Hydrogen Mitigation - CNSC Focus and Expectations Following Fukushima

Abstract

This paper revisits CNSC expectations for resolution of hydrogen safety in the light of the CNSC Fukushima task force’s recommendations. Focusing on CANDU NPPs, present strategies for reduction of hydrogen in containment and steps to mitigation, assumptions, interpretation and modeling codes are discussed. Ensuring greater robustness for BDBAs rather than detailed modeling, PSA and calculation of margins is perceived to be the preferred approach. Proposed recommendations that should be the focus for future resolution of hydrogen safety and mitigation are related to present gaps and uncertainties.