ML20198H018

Forwards Attachment Addressing New Info & Modifying 980505 Submittal Re Request for Change to Licensing Bases for ECCS Overpressure,In Response to NRC Bulletin 96-03, Potential Plugging of ECCS by Debris in Bwrs

ML20198H018
Person / Time
Site:	Oyster Creek
Issue date:	12/22/1998
From:	Roche M GENERAL PUBLIC UTILITIES CORP.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
1940-98-20692, IEB-96-003, IEB-96-3, TAC-MA1719, NUDOCS 9812290218
Download: ML20198H018 (2)

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{ GPU Nuclear. Inc.

(- U.S. Route #9 South NUCLEAR Post Office Box 388 Forked River, NJ 08731-0388 I

Tel 609-9714000 -

December 22,1998 1940-98-2 % 92 U. S. Nuclear Regulatory Commission

' Attn: Document Control Desk Washington DC 20555

Subject:

Oyster Creek Nuclear Generating Station Docket No. 50-219 Request for a Change to the Licensing Bases ECCS Overpressure (TAC NO. MA1719)

By letter dated May 5,1998, GPU Nuclear Inc. submitted a request for a change to the licensing bases for the Oyster Creek Nuclear Generating Station. This request identified that proper operation of the new Emergency Core Cooling Suction Strainers would require taking credit for 1.25 psig of containment overpressure.

I During the design verification of the 1.25 psig setpoint, it was determined that although  ;

procedural controls te raise the old action point were required, the existing 0.6 psig setpoint on the pressure sensor could not be changed. Attachment I to this letter addresses this new information and modifies our May 5,1998, submittal.

If any additional information or assistance is required, please contact Mr. John Rogers of my staff at 609.971.4893.

Very truly yours, /

981229021e 981222

_ ) d Michael B. Roche f "" OY[I;; Vice President and Director nq' ~

Oyster Creek O/

MBR/JJR c- J' Attachment cc: Administrator, Region I NRC Project Manager Senior Resident Inspector

l i

. Attachment I l Request for a Change to the Licensing Bases In response to NRC Bulletin 96-03 " Potential Plugging of Emergency Core Cooling Strainers by Debris in Boiling Water Reactors", the Oyster Creek Nuclear Generating Station docketed a request on May 5,1998, to change the licensing bases of the plant to allow for the inclusion of 1.25 psig overpressure in the containment for one hour following a Loss of Coolant Accident.

The submittal identified that post LOCA drywell pressure would initially increase to approximately 40 psig, and then decrease to approximately 20 psig within the first few minutes of the event. Following this, operator actions to initiate Containment Spray would lower that pressure. Existing procedures direct the operators to initiate Containment Spray at 12 psig and maintain the drywell pressure between 4 and 12 psig. This procedure further requires that the operators must secure spray flow to the drywell at 1.0 psig.

The May 5,1998, submittal credits operator actions to maintain pressure between 4 and 12 psig. It additionally committed to change the containment spray procedures to raise the minimum pressure from 1.00 psig to 1.25 psig. These commitments remain unchanged.

The May 5,1998 submittal also described a Non-Safety Related pressure switch that would automatically trip the containment spray pumps at 0.6 psig. The submittal committed to raising that automatic setpoint to 1.25 psig to provide defense in depth for the operator actions.

During the design verification of the setpoint change documentation, it was determined that changing the setpoint for the automatic trip was not desirable for certain accident management

! considerations. Once the operators are in full control of the core spray systems, and it is no longer necessary to maximize the available net positive suction head (i.e. the 1.25 psig overpressure is no longer required), it is acceptable, and may be desirable, to further reduce containment pressure. By maintaining the trip setpoint at its current value, the containment spray system would be available to provide a means of reducing containment pressure further

(< 1.25psig) without needing to vent the containment to atmosphere.

Therefore, by this letter, GPU Nuclear, Inc. modifies our original May 5,1998 submittal to remove the commitment to increase the setpoint for the containment spray pump low pressure trip.

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