FEATURES OF IDENTIFICATION OF FUEL DETAILS OF RESEARCH REACTORS

This report is prepared on the basis of research executed under contract B513798 between RFNC-VNIITF and LLNL. Problems in the identification of nuclear materials from research reactors are considered, with a view toward nonproliferation and counteracting the illegal circulation of nuclear materials. It will be shown that, in most cases in which the fuel detail is stolen entirely, labor-intensive and high-precision techniques for preliminary identification are not required. It is possible, in most cases, to limit identification techniques to an external survey and measurement of the geometrical sizes, density, and enrichments. It will also be shown in this report that, from a fragment of a fuel detail, it is possible to reconstruct with some probability the initial form of the detail in many cases. Approaches to solving this problem have been developed. However, if the fuel detail of a reactor was fused, dissolved, transformed in a scrap, etc. it is necessary to measure enrichment, alloying additives, and impurity levels in order to identify the “unknown” fuel material. However, even these measurements do not always solve the problem. Therefore, the choice and substantiation of identification attributes should be a subject of special research. For strengthening confidence in the identification of unknown NM, it is recommended to create independent research laboratories.