Abstracts and Available Papers Presented at the
2002 International RERTR Meeting

USING MOLYBDENUM DEPLETED IN 95Mo IN UMo FUEL

K. Bakker, F. Wijtsma

NRG-Petten, P.O. Box 25, 1755 ZG  Petten, The Netherlands.

A. Bos, C. Mol, H. Rakhorst,

Urenco Nederland B.V., P.O. Box 158, 7600 AD  Almelo, The Netherlands.

M. Bretscher, G. Hofman, J. Snelgrove

Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Il 60439-4815.

ABSTRACT

In recent years significant interest was gained in UMo fuel to be used in Material Test Reactors. This interest was induced by the fact that UMo fuel is mechanically stable, even at high uranium concentrations and high U-burnup. These properties are required in order to use Low Enriched Uranium (LEU) and still be able to achieve high flux and burnup values and, thus, to facilitate the conversion from High Enriched Uranium (HEU) to LEU.

Neutronics computations have shown that, although the Mo concentration in UMo fuel is not very high (about 5 - 10w%), the neutron absorption cross sections of natural Mo are sufficiently high to have a considerable negative impact on the reactivity of this UMo fuel. In the present research the neutron absorption cross sections of natural Mo are discussed and the option to reduce the cross section of molybdenum by depleting the Mo in ⁹⁵Mo is described. Finally the economic consequences of using Mo depleted in ⁹⁵Mo are briefly discussed.