ML16131A391
| ML16131A391 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 07/17/1992 |
| From: | Wiens L Office of Nuclear Reactor Regulation |
| To: | Hampton J DUKE POWER CO. |
| References | |
| GL-88-20, TAC-M74440, TAC-M74441, TAC-M74442, NUDOCS 9207230200 | |
| Download: ML16131A391 (5) | |
Text
July 17, 1992 Docket Nos. 50-269, 50-270 and 50-287 Mr. J. W. Hampton Vice President, Oconee Site Duke Power Company P. 0. Box 1439 Seneca, South Carolina 29679
Dear Mr. Hampton:
SUBJECT:
REQUEST FOR ADDITIONAL INFORMATION - OCONEE GENERIC LETTER 88-20 INDIVIDUAL PLANT EXAMINATION (IPE) SUBMITTAL (TACS M74440/M74441/M74442)
The NRC staff is continuing its review of the Duke Power Company (DPC) Generic Letter 88-20 IPE submittal provided to the staff in December 1990. The staff finds that additional information is needed in order to complete its review.
Accordingly, please provide responses to the questions identified in the enclosure within 30 days of the date of this letter. These questions have been previously discussed by telephone with members of DPC staff. If you have any questions, please contact me at (301) 504-1495.
This requirement affects fewer than 10 respondents and, therefore, is not subject to Office of Management and Budget clearance under P.L.96-511.
Sincerely,
/s/
by T.REED for L.WIENS Leonard A. Wiens, Project Manager Project Directorate 11-3 Division of Reactor Projects-I/II Office of Nuclear Reactor Regulation
Enclosure:
IPE Questions cc w/enclosure:
See next page DISTRIBUTION:
Docket File DMatthews NRC/Local PDRs LWiens PDII-3 R/F LBerry Oconee R/F OGC, 15Bl8 SVarga ACRS (10), P-315 GLainas LReyes, RH OFC PDII-PD D:
3 NAME L. Berry L.
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// /92 1/
11/92
/ 792 Document Name:
C:/IPERAI.OCO 9207230200 920717 IfdE E
PDR ADOCK 05000269 P
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555 July 17, 1992 Docket Nos. 50-269, 50-270 and 50-287 Mr. J. W. Hampton Vice President, Oconee Site Duke Power Company P. 0. Box 1439 Seneca, South Carolina 29679
Dear Mr. Hampton:
SUBJECT:
REQUEST FOR ADDITIONAL INFORMATION - OCONEE GENERIC LETTER 88-20 INDIVIDUAL PLANT EXAMINATION (IPE) SUBMITTAL (TACS M74440/M74441/M74442)
The NRC staff is continuing its review of the Duke Power Company (DPC) Generic Letter 88-20 IPE submittal provided to the staff in December 1990. The staff finds that additional information is needed in order to complete its review.
Accordingly, please provide responses to the questions identified in the enclosure within 30 days of the date of this letter. These questions have been previously discussed by telephone with members of DPC staff. If you have any questions, please contact me at (301) 504-1495.
This requirement affects fewer than 10 respondents and, therefore, is not subject to Office of Management and Budget clearance under P.L.96-511.
Sincerely, Leonard A. Wiens, Project Manager Project Directorate 11-3 Division of Reactor Projects-I/Il Office of Nuclear Reactor Regulation
Enclosure:
IPE Questions cc w/enclosure:
See next page
Mr. J. W. Hampton Duke Power Company Oconee Nuclear Station cc:
Mr. A. V. Carr, Esquire Mr. M. E. Patrick Duke Power Company Compliance 422 South Church Street Duke Power Company Charlotte, North Carolina 28242-0001 Oconee Nuclear Site P. 0. Box 1439 J. Michael McGarry, III, Esquire Seneca, South Carolina 29679 Winston and Strawn 1400 L Street, NW.
Mr. Alan R. Herdt, Chief Washington, DC 20005 Project Branch #3 U. S. Nuclear Regulatory Commission Mr. Robert B. Borsum 101 Marietta Street, NW. Suite 2900 Babcock & Wilcox Atlanta, Georgia 30323 Nuclear Power Division Suite 525 Ms.'Karen E. Long 1700 Rockville Pike Assistant Attorney General Rockville, Maryland 20852 North Carolina Department of Justice Manager, LIS P. 0. Box 629 NUS Corporation Raleigh, North Carolina 27602 2650 McCormick Drive, 3rd Floor Clearwater, Florida 34619-1035 Mr. R. L. Gill, Jr.
Licensing Senior Resident Inspector Duke Power Company U. S. Nuclear Regulatory Commission P. 0. Box 1007 Route 2, Box 610 Charlotte, North Carolina 28201-1007 Seneca, South Carolina 29678 Regional Administrator, Region II U. S. Nuclear Regulatory Commission 101 Marietta Street, NW. Suite 2900 Atlanta, Georgia 30323 Mr. Heyward G. Shealy, Chief Bureau of Radiological Health South Carolina Department of Health and Environmental Control 2600 Bull Street Columbia, South Carolina 29201 Office of Intergovernmental Relations 116 West Jones Street Raleigh, North Carolina 27603 County Supervisor of Oconee County Walhalla, South Carolina 29621
ADDITIONAL OCONEE IPE QUESTIONS
- 1.
Please briefly describe how the recovery time was analyzed for the air-operated valves that belong to the Emergency Feedwater system.
- 2.
What is the percentage of the time that the plant was operating with the primary side PORV block valve in a closed position?
Please briefly discuss how sensitive is this parameter to the overall core damage frequency.
- 3.
Please provide the zone-specific details with respect to room cooling for the E breakers of all three units. Please provide a summary of the IPE's results for the loss of switchgear room cooling event (as an initiating event) for each of the three Units.
- 4.
Please provide a brief discussion related to the treatment of the low pressurizer pressure signal as an initiating event.
- 5.
Please provide a summary of the peer review findings made by the in-house engineering group related to the PRA/IPE analyses and activities and their dispositioning into the final IPE.
- 6.
Please provide additional information about how the NSAC PRA HRA was used in the HRA for the IPE submittal.
Specifically, please address how the human actions identified in the NSAC PRA were used in the IPE analysis, how HRA methods used in the NSAC PRA were or were not used and rationale as to why they were or were not used. Also, please identify any human actions are not common to both PRAs.
- 7.
In answer to a previous question, Oconee staff indicated that PSFs were not explicitly treated in the IPE, but that PSFs were inherent in the HCR method. Please provide additional information about qualitative information used in the development of the HEPs and what qualitative insights were gained from performing the HRA for the IPE analysis.
- 8.
With regard to your response to Question 7:
a)
How does the containment capacity analysis of Appx G of the OPRA account for failure of elastomer seals? The Vm factor of 0.1 appears to be utilized to account for Ananalyzed structural failures.
b)
Are any thermal analyvses used to evaluate the fail-ures-potent4al for double barrier elastomer seal performance under-containment atmospheric temperatures representative of DCK events? If so describe them.
- 9.
Please specify what specific revision(s) of the MAAP-3.OB code were used for the OPRA. Please address the Gabor Kenton & Associates report prepared for EPRI ("Recommended Sensitivity Analyses for an Individual Plant Examination using MAAP-3.OB).
In particular with respect to Appendix A of the report, please indicate for each of the 78 indicated parameters:
a)
If you used the recommended value(s) b)
If you used a value(s) other than the recommended value(s) and the basis for your choice; or c)
If you did not perform the sensitivity study indicated and your reasons for omitting the recommended analyses.
- 10. With regard to your responses to Question 10 -
please specifically state how the likelihood of a random ignition occurring is tied to the availability of power.
- 11.
In the OPRA containment event tree quantification sections some of the hydrogen overpressure event descriptions reference section 6.2.4.4 of the OPRA. Still other event descriptions reference sections of the OPRA from 6.2.4.4 to 6.2.4.63.
The Rev. 1 OPRA which we are using does not have section 6.2.4.4 through 6.2.4.63, nor does the index indicate that said sections exist. Please provide the information omitted in order that we may have an accurate understanding of the basis for the quantification of many of the important specific events.
- 12.
You have dismissed the potential for hydrogen pocketing and detonation as insignificant contributors to the containment failure probability and therefore did not include them in the CET. Your general basis for this assessment is the "openness" of the containment interior design. Please substantiate your perceptions by providing information requested in NUREG-1335 (Section 2.2.2.1), i.e., accurate but simple representations of the containment showing the Instrument Tunnel, Reactor Cavity compartment, Loop compartment(s), Annular compartment(s) and Upper compartment with specific identification of potential reactor release points and vent paths indicated. Estimates of compartment free volumes and vent path flow areas should also be provided. Please specifically address how this information supports your assessment of a very low probability (negligible) of local H2 pocketing and detonation.