Abstracts and Available Papers Presented at the
1998 International RERTR Meeting

A NEW STANDARD FOR URANIUM METAL INTENDED FOR
RESEARCH REACTOR FUEL FABRICATION

Juergen Laucht*, Hans Mueller*

*N U K E M Nuklear GmbH
Fuel Cycle Services
D-63754 Alzenau, Germany

ABSTRACT

After many years of recommendation by NUKEM the ASTM Subcommittee C 26.02 has established a draft standard for uranium metal 15 - 20% enriched in U-235 to be used in research reactors. The standard applies to both unirradiated (Enriched Commercial Grade Uranium Metal) and reprocessed uranium (Enriched Recovered Uranium Metal).

The standard unifies both materials, unirradiated and recovered to be referred as "Commercial Grade Enriched Uranium Metal" within the same specification. No distinction is made – not even for transuranic element and fission product contents. For both materials the same limits apply.

For radionuclides, the standard establishes a common specification table of U-isotopes for both, unirradiated and recovered uranium. Although it is considered that unirradiated uranium has much lower contents of the U-isotopes U-232, 234, 236, the specification deals with the same specification values as an envelope for both.

For impurities only 21 individual elements were specified. A maximum limit for the total of impurities and a boron equivalent content (EBC) for limitation of the most sensitive neutron absorbing elements completes the short list of impurity requirements.

The simplification in the draft standard being made by the ASTM is a great progress for buyers and sellers of uranium for research reactors, making uranium procurement a little bit more easy.