Status of Deuterium Nuclear Data for the Simulation of Heavy Water Reactors

Abstract

An overview is presented of the status of the deuterium nuclear data used in reactor physics simulations of heavy water (D2O) reactors and of ongoing activities to improve their accuracy. The main subjects having noticeable reactivity impact for critical systems involving D2O are the degree of backscatter in D(n,n)D elastic scattering at neutron energies <3.2 MeV, the value of the elastic scattering cross section at thermal neutron energies and the adequacy of their numerical representation in evaluated nuclear data libraries. The scope includes fundamental nuclear-data measurements; three-body nuclear-theory calculations; and MCNP5 simulations of experiments involving D2O or deuterated targets.