ML18094A900
| ML18094A900 | |
| Person / Time | |
|---|---|
| Issue date: | 03/13/2018 |
| From: | Thomas Wellock NRC/SECY |
| To: | |
| Moulton C | |
| References | |
| Download: ML18094A900 (20) | |
Text
Quantifying Reactor Accident Risk: A History Panel W20: The Metamorphosis to a More Risk
-Informed RegulatorTom Wellock NRC Risk-Informed, Performance
-Based*A "New Paradigm"
-Efficiency
-Safety Significant
-Relieve Regulatory Burden
- PRAs: "Significant Limitations"
-Industry-NRC gap-Methodology
-Data-Peer Review
- New Safety IssuesNRC Chairman Shirley Jackson 2
Three Ds of the Deterministic Era
-Deterministic Design
-Design Basis Accidents-Defense-in-Depth*Inherent Safety
- Active Systems
- Siting*Static Layers (containment) 3 4
WASH-1400 and the Roots of PRA
- Methodology: Models and Goals in the 1960s
- Regulatory Necessity
- Political Necessity 5
6Accident Modeling in the 1960s Farmer Curve 7Chauncey Starr
- Loss of Coolant and the China Syndrome
-ECCS*Anticipated Transient Without Scram
-Beyond the Design Basis Accident-Need for regulatory risk expertiseNew Safety Issues 8
AEC Under Siege
- Anti-nuclear Movement
- Environmental Protection Agency-Class 9 accidents
.-Growing interest in risk
- Congress Henry Kendall, UCS 9 WASH-1400: Positives
- New tool for regulators
- Aspectrum of accidents
- Core damage more likely but lower consequences 10 Small LOCA Event Tree from WASH
-1400 11 WASH-1400: Negatives
- Large error bands
- Inappropriate comparisons to other risks
- Some accidents not analyzed
- Lacked adequate peer review
- Lewis Committee (1978) 12 13WASH-1400, Executive Summary 14UCS Critique of WASH
-1400 Three Mile Island and WASH
-1400 Human factors and operationsSevere accidentsSafety systems other than ECCS 15TMI Control Room, March 1979 1980s: Beneficially Unfocused
-Beyond the Design Basis: ATWS, SBO, severe accidents
-Unresolved Questions: Generic issues, older plants
-Operating Reactors: Evaluating events
-New Reactors: Design certification
-Methodology: Industry PRAs and NUREG
-1150-Goals: Safety Goal Policy and Backfits 16 Toward Risk
-Informed Regulation, 1990sIndividual Plant ExaminationsTowers-Perrin ReportMaintenance RulePRA Policy Statement (1995) and Implementation Plan (1994) 17 References
- Slide 2: U.S. NRC, "An Evening with Dr. Shirley Ann Jackson," November 15, 1995, U.S. NRC ADAMS Main Library, ML003710152.
- Slide 4: C.A. Bennett to A.B. Greninger, "Evaluation of Probability of Disasters, HW-28767," July 20, 1953, DOE Public Reading Room Catalog, Accession # D8451637.*Slide 6: P.A. Crosettiand R.F. Furrer, "Comparative Reliability Analysis
-K-Reactor Secondary Coolant System, DUN
-4461" (Hanford, WA: Douglas United Nuclear, September 9, 1968), U.S. Department of Energy Opennet,,https://www.osti.gov/opennet/detail.jsp?osti
-id=16413875; B.J. Garrick, Reliability Analysis of Nuclear Power Plant Protective Systems, HN
-190 , May 1967, (Los Angeles: Holmes & Narver, May 1967); R.S. Hart and W.T. Harper, Final SNAPSHOT Safeguard Report, NAA
-SR-10022(Rev.) (San Diego, CA: Atomics International, March 20, 1965
).*Slide 7: F.R. Farmer, "Siting Criteria
-A New Approach," Containment and Siting of Nuclear Power Plants, Proceedings of a Symposium, Vienna 3
-7 April 1967 (Vienna: International Atomic Energy Agency, 1976) 322; Chauncey Starr, "Social Benefit vs. Technological Risk," Science165 no. 3899, September 19, 1969, 1232
-38. 18 References (cont.)
- Slide 9: Archive of the Norfolk Charitable Trust, Sharon, MA.
- Slides 11 and 13: U.S. NRC, Reactor Safety Study: An Assessment of Accident Risks in U.S. CommericalNuclear Power Plants, WASH
-1400 (NUREG
-75/014) (DC: U.S. NRC, October 1975).
- Slide 14: Sierra Club and Union of Concerned Scientists, Preliminary Review of the AEC Reactor Safety Study(San Francisco
-Cambridge, December 1974), 100B.*Slide 15: "TMI Control Room in 1979," U.S. NRC Flickr, https://www.flickr.com/photos/nrcgov/7447591188/in/album
-72157628998200797/.
19 Acronyms*ATWS: Anticipated Transient Without Scram
- SBO: Station Blackout
- WASH: AEC Headquarters, Washington, DC 20