ML20090H693

Forwards Status Rept on Open Items Re GDC 17 Analysis,In Response to NRC 840417 Request.All Regulatory Commitments & Mods to Be Completed at End of Present Unit 1 & Upcoming Unit 2 Refueling Outages

ML20090H693
Person / Time
Site:	North Anna
Issue date:	07/18/1984
From:	Stewart W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	Harold Denton, John Miller Office of Nuclear Reactor Regulation
References
253B, NUDOCS 8407270040
Download: ML20090H693 (4)

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VIRGINIA ELECTRIC AND POWER COMPANY Ricnwown,VINGINIA 20261 W. L. STswutt

- vice r...io=== July 18, 1984 Serial No. 253B EC:BSD:baj:2000N Docket Nos. 50-338 50-339 License Nos.NPF-4 NPF-7 Mr. Harold R. Denton, Director O'fice of Nuclear Reactor Regulation Attention: Mr. James R. Miller, Chief Operating Reactors Branch No. 3 Division of Licensing U. S. Nuclear Regulatory Commission Washington, D.C. 20555 Gentlemen:

GENERAL DESIGN CRITERIA 17 ANALYSIS VIRGINIA ELECTRIC AND POWER COMPANY NORTH ANNA UNIT NOS. 1 AND 2 Your letter of April 17, 1984 requested that Vepco provide a monthly status update for completing remaining open items regarding General Design Criteria 17 Analysis for North Anna Units 1 and 2. The attachment of this letter provides updated information.

The attachment does not address Item IA,B,C,D and E as they have been addressed in previous letters and no change is anticipated. Should a change occur in any of these-items, the item will be addressed in a future letter. In addition, the attachment does not address Item II A, since the remaining work on the motor operated valves is not required to meet our GDC-17 commitment.

The work on Items II B,C,E,F, and H is interrelated and is being performed-under one Design Change Package. For this reason we will report on these items in one status update.

The expected completion of all regulatory commitments and modifications related to General Design Criteria 17 for North Anna Units 1 aad 2, except motor control center contactor coils, is scheduled for the end of the present Unit 1 and upcoming Unit 2 refueling outages. The North Anna Unit . outage has been revised and is currently scheduled to be completed in August, 1984 and the

North Anna Unit 2 outage in October,1984. However, this schedule has become questionable due to procurement problems. We are reviewing the impact of this problem and will advise you in our next letter prior to Unit 1 startup. The problem is discussed in more detail in our status update on Items II B,C,E,F, 8407270040 84071s M p DR ADOCK 05000338 PDR $h -

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'Vanotw A Es.acTaic aun POwra COMPANY TO

. and H. The motor control center-contactor coil test results are scheduled to

- be available to Vepco in late December,1984 but our final report will not be available to you until January, 1985. This item is discussed in greater detail in Item III A.

We will continue to provide you with updates per your request.

Very truly yours,

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WL$?vd y 'Y W. L. Stewart Attachment-BSD/baj 1

cc: Mr. James P. O'Reilly i Regional Administrator

• Region II

.Mr. M. W. Branch NRC Resident Inspector

. North Anna Power Station i

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STATUS AND SCHEDULE FOR GDC-17 ANALYSIS i COMMITMENTS Item I: Operating Restrictions: Previously reported. Information will be updated if any changes occur.

Item II: Modifications:

Comitment A: Previously reported, remaining work on MOVs is not required to meet our GDC-17 commitment.

Comitment B: Install a load shed scheme to remove certain motors when Unit 2 transfers to the RSSTs simultaneously with a Safety Injection (SI) or Containment Depressurization Actuation (CDA) occurrence on Unit 1.

Comitment C: Trip the 34.5 KV reactors in the switchyard when an SI or CDA occurs on either unit.

Comitment E: Modify RSST load tap changer (LTC) control to eliminate all delays in LTC response during the first three minutes of a SI or CDA event on either unit and on transfer of unit loads to the RSS system. '

Commitment F: Block the auto starting of large non-IE motors, when the station i service bus feeding the motor is fed from the same source as an emergency bus of a unit experiencing an SI or CDA.

Comitment H: When a unit experiences an SI or CDA and the "G" bus tie breaker is closed, then all circulating water pumps on the unit experiencing the accident will be tripped.

Status B,C,E,F and H: Four relays have been lost in transit to North Anna.

These relays may require 20 weeks to replace if they are not recovered undamaged. Since these relays are critical for the completion and testing of this control circuitry, the completion of Items II B,II C, II E, II F and II H may be delayed.

Vepco is presently evaluating the impact of this material problem. The majority of the relays needed for Items II B,C,E,F and H are available and by switching available relays between locations partial t testing may be performed. Vepco will attempt to determine which portions if any of these comitments i can be met with the remaining relays and will expedite their replacement. We will have further information on j possible impact in our next letter.

Commitment D: Install overvoltage Oiarms on 4160 and 480 volt emergency buses to alert station personnel to the need to protect equipment i

against high voltage. i l .- . . . - --..- . - - - . -...- - - - - - - - - -- - - -

D Status D: A DCP for each unit has been prepared to install this circuitry.

The DCP has been approved for Unit 1. The Unit 1 DCP has been installed, is undergoing testing, and is scheduled to be completed during the Unit I refueling.

The DCP for Unit 2 should be available and implemented during the Unit 2 outage.

Commitment G: Eliminate the automatic transfer of emergency buses from the Reserve Station Service to the Normal Station Service.

Status G: A DCP has been prepared and approved to eliminate the automatic transfer for Unit 1 emergency buses from the Reserve Station Service Transformers to the Normal Station Service Transformers.

The modifications to control circuitry have been made, are undergoing testing, and scheduled to be completed during the Unit 1 outage. The DCP, which has been prepared to install similar bus ties for Unit 2, has been modified to delete the automatic transfer. Vepco at this time is not planning the installation of these bus ties for Unit 2.

Item III: Additional Commitments Commitment A: In our letter of June 7,1983 (Serial No. 326) Vepco stated that tests would be performed on motor control center contactor coils to determine the effe cts of overvoltage. In our letter of March 26,1984 (Serial No. 326A) we stated our current schedule was for completing the overvoltage test by May, 1984, obtaining a test report in June,1984, and providing results to the NRC in July, 1984.

Status A: Based on presently available information we anticipate the test report will be available to Vepco in late December 1984. Based on receipt of the report in late December, Vepco will submit results and formal report to the NRC in January 1985. We continue to believe that this is not a serious concern and that no corrective actions will be required.

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