1.1 本指南介绍了从含有乏核燃料后处理过程中产生的高放射性废物的储罐中获取样本的技术。美国环境保护局（EPA）还提供了关于为《资源保护和回收法案》（RCRA）所涵盖的废物选择适当采样装置的指导 ( 1. ) . 2. 本指南不包括顶部空间的蒸汽取样，因为它不会显著影响泥浆回收、管道运输、堵塞或混合。 1.2 以英寸-磅为单位的数值应视为标准值。本标准不包括其他计量单位。 1.3 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。 1.4 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）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》中确立的国际公认标准化原则制定的。 ====意义和用途====== 4.1 获取乏核燃料后处理过程中产生的高放废物样本是一项独特的挑战。通常，高放废物储存在通道有限的储罐中，以减少人员受到辐射的可能性。由于散装材料和样品的高辐射剂量，必须远程获取样品，样品在搬运、运输和储存时需要屏蔽。由于样品的危险性及其高辐射剂量，因此可以获得和运输的样品数量较少。 4.2 许多高放废物已被处理以去除锶（Sr）或铯（Cs）或两者，或通过泵送和强制蒸发减少液体体积，或经过pH值修改，或两者兼而有之，以减少储罐的腐蚀。 这些过程以及从多个加工厂操作中添加的废物流通常会导致沉淀，并产生多相废物。由于与高放废物相关的高热负荷，以及通过泵送和有意蒸发处理，一些储罐中出现了来自具有显著溶解盐浓度的废物的水蒸发，从而形成盐饼或结壳，或两者兼而有之。一些废物槽中存在有机层，从而在废物中产生额外的不均匀性。 4.3 许多取样系统都有局限性，包括对罐中不同深度的样品进行取样的能力和取样深度。汉福德储罐中的取样受立管直径、立管位置和立管可用性的限制。 4.4 由于这些非同寻常的挑战，在研究和开发方面付出了巨大的努力，以开发技术，提供高质量内容的抓取样本- 将垃圾箱放平。从高放废物槽中获取样品的主要技术总结见 表1 . 这些技术将在本指南中进行总结，假设在采样期间储罐顶部空间充分通风。

1.1 This guide addresses techniques used to obtain samples from tanks containing high-level radioactive waste created during the reprocessing of spent nuclear fuels. Guidance on selecting appropriate sampling devices for waste covered by the Resource Conservation and Recovery Act (RCRA) is also provided by the United States Environmental Protection Agency (EPA) ( 1 ) . 2 Vapor sampling of the head-space is not included in this guide because it does not significantly affect slurry retrieval, pipeline transport, plugging, or mixing. 1.2 The values stated in inch-pound units are to be regarded as standard. No other units of measurement are included in this standard. 1.3 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. 1.4 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 ====== 4.1 Obtaining samples of high-level waste created during the reprocessing of spent nuclear fuels presents unique challenges. Generally, high-level waste is stored in tanks with limited access to decrease the potential for radiation exposure to personnel. Samples must be obtained remotely because of the high radiation dose from the bulk material and the samples, samples require shielding for handling, transport, and storage. The quantity of sample that can be obtained and transported is small due to the hazardous nature of the samples as well as their high radiation dose. 4.2 Many high-level wastes have been treated to remove strontium (Sr) or cesium (Cs), or both, have undergone liquid volume reductions through pumping and forced evaporation or have been pH modified, or both, to decrease corrosion of the tanks. These processes, as well as waste streams added from multiple process plant operations, often resulted in precipitation, and produced multiphase wastes that are heterogeneous. Evaporation of water from waste with significant dissolved salts concentrations has occurred in some tanks due to the high heat load associated with the high-level waste and by pumping and intentional evaporative processing, resulting in the formation of a saltcake or crusts, or both. Organic layers exist in some waste tanks, creating additional heterogeneity in the wastes. 4.3 Many of the sampling systems have limitations including the ability to sample varying depths in the tank and the depth of sampling. Sampling in Hanford tanks is constrained by riser diameter, riser location and riser availability. 4.4 Due to these extraordinary challenges, substantial effort in research and development has been expended to develop techniques to provide grab samples of the contents of the high-level waste tanks. A summary of the primary techniques used to obtain samples from high-level waste tanks is provided in Table 1 . These techniques will be summarized in this guideline with the assumption that the tank headspace is adequately ventilated during sampling.