ML20057B684

Discusses 930614 Response to GL 92-04 & NRC Bulletin 93-03 Re Resolution of Issues Re Reactor Vessel Water Level Instrumentation in Bwrs.Util Response to GL Unacceptable. Subj Instrumentation Should Be Modified During Next Outage

ML20057B684
Person / Time
Site:	Oyster Creek
Issue date:	09/20/1993
From:	Partlow J Office of Nuclear Reactor Regulation
To:	J. J. Barton GENERAL PUBLIC UTILITIES CORP.
References
GL-92-04, GL-92-4, IEB-93-003, IEB-93-3, TAC-M86904, NUDOCS 9309230129
Download: ML20057B684 (4)

Text

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i s mau a ,1 E UNITED STATES

'! NUCLEAR REGULATORY COMMISSION )

(%[v g ,/ WASHINGTON, D.C. 20555-0001 September 20, 1993 l Docket No. 50-219 i

l Mr. John J. Barton Vice President and Director GPU Nuclear Corporation Oyster Creek Nuclear Generating Station Post Office Box 388 Forked River, New Jersey 08731

SUBJECT:

RESPONSE TO NRC GENERIC LETTER 92-04, " RESOLUTION OF THE ISSUES RELATED TO REACTOR VESSEL WATER LEVEL INSTRUMENTATION IN BWRS PURSUANT TO 10 CFR 50.54(F), DATED AUGUST 19, 1992, AND NRC BULLETIN 93-03, " RESOLUTION OF ISSUES RELATED TO REACTOR VESSEL WATER LEVEL INSTRUMENTATION IN BWRS" (TAC N0. M86904)

In our letter of August 4,1993, we acknowledged receipt of your response, dated June 14, 1993, to NRC Bulletin (NRCB) 93-03. The NRCB was issued May 28, 1993, to all holders of operating licenses or construction permits for Boiling Water Reactors (BWRs) with the exception of Millstone, Unit 1, and Big Rock Point. It requested licensees to take short-term compensatory actions within 15 days of the Bulletin to ensure operators can identify and mitigate potential level errors. The NRCB also requested licensees to implement hardware modifications at the first cold shutdown after July 30, 1993, to ensure the level instrumentation system design of high functional reliability for long-term operation.

By letter dated June 14, 1993, GPU Nuclear Corporation (GPUN), submitted a 15-day response to Bulletin 93-03 " Resolution of Issues Related to Reactor Vessel Water Level Instrumentation in BWRs." This report states why the GPUN did not take the requested short term actions.

In a letter dated August 4, 1993, the NRC stated that they have reviewed the submitted report. The short-term actions by Bulletin 93-03 do not apply to Oyster Creek Nuclear Generating Station's (OCNGS) configuration and are not needed. GPUN indicated that they do intend to provide, by July 30, 1993, details of plans to eliminate errors associated with noncondensible gases in the cold leg fuel zone level instrumentation.

In your letter of July 30, 1993, regarding Generic Letter 92-04, you stated that although OCNGS does not rely upon cold reference leg instrumentation for safety system actuation, GPUN recognized the importance of maintaining all instrumentation as accurate as possible, and of accounting for these situations which impact instrument accuracy.

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Mr. John J. Barton You further stated that "In order for errors due to entrained noncondensible gases to occur, two conditions must be present: (1) a concentrating mechanism which occurs when gases are stripped from condensate returning to the reactor vessel by inlet steam to the chamber, and (2) reference leg leakage enabling-concentrated noncondensible gases dissolved in the condensate to be drawn into the reference leg. To preclude the possibility for thfs type of error at OCNGS, GPUN intends to modify the steam line/ condensing chamber configuration so as to eliminate the counterflow of steam and condensate, thereby eliminating the concentrating mechanism. GPUN intends to install this modification consistent with the Integrated Scheduling Plan. At present, this  ;

plan calls for installing the modification during the 15R refueling outage, '

scheduled to begin in October 1994."

We consider your response to NRC Generic Letter (GL) 92-04 unacceptable, in that the implementation schedule you proposed is not consistent with the intent of the NRC GL 92-04 and NRCB 93-03 or the safety significance of the issue. Therefore, we are preparing orders to bring your facility in line with l the NRC GL 92-04 and NRCB 93-03. We request that you modify the reactor vessel level instrumentation during the next cold shutdown after October 1, 1993. Any modification to your currently proposed implementation schedule l communicated to your project manager within 2 weeks of this letter will be considered in the staff's forthcoming actions.

Sincerely, j

\

Janes G. Partlow As'sociate Director for Projects Office of Nuclear Reactor Regulation cc: See next page 9

Mr. John J. Barton September 20, 1993 l 4

You further stated that "In order for errors due to entrained noncondensible )

gases to occur, two conditions must be present: (1) a concentrating mechanism which occurs when gases are stripped from condensate returning to the reactor vessel by inlet steam to the chamber, and (2) reference leg leakage enabling ,

concentrated noncondensible gases dissolved in the condensate to be drawn into l the reference leg. To preclude the possibility for this type of error at 0CNGS, GPUN intends to modify the steam line/ condensing chamber configuration so as to eliminate the counterflow of steam and condensate, thereby eliminating the concentrating mechanism. GPUN intends to install this modification consistent with the Integrated Scheduling Plan. At present, this plan calls for installing the modification during the 15R refueling outage, scheduled to begin in October 1994."

We consider your response to NRC Generic Letter (GL) 92-04 unacceptable, in that the implementation schedule you proposed is not consistent with the intent of the NRC GL 92-04 and NRCB 93-03 or the safety significance of the issue. Therefore, we are preparing orders to bring your facility in line with the NRC GL 92-04 and NRCB 43-03. We request that you modify the reactor vessel level instrumentation during the next cold shutdown after October 1, ,

1993. Any modification to your currently proposed implementation schedule I communicated to your project manager within 2 weeks of this letter will be considered in the staff's forthcoming actions.

Sincerely, Original signed by James G. Partlow Associate Director for Projects Office of Nuclear Reactor Regulation cc: See next page i

DISTRIBUTION:

Docket File NRC & Local PDRs i PDI-4 Plant SVarga JCalvo SNorris '

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NAME SNorris ADromerick F JStolz Y GKalman JCalvo DATE

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OFFICIAL RECORD COPY Document Name: G:\DROMERICK\RESPGL.BUL

Mr. John J. Barton Oyster Creek Nuclear GPU Nuclear Corporation Generating Station cc:

Ernest L. Blake, Jr., Esquire Resident Inspector Shaw, Pittman, Potts & Trowbridge c/o U.S. Nuclear Regulatory Commission 2300 N Street, NW. Post Office Box 445 Washington, DC 20037 Forked River, New Jersey 08731 Regional Administrator, Region I Kent Tosch, Chief U.S. Nuclear Regulatory Commission New Jersey Department of 475 Allendale Road Environmental Protection King of Prussia, Pennsylvania 19406 Bureau of Nuclect Engineering CN 415 BWR Licensing Manager Trenton, New Jersey 08625 GPU Nuclear Corporation 1 Upper Pond Road Parsippany, New Jersey 07054 Mayor Lacey Township 818 West Lacey Road Forked River, New Jersey 08731 Licensing Manager Oyster Creek Nuclear Generating Station Mail Stop: Site Emergency Bldg.

Post Office Box 388 Forked River, New Jersey 08731 L_