Optimization of DNA Measurements in Field Conditions for Safeguards Purposes

摘要

The second part of the campaign has been carried out on LWR fuel assemblies at the FBFC facility (Franco-Belge de Fabrication de Combustibles). The main results are the following: 1. Active assay for exp 235 U. The statistical precision for a 1000-s run varies from 0.6-0.9% depending on the type of assembly. For longer counting periods, the ultimate precision is about 0.1% for repeat runs with a fixed geometry. 2. Passive results for exp 238 U. The counting rates for the passive measurements are much lower than in the active case. The standard deviation is 1.6 percent (1000s) but the results are influenced by neutron background variations. (Atomindex citation 13:648507)