Calculation and Comparisons With Measurement of Fast Neutron Fluxes in the Material Testing Facilities of the NRU Research Reactor

Abstract

The NRU reactor at Chalk River provides three irradiation facilities to study the effects of fast neutrons (E> 1 MeV) on reactor materials for assessing material damages and deformations. The facilities comprise two types of fast neutron rods (Mark-4 and Mark-7), and one type of Material Test Bundles (MTB). This paper describes the neutronic simulations in these facilities using the WIMS-AECL and TRIAD code, and comparisons with the fast neutron flux measurements using iron-wire activation techniques. It also provides the comparisons of flux levels, neutron spectra, and the size limitations of the experimental cavities between these facilities.