Tomographic Gamma Scanning to Assay Heterogeneous Radioactive Waste
Tomographic Gamma Scanning to Assay Heterogeneous Radioactive Waste
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DOI：
10.13182/nse94-a19380
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发表时间：
1994-11
影响因子：
1.2
通讯作者：
R. Estep;T. Prettyman;G. Sheppard
中科院分区：
文献类型：
--
作者：
R. Estep;T. Prettyman;G. Sheppard
摘要目前对208升桶中的特殊核材料（SNM）和超铀（TRU）废物进行非破坏性分析的方法，当桶基质和/或放射性核素分布不均匀时，分析误差可达100%或更大。这个问题是解决的断层扫描仪（TGS）的方法，用于分析非均质鼓SNM/TRU废物的发展。TGS方法通过对鼓进行低分辨率断层扫描发射和透射扫描，改进了完善的分段伽马扫描仪（SGS）方法，得到了基质密度和放射性核素分布的粗糙三维图像。这些图像用于进行精确的点对点衰减校正。TGS几何计数效率是典型SGS装置的60%，允许使用单检测器系统的TGS测定时间仅为28分钟/桶。TGS方法也可用于无损检测。目前，TGS是鼓中成像SNM的唯一实用方法。
AbstractCurrent methods for the nondestructive assay of special nuclear materials (SNM) and trans-uranic (TRU) waste in 208-l drums can give assay errors of 100% or more when the drum matrix and/or radionuclide distribution is nonuniform. This problem is addressed by the development of the tomographic-gamma-scanner (TGS) method for assaying heterogeneous drummed SNM/TRU waste. The TGS method improves on the well-established segmented-gamma-scanner (SGS) method by performing low-resolution tomographic emission and transmission scans on the drum, yielding coarse three-dimensional images of the matrix density and radionuclide distributions. The images are used to make accurate, point-to-point attenuation corrections. The TGS geometric counting efficiency is 60% that of a typical SGS device, allowing a TGS assay time of only 28 min/drum with a one-detector system. The TGS method may also be useful for nondestructive examination. Currently, TGS is the only practical method of imaging SNM in drums.