ML20003D677

Forwards Response to NRC Re N-1 Loop Operation for Facility.Actions Re Reactor Protection Sys Will Be Completed W/Reactor Subcritical in Mode 3,prior to Operation W/One Loop Out of Svc

ML20003D677
Person / Time
Site:	Beaver Valley
Issue date:	03/24/1981
From:	Dunn C DUQUESNE LIGHT CO.
To:	Varga S Office of Nuclear Reactor Regulation
References
TAC-10386, NUDOCS 8103300302
Download: ML20003D677 (5)

Text

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Director of Nuclear Reactor Regulation

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Mr. Steven A. Varga, Chief 3

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Operating Reactors Branch No. 1

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Divisica of Licensing i

Washington, DC 20555

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Reference:

Beaver Valley Power Station, Unit No. 1 Docket No. 50-334, License No. DPR-66 N-1 Loop Operation Gentlemen:

In response to your letter of January 29, 1981, attached please find the responses to your questions on N-1 Loop Operation for the Beaver Valley Power Station. I would like to request an expediticus review of the attached questions and N-1 Loop Operation for Beaver Valley.

Ver" truly yours,

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w C. N. Dunn Vice President, Operations cc:

D. A. Beckman, Resident Inspector U.S. Nuclear Regu12 tory Commission Beaver Valley Power Station Shippingport, PA 15077 ool U.S. Nuclear Regulatory Commission c/o Document Management Branch 5

Washington, DC 20555

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Ouestion 1: D: scribe the modifications you procese to make to tne 1

reactor protection system to facilitate changing of ne overpcwer trip set;:cints when enanging to cparation modes with less than a full ccmolement of reactor cooling ico::s (N-1).

Gescribe h:w nese mocifications will satisfy :ne requirements of IEEE Std. 279-1.15 and Sranen Technical Position EICSB 12 (attached) regarding multiple set points and their control, and hcw administrative control of tne centrol caninets is maintained both for the initial mccifi-cation and for each subsequent changeover.

Resconse to Question 1:

The following actions regarding the reac:ce protection system will be ccmoleted with the react:r subcritical in Bicde 3 price to operation with I loop cut of service.

a.

The overtemperature a7 trip se:pcint will be reduced by reset-ting ccnstant X to 1.1 as per Table 2.2-1 of the technical 3

specifications.

b.

The overpcwer aT and overtemperature a7 bistai.:as associated with the cut of service lecp will be placed in :ne trip cendition as per specification 3/4.4.1.

c.

For operaticn abcve the ncminal F-8 set;oint (315), rese: :ne P-8 setpoint to 715 for operation with 1 cop step valves closed in tne inactive lecp as per specificatien 3/4.4.1.

Ccmpliance with the above actions ic also specified in existing plant precedures written specifically for operation in the N-1 (2) locp mcde and is administratively controlled.

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Branch Technical Position EICSB 12 allcws plants without autcmatic setpoint reduction to reset the setpcint manually to the more restric-tive value with the reactor subcritical as specified in the plant technical specificaticns. Beaver Valley meets this requirement as

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described above.

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Setpoints apprcpriata for operation with one 1 cop cut of service have been included in the technical specifications as described above. The i.

resetting of the overtemperature AT trip setpoint will be carried cut in accordance with the technical specificatione and prescribed adm.inistra-tive precedures and only under the direction r ? authorized supervision.

1 The requirements of IEEE Standard 279-4.15 are therefore satisficd.

Subsequent entry into the reactor protection cabinets is similarly centrolled.

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Quastien 2: What instrument readinos and indications in :ne centrcl reca will change for ("-1) cooling lcop mcce Of cperaticn and what recalibrations, adjusc=ents and tecperary notices will be required tc avoic ancmalcus indica icns as recuired cy IEEE S td. 279-4.202?

Resconse to Question 2:

The follcwing instru=ent readings and indica:icns will be ancmalcus during N-1 (2) Icop, cperatten.

Idle Leco

1. Wide Range RTO's (a)

2. RTD Narrcw Range 7,,/e and a?

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3. Steam Generater Pressure

4. Steam Genera:ce Level j

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5. Steam icw

5. Feed Ficw

7. Reac ce Ccolant System Ficw (c) a.

Reacter cccient lecp is isciated - instru=ents will read temperature of stagnant ecclant.

b.

If the steam genera:ce is isolated, steam genera:ce pre'ssure and level will be independent of the cperating pertion of the plant with the qualification that integrity limits will net be exceeded (1600 psi a; primary te seccndary, <200 cri if tamcerature l

<70*F), if the staam generater f.e. not isclated stema pressure will equal operating 'staas pressure; level will be independently centroll ed. Steam ficw and feed ficw will be 0.

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c.

Reactor Ccolant System Flow will be 0.

The felicwing

. ument readings will change during N-1 (2) Icep operaticn.

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Oceratinc Lcces 1.

aT in %

Will be equivalent to the 100% pcwer a7 of ne maxi =um allcwed pcwer of 56 %.

Since T,jg is pregrammed according to turoine impulse g

pressure, T will be ecuivalent to the 55% pcwer Tgyg, t.5is 4yg will cause T and T 00 be I wer than ney w uid be at 10C%

HOT CCLD powe r.

Mcwever, T may be higher than normally ocserved a: 55 %

HOT pcwer and T my e cwer.

CCLD 2.

Reactor Cacian: System. lcw Will pecbably indicate slightly higher than it wculd for 3 loc; operation due to decreased system resistance.

It is not anticipated :nat any recalibrations or adjustments will be required for N-1 (2) icap cperation.

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