Revised Delayed Neutron Data for Pickering NGS B

Abstract

Revised delayed neutron fractions and constants were calculated specifically for Pickering NGS B using the latest available delayed neutron data for fissionable isotopes, the currently recommended CANDU delayed photoneutron data, and the formulae provided by Laughton. Burnup-dependent number densities of the fissionable isotopes were computed with WIMS-AECL-IST. Validation and assessment of the new fractions and constants was performed by comparison of historical operating data with point kinetics simulation using the new values. Recommendations are made regarding possible improvements to the delayed neutron data.