ML20023D271

Forwards Rev 5 to Emergency Operating Procedure EOP-5, Recovery from Reactor Trip, in Response to IE Bulletins 83-01 & 83-04.Procedure Revised to Require Manual Reactor Trip Upon Automatic Reactor Trip Condition

ML20023D271
Person / Time
Site:	Summer
Issue date:	05/12/1983
From:	Dixon O SOUTH CAROLINA ELECTRIC & GAS CO.
To:	Harold Denton Office of Nuclear Reactor Regulation
Shared Package
ML20023D272	List: ML20023D271 ML20023D305
References
REF-SSINS-6820 IEB-83-01, IEB-83-04, IEB-83-1, IEB-83-4, NUDOCS 8305200311
Download: ML20023D271 (5)

Text

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SOUTH CAROLINA ELECTRIC & GAS COMPANY POST OPPIC. 7s4 COLuuslA. SOUTH CAMOUNA 29218 O. W. DixON. JR.

uve$*.'l"o',','.fr%,.. May 12, 1983 Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D.C. 20555

Subject:

Virgil C. Summer Nuclear Station Docket No. 50/395 Operating License No. NPF-12 Reactor Trip Breakers

Dear Mr. Denton:

Since the initial discovery of potential problems with the Westinghouse Model DS-416 reactor trip breakers, South Carolina Electric and Gas Company (SCE&G) has followed the development of this issue through industry publications and attendance at several meetings with both industry and the NRC Sta f f. In letters dated March 3, 1983, March 10, 1983 and March 23, 1983, SCE&G described the actions taken in response to I.E.Bulletins 83-01 and 83-04, related to the DS-416's at the Virgil C. Summer Nuclear Station. In LER 83-28 dated April 20, 1983, SCE&G reported the results of our breaker inspection and notified Region II of a Substantial Safety Hazard as required by 10CFR21. Specifically, actions taken by SCEEG have included:

1. Replacement of UV devices with modified devices that have all identified manuf acturing problems corrected and with modified grooves to accommodate improved retaining rings.

2. Installation testing of modified UV devices by performance of ten (10) successive operations with thirty (30) minute intervals between each operation.

3. Installation checks on the modified UV devices to verify proper alignment.and interface with the breaker trip shaft.

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l Mr. Harold R. Denton Reactor Trip Breakers May 12, 1983

Page #2 I l 1 l

4. Maintenance of the DS-416's in accordance with i Westinghouse recommendations.

5. All licensed operators on shift rotation have been notified of the Salem and San Onofre events and the appropriate Station Emergency Operating Procedures (EOP) have been reviewed and revised to require manual reactor trip upon an automatic reactor trip condition..(See Attachment) i Additionally, all licensed operators on shif t rotation will receive training on the previously mentioned revised E0P's.

, This training will' be accomplished prior to startup after the current plant outage.

1 SCE&G has completed all recommended corrective actions des-cribed in Westinghouse letter dated April 21, 1983 and NRC required actions described in I.E.Bulletins 83-01 and 83-04.

l It is our position that by. completing the recommended correc-

! tive actions, provided by Westinghouse and NRC, the concerns of potential for misoperation~ associated with the reactor trip breakers have been adequately addressed.

In addition to the above described actiens, the NRC Staff has recommended additional actions to further assure the reli-ability of the subject breakers. SCE&G commits to perform the following in response to Staff recommendations.

1. Pre-Startup Testing, If Not Performed Within The Previous Seven (7) Days (Main Breakers)

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a) Functional test of the reactor trip breakers via. the l main control board trip switches.

b) Independent Test of UV and Shunt Trip Devices NOTE: The present design does not allow performance of these functional tests using installed equipment. A design to allow this testing is expected to be complete during June 1983.

Installation of this change will be completed during the first outage of sufficient duration af ter completion of design and receipt of material.

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Mr. Harold R. Denton Reactor Trip Breakers May 12, 1983 Page #3

2. Monthly Testing, Every Thirty-One (31) Days (Main Breakers)

a. Functional test of UV devices by Reactor Protection System (RPS) actuation including response time testing of the breaker.

NOTE: The present design does not allow performance of the response time test using installed equipment. A design to allow this testing is expected to be complete during June 1983.

Installation of this change will be completed during the first outage of sufficient duration after completion of design and receipt of material.

b. Functional manual test of shunt device (See note to Item lb)

3. Six Month Surveillance and Maintenance (Bench Test of Main and Bypass Breakers) to be Performed at First Shutdown After Six Month Interval

a. Breaker response time measurement by tripping UV device and by tripping shunt coils independently.

b. Measurement of force required to actuate trip bar.

I c. Measurement of force exerted by UV device output.

l NOTE: The performance of items (b) and (c) is l

l predicated on the ability of SCE&G and Westinghouse to develop accurate and repeatable field test techniques with appropriate acceptance criteria, which will provide baseline data to be considered in future breaker maintenance activities.

Development of procedural guidance is scheduled for August 1983,

d. Perform Westinghouse recommended preventive i maintenance as noted on Page #2, Item #4.

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i Mr. Harold R. Denton Reactor Trip Breakers May 12, 1983 Page #4 t

4. Provide'RPS Actuation of the Shunt Trip In conjunction with the design change described in Items 1.b and 2.b, this capability will be added. This design is expected to be consistent with that of the Westinghouse Owners Group /which will be presented to the NRC for review by early June, 1983.

5. UV Device' Confirmatory Life Testing SCE&G and Westinghouse will develop a program for confirming, via test and/or calculation, the expected life of the UV devices. The scope, objectives and schedule for this program are expected to be completed during June 1983.

As discussed with the NRC Staff, SCE&G considers the extended maintenance and surveillance program described herein to be temporary.- The on-line monthly testing described in Item #2 on Page #3 places the plant in a "less-desirable" condition for the duration of the test. SCE&G considers monthly testing of this type for an extended period of time to be unnecessary.

In this regard an expeditious resolution to the DS-416 breaker t issue is mandatory. It is our understanding that generic guidance on this issua may be forthcoming from the Staff.

Issuance of this generic guidance and/or increased knowledge gained from the programs outlined in this submittal may require re-evaluation of these commitments by SCE&G.

If you have any questions, please contact us.

Very truly yours, 7

hI O. W. Dixon, .

NEC:0WD/fjc cc: (See Page #5) 4

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g e Mr. Harold R. Denton Reactor Trip Breakers i May 12, 1983 Page #5 cc: V. C. Summer T. C. Nichols, Jr./O. W. Dixon, Jr.

E. C. Roberts H. N. Cyrus >

J. P. O'Reilly Group / General Managers O. S. Bradham R. B. Clary C. A. Price

- A. R. Koon C. L. Ligon (NSRC)

G. J. Braddick

, J. C. Miller J. L. Skolds J. B. Knotts, Jr.

NPCF File (Lic./Eng.)

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