ML17332A688
| ML17332A688 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 03/17/1995 |
| From: | Fitzpatrick E INDIANA MICHIGAN POWER CO. (FORMERLY INDIANA & MICHIG |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| AEP:NRC:1096G, NUDOCS 9503230165 | |
| Download: ML17332A688 (5) | |
Text
P RIORITY 1 iACCELERATEDRIDS PROCESSING)
DOCKET 05000315 05000316 El
SUBJECT:
Submits interim rept on Westinghouse Alloy 600 SG mechanical plugs, as requested by NRC in response to recent field experience w/Westinghouse Alloy 600 thermally treated mechanical plugs.
DISTRIBUTION CODE:
A023D COPIES RECEIVED:LTR ENCL SIZE:
TITLE: Westinghouse Alloy 600 Issues NOTES REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS) r ACCESSION NBR:9503230165 DOC.DATE: 95/03/17 NOTARIZED: NO FACIL:50-315 Donald C.
Cook Nuclear Power Plant, Unit 1, Indiana M
50-316 Donald C.
Cook Nuclear Power Plant, Unit 2, Indiana M
AUTH.NAME AUTHOR AFFILIATION FITZPATRICK,E.
(formerly Indiana &.Michigan e
RECIP.NAME RECIPIENT AFFILIATION Document.Control Branch (Document Control Desk)
RECIPIENT ID CODE/NAME PD3-1 LA HICKMAN,J INTERNAL: FIXE CENTER" =01
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1 NOTE TOALL "RIDS RECIPIENTS:
PLEASE HELP US TO REDUCE iVASTE!CONTACTTHE DOCUMENTCONTROL DESK, ROOhI P!-37 (EXT. S04-2083 ) TO ELIMINATEYOUR NAMEFROM DISTRIBUTIONLISTS I'OR DOCUMENTS YOU DON"I'EED!
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Indiana Michigan Power Company P.O. Box 16631 Coiumbus, OH 43216 March 17, 1995 AEP:NRC'1096G Docket Nos.:
50-315 50-316 U.
S. Nuclear Regulatory Commission ATTN:
Document Control Desk Washington, D. C.
20555 Gentlemen:
Donald C.
Cook Nuclear Plant Units 1 and 2
INTERIM REPORT ON WESTINGHOUSE ALLOY 600 STEAM GENERATOR MECHANICAL PLUGS The following status is provided as requested by the NRC staff in response to recent field experience with Westinghouse Alloy 600 Thermally Treated (TT) mechanical plugs.
This letter serves to provide the staff with our intended response to this latest field data and schedule for submitting our action plan to the NRC.
In December 1994, Westinghouse notified us of recent field experience with Alloy 600 mechanical plugs that necessitated a revision to the corrosion algorithm presented in WCAP-12244 Rev. 3.
This revision in the corrosion algorithm had the potential to affect our previously developed schedule and action plan for addressing Alloy 600 TT mechanical plugs in service in our steam generators.
Utilit Res onse No Westinghouse Alloy 600 mechanical plugs are installed in the Unit 2 steam generators and therefore no further actions are required for that unit.
The last of the Westinghouse Alloy 600 TT mechanical hot leg plugs were removed during the Cook Nuclear Plant Unit 1 1992 refueling outage.
At present, Unit 1 has a total of 425 Westinghouse Alloy 600 TT mechanical plugs in service in our steam generators, all of which are cold leg plugs.
Of these, a total of 89 plugs are present in tubes where plug top release may lead to tube perforation.
- However, the potential of this occurring is extremely limited since all tubes Q
9SOmvoae5 mOZ17 PDR ADOCK 05000315 P
PDR Qj
~4.S. Nuclear Regulatory Commission Page 2
AEP'NRC:1096G in the steam generators are partial depth rolled tubes.
Table 1
(attached) provides the current plant configuration with the installed mechanical plugs.
Westinghouse has revised the plug life algorithm based on the St. Lucie plug experience.
This revised algorithm is in an addendum to WCAP-12245, Rev.
3, entitled "Addendum 3 to Steam Generator Tube Plug Integrity Summary Report," which was issued in January 1995.
The plug life algorithm contained in the report shows that the year 2057 is the earliest the first heat. of cold leg plugs needs to be repaired or removed.
The Cook Nuclear Plant Unit: 1 operating license expires in 2014; therefore, no further action is required regarding the cold leg plugs.
Sincerely, ED E. Fitzpatrick Vice President eh Attachment CC:
A. A. Blind G. Charnoff J.
B. Martin - Region III NFEM Section Chief NRC Resident Inspector
- Bridgman J.
R. Padgett
TABLE 1s ALLOY 600 -
COOK UHlT 1
COLD LEG PLUG STATUS SG HO.
Heat No.
4523 6135 1989 1989 2387 2387 2387
'TOTALS TOTAL CL PGS TOTAL CL PGS Date-Jul 1987 Nay 1989 Hay 1989 Dec Sep Jut 1980 1983 1982 Aug 1983 Jm 1985 CL PGS REHOVED REMAIHlHG 69 91 0
10 180 112 12 40 10 148 117 13 24 93
'10 142 82 57 10
'66 52 114 TOTAL 636 211 425