ML20086R059

Application for Amend to License DPR-28,consisting of Proposed Change 165,changing Tech Spec Surveillance & Calibr Requirements in Table 4.2.2 to Reflect Replacement of Existing Pressure Switches W/Analog Loop Instrumentation

ML20086R059
Person / Time
Site:	Vermont Yankee File:NorthStar Vermont Yankee icon.png
Issue date:	12/23/1991
From:	Pelletier J VERMONT YANKEE NUCLEAR POWER CORP.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20086R062	List: ML20086R059 ML20086R077
References
BYV-91-120, NUDOCS 9112310136
Download: ML20086R059 (4)

Text

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Vl!!tMONT YANKl!!!

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( - / (no7> n7-5771 December 23, 1991 BVY 91120 United States Nuclear Regulatory Commission ATTN: Document Control Desk Washington,-DC 20555 Rotorencos: (a) License No. OPR 28 (Docket No. 50 271)

(b) Lottor, VYNPC to USNRC, WVY 80 49, dated March 17, 1980, Proposed Change No. 79 (c) Lotter, VYNPC to USNRC, FVY 83 01, dated January 10,1983, Proposed Chango No.103 (d) Letter, VYNPC to USNRC, FVY 86 80, dated August 26, 1986, Proposed Chango 134

Subject:

Proposed Change No. 16 to Reflect Analog System Replacement

Dear Sir:

Fursuant to Section 50.90 of the Commission's Rules and Regulations, Vormont Yankee Nuclear Power Corporation hereby proposes the following change to Appendix A of the operating license (Reference a).

Proposed Channo Replace Pago 54 o' the Vermont Yankoo Technical Specifications with the attached revised Page 54. A change to Pa e 54 is being proposed to reflect a chango in surveillance regulromon a result from the u actuated instrumentation, differential pressure switches, pgrado with of mechanical-an analog trip cystem. This instrumentation provides the Main Steam Line High Flow Inputs to the Primary Containment Isolation SyJtem Logic.

The specific change is to extend -the calibration interval for the H10h Steam Lino Flow instrumentation from'overy throo months to once/oporating cycle.

Eoason for Chan_ge We are proposing a change to the Tcchnical Specification surveillance and calibration requirements in Tablo 4.2.2 to reflect the replacement of- existing -

differential pressuro switches with analog loop instrumentat on. The replacement of these switches is consistent with Vermont Yankee's past practice of replacing mechanically actuated switches with newer and more reliable analog loop instrumentation.

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VCHMONT YANKEE NUCLE AR POWER CORPOR ATION US Nuclear Regulatory Commission December 23, 1991 Page 2 Ba_ sis _ for Chango The surveillanco and calibration requirements havo boon modiflod to agroo with thoso which have previously been approved for similar analog Instrumentation in uso at Vermont Yankee (References b, c, and d). Replacement of existing differential pressure switches with more rollable instrumentation will improve plant operations, while at the samo timo, not pose any change to the design basis, protective function, redundancy, trip point, or logic of the orl 0lnal system.

The reduction in calibration frequency will reduce the timo of the Inoperability of instrumentation during the performance of calibration and the potential of Inoperability following calibration due to human error. In addition, the 30tential for challengt s to systems and operation is reduced by reculring less cal brations during plant ooeration and by providing the option of periorming this calibration during plant shutdown.

Safety Evaluation The replacement of existing Primary Containment Isolation System differential vressure switch instrumentation for high steam line flow with analog loop nstrumentation will re 31 ace mechanica and proven more reliab o instrumentation.yThis actuated instrumentationwill now Instrumentation with newer maintain the required redundancy and protective function. The new instrumentation is also environmentally and seismically quallflod.

The resultant proposed change in calibration frequency from overy throo months to onco / operating cycle for the high steam line flow tria function instrumentation will continuo to meet the intent of Technical Spec fication requirements for assuring component operability. Exporlence at Vermont Yankoo with similar analog loop instrumentation over the past 11 years has shown this equipment to have an excellent operating history.

Plant safety would be enhanced by reducing the frequency of performing this calibration during reactor operation by allowing for the option of performing calibration during plant shutdown, thus, minimizing potential for challenges to plant systems during operation.

The requested change to the calibration frequency does not impact any FSAR safety analysis nor does it involve any change in Technical Specification setpoints, plant operat!on, protective function or design basis of the plant.

Assurance of equipment operation is still provided such that required control and alarm functions are provided to provent uncovering the fuel from mass inventory loss due to a worst case main steam line break and the release of significant amounts of radioactive material from the nuclear system process barrier.

The proposed change has been reviewed by the Plant Operations Review Committee and the Vermont Yankee Nuclear Safety Audit and Review Committee.

VCHMONT YANKtt NUCLE AR POWER CORPor1ATION US Nuclear Regulatory Commission .

December 23, 1991 Page 3 Slanificant Hazards Considera!bns The standards used to arrivo at a determination that a request for amendment involves no significant hazards consideration are included In the Commissions' Regulations, < 0CFR50.92, which state that the operation of the facility in ,

accordance with the proposed amendment would not: 1) Involve _a significant increase in the probabl!!t/ or consequences of an accident previously evaluated,

2) create the possibility of a now or different kind of accident from any accident previously evaluated, or 3) involve a significant reduction in a margin of safety.

The discussion below addresses the proposed changes with respect to these three criteria and demonstrates that the proposed amendrnent involvos a no- '

significant hazards consideration:

1. The proposed change to extend the high steam line itow calibration Interval from overy three months to once/ operating cycle reflects the replacement of differential pressuto switches with analog instrumentation.

The proposed calibration interval is consistent with those previously approved for similar analog instrumentation utilized at Vermont Yankee (References b, c, and d). A calibration Interval of once/ operating cycle has been demonstrated to be appropriate for similar instrumentation installed at Vermont Yankee. The requested change to the existing calibration Interval does not impact any FSAR cafety analysis. Under this proposed change, operability is assured and valve closure functions for preventing excessive loss of reactor coolant and release of cignificant amounts of radioactive material from the nuclear system process barrier are provided. Therefore, it is concluded that the proposed change does not involve a significant increase in the probability or consequence of an ,

accident previously evaluated.

2. The proposed change to increase the calibration interval for high steam line flow instrumentation meets the intent of Technical Specification requirements for assuring operation of equipment as designed. Based upon past operational history for similar Instrumentation installed at Vermont Yankee, performance of calibration requirements once/ operating cycle will adecuately assure operation as designed. The proposed change I does not involvo any change in Technical Specification setpoints, plant operation, rodundancy, protective function or design basis of the plant.

Therefore, the proposed change does not create the possibility of a new or different kind of accident from any accident previously evaluated.

i VCRMONT YANKEE NUCLE AR POWER CORPORATION US Nuclear Re0ulatory Commission Docomber 23, 1991 Page 4

3. The proposed chango represents an increaso in safety since existing Instrumentation is bein0 replaced with newer more rollable instrumentation while maintaining system iunction and design basis. The occurrence of trip system inoperability during the performance of calibration or following calibration due to possible human error is reduced by requiring less frequent calibration. In addition, the potential for inadvertent steam lino Isolations or challongos to plant systems and operation is reduced by callbration during plant shutdown.

providing B- ased uponthe theoptionabove,of performln;d it is concluco that the proposed chango does not involvo a significant reduction in a margin of safety.

Based upon the above, we conclude that the proposed chango involvos a no-significant. hazards consideration as defined in 10CFR50.92(c).

Scheduto_of Chango Because Vermont Yankoo will replace er.lsting high steam lino flow instrumentation with analog loop instrumentation during the next iofueling outage, currently scheduled to begin in March, 1992, we request approval of this proposed change by April,1992.

Wo trust that the information provided above adequatoly supports our request, howevor, should you have any questions on this matter, please contact us, Very truly yours, Vermont Yankee Nuclear Power Corporation frush James P. Pollotler Vice President Engincoring cc: USNRC Region i Administrator t USNRC Resident inspector VYNPS

USNRC Project Manager VYNPS

VT Dept. of Public Sorvice i

STATE OF VERMONT 1 WINDHAM COUNTY V[e[rs . $.ngIn o, V tr$on Yankee ea o e, orpor t on, ah is uly authori ed to c?#,*a *on? E'e'",*ai Ne hfifn/n","'in,'e'In'"!,lt,*:

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fo"'ihe oTofn'il fnetieoie' Mtile' nia n i My Commission expires February 10, 1995 GINA M. FONTAINE NOTARY PUBUC WINDliAM COUNTY, VEBMON1 My Term ExpiresM685_

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