ML20100K532

NRC Fbts Workshop - Intro Slides

ML20100K532
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Issue date:	03/12/2020
From:	NRC/RES/DRA
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Littlejohn J (301) 415-0428
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Welcome Flood Barriers Testing Strategies Public Meeting NRC HQ, Rockville, MD March 12, 2020 1

Room Audio: call 888-748-8559 participant passcode: 79389 press *6 to mute your phone line

Evacuation Room Audio: call 888-748-8559 participant passcode: 79389 press *6 to mute your phone line

Talking Points Present preliminary research results from the INL-NRC project including:

- An overview of flood barriers in the project scope

- A review of potential flood barrier testing facilities, including decommissioning plants for potential harvesting We are seeking input and insights on testing strategies for flood barriers

Regulatory Context The regulatory criterion for protection of structures, systems, and components (SSCs) important to safety against natural phenomena is provided in 10 CFR Part 50 Appendix A, General Design Criterion (GDC) 2 Design bases for protection against natural phenomena. GDC-2 states that SSCs important to safety shall be designed to withstand the effects of natural phenomena that have been historically reported for the site and surrounding area, with sufficient margin for the limited accuracy, quantity, and period of time in which the historical data have been accumulated.

The regulation also states that the design bases shall reflect appropriate combinations of the effects of normal and accident conditions with the effects of the natural phenomena.

The requirements for the contents of applications for new reactors is provided in 10 CFR Part 52, more specifically 10 CFR Part 52.17(a)(1)(vi), for early site permits (ESPs) and 10 CFR Part 52.79 (a)(1)(iii), for combined licenses as they relate to the hydrologic characteristics of the proposed site with appropriate consideration of the most severe of the natural phenomena that have been historically reported for the site and surrounding area and with sufficient margin for the limited accuracy, quantity, and period of time in which the historical data have been accumulated.

Technical Context The most common flood protection features are seals for penetrations in external walls (and internal walls) of safety related structures that allow cables, conduits, cable trays, piping etc., to pass through the walls. Other flood protection features include water-tight doors, as well as temporary flood barriers (e.g.,

temporary walls, stop-logs).

Operational experience (domestic and international) provides clear indication that flood barrier performance may have significant safety implications, especially as reactor fleet ages. Performance of flood protection features at NPPs has been ongoing safety issue for some time.

Industry and NRC have appropriate analysis tools for addressing the risk-significance of flood barrier performance (i.e. PRA models), but basic performance/reliability data on in-service components is lacking. This research project will identify and assess options and develop strategies for testing NPP flood barriers.

Fort Calhoun NPP (now decomm.) 2011

2019 -- Before (Looking North)

2019 --After (Looking North)