ML17334B404

Forwards Response to NRC Bulletin 89-001 Suppl 2 Entitled, Failure of Westinghouse Steam Generator Tube Mechanical Plugs.

ML17334B404
Person / Time
Site:	Cook
Issue date:	07/29/1991
From:	Fitzpatrick E INDIANA MICHIGAN POWER CO. (FORMERLY INDIANA & MICHIG
To:	Murley T NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM), Office of Nuclear Reactor Regulation
References
AEP:NRC:1096C, IEB-89-001, IEB-89-1, NUDOCS 9108020118
Download: ML17334B404 (17)

Text

ACCELERATED DISTRIBUTION DEMONS TION SYSTEM REGULATORY INFORMATXON DXSTRIBUTION SYSTEM (RIDS)

ACCESSION NBR: 9108020118 DOC. DATE: 91/07/29 NOTARIZED: NO DOCKET FACIL:50-315 Donald C. Cook Nuclear Power Plant, Unit 1, Xndiana & 05000315 50-316 Donald C. Cook Nuclear Power Plant, Unit 2, Indiana & 05000316 AUTH. NAME AUTHOR AFFILIATION FITZPATRICK,E. Indiana Michigan Power Co. (formerly Indiana & Michigan Ele RECIP.NAME RECIPIENT AFFXLXATION R MURLEY,T.E. Office of Nuclear Reactor Regulation, Director (Post 870411

SUBJECT:

Forwards response to NRC Bulletin 89-001 Suppl 2 entitled, "Failure of:Westinghouse Steam Generator Tube Mechanical Plugs."

DISTRIBUTION CODE: A009D COPIES RECEIVED:LTR ENCL SIZE: /

TITLE: OR/Licensing Submittal: Appendix I NOTES:

A RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL D PD3-1 LA 1 1 PD3-1 PD 1 1 COLBURN,T. 2 2 D INTERNAL: NRR/BRADFUTE,J 1 1 NRR/DREP DIRlOE 1 0 NRR/DREP/PRPB11 1 1 NUDOCS-ABSTRACT 1 1 1 0 OGC/HDS2 1 0 1 1 RGN3 . DRSS/RPB 1 1 EXTERNAL: EG&G AKERS, D 1 1 NRC PDR 1 1 PNL/BAKER,D.A. 1 1 D

A D

D NOTE TO ALL "RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE WASTE! CONTACT THE DOCUMENT CONTROL DESK, ROOM P 1-37 (EXT. 20079) TO ELIMINATEYOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED! .

TOTAL NUMBER OF COPIES REQUIRED: LTTR 15 ENCL 12

indiana Michigan Power Company P.O. Box 16631 Columbus, OH 43216 AEP:NRC:1096C Donald C. Cook Nuclear Plant Units 1 and 2 License Nos. DPR-58 and DPR-74 Docket Nos. 50-315 and 50-316 RESPONSE TO NRC BULLETIN 89-01 SUPPLEMENT 2:

FAILURE OF WESTINGHOUSE STEAM GENERATOR TUBE MECHANICAL PLUGS U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D.C. 20555 Attn: T. E. Murley July 29, 199l

Dear Dr. Murley:

This letter provides our response to NRC Bulletin 89-01 Supplement 2 entitled, "Failure of Westinghouse Steam Generator Tube Mechanical Plugs." The bulletin discusses problems with stress corrosion cracking of steam generator tube plugs supplied by Westinghouse. The response is specific to Unit 1 of the Cook Nuclear Plant. Unit 2 is operating in its second cycle following replacement of all steam generators and has no mechanical plugs installed.

The specific information requested in the bulletin is provided in the attachment to this letter. Our response is based on historical and current operating parameters for the Cook Nuclear Plant. We are currently considering implementing, within the existing technical specifications, a slight increase in the Unit 1 primary side operating temperatures. The impact of this change will be reviewed prior to implementation to determine its impact on the conclusions presented in the attachment to this letter.

NRC Bulletin 89-01 Supplement 2 pertains to plugs fabricated from Group 2 heats. Plugs fabricated from Group 1 heats were the topic of the original NRC Bulletin 89-01. As indicated in our letter AEP:NRC:1096B, dated May 30, 1991, 269 hot leg plugs from a group 1 heat were removed and replaced during the past Unit 1 refueling outage. The 269 plugs from the same heat installed in the cold legs PDR 9> 0725 R 'jgPQ('~OOO FDR

Dr. T. E. Murley AEP:NRC:1096C have sufficient remaining life such that repair or replacement is not necessary. (A letter dated June 4, 1991 from Colburn (NRC) to Fitzpatrick (I&M) incorrectly stated that 538 mechanical plugs were to have been replaced during the previous Unit 1 refueling outage.)

Our response to NRC Bulletin 89-01 Supplement 2 was requested to be made under oath or affirmation according to the provisions of Section 182a of the Atomic Energy Act of 1954, as amended, and 10 CFR 50.54(f). As such, an oath is included with this letter.

Sincerely, EF Vice President ldp Attachment

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Dr. T. E. Murley AEP:NRC:1096C cc: D. H. Williams, Jr.

A. A. Blind - Bridgman J. R. Padgett G. Charnoff A. B. Davis - Region III-NRC Resident Inspector Bridgman NFEM Section Chief

Dr. T. E. Murley AEP:NRC:1096C bc: S. J. Brewer/M. S. Ackerman T. 0. Argenta/R. F. Kroeger J. G. Feinstein M. L. Horvath - Bridgman J. F. Kurgan J. J. Markowksy J. B. Shinnock S. H. Steinhart/S. P. Hodge T. Colburn, NRC - Washington, D.C.

DC-N-6015.1 AEP:NRC:1096C

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COUNTY OF FRANKLIN E. E. Fitzpatrick, being duly sworn, deposes and says that he is the Vice President of licensee Indiana Michigan Power Company, that he has read the foregoing response to NRC Bulletin 89-01 Supplement 2: Failure of Westinghouse Steam Generator Tube Mechanical Plugs and knows the contents thereof; and that said contents are true to the best of his knowledge and belief.

Subscribed and sworn to before me this ~4~

day of I 199 I NOTARY PUBLIC anA o. HlLL OF OHIO TIOTARY PUBLIC. STATE

ATTACHMENT TO AEP:NRC:1096C RESPONSE TO NRC BULLETIN 89-01

AEP:NRC:1096C This attachment provides the information requested by NRC Bulletin No. 89-01, Supplement 2. The responses are applicable to Unit 1 of the Cook Nuclear Plant. Unit 2 is operating in its second cycle following replacement of all steam generators and has no mechanical plugs installed.

Action Item 1 Summar of Re est Verify that information contained in Table 2 of Addendum 2 to Westinghouse report WCAP-12244, Revision 3, titled "Steam Generator Tube Plug Integrity Summary Report" is correct for plugs fabricated from group 2 heats. Specifically, verify the number of Westinghouse mechanical plugs installed in the hot and cold legs of each steam generator, heat number and date of installation, and plug operating temperatures.

Also, it should be stated if plants have not installed Westinghouse mechanical plugs from group 2 heats.

~Res ense The information contained in Table 2 of Westinghouse Report WCAP-12244, Revision 3, Addendum 2, dated June 1991, was reviewed for each steam generator to verify the number of Westinghouse mechanical plugs installed from group 2 heats in the hot leg and cold legs by heat number, date of installation, and operating temperatures. An inconsistency was found for the number of plugs installed and removed in steam generator No. 14 for August 1983.

Two tubes were plugged in steam generator No. 14 in August 1983 requiring installation of two plugs on the hot leg and two plugs on the cold leg. Subsequently one of the hot leg plugs was removed during tube sample removal in September 1983 and the remaining tube hole on the hot leg plugged with a welded Inconel 600 plug. Westinghouse was informed of the inconsistency and has provided the attached corrected (non-proprietary) Table 2, dated July 11, 1991. No other inconsistencies were found in the table.

Action Item 2 a-f Summar of Re est Addressees are requested to take the following actions, to be implemented initially during any refueling outage or extended outage (greater than four weeks) which ends 60 days or more following receipt of this bulletin and during all future refueling outages. For the period of time between receipt of the bulletin and 60 days, the actions requested in the original version of this bulletin continue to be applicable for plugs fabricated from group 1 heats.

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AEP:NRC:1096C Item 2 a)

Addressees should implement appropriate remedial actions (i.e., repair and/or replacement) for all plugs whose estimated lifetime in item 2b, below does not extend to the next refueling outage.

Item 2 b)

Remaining lifetime estimates (in effective full power days (EFPD)) are given in Table 2 of Reference 4 in the column entitled "Remain EFPD to MIN." These remaining lifetime estimates are 'relative to reference dates given in the column entitled "Reference CALC Dates." These remaining lifetime estimates may be used directly. These estimates should be adjusted to reflect any corrections noted in

~Res onse Based on plug information contained in the attached table, no plugs require repair and/or replacement prior to the next refueling outage, which is tentatively scheduled for June 1992.

Plugs will be repaired and/or replaced prior to exceeding the effective full power day limits listed in the table during future refueling outages.

Item 2 c)

For refueling outages or extended outages ending prior to November 30, 1991, remedial actions for plugs fabricated from NX-5222 may be deferred until the next scheduled refueling outage.

~Res onse No plugs from heat No. NX-5222 are installed in any of the steam generators.

Item 2 d)

Installation of Westinghouse mechanical plugs fabricated from Inconel 600 should be discontinued.

~Res onse Installation of Inconel 600 mechanical plugs has been discontinued. Mechanical plugs manufactured from thermally treated Inconel 690 are now being used to plug tubes.

AEP NRC 1096C Item 2 'e)

If for any refueling outage, the satisfy items 2a to 2d above, an addressee does not plan alternative plan for to insuring plug integrity, with appropriate technical justification, should be submitted to the NRC at least 30 days before the end of the refueling outage.

~Res onse As

'f previously stated in response to items 2a-d, plugs will be repaired and/or replaced prior to exceeding the effective full power day limits listed in the table. these plans change, an alternative plan for ensuring plug integrity will be'submitted to the NRC at least 30 days before the end of the refueling outage that occurs prior to the date of the remaining EFPD limit listed in the table.

Item 2 f)

Prior to any plug repairs or replacement, addressees are reminded that their responsibilities under ALARA require analysis of the various plug repair or replacement methods.

In choosing a plug repair or replacement method, the licensee should consider the accessibility of the plugs and the dose reduction benefit of using robotic manipulators.

Prior to plug repair or replacement, the licensee should consider steam generator decontamination and/or local shielding to reduce working area dose rates.

~Res onse ALARA considerations will be addressed when formulating plans for the repair or replacement activity. This will include the use of robotics and the appropriate employment of shielding and decontamination measures.

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I Alloy 600 Mechanical Plug S ro Oate Reviee d: O?)11/91 M

Table 2: Westinghouse Alloy 600 Mechanical Plug lnforrnation IBfi'K TA TEMPE OATA Pre veus at ~ing hg Mrn. nit EFPD F Aern n eaf to PIUge P}uye T/S Sla Plug Plug HL Cycle PF) ('F) factor Size Ug. CFPD Mutt. to Aef. EFPD Repair Ro- Re- h1 Plant tnst Heat SQ or Cycte to tNN actor Dale to MlN Plugs pe}$ - OV- }tpe Alpha Oate Mo. CL HL CL ~d ~ d gQ G G A,C.E 07-87 24 4S23 13 HL 536.0 582.0 518.0 7/8 549 10/20/90 0.75 6512 0 < Ref. PR 07-87 69 4523 11 HL 600.0 518.0 7/8 549 10/20/90 O.T5 551.2 0 < Ref PR O 07-8? 90 4528 14 HL 600.0 536.0 582.0 51B.O 7/8 549 10/20/90 0.75 5512 0 < Ref. PA O?-87 4523 l2 HL 600.0 536.Q 582.0 51B.O 7/8 549 10/20/90 0.75 5512 0 < Ref. PA 05-89 20 6323 14 HL 582.0 51B.O 7/8 746 10/20/90 0.75 193,a 1156 1994 PR n 05-89 93 6323 13 HL 582.0 518.0 TIB r46 10/20/90 O.TS 193.8 1156 1994 PA Z 05-89 91 6828 11 HL 6QQ.O 582.0 518.0 T/8 T46 10/20/90 O.?S 193.8 1156 1994 PR V) 05-89 40 6323 12 HL 582.0 518.0 7!B 746 10/20/90 O.TS 193.8 1156 1994 PR 05-89 3? 6135 l4 HL 600.0 582.0 518.0 TIB 2272 10/20/90 193.8 4349 2005 PR &

12-80 10 1989 11 HL 600.0 586.0 5820 518.0 l/8 5131 10/20/90 0.75 1880.? 690T 2014 PR 12-80 10 1989 14 HL 536.0 582.0 518.0 TIB 5131 10/20/90 0.75 1830? 690? 20t4 PA 07-82 10 2887 12 HL 536.0 582.0 618.0 7/8 5131 10/20/90 0.75 1567.1 7459 2016 PA 0?-82 10 2887 13 HL 582.0 518.0 ?IB 5131 10/20/90 0.75 1567.1 7459 2016 PR 08-83 2 2387 14 HL 600,0 586.0 582.0 51B.Q TIB St31 10/20/90 0.25 1302.1 8013 2618 PA 08-83 2 2887 11 HL 600.0 536.0 582.0 618.0 l/8 5131 10/20/90 0.75 1302.1 8013 2018 PA 08-83 9 2387 13 HL 600.0 586.0 582.Q 618.0 T/8 5131 10/20/90 0.75 1302.1 8013 2018 PA 08-83 3 2387 12 HL 600.0 586.0 582.Q 518.0 7/8 St81 10/20/90 0.25 13Q2.1 8013 2018 PR 06-85 5 2387 l4 HL 536.0 582.0 518.0 7/8 5131 10/20/90 0.75 891.6 SB?2 2022 PR 06-85 6 2887 13 HL 536.0 682.0 518.0 7/8 5131 10/20/90 0.76 891.6 8872 2022 PR 06-85 8 2887 1'I HL 536.0 582.0 518.0 7/8 5131 10/20/90 0.75 891.6 S872 2O22 PR 06-85 9 2887 'l2 HL 536.0 582.0 518.0 2/8 5131 10/20/90 0.25 891.6 6872 2022 PR 07-87 90 4528 14 CL 536.0 5820 518.0 7/8 8562 10/20/90 0.75 551.2 18511 2057 PR 07-87 86 4528 12 CL 600.0 536.0 582.0 518.0 7/8 8562 10/20/90 0.76 551.2 185'l1 205? PR 6512 18511 205? O 07-87 24 4528 13 CL 600.0 536.0 6820 518.0 7/8 8562 10/20/90 0.75 PR 0?-8? 69 4528 -CL 6OO.O 536.0 582.0 518.0 TIS 8562 10/20/90 0.76 551.2 18511 2057 PA ll 05-89 40 6323 12 CL 600.0 536.0 582.0 518.0 7/8 11645 10/20J90 0.75 193.8 26459 2086 PR n m

06-89 91 6328 11 CL 600.0 536.0 582.0 518.0 7/S 11645 10/20/90 0.75 193.8 26459 2086 PR 05-89 98 6328 13 CL 536.0 582.0 518.0  ?/B 11645 10/20/90 0.75 193.8 26459 2086 PR 05-89 ST 6185 14 CL 600.0 536.0 SS2.0 518.0 7/8 85448 10/20/90 0.75 198.8 81461 2286 PR 12-80 10 1989 11 CL 600.0 536.0 582.0 518.0 7/8 8005? 10/20/90 0.75 1830.7 180766 264T PA 12-80 10 1989 14 CL 600.0 582.0 518.0 TIB 8005? 10/20/90 0.75 1830.7 180756 264? PR D 181366 2650 PR 07-82 10 2387 13 CL 600.0 582.0 518.0 7/8 8005? 10/20/90 0.75 1567.1 m 07-82 10 2387 12 CL 600.0 536.0 682.0 518.0  ?JB 8006? 10/20/90 0.75 1567.1 181366 2650 PR 6) 08-88 9 2387 13 CL 600.0 536.0 582.0 618.0 TIB 8005? 10/20/90 0.75 1302.1 181978 2652 PR (9 0.75 1802.1 181978 2652 PA re ta-88 2 2387 11 CL 536.0 S<B.O 7/8 8005? 10/20/90 08-83 3 288? 12 CL 536.0 582.0 518.0 T/8 8005? 10/20/90 Q.?5 1302.1 181978 2652 PA Table 2. Page 1 of 70 11-tu}-91

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