Year
1969
Abstract
In the normal course of plutonium nuclear fuel fabrication, quantities of con- taminated solid waste materials are generated. Some common forms of this waste include metal turnings, metal oxides, graphite and ceramic crucibles, paper, polyvinylchloride bags, and rubber gloves. These materials may be differentiated from plutonium scrap in that they usually contain lower Quantities of plutonium, and they require some form of pre-treatment prior to the normal dissolution pro- cesses of a scrap-recovery plant. Both nuclear materials management and operations control require that these ma- terials be assayed for their plutonium contents. Destructive assay techniques are usually limited by the problem of obtaining a representative sample of these complex, inhomogeneous compositions. Nondestructive techniques such as direct gamma or neutron counting have been used for many years in most plutonium-pro- cessing facilities, but the methods are generally too inaccurate or too insensi- tive for the demands of industrial, large-scale plutonium management. Neutron- monitoring methods are limited by cx,n reactions and by neutron attenuation in hydrogenous material; gamma pulse-height analysis using Nal(Tl) detectors is lim- ited by resolution and interfering activities which cannot be resolved from plu- tonium activities.