ML17279A321

Forwards Info Re Mods Proposed to Ensure Isolation of RHR-V-8 or RHR-V-9 Valve & Schedule for Completion of Mods, Per 870513 Request Re Generic Ltr 86-10 Interpretation of High/Low Pressure Interface Concerns

ML17279A321
Person / Time
Site:	Columbia
Issue date:	06/03/1987
From:	Sorensen G WASHINGTON PUBLIC POWER SUPPLY SYSTEM
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
GL-86-10, GO2-87-0190, GO2-87-190, TAC-63528, NUDOCS 8706110011
Download: ML17279A321 (8)

Text

REQU 0 INFORNATION DISTR IBU N 'TEN (R IDB)

ACCESSION NBR: 8706110011 DOC. DATE: 87/06/03 NOTARIZED: NO DOCKET FACIL: 50-,397 4IPPBS Nuclear Project> Unit 2> Washington Public Poue 05000397 AUTH. NQNE AUTHOR AFFILIATION BORENSEN> Q. C Mashington Public Pouer Supply System.

REC IP. NAl'1E RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)

SUB JECT: Responds to Generic Ltr 86-10 interpretation of hig h/lov pressure interface concerns.

DIBTRIBVTIDN CDDE A046D CDPIEB RECEIVED: LTR i ENCL Q SIZE:

TITLE: OR Submittal: TNI Action Plan Rgmt NUREQ-0737 Kc NUREQ-0660 NOTES:

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-.AS/ILRB OQC/HDS2 1 01 1 RES DEPY QI EXTERNAL: LPDR NRC PDR NSlC TOTAL NUii)HER OF COPIEB REQUIRED: LTIR 31 ENCL 28

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Washington Public Power Supply System

.3000 George Washington Way P.O. Box 968 Richland, Washington 99352-0968 (509)372-5000 8706110011 870+03 PDR ADOCK 05000397 P PDR June 3, 1987 G02-87-0190 Docket No. 50-397 U.S. Nuclear Regulatory Commission Attn: Document Control Desk ltashington, D.C. 20555 Gentlemen:

Subject:

NUCLEAR PLANT NO. 2 RESPONSE TO GENERIC LETTER 86-10 INTERPRETATION OF HIGH/LOW PRESSURE INTERFACE CONCERNS

Reference:

1) Letter, G.W. Knighton (NRC) to G.C. Sorensen (SS),

"Compliance with Requirements of Appendix R to 10 CFR Part 50 Relating to Prevention of LOCAs at High/Low Pressure Interfaces", dated Pay 13, 1987

2) Letter, G02-86-1049, G. C. Sorensen (SS) to E.G.

Adensam (NRC), "WNP-2 Fire Protection, Request for Additional Information", dated December 1, 1986 The purpose of this correspondence is to provide the information requested in Reference 1). This reference requested the Supply System to advise the Staff of modifications proposed to ensure isolation of either the RHR-V-8 or RHR-V-9 valve and provide a schedule for completion of the modifications.

As discussed during our telephone conference call of June 2, several letters have been sent to the Staff that presented various technical positions as well as safety considerations supporting the conclusion that a plant modification is unnecessary. The Supply System has attempted to reconcile the issue based on mechanistic failure considerations. The Staff appears to have adopted a non-mechanistic fa'ilure mode that wi 11 only recognize a configuration not affected by a selectively destruc-tive, instantaneous fireball in the Control Room. The Supply System is interested in resolving this issue in a safe, expeditious and cost effective manner. Options identified to date include the following:

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Page Two June 3, 1987 RESPONSE TO GENERIC LETTER 86-10" INTERPRETATION OF HIGH/LOW PRESSURE INTERFACE CONCERNS I) De- energi ze RHR- V-8 or 9.

2) Provide separate transfer switch at a remote shutdown panel for the RHR-V-8 or 9.

3) Design a redundant interlock to maintain RHR-V-8 or 9 closed that is outside the control room.

4) Relocate one of the interlock relays outside the control room.

5) Relocate the RHR-V-8 or 9 power supply to outside the Reactor Bui 1 ding.

Each option varies in complexity, cost, installation limitations while operating, and regulatory complication. The safety analysis has not been performed f'r any of the options, but each is considered to have a high potential for becoming an unreviewed safety question per 10 CFR 50.59. Most of the options are considered implementable only during plant shutdown. As discussed during our June 2 conference call, the Supply System will evaluate the options and provide the NRC with our preferred ootion by mid August 1987. Subsequent design, procurement, installation and testing is expected to be completed prior to startup from the spring 1988 refueling outage. In the interim, it is our under-standing, based on the June 2 discussion that the Staff concurs that plant startup and operation is acceptable based on the compensatory measures which have been taken.

With respect to the discrepancy in FSAR Amendment 37, the decision to de-energize RHR-V-8 and 9 was ini ti ally made to satisfy the NRC position and without knowledge of the conf1ict with the Emergency Procedure Guidelines and NUREG-0737, item II. B. 2. The Supply System subsequently reversed its position as comnunicated to the Staff in telephone conver-sation and documented in our letter of December 1, 1986 (Reference 2).

Unfortunately, we did not formal1y document the need to revise the FSAR, but it was discussed in a telephone conversation shortly after submittal.

This subject was clearly not resolved as evidenced by the numerous conversations and correspondence subsequent to the submittal of Amend-ment 37. Failure to revise the FSAR should be regarded as a simple ll oversight and the FSAR wi be revised in a subsequent update to reflect the final resolution.

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.. June 3, 1987 RESPONSE TO. GENERIC, LETTER 86-10 INTERPRETATION OF HIGH/LOW PRESSURE INTERFACE CONCERNS We share the NRC's desire to resolve this issue as soon as possible. As discussed on June 2, we view the Staff's request to modify the system to be a potential backfit as defined by 10CFR 50.109. Simultaneous, with the actions described above, we will pursue this issue with the Staff. ".,

Should you have any questions, please contact Hr. P. L. Powell, Manager, WNP-2 Licensing.

Very truly yours, G. C. Sorensen, Manager Regulatory Programs

'HRW/bk cc: GW Knighton - NRC JB Hartin - NRC RV NS Reynolds - BCPSR RB Samworth "-'RC DL Wi 1'liams - BPA, 399 NRC Site Inspector - 901A

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