- Author
-
Ravindra, M. K.
|
Baron, H.
- Title
- Methods for External Event Screening Quantification: Risk Methods Integration and Evaluation Program (RMIEP) Methods Development.
- Coporate
- Sandia National Labs., Albuquerque, NM
- Sponsor
- Nuclear Regulatory Commission, Washington, DC
- Report
-
SAND87-7156
July 1992
116 p.
- Distribution
- Available from National Technical Information Service
- Contract
- GRANT-A1386
- Keywords
-
nuclear power plants
|
risk assessment
|
methodology
- Identifiers
- Probabilistic Risk Assessment (PRA); Risk Methods Integration and Evaluation Program (RMIEP); LaSalle Nuclear Power Plant; external events; screening procedures
- Abstract
- In this report, the scoping quantification procedures for external events in probabilistic risk assessments of nuclear power plants are described. External event analysis in a PRA has three important goals: 1) The analysis should be complete in that all events are considered; 2) By following some selected screening criteria, the more significant events are identified for detailed analysis; 3) The selected events are analyzed in depth by taking into accountthe unique features of the events: hazard, fragility of structures and equipment, external-event initiated accident sequences, etc. Based on the above goals, external event analysis may be considered as a three-stage process: Stage I: Identification and Initial Screening of External Events; Stage II: Bounding Analysis; Stage III: Detailed Risk Analysis. In the present report, first, a review of published PRAs is given to focus on the significance and treatment of external events in full-scope PRAs. Except for seisimic, flooding, fire, and extreme wind events, the contributions of other external events to plant risk have been found to be negligible. Second, scoping methods for external events not covered in detail in the NRC's PRA Procedures Guide are provided. For this purpose, bounding analyses for transportaion accidents, extreme winds and tornadoes, aircraft impacts, turbine missiles, and chemical release are described.