ML20059M941

Special Rept:On 930922,seismic Monitor 2ERS-RRA-1 Declared Inoperable.Caused by High Radiation Dose Rate in SG Support Cubicle Elevation 718'6.Monitor Repaired & Returned to Operable Status on 931014

ML20059M941
Person / Time
Site:	Beaver Valley
Issue date:	11/15/1993
From:	Freeland L DUQUESNE LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM), Office of Nuclear Reactor Regulation
References
ND3MNO:3508, NUDOCS 9311300010
Download: ML20059M941 (4)

Text

l l

e T?d@

Telephone (412) 393-6000 Mar Group Shippmgport. PA 15077 0004 l

1 November 15,1993 ND3MNO:3508 Beaver Valley Power Station, Unit No. 2 Docket No. 50-412, Licensee No. N1 F-73 Snecial Report _

United States Nuclear Regulatory Commission Attn: Director, Office of Nuclear Reactor Regulation Document Control Desk Washington, DC 20555 Gentlemen: ,

In accordance with Appendix A, Beaver Valley Technical Specification 3.3.3.3,

" Seismic Monitoring ", the following Special Report is submitted. This report documents the >

malfunction of Seismic Monitor 2ERS-RRA-1 and plans for resolving this problem.

The self contained triaxial time history accelerograph, mark no. 2ERS-RRA-1, model DUA-333 (vendor: Terra Technology), is located in the Steam Generator Support Cubicle, elevation 718' 6" and has been found inoperable at the beginning of'each Unit 2 refueling outage. On September 22,1993, 2ERS-RRA-1 was declared inoperable,- repaircd, and on October 14,1993, the monitor was restored to operable status.

During the investigation into the apparent recurring failures, it was determined that the high radiation dose rate in the Steam Generator Support Cubicle el. 718'6" was the cause of' the instrument malfunction. This instrument is in an area that has a radiation dose rate of approximately 5 rem /hr at 100% power. Beaver Valley Power Station Engineering determined.

that the electronics contained in this accelerograph should be limited to an integrated dose of 1000 rads to maintain operability during a cycle. There is a high probability that with the existing installation, the instrument would fail again in a similar manner.

9311300010 931115 Y -

PDR- ADOCK 05000412; 23- . . I D-S PDRg UU

, November 15,1993 ,

ND3MNO:3508 l Page 2 i l

l In addition, the BVPS UFSAR Section 3.7B.4, conforming to the requirements specified by ANSI /ANS 2.2 and Regulatory Guide 1.12 rev.1, states that the self contained triaxial accelerograph shall be located on the Steam Generator Support in cubicle no.1, elevation 718' 6". The actual location of the instrument is in the Steam Generator Cubicle, elevation 718' 6", on a concrete pad on the floor next to the support. The actual location does meet the requirements of the Technical Specification which states that the instrument is located in the.

Steam Generator Support Cubicle, el. 718' 6", however, it does not conform to the Power StaSn's Updated Final Safety Analysis Report or Regulatory Guide 1.12.

2ERS-RRA-1 was declared inoperable on November 5,1993, since it does not provide ,

it.s intended function, due to its non-conformance with the UFSAR and Regulatory Guide 1.12,.

and its inability to remain operable in the radiation field that exists in the Steam Generator Support Cubicle during reactor power operation. The instrument was removed from service '

on November 6,1993.

Beaver Valley is currently evaluating the available options for resolving this problem. ,

Options requiring a physical change to the instrument would not be possible during power operation due to the high radiation fields present in the area where the instrument is located.

One potential option under evaluation involves retiring the instrument from service, since a preliminary review has shown that sufficient containment structural monitorir4 : vill exist without this instrument.

Seismic monitor 2ERS-RRA-A will be removed from service for the current fuel cycle.

This seismic monitor is not relied upon for plant operation, automatic reactor shutdown, or to mitigate the consequences of an accident. Removal of this instrument for one fuel cycle will not impact the safe operation of the plant. All other seismic instrumentation required by ,

Technical Specification 3.3.3.3 are operable. In addition, the containment structure is actively -

monitored for seismic response at elevations above and below the subject monitor (2ERS- i ACS-1: el, 692' 11", 2ERS-ACS-2: el. 769'4") and confirmation of the structural model after an Operational Basis Earthquake will still be possible.

L. . Freelan General Manager Nuclear Operations.

GFZ/ke Attachment h

, l, o

, . November 15, 1993 ND3MNO:3508 Page 3 cc: Mr. T. T. Martin, Regional Administrator United States Nuclear Regulatory Commission Region 1 ,

475 Allendale Road King ofPrussia, PA 19406 Mr. G. E. Edison, BVPS Licensing Project Manager United States Nuclear Regulatory Commission Washington, DC 20555 Lany Rossbach, Nuclear Regulatory Commission, BVPS Senior Resident Inspector J. A. Holtz, Ohio Edison 76 S. Main Street Akron, OH 44308 Larry Beck Centerior Energy 6200 Oak Tree Blvd.

Independence, OH 44101-4661 INPO Records Center 700 Galleria Parkway Atlanta, GA 30339-5957 Mr. Robert Barkanic Department of Enviromnental Resources P.O. Box 2063 lo iloor, Fulton Building '-

. Harrisburg, PA 17120 Direct ., Safety Evaluation & Control

- Virginia Electric & Power Co.

P.O. Box 26666 One James River Plaza Richmond, VA 23261 -

W. Hartley Virginia Pown Company

-5000 Dominion Blvd.

2SW Glenn Allen, VA 23060

< . t

. November 15,1993 ND3M.NO:3508 Page 4 J. M. Riddle Halliburton NUS Foster Plaza 7 661 Anderson Drive Pittsburgh, PA 15220

, Bill Wegner, Consultant 23 Woodlawn Terrace Fredricksburg, VA 22405 t

-t b

?

J d

., , , , , .- - _ - -