ML18038A143

Forwards Table Entitled NMP-1 Guidelines for Repair of Leaking CRD Penetrations, Per 851118 Request.Basis for Leakage Limits in Guideline Include Available Test Info on Rolled tube-to-tube Sheet Joints in Steam Generators

ML18038A143
Person / Time
Site:	Nine Mile Point
Issue date:	03/14/1986
From:	Mangan C NIAGARA MOHAWK POWER CORP.
To:	Zwolinski J Office of Nuclear Reactor Regulation
References
NMP1L-0037, NMP1L-37, NUDOCS 8603240206
Download: ML18038A143 (7)

Text

REGULATORY I ORMATI ON DISTRIBUTION SYS 'l ( R I DS )

i ACCESSION'. NBR: 8603240206 DOC. DATE: 86/03/14 NOTARIZED: NO DOCKET FACIAL: 50-220 Nine Mile Point Nuclear Station> Unit ie Niagara Powe 05000220 AUTH. NAME AUTHOR AFFILIATION MANGANd C. V. Niagara Mohawk Power Corp.

RECIP. NAME RECIPIENT AFFILIATION ZWOLINSKId J. A. BWR Prospect Directorate 1-

SUBJECT:

Forwards table entitled "NMP-1 Guidelines for Repair of.

Leaking CRD Penetrations." per 851118 request. Basis for leakage limits in guideline include available test info on rolled tube-to tuhe sheet doints in steam generators.

DISTRIBUTION CODE: AOOID COPIES RECEIVED: LTR ENCL I EIIE:

TITLE: OR Submittal: General Distribution NOTES:

RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL BWR ADTS 1 0 BWR EB 1 BWR EICSB 2 2 BWR FOB 1 1 BWR PD1 PD 01 5 5 KELLYiJ 1 BWR PSB 1 BWR RSB 1 INTERNAL: ADM/LFMB 1 0 ELD/HDS3 1 0 NR D TSCB 1 NRR/ORAS 1 0 EG 04 1 RGN1 1 1 EXTERNAL: 24X 1 1 EGZ<G BRUSKEd S 1 LPDR 03 1 1 NRC PDR 02 1 NSIC 05 1 1 TOTAL NUMBER OF COPIES REQUIRED: LTTR 24 ENCL 20

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fV V Mlle%,IRK 5J 9 MQog@%K NIAGARA MOHAWK POWER CORPORATION/300 ERIE BOULEVARD WEST, SYRACUSE. N.Y. 13202/TELEPHONE (315) 474-1511 March 14, 1986 NMP1L 0037 Director of Nuclear Reactor Regulation Attention: Mr. John A. Zwolinski, Project Director BWR Project Directorate Number 1 Division of BWR Licensing U.S. Nuclear Regulatory Commission Washington, D.C. 20555 Re: Nine Mile Point Unit 1 Docket No. 50-220 DPR-63

Dear Mr. Zwolinski:

During the Nine Mile Point Unit 1 spring 1984 Refueling and Maintenance Outage, leaking control rod drive penetrations were detected. These penetrations were repaired by rolling of the control rod drive housing into the reactor vessel. A post repair hydrostatic test was performed which confirmed their leak tightness. In addition, our letter of October 1, 1984 provided our plans for future nondestructive examination of control rod drive housing assemblies.

We met with members of your staff on November 18, 1985 to present a summary status of our repair program. This summary included discussion of the repair efforts completed during the spring 1984 outage, inspection plans for the spring 1986 outage, preparations for the spring 1986 outage repairs, if required, and development work for long term alternate repair methods. A letter dated December 2, 1985 from Mr. Robert A. Hermann of your staff, provided a summary of the November 18, 1985 meeting and requested Niagara Mohawk to formally submit its guidelines for the repair of leaking control rod drive penetrations for staff review and approval. In response to your request, a handout (copy attached) provided by Niagara Mohawk at the November 18, 1985 meeting contained a Table titled "NMP-1 Guidelines For Repair of Leaking Control Rod Drive (CRD) Penetrations." The basis for the leakage limits presented in this guideline were derived from the following information:

l. Available test information on rolled tube-to-tube sheet joints in steam generators.

8603240206 8603i4 PDR ADOCK 05000220 P

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2. The results of mockup tests performed in support of the rolled repair of a control rod drive penetration at Big Rock Point.

3. Experience with leaking control rod drive penetration at a foreign plant.

These repair guidelines will be used as a basis for implementing the repair method of any control rod drive penetration found to be leaking during the spring 1986 outage.

Sincerely, NIAGARA MOHAWK POWER CORPORATION C. V. Manga Senior Vice President RJP'bd

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