ML20235P550

Application for Amends to Licenses NPF-37,NPF-66 & NPF-72, Increasing Setpoint for Enabling Anticipatory Reactor Trip Upon Turbine Trip from Greater than 10% Reactor Power to Greater than 30% Reactor Power.Fee Paid

ML20235P550
Person / Time
Site:	Byron, Braidwood, 05000000
Issue date:	09/30/1987
From:	Ainger K COMMONWEALTH EDISON CO.
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
Shared Package
ML20235P553	List: ML20235P550 ML20235P607
References
3654K, NUDOCS 8710070308
Download: ML20235P550 (4)

Text

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      .,.            O Commonwealth Edison.

[ v E One First National Plaz2, Chicago, Illinois Address R; ply to: Post Office Box 767

    .,-                       Ch;cago, Illinois 60690 0767
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September 30, 1987 U.S. Nuclear. Regulatory Commission-Attn: ' Document Control Desk Washington, DC 20555

Subject:

Byron Station Units 1 and 2 Braidwood Station Units 1 and 2 Application for Amendment to Facility Operating Licenses NPF-37,-NPF-66, and.NPF-72, i Appenilx A, Technical Specifications J NRC Docket Nos. 50-454/455 and 50-456/457 l Gentlemen: Pursuant to 10 CFR 50.90, Commonwealth Edison is hereby applying for- , an amendment to Facility Operating Licenses NPF-37, NPF-66 and NPF-72, j j Appendix A, Technical Specifications. This amendment involves a plant- . modification and associated Technical Specification changes. The modification  ! increases the setpoint for enabling the anticipatory reactor trip upon turbine trip from greater than 10% reactor power to greater.than 30% reactor power. A l description of the modification is provided in Attacnment A of this letter. l Attachment B contains the proposed changes to Technical Specification 3/4.3.1 (reactor trip system instrumentation) and the associated bases. Since this modification will not be installed concurrently on all four units, the.  ; Technical Specification changes have been worded to permit operation with or?  ; without this modification' installed. The proposed Technical Specification changes have been reviewed and j approved by both On-site and Off-site review in accordance with Commonwealth Edison Company procedures. We have reviewed this' amendment'in accordance with 10 CFR 50.92(c) and determined that no significant hazards consideration l l exists. Our evaluation is documented in Attachment C. l Commonwealth Edison is notifying the State of Illinois of our . application for this amendment by transmitting a copy of.this letter and its attachments.to the designated State' Official. 1 i i i 8710070308 870930 4; gl DR ADDCK 050

                                                                                         . g S( ,

I W U.S. NRC Szptember 30, 1987 I I In accordance with 10 CFR 170, a fee remittance in the amount of )

        $150.00 is onclosed.

Please direct any questions'regarding this matter to this office 1 1

                                              'Very truly yours, _
                                                                                                                 ]
                                                          .        41 K. A. Ainger Nuclear Licensing Administrator

! j Attachments (A): Description of Modification ' (B): Proposed Technical Specification Changes (C): Evaluation of Significant Hazards Consideration J cc: Byron Resident Inspector Braidwood Resident Inspector L. N. Olshan - NRR S. P. Sands - NRR ] M. C. Parker - State of Illinois i NRC Region III Office 1 i 1 l l l l l 1 l i l I i 3654K .;

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ATTACHMENT A DESCRIPTION OF MODIFICATION The Byron and Braidwood Units are designed with 50% load rejection capability. Therefore, a reactor trip on turbine trip should not be required below 50% reactor power. However, to enhance the overall reliability of the reactor trip system, a design feature exists to initiate an anticipatory reactor trip upon turbine trip when reactor power is above the.P-7 setpoint (10%). A modification is proposed to increase the setpoint at which the anticipatory reactor. trip upon turbine trip is enabled from 10% to 30% reactor power. This modification will delete the reactor trip function from the P-7 permissive and add it to the existing P-8 permissive. The P-8 permissive currently enables a reactor trip on low flow in one or more reactor coolant loops and has a setpoint of greater than or equal to 30% rated thermal power. Below the P-8 setpoint the trip functions will be automatically blocked. This modification should reduce the number of unnecessary reactor trips during startup, shutdown and low power operations. Avoiding these unnecessary reactor trips will result in fewer transients imposed on the plant, less challenges to safety systems and an overall increase in plant availability. It should be noted that 14 other Westinghouse PWR's across i the nation have this increased permissive for reactor trip on turbine trip. l The reactor trip upon turbine trip is an anticipatory trip and no credit is taken for this trip in the FSAR Chapter 15 accident analyses. The turbine trip accident analysis is modeled assuming that a reactor trip would be initiated from the reactor protection system. As a result, revising the setpoint for enabling this anticipatory trip will have no impact on the accident analysis. l 3654K

l l l ATTACHMENT B l 1 1 PROPOSED CHANGES TO APPENDIX A,. 1 TECHNICAL SPECIFICATIONS, OF FACILITY OPERATING LICENSES 4 1 NPP-37, NPF-66 and NPF-72 l i I Revised Pages: Byron Braidwood B 2-8 B 2-8 B 2-9 B 2-9 j 3/4 3-3 3/4 3-3 J 3/4 3-8 3/4 3-8 3/4 3-10 3/4 3-10 i i l Hr 1 1 1 1

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