Sensitivity of Fast Reactor Static and Dynamic Parameters to Different Fission-Product Cross-Section Data

Fast reactor static and dynamic parameters of “clean” and 100 000 MWd/MT cores were evaluated. The calculations were performed with five different fission-product cross-section sets (FPCS). The following results were obtained:

1. The k_eff is reduced by up to 10% after burnup of 100 000 MWd/MT; however, only small differences were found when using different FPCS.
2. The positive sodium void effect is doubled, and up to 50% differences are observed when using different FPCS.
3. Minor differences in plutonium isotopic concentration were found after burnup of 100 000 MWd/MT when using different FPCS in the calculations.
4. The effective delayed-neutron fraction, β_eff, is changed considerably during the burnup process, but only small differences were observed when β_eff was calculated with different FPCS.
5. The prompt-neutron lifetime, l_eff, may change by 10%; it is affected by using different FPCS.
6. The spatio-temporal behavior of a high-burnup reactor undergoing a local step perturbation differs by several orders of magnitude from the “clean” reactor, and significant differences were obtained between transient solutions using different FPCS.