Fast Reactors and Accelerator Driven Systems Knowledge Base

Conference Article: IAEA Accelerator driven system neutronic benchmark

Abstract

Reactivity and bum-up simulations have been done for the first stage of the IAEA Co-otclinated Research Program on Accelerator Driven Systems. Neutron multiplication and flux distributions were calculated using the MCNP Monte-Carlo code. Multiplication eigenvalues to the neutron transport equation were obtained by running MCNP in the KCODE mode. Our investigation shows that the space-time dependent distribution of fission events features a pronounced generation dependence, which is an inherent property of sub-critical systems having separated neutron source and core/blanket regions. The power peaking in the vicinity of the external neutron source is enhanced by slowing down of fission neutrons in the spallation target Thus the behaviour of the system is not well described by global parameters like eigenvalue, eigenflux or source importance. It is suggested that physically mote relevant entities like effective multiplication constants and generation-dependent fission distributions should be used to characterize the system.

view the full text of this article (17 pages, format: PDF, size= 778kB)

Reference:

Technical Committee Meeting, Madrid, Spain 17-19 September 1997

International Atomic Energy Agency, Vienna (Austria)

IAEA-TC--903.3, pp:535-551