ML20090G278

Forwards Addl Info Re Application for Amend to License DPR-56,changing Tech Specs to Allow Operation at Increased Core Flow,Per NRC Request.Info Concerns Implementation of SIL-380, BWR Core Thermal Hydraulic Stability

ML20090G278
Person / Time
Site:	Peach Bottom
Issue date:	07/17/1984
From:	Daltroff S PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Stolz J Office of Nuclear Reactor Regulation
References
NUDOCS 8407240333
Download: ML20090G278 (2)

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PHILADELPHIA ELECTRIC COMPANY i 23O1 M ARKET STREET P.O. BOX 8699 PHILADELPHI A. PA.19101 SHIELDS L. DALTROFF ELECTm C PR O CION July 17, 1984 Docket No. 50-278 Mr. John F. Stolz Operating Reactors Branch #4 Division of Licensing U. S. Nuclear Regulatory Commission Washington, DC 20355

Dear Mr. Stolz:

During recent discussion between U.S. NRC staf f and Philadelphia Electric Company ccncerning the proposed amendment to the Peach Bottom Atomic Power Station Unit 3 Technical Specifications to allow operation at increased core flow, the staff requested additional informatlon regarding the iraplementation of SIL-380, BWR Core Thermal Hydraulic Stability, at Peach Bottom. This information is presented in Attachment I to this letter.

If you have any questions or require additional information, please do not hesitate to contact us.

Very truly ,ours, cc: A. R. Blough, Site Inspector 8407240333 840717 PDR ADOCK 05000278 P PDR 1

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Docket No. 50-278 l

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ATTACHMENT I SIL-380, BWR Core Thermal Hydraulic Stability, provided various I recommendations to minimize the possibility of thermal hydraulic l instability in a BWR. These conditions of instability are most I likely to occur at the high power / low flow corner of the power / flow map. This area of potential instability of the j

power / flow map is routinely avoided during operations at Peach Bottom Atomic Power Station (PBAPS). Additionally, the applicable operating procedures are being reviewed and revised to ensure that operation in this region will continue to be recognized and minimized.

The applicable operating procedures to be revised are:

GP-2/GP-2A Startup GP-3 Shutdown -

GP-9 Fast Reactor Power Reduction OT-1.12 Recirculation Pump Trip ST-3.3.2A APRM Calibration for Single Loop Operation ST-9.1 Surveillance Log-Single Loop Operation Generally, the procedural revisions will direct that operations in the region of concern be avoided. Ii the unlikely event of extended, rather than transient or transient recovery, operations within the region of concern, as described in SIL-380, reactor engineering surveillance shall be provided to ensure that unrecognized conditions of instability do not develop and that corrective action is taken to minimize such instability if it does occur.

These procedural revisions are expected to be completed by August 15, 1984, and in no case later than the end-of-cycle scheduled reduction in feedwater temperature on PBAPS Unit 3.

July 17, 1984 ,

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