RISK-INFORMED DETERMINISM: AN ALTERNATIVE TO RISK-INFORMED REGULATION FOR ESTABLISHING NEW OR TOTALLY REPLACING EXISTING LICENSING BASES

摘要

Since the NRC and nuclear industry adopted the philosophy to incorporate probabilistic risk assessment (PRA) insights as "risk-informed regulation (RIR)," there have been many success stories when applied on a limited basis. Instrumental has been the use of RG 1.174, An Approach for Using PRA in Risk-Informed Decisions on Plant-Specific Changes to the Licensing Basis, although not intended for establishing totally new or replacing in toto existing licensing bases. When so applied, difficulties are encountered. I have learned that a different framework is appropriate for establishing a new or totally replacing an existing licensing basis. Call it "risk-informed determinism (RID), " admitting that it could have elements of being "risk-based" depending upon how well the traditionally "qualitative" PRA aspects can be quantified. RID would use PRA, including quantification of defense-in-depth and safety margin to the extent possible, to establish deterministic quantitative criteria for the licensing basis. This paper examines four previously published examples in the area of fire protection/PRA of just how this might work.