ML20034F485
| ML20034F485 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 02/26/1993 |
| From: | Shelton D CENTERIOR ENERGY |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20034F486 | List: |
| References | |
| REF-GTECI-023, REF-GTECI-065, REF-GTECI-077, REF-GTECI-105, REF-GTECI-128, REF-GTECI-143, REF-GTECI-153, REF-GTECI-A-17, REF-GTECI-A-45, REF-GTECI-DC, REF-GTECI-NI, REF-GTECI-SY, TASK-023, TASK-065, TASK-077, TASK-105, TASK-128, TASK-143, TASK-153, TASK-23, TASK-65, TASK-77, TASK-A-17, TASK-A-45, TASK-OR GL-88-20, NUDOCS 9303030295 | |
| Download: ML20034F485 (3) | |
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CENTERSOR W
ENEACY' e-Donald C. Shelton 300 Maison Avenue l'
Vice President Nuclear Toledo, OH 436520031 Davis Besse (419)249-2300 Docket Number 50-346 License Number NPF-3 Serial Number 2119 February 26, 1993 United States Nuclear Regulatory Commission Document Control Desk Vashington, D.
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20555 Subj ect: Individual Plant Examinatien (IPE) for Severe Accident Vulnerabilities for the Davis-Besse Nuclear Power Station, Unit 1 (Response to NRC Generic Letter 88-20)
Gentlemen:
Nuclear Regulatory Commission Generic Letter (GL) 88-20, Individual Plant Examination for Severe Accident Vulnerabilities, dated November 23, 1938, and GL 88-20, Supplement 1, dated August 29, 1989, requested each utility to perform an Individual Plant Examination (IPE) to identify any severe accident vulnerabilities.
In response to this request, by letter dated October 27, 1989 (Serial Number 1723), Toledo Edison (TE).cotmitted to perform a Level 1 Probabilistic Risk Assessment (FRA) and a containment performance analysis for the Davis-Besse Nuclear Power Station (DBNPS). Toledo Edison has completed the IPE for the DBNPS. The purpose of this letter is to transmit the summary report for the DBNPS~IPE.
The DBNPS IPE fulfills the NRC objectives for the IPE outlined in GL 88-20. The IPE was accomplished through the performance of a Level 2 PRA, using primarily TE personnel. This has resulted in TE obtaining the maximum benefit from the IPE, and development of'in-house expertise for future use of the DBNPS IPE models. The models were developed and documented in a manner to accommodate possible future updatinF to reflect plant changes, emerging information on severe accident behavior, or to address safety and regula.sry issues as they arise.
In addition to extensive internal review by TE personnel, the DBNPS IPE process was reviewed by an independent consultant experienced in probabilistic risk assessment.
The results of the IPE provide a perspective on the types and frequencies of potential severe. accident sequences that could be important for the DBNPS. Overall, the IPE identified no severe 9303030295 9302f6^'"
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License Number NPF-3 Serial Numbar 2119 Page 2 acc8 dent vulnerabilities for the DBNPS. The IPE indicates that core damage frequency and containment performance for the DBNPS is comparable to that of other plants. Although no severe accident vulnerabilities or itstances of unusually poor containment perforr nae vere identified, several potential enhancements based on tha in sights gained from the IPE are being considered for future implementation.
These insights and potential enhancements are described in the summary report.
In addition to addressing Unresolved Safety Issue (USI) A-45, Shutdown Decay Heat Removal Requirements, as requested by GL 88-20, the IPE directly addresses c.ther USI and Generic Safety Issues (GI) for the DBNPS. The USIs and GSIs addressed by the IPE include USI A-17 Systems Interactions GI-23 Reactor Coolant Pump Seal Failures f
GI-105 Interfacing Systems Loss of Coolant Accidents l
in Pressurized Vater Reactors GI-65 Probability of Core Melt due to Component Cooling Water System Failures GI-77 Flooding of Safety Equipment Compartments by Backflow Through Floor Drains GI-128 Electrical Power Reliability and Related Issues GI-143 Availability of Chilled Vater Systems and Room Cooling GI-153 Loss of Essential Service Vater in Light t
Vater Reactors Based on the results of the DBNPS IPE, TE considers these USIs and GIs rest '.ved.
If you have any questions regarding the information provided by this letter, plerse call Mr. R. V. Schrauder, Manager - Nuclear Licensing at (419) 249-2366.
Very ru y yours, dp j
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l PVS/dle Enclosures cc:
A. B. Davis, Regional Administrator, NRC Region III J. B. Hopkins, NRC/NRR DB-1 Senior Project Manager S. Stasek, NRC Region III, DB-1 Senior Resident Inspector Utility Radiological Safety Board i
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r Docket Numbar 50-346 License Number NPF-3 i
Lerial Number 2119 Enclosure Page 1 TRANSMITTAL OF
SUMMARY
REPORT 7
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OF THE INDIVIDUAL PLANT EXAMINATION FOR SEVERE ACCIDENT VULNERABILITIES FOR DAVIS-BESSE NUCLEAR POVER STATION l
UNIT NUMBER 1 IN RESPONSE TO GENERIC LETTER NUMBER 88-20 l
Toledo Edison's summary report of the Individual Plant Examination.for the Davis-Besse Nuclear Power Station in response to Generic Letter Number 88-20 Individual Plant Examination for Severe 1 cident Vulnerabilities, is hereby submitted under letter Serial Number 2119.
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D. C. Shelton, Vice President Nuclear j
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Svc n and subscribed before me this 26th day of February, 1993.
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