ML14183A570
| ML14183A570 | |
| Person / Time | |
|---|---|
| Site: | Robinson  |
| Issue date: | 08/17/1994 |
| From: | Mozafari B Office of Nuclear Reactor Regulation |
| To: | Hinnant C CAROLINA POWER & LIGHT CO. |
| Shared Package | |
| ML14183A571 | List: |
| References | |
| GL-88-20, TAC-M74460, NUDOCS 9408220211 | |
| Download: ML14183A570 (5) | |
Text
UNITED STATES 0
NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 August 17, 1994 Docket No. 50-261 Mr. C. S. Hinnant, Vice President Carolina Power & Light Company H. B. Robinson Steam Electric Plant, Unit No. 2 Post Office Box 790 Hartsville, South Carolina 29551-0790
SUBJECT:
SAFETY EVALUATION OF THE H. B. ROBINSON STEAM ELECTRIC PLANT, UNIT NO. 2, INDIVIDUAL PLANT EXAMINATION (IPE) SUBMITTAL - INTERNAL EVENTS (TAC NO. M74460)
Dear Mr. Hinnant:
On August 31, 1992, the Carolina Power & Light Company (the licensee) submitted the H. B. Robinson Steam Electric Plant, Unit No. 2 (HBR2),
Individual Plant Examination (IPE) in response to Generic Letter (GL) 88-20 and its associated supplements. The IPE submittal described the application of a Level 2 probabalistic risk assessment to identify vulnerabilities consistent with GL 88-20. The IPE submittal contains the results of an evaluation of internal events, including internal flooding.
The licensee's IPE analysis of HBR2 resulted in a mean core damage frequency (CDF) for internal events, including internal flooding, of 3.2E-04/yr.
Contributions from the most important initiating events include loss-of cooling accidents (LOCAs) (23 percent), loss of offsite power (18 percent),
loss of either division of emergency AC power bus El or E2 (10 percent), loss of service water (9 percent), and loss of component cooling water (5 percent).
In addition, a large fraction of the CDF is associated with sequences that are contained in functional groupings like reactor coolant pump seal LOCAs (21 percent), internal flooding (21 percent) and station blackout (10 percent). The submittal also provides a discussion of the 23 highest frequency sequences, the first 10 of which account for about 85 percent of the total CDF.
Enclosed is the NRC staff's Safety Evaluation (SE) on the internal events portion of submittal.
The staff's conclusions are based on a "step 1" review performed by the staff with the assistance of Science and Engineering Associates, Inc.; Scientech, Inc.; and Concord Associates, Inc.
The staff's observations are summarized in the Executive Summary provided with the enclosed SE. Other significant insights are presented in the Appendix to the SE.
The licensee's improvements under consideration include development of a more extensive preventative maintenance program for the dedicated shutdown diesel and modification of plant safety-related batteries, including possible extension of battery capacity from one to four hours. The IPE also identified numerous other improvements listed in the SE that could further reduce the
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-2 core damage frequency. In view of the relatively high core damage frequency of HBR2, and because the benefit of these improvements could be substantial, the staff strongly encourages the licensee to implement the proposed improvements.
The licensee plans to provide a separate submittal on findings stemming from the IPE external events analysis (IPEEE).
The staff will review the IPEEE separately, within the framework prescribed in GL 88-20, Supplement 4.
Based on the review of the HBR2 IPE submittal and its associated documentation, the staff concludes that the licensee has met the intent of GL 88-20.
Sincerely, Brenda Mozafari, Project Manager Project Directorate II-1 Division of Reactor Projects -
I/II Office of Nuclear Reactor Regulation
Enclosure:
As stated cc w/enclosure:
See next page
August 17, 1994
-2 core damage frequency. In view of the relatively high core damage frequency of HBR2, and because the benefit of these improvements could be substantial, the staff strongly encourages the licensee to implement the proposed improvements.
The licensee plans to provide a separate submittal on findings stemming from the IPE external events analysis (IPEEE).
The staff will review the IPEEE separately, within the framework prescribed in GL 88-20, Supplement 4.
Based on the review of the HBR2 IPE submittal and its associated documentation, the staff concludes that the licensee has met the intent of GL 88-20.
Sincerely, ORIGINAL SIGNED BY:
Brenda Mozafari, Project Manager Project Directorate II-1 Division of Reactor Projects -
I/II Office of Nuclear Reactor Regulation
Enclosure:
As stated cc w/enclosure:
DISTRIBUTION:
See next page See attached page OFC LA:P 41 DI -1 D:P
_1 NAME PAndr on BMozafari/rs 0 D,_ews DATE
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/94 S'/
/94 O/.4 /94 OFFICIAL RECORD COPY DOCUMENT NAME:
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Mr. C. S. Hinnant H. B. Robinson Steam Electric Carolina Power & Light Company Plant, Unit No. 2 cc:
Mr. H. Ray Starling Mr. Dayne H. Brown, Director Manager - Legal Department Department of Environmental, Carolina Power & Light Company Health and Natural Resources Post Office Box 1551 Division of Radiation Protection Raleigh, North Carolina 27602 Post Office Box 27687 Raleigh, North Carolina 27611-7687 Karen E. Long Assistant Attorney General Mr. Robert P. Gruber State of North Carolina Executive Director Post Office Box 629 Public Staff - NCUC Raleigh, North Carolina 27602 Post Office Box 29520 Raleigh, North Carolina 27626-0520 U.S. Nuclear Regulatory Commission Resident Inspector's Office Mr. Max Batavia, Chief H. B. Robinson Steam Electric Plant Bureau of Radiological Health Route 5, Box 413 South Carolina Department of Health Hartsville, South Carolina 29551 and Environmental Control 2600 Bull Street Regional Administrator, Region II Columbia, South Carolina 29201 U.S. Nuclear Regulatory Commission 101 Marietta St., N.W., Ste. 2900 Mr. H. W. Habermeyer, Jr.
Atlanta, Georgia 30323 Vice President Nuclear Services Department Mr. Marc P. Pearson Carolina Power & Light Company Plant Manager Post Office Box 1551 Carolina Power & Light Company Raleigh, North Carolina 27602 H. B. Robinson Steam Electric Plant Post Office Box 790 Hartsville Memorial Library Hartsville, South Carolina 29551 147 West College Avenue Hartsville, South Carolina 29550 Public Service Commission State of South Carolina Post Office Drawer 11649 Columbia, South Carolina 29211 Mr. R. M. Krich Manager - Regulatory Affairs Carolina Power & Light Company H. B. Robinson Steam Electric Plant, Unit No. 2 Post Office Box 790 Hartsville, South Carolina 29551-0790
DISTRIBUTION Docket File NRC & Local PDRs PDII-1 R/F E. Rodrick E. Chow C. Gallagher G. Holahan, AEOD R. Hernan, PDI-4/NRR B. Mozafari, PDII-1/NRR D. Houston, ACRS E. Beckjord T. Speis B. Sheron J. Murphy C. Ader J. Flack D. Matthews, PDII-1 P. Anderson OGC ACRS (10)
J. Johnson, SPSB/NRR M. Slosson, HHFB/NRR R. Barrett, CSAB/NRR A. Gibson, RII A. Thadani, ADT/NRR J. Roe, ADPR/NRR S. Varga, DRPE/NRR G. Lainas, ADR2/NRR J. Schiffgens E. Butcher