Proposed Extension of Raschig Ring Standard to Low Enriched Uranium Fuels

Subcommittee 8 of the Standards Committee of the American Nuclear Society has conducted the prescribed five-year review and update of ANSI N16.4-1971, which provides guidance for the use of borosilicate glass Raschig rings as a neutron absorber in solutions of highly enriched fissile materials. The proposed revision to the Standard extends its application to low enriched ²³⁵U fuels based on the ²³⁵U concentration in the vessel and to a limited range of alkaline environments. It incorporates standard American Society for Testing and Materials chemical acceptance tests for the glass, a chemical acceptance test for its acceptability in an alkaline environment, and a test that provides information on volume loss due to chemical reaction in addition to that due to settling.