distribution of the nuclear material. The precision of the measurement results is related to the quantity of nuclear material and the count time of the measurement. For both the matrix-specific and the matrix-correction approaches, the method assumes the calibration materials match the items to be measured with respect to the homogeneity and composition of the matrix, the neutron moderator and absorber content, and the quantity of nuclear material, to the extent they affect the measurement. It is recommended that measurements be made on small containers of scrap and waste before they are combined in large containers. Special arrangement may be required to assay small containers to best effect in a large cavity general purpose shuffer. It is recommended that measurements be made on containers with homogeneous contents. In general, heterogeneity in the distribution of nuclear material, neutron moderators, and neutron absorbers has the potential to cause biased results. This test method requires that the relative isotopic compositions of the contributing elements are known. This test method assumes that the distribution of the contributing isotopes is uniform throughout the container when the matrix affects neutron transport. This test method assumes that lump affects are unimportant — that is to say that large quantities of special nuclear material are not concentrated in a small portion of the container. For best results from the application of this test method, appropriate packaging of the items is required. Suitable training of the personnel who package the scrap and waste prior to measurement should be provided (for example, see ANSI 15.20, Guide C 1009 , Guide C 1490 , and Guide C 1068 for training guidance). Sometimes site specific conditions and requirements may have greater bearing.