ENSURING EFFECTIVENESS OF PRA CONFIGURATION CONTROL PROGRAMS

摘要

An important part of the assessment of PRA quality is that of evaluating the Configuration Control (also referred to as Maintenance and Update [MU]) procedures and practices that are in place to ensure that the PRA is being maintained current with the as-built, as-operated reference plant. The ASME Standard Peer Review is a "snapshot in time" with respect to the technical adequacy of a PRA. Since there is a large financial commitment typically required to develop a model to meet the majority of the ASME Standard supporting requirements and since the higher the quality of the PRA, the higher the likelihood of acceptance from the regulator for risk-informed applications, it is highly desirable to ensure that the models are being effectively maintained through the "routine" configuration control process. It is recommended that the industry develop a process to ensure that the PRA model and associated documentation is being maintained to a level of quality that is commensurate with the supported risk-informed applications and is as high as (or greater than) that achieved during prior full or partial scope ASME Standard Peer Reviews. The process which is proposed consists of a "tiered" approach which combines: 1) existing utility and owners group procedures 2) a robust internal (to a given plant or utility) review process consisting of examination of modeling changes, self-assessments, industry benchmarking, and the use of existing oversight processes 3) focused scope Peer Reviews limited to the subject of configuration control and model maintenance.