Abstracts and Available Papers Presented at the 1999 International RERTR Meeting
ALTERNATIVE LEU DESIGNS FOR THE FRM-II
WITH
POWER LEVELS OF 20-22 MW*
N. A. Hanan, R. S.
Smith, and J. E. Matos
Argonne National
Laboratory
Argonne, Illinois
60439-4815 USA
ABSTRACT
Alternative
LEU Designs for the FRM-II have been developed by the RERTR Program at Argonne
National Laboratory (ANL) at the request of an FRM-II Expert Commission
established by the German Federal Government in January 1999 to evaluate the
options for using LEU fuel instead of HEU fuel in cores with power levels of 20
MW. The ANL designs would use the same
building structure and maintain as many of the HEU design features as
practical. The range of
potential LEU fuels was expanded from previous studies to include
already-tested silicide fuels with uranium densities up to 6.7 g/cm3
and the new U-Mo fuels that show excellent prospects for achieving uranium
densities in the 8-9 g/cm3 range. For each of the LEU cores, the design parameters were chosen to match
the 50 day cycle length of the HEU core and to maximize the thermal neutron
flux in the Cold Neutron Source and beam tubes. The studies concluded that an
LEU core with a diameter of about 29 cm instead of 24 cm in HEU design and
operating at a power level of 20 MW would have thermal neutron fluxes that are
0.85-0.86 times that of the HEU design in the Cold Neutron Source. With a potential future upgrade to a power
of 22 MW, this ratio would increase to 0.92-0.93.