BVY-92-041, Forwards Response to NRC 920302 Request for Addl Info Re 911223 Proposed Change 165 to License DPR-28,changing Surveillance Requirements Resulting from Upgrade of mechanically-actuated Instrumentation W/Analog Trip Sys

Forwards Response to NRC 920302 Request for Addl Info Re 911223 Proposed Change 165 to License DPR-28,changing Surveillance Requirements Resulting from Upgrade of mechanically-actuated Instrumentation W/Analog Trip Sys

ML20094P237
Person / Time
Site:	Vermont Yankee
Issue date:	03/31/1992
From:	Tremblay L VERMONT YANKEE NUCLEAR POWER CORP.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
BVY-92-041, BVY-92-41, NUDOCS 9204070299
Download: ML20094P237 (4)

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V'ERMONT YANKEE NUCLEAR POWER CORPORATION

.. % s Ferry Road, Brattloooro VT 05301-7002 D) ENGINEERING OFFICE y- ~- m iw% w c r wonmm

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March 31,1992 BW 92-041 United States Nuclear Regulatory Commission A'ITN: Docur.: nt Control Desk Washington, DC 20555

References:

a. License No. DPR 28 (Docket No. 50-271)

b. letter, VYNPC to USNRC, WVY 80-49, dated March 17,1980 (Proposed Change No,79).

c. Letter, VYNPC to USNRC, FVY 83-01, dated January 10,1983 (Proposed Change No.103).

d. Letter, VYNPC to USNRC, FVY 86-80, dated August 26,1986 (Proposed Change No.134),

e. Letter, VYNPC to USNRC, BVY 91-120, dated December 23,1991 (Proposed Change No.165).

f. Letter, USNRC to VYNPC, NVY 92-35, dated March 3,1492 (Request for Additional Information - Proposed Change No.165).

Subject:

Response to Request for Additional Information Regarding Proposed Change No.165 to Reflect Analog System Replacement

Dear Sir:

By Reference (e), Vermont Ya..xee requested a change to the Technical Specifications to renect a change in surveillance requirements resulting from the upgrade of mechanically-actuated instrumentation (differential pressure switches) with an analog trip system. The subject instrumentation provides the Main Steam Line High Flow inputs to the Primary Containment-Isolation System logic. The specific change requested was to extend the calibration interval for the High Steam Line Flow Instrumentation from every three months to once per operating cycle By Reference (0, NRC transmitted a request for additional in:armation to complete review of Proposed Change No.165. Attached to this letter, please f'md Vermont Yankee's responses to the -

specific questiou raised in Reference (O.

Vermont Yankee is aware of the conceins with TR relays as described in regulatory documents and summarized in your letter of Reference (O. We have reviewed these concerns as l applicable to r:6ys installed at Vermont Yankee during implementation of the 10CFR50.49 L Equipment Qualirication Program. The concerns expressed in Reference (O have not been a t

concern for relays installed at Vermont Yankee. The operational history of TR relays installed at Vennont Yankee has been excellent.

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9204070299 920331

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VERMONTYANKEE NUCLEAR POWER CORPORA TlON United States Nuclear Regulatory Commission March 31,1992-

. Page 2 In addition, the equested change in the frequency of the calibration interval for the liigh Steam Line Flow instrumentation from once every three months to once per operating cycle does not impact the reliability of the TR relays since the relays are tested during function 9 tests which an: prewntly performed once per meath in accordance with Technical Specificar.ons.

We trust that this information satisfactorily addresses your concerns; however, should you require any further infom1ation regarding the subject proposed change to Technical Specifications, please contact this office.

Very truly yours.

VERMONT YANKEE NUCLEAR POWER CORIORATION cy .

1. b , , .

Leonard A. Tremblay, Jr. 's Senior Licensing Engineer Enclosure 1 attached, cc: USNRC Region 1 Administrator -

USNRC Resident Inspector. VYNPS -

USNRC Project Manager- VYNPS I '

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Enclosure 1 Page 1-of 2 Additior.a1 Information Pertaining To Trip Relays (TRs)

Proposed Change No. 165 to Reflect Analog System Replacement

1. Request Identify the systeme and numbers of TR relays that are normally energized.

Response

The following systems are designated based upon TR relay functions:

(See Note 1 below)

System No. of Relays

' Reactor Protection System (RPS) 38 Control Rod Drive 2 Primary Containment Isolation System (PCIS) 8 Emergency Core Cooling System (ECCS) 8 l

Total 56

! 2. Request Identify the TR relay vendor, style and model number.

Response

Vendor: AGASTAT _ (Amerace Corp. )

Style: EGP Power Relay Model: EGPB002/003 (normally energized) l

3. Request

. Identify the years-of service life for the normally energized TR relays.

Response

Based upon documentation available in our files, the service life for the normally energized TR relays per GE/AGASTAT is 4.5 years.

A recent call.t^ AGASTAT did not result in any new information.

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4. Request If the service life is known, have the previously installed normally energized TR relays been replaced in a timely manner? ,

Does the licensee have a program for routine relay replacement?

Eesponse All the subject normally energized relays are presently addressed in the NRC-reviewed Vermont Yankee Environment 1 Qualification Program which determined qualification and replacement requirements. Based upon specific VY environments, relay l functions and design and operating conditions, this program requires routine review and replacement of reltys based upon i calculated qualified lives due to aging. A review of recorded j service life information has determined that all subject relays i required to be environmentally qualified have been installed for less than 3.5 years. In addition, routine  :

surveillance / maintenance performed on the relays should identify j any failed relays / contacts. To date operating history of this i type of relay has been excellent.

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5. Request Describe the method of seismic restraint of the TR relay to its base. Is the restraint used a wire or a strap?

Response

Subject TR relays are provided with heavy duty loc' ing straps.

6. Roquest [

Are there any TR relays used in circuits where 24 milli-ampere or less is continually conducted through its contacts?

Response

l The majority of the TR relays provide contacts in trip circuits and are used to energize other relays in those circuits. These contacts have.a current continually conducted through them which is greater than 24 milli-ampere. The only circuits which would have 24-milli-ampere or less continually conducted through the TR relay contacts would be those used for non-nuclear safety annunciation or computer input functions.

Notes:

1. The TR relays discussed above refer to the relays which are normally energized by analog trip / calibration cards presently installed at Vermont Yankee.

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