K-effective evaluation of the C-400/409 acidification and storage tank arrays at the Paducah Gaseous Diffusion Plant.

摘要

The objective of the task is to develop k-effective data applicable to the acidifying and storage tanks in building C-400 and building C-409 and provide documentation suitable to support criticality safety evaluation and approval. Buildings C-400 and C-409 at the Paducah Gaseous Diffusion Plant house vertical arrays of 20 foot long, 10 inch IPS 304 stainless steel tanks. The tanks are analyzed to contain solutions of uranyl fluoride and water. The Martin Marietta Energy Systems Nuclear Criticality Safety Software for the SCALE 4 system containing the KENO-V.a Monte Carlo code with the 27GROUPNDF4 cross-section set is used. The SCALE 4 system includes the NITAWL and BONAMI codes to perform appropriate cross-section processing before the KENO code is used. The Monte Carlo Neutron Particle (MCNP) code with the Evaluated Nuclear Data File/B-V (MCNP/B-V) is also used as a check on a portion of the KENO calculations. K-effective values are calculated for normal conditions, contingency conditions, and accident conditions. The upper limit k-effective values (k-effective + 2 sigma) calculated in this study are below 0.95.