Development of transient initiating event frequencies for use in probabilistic risk assessments

Technical Report · Wed May 01 00:00:00 EDT 1985

DOI:https://doi.org/10.2172/5573321· OSTI ID:5573321

Mackowiak, D P; Gentillon, C D; Smith, K L

Transient initiating event frequencies are an essential input to the analysis process of a nuclear power plant probabilistic risk assessment. These frequencies describe events causing or requiring scrams. This report documents an effort to validate and update from other sources a computer-based data file developed by the Electric Power Research Institute (EPRI) describing such events at 52 United States commercial nuclear power plants. Operating information from the United States Nuclear Regulatory Commission on 24 additional plants from their date of commercial operation has been combined with the EPRI data, and the entire data base has been updated to add 1980 through 1983 events for all 76 plants. The validity of the EPRI data and data analysis methodology and the adequacy of the EPRI transient categories are examined. New transient initiating event frequencies are derived from the expanded data base using the EPRI transient categories and data display methods. Upper bounds for these frequencies are also provided. Additional analyses explore changes in the dominant transients, changes in transient outage times and their impact on plant operation, and the effects of power level and scheduled scrams on transient event frequencies. A more rigorous data analysis methodology is developed to encourage further refinement of the transient initiating event frequencies derived herein. Updating the transient event data base resulted in approx.2400 events being added to EPRI's approx.3000-event data file. The resulting frequency estimates were in most cases lower than those reported by EPRI, but no significant order-of-magnitude changes were noted. The average number of transients per year for the combined data base is 8.5 for pressurized water reactors and 7.4 for boiling water reactors.

• Research Organization: EG and G Idaho, Inc., Idaho Falls, ID (United States)
• Sponsoring Organization: Nuclear Regulatory Commission (NRC), Washington, DC (United States)
• DOE Contract Number: AC07-76ID01570
• OSTI ID: 5573321
• Report Number(s): NUREG/CR-3862; EGG-2323; ON: TI85013441
• Resource Relation: Other Information: Includes 2 sheets of 24x reduction microfiche; Related Information: Appendices included in microfiche form have been digitized and added to the electronic version at the end of the document
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
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RISK ASSESSMENT
NUCLEAR POWER PLANTS
PWR TYPE REACTORS
DATA ANALYSIS
DATA BASE MANAGEMENT
EPRI
EVALUATION
PROBABILITY
REACTOR OPERATION
TRANSIENTS
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VALIDATION
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NATIONAL ORGANIZATIONS
NUCLEAR FACILITIES
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WATER MODERATED REACTORS
220900* - Nuclear Reactor Technology- Reactor Safety
210200 - Power Reactors
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210100 - Power Reactors
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