10 CFR 50.69

1. 10 CFR 50.69 50.69 Risk-Informed Categorization and Treatment of Structures, Systems and Components for Nuclear Power Reactors NESCC November 3, 2014 Stephen Dinsmore Senior Reliability and Risk Analyst Division of Risk Assessment Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission

2. 10 CFR 50.69 Overview • Voluntary alternative rule • Determine safety significance of SSCs after defining the population of safety-related components • Modify special treatment requirements on SSCs based on their safety significance • Treatment of low-safety-significance SSCs being addressed in draft new inspection manual procedure 37060 • Vogtle Submitted Pilot Application August 31, 2012 • NRR SER in final review phase

3. 10 CFR 50.69 Four-Box Categorization

4. 10 CFR 50.69Categorization Process • Minimum of a Level 1, internal events PRA • External events and Shutdown using PRA or using conservative evaluations • Non-PRA functions and defense-in-depth addressed with questions that Integrated Decision-making Panel answers • Active component significance based on • Risk increase caused if component failed (Risk Achievement Worth) and • Nominal contribution to current risk (Fussel-Vessly) • Quantitative sensitivity studies for key uncertainties • Passive component pressure retaining (rupture) significance based on consequences of failure • Performance monitoring linked to unreliability increases • Change-in-risk primarily verifies categorization and subsequent monitoring guideline values