BECO-LTR-91-998, Suppls 911017 Response to Violations Noted in Insp Rept 50-293/91-17 on 910707-0824.Corrective Actions:Procedure Revised to Ref Drawing of Drywell Head/Top Flange Assembly & to Include Two Torquing Phases

Suppls 911017 Response to Violations Noted in Insp Rept 50-293/91-17 on 910707-0824.Corrective Actions:Procedure Revised to Ref Drawing of Drywell Head/Top Flange Assembly & to Include Two Torquing Phases

ML20086G891
Person / Time
Site:	Pilgrim
Issue date:	11/27/1991
From:	Gina Davis BOSTON EDISON CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
BECO-LTR-91-998, NUDOCS 9112060210
Download: ML20086G891 (3)

Text

__ _

. . 10 CFR 2.201

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BOSTON EDISON Pilgum Nuclear Power Station Rocky Hill Roed P'vmouth, Massachusetts o236o George W. Davis November 27, 1991 senor v.c. a.s. dent - Nucicar BECo Ltr 91-998 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Hashington, D.C. 20555 Docket No. 50-293 License No. DPR-35

SUBJECT:

SUPPLEMENTAL REPLY TO A NOTICE OF VIOLATION, (REFERENCE NRC REGION I INSPECTION REPORT NO. 50-293/91-17)

Dear Sir:

Enclosed is Boston Edi;on Company's supplemental reply to the Notice of Violation contained li, the subject inspection report. The portions of this reply containing supplemental information are identified by a vertical line in the applicable margin. This supplemental reply is submitted in response to Resident Insoector questions regarding the initial reply submitted on October 17, 1991 (BECo Ltr.91-133).

Please do not hesitate to contact me if there are any questions regarding the enclosed reply, f} / i G. H.

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Enclosures:

Supplemental Reply to the Notice of Violation cc: Mr. Thomas T. Martin Regional Administrator, Region I U.S. Nuclear Regulatory Commission 475 Allendale Rd.

King of Prussia, PA 19406 Scc Hr. R. B. Eaton Qt Div. 1,' Reactor Projects I/II

-o Office of NRR - USNRC 28 One Hbite Flint North - Hail Stop 14D1

• C 11555 Rockville Pike Rockville, MD 20852 Q

no Sr. NRC Resident Inspector - Pilgrim Station

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SR!1[ MENTAL REPLY TO THE NOTICE OF VIOLAT108 T Boston Edison Company Docket No. 50-293 Pilgrim Nuclear Power Station License No. OPR-35 As a result of the inspection conducted at Pilgrim Nuclear Power Station from July 7, 1991 through August 24, 1991 and in accordaate with the NRC Enforcement Policy (10 CFR Part 2, Appendix C), the following Violation was identified:

N0flCE OF. VIOLATION Technical Specification 6.8.A requires the establishment of the applicable procedures recommended in Appendix A of Regulatory Guide 1.33. Section 9 of Appendix A specifies that maintenance which can affect the performance of safety-related equipment should be properly prtplanned and performed in accordance with written procedure, documented instructions, or drawings appropriate to the circumstances.

Contrary to the above the licensee procedure for drywell head installation 3.H.4-48, Revision 13, " Opening and Closing of the Reactor Pressure Vessel" was not preperly established in that the procedure did not specify the proper orientation of drywell head washers during installation, nor proceduralized a final torque check following completion of the planned drywell head torque sequence.

This is a Severity Level IV violatior, (Supplement I).

REASON FOR THE VIOLAT[QN Procedure 3.H.4-48 (Rev. 12) was technically reviewed prior to the refueling o'J t ag e . The review identified improvements in other portions of the procedure.

The improvements were incorporated and Procedure 3.H.4-48 (Rev.13) was issued on May 3, 1991. The Drywell head was reinstalled in late July 1991, lear the end of the recent refueling outage. A critique on July 30, 1991 and subsequent root cause analysis of the drywell head washer failures identified previously unidentified weaknesses in the drywell head installation portion of the procedure (Rev. 13) that were a contributor to installing some washers in an inverted orientation.

The plant drawing (CI A-10-4) of the drywell head / top flange assembly identifies the crientation of the drywell head washers. The drawing was available but was not specifically referenced in Procedure 3.H.4-48 (Rev.13). The procedure contained I instructions for drywell head gasket installation, drywell head installation, and drywell head bolt torquing but did not include details regarding how the drywell head washer sets were to be installed. Plar.t and contractor personnel experienced in drywell head installation did not believe that additional drywell head washer installation detail was necessary to be specifically identified in the procedure when Procedure 3.H.4-48 (Rev. 12) was reviewed. Therefore, the procedure (Rev. 13) did not include details regarding how the drywell head washers were to be installed.

A final torque check following completion of the drywell head bolt torque sequence was not proceduralized because a final torque check was considered to be part of the final torque sequence. In the closure of a bolted joint where a final torque value is specified and is the criteria for which the joiat is accepted, verification of the final torque value is standard practice. The final torque sequence and final torque value were identified in the procedure (Rev. i2). These i instructions were also reviewed by experienced plant and contractor personnel prior to the refueling outage and were considered acceptable.

I.

, $UfTLG@lALRELY T0 TiiLNQllCE OF V10LAl103 (CONTINUED)

CORRECTIVE ACTION TAKEN AND_ REjiULISlCillLVID The orientation of tte drywell head washers was identified in the work package used for the reinstallation of the drywell head. The work package included a  ;

satisfactory final cover pass torque of all drywell head bolts. l CORRECTIVE ACTION TO PRECLUALRCCURRENCE To preclude recurrence of timilar violations, Boston Edison will implement  ;

additional corrective actions that include the following:

• The procedure will be revised to include specific detail regarding how the drywell head upper and lower washer sets are to be installed.

• The procedure will be revised to reference the drawing of the drywell head / top flange assembly.

• The drawing of the drywell head / top flange assembly will be enhanced relative to the detail of the drywell head washers.

• The procedure will be revised to include two torquing phases. The first phase compresses the drywell head garket and brings the drywell head flanges to a metal-to-nietal contact. The second phase preloads the bolts to the final torque value using a minimum of two torque passes. The satisfactory completion of the last torque pass ensures that all drywell head bolts are left at the desired torque value, Other corrective actions are identified in the root cause analysis for Failure and Malfunction Report 91-348. These actions will be addressed separately from this violation response.

DATE WHEN FULL COMPLIANCE HILL BE ACHIEVE 0 Full compliance will be achieved when the drawing is revised and the changes have been incorporated into the procedure. The drawing and procedure changes are expected to be completed by 09cember 20, 1991; however, if the drawing and i procedure changes are not coraleted by December 20, 1991 the changes will be I completed prior to the next removal of the drywell head.

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