ML18136A005
| ML18136A005 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 08/31/1979 |
| From: | Stallings C VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| NUDOCS 7909290343 | |
| Download: ML18136A005 (3) | |
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VIHGINIA ELECTRIC AND POWER COMPANY RICHMOND,VIBGUiIA 23261 "ugust 31, 1979 Mr. James P. O'Reilly, Director Office of Inspection and Enforcement U. S. Nuclear Regulatory Commission Region II 101 Marietta Street, Suite 3100 Atlanta, Georgia 30303
Dear Mr. O'Reilly:
Serial No. 621 PO/DLB:scj Docket Nos. 50-280 50-281 License Nos. DPR-32 DPR-37
Subject:
IE Bulletin 79-05C and 06C This is in response to IE Bulletin Nos.79-05C and 79-06C, "Nuclear Incident at Three Mile Island - Supplement".
Our response for Surry Power Station Unit Nos. 1 and 2 is attached.
Vice and cc: Director, Office of Inspection and Enforcement U. S. NRC, Washington, D. C.
20555 Director, Office of Nuclear.Reactor Regulation U. S. NRC, Washington, D. C.
20555 Very truly yours, 7H~
C. M. Stallings
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President-Power Supply Production Operations
e RESPONSE TO IE BULLETIN 05C and 06C SURRY POWER STATION UNIT NOS. 1 AND 2 Responses are numbered as in the Bulletin
- 1. a.
The applicable station procedures have been revised to direct trippiJlg of all operating RCP's upon initiation of RPI (Safety Injection at Surry) caused by low reactor coolant system pressure.
.b.
Two l1censed operators will be in the control room at all times during single unit operation to accomplish this action and other immediate and followup actions required during such an occurrence.
During two unit operation a total of three licensed operators will be in the control room at all times.
- 2.
A series of Loss of Coolant Accident (LOCA) analyses for a range of break sizes and a range of time lapses between initiation of break and pump trip applicable to the 2, 3 and 4 loop plants has been performed by the Westing-house Owner's Group.
A report summarizing the results of the analysis of delayed Reactor Coolant Pump trip during small loss of coolant accidents for Westinghouse NSSS, will.be submitted to Mr. D. F. Ross by Mr. Cordell Reed on August 31, 1979.
In the report, maximum PCT's for each break size considered and pump shutoff times have been provided.
The report concludes that if the reactor coolant pumps are tripped prior to~the reactor coolant system pressure reaching 1250 psia, the resulting peak clad temperatures are less than or equal to those reported in the FSAR.
In addition, it is shown that there is a finite range of break sizes and RCP trip times (in all cases 10 minutes or later) which will result in PCT's in excess of 0
2200 Fas calculated with conservative Appendix K models.
The operator in any event woulc have at least 10 minutes to trip the RCP's following a small break LOCA, especially in light of the conservatism in the calcula-tions.
This is appropriate for manual rather than automatic action, based on the guidelines for termination of RCP operation presented in WCAP-9600.
- 3.
The Westinghouse Owners' Group has developed guideiines which were submitted to the NRC in Section 6 and Appendix A of WCAP 9600.
The analyses provided as the response to item 2 are consistent with the guidelines in WCAP 9600.
No changes to these guidelines are needed for either LOCA or non-LOCA transi-ents.
- 4.
The Owners' Group effort to revise emergency procedures covers many issues, including operation of the Reactor Coolant Pumps.
The expected schedule for revising the LOCA, steamline break and steam generator.tube rupture emergency procedures is the following:
Mid-October:
Guidelines which have been reviewed by the NRC will be provided to each utility. Appropriate utility personnel associated with writing procedures will meet with the Owners' Group Subcommittee on Pro-cedures and Westinghouse will provide the background for revising their emergency procedures.
*Ir'!
1 to 2 months from:
Mid-October 3 to 4 months from:.
Mid-October
- Plant specific procedures will be revised.
Revised procedures will be implemented and operators trained.
- 5.
Analyses related to inadequate core cooling and definition of conditi~ns under which a restart of the RCP's should be attempted will be performed.
Resolution of the requirements for the analyses and an acceptable schedule for providing the analyses and guidelines and procedures resulting from the analyses will be arrived at between the Westinghouse Owners' Group and the NRC *staff.
Long Term As discussed in our response to short-term item 2, we do not believe that auto-matic tripping of the RCP's is a required.function based.on the analyses that have been performed and the guidelines that have been developed for manual RCP tripping.
We propose that this item be discussed with the NRC staff following their review of the Owners' Group Submittal.
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