ML20077J977
| ML20077J977 | |
| Person / Time | |
|---|---|
| Site: | Seabrook  |
| Issue date: | 07/30/1991 |
| From: | Feigenbaum T PUBLIC SERVICE CO. OF NEW HAMPSHIRE |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| IEB-89-001, IEB-89-1, NYN-91121, NUDOCS 9108050310 | |
| Download: ML20077J977 (2) | |
Text
,
' New Hampshire Yankee
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Chief becutwe Othcer NYN 91121 July 30,1991 Document Control Desk United States Nuclear Regulatory Commission Washington, DC 20$$5
References:
(a)
Facility Operating License NPF 86, Docket No. 50-443 (b)
NRC llulletin No. 89 01, Supplement 2 dated June 28,1991,
- Failure of Westinghouse Steam Generator Tube hicchanical Plugs *
(c)
Westinghouse Reports WCAP 12244 (proprietary version) and WCAP 12245 (non proprietary version),
- Steam Generator Tube Plug Integrity Summary Report," Addendum 2 to Revision 3, dated J une,1991 v
(d)
NilY Letter NYN 89073 dated June 15,1989,
- Response to NRC Ilulletin 89 01: Failure of Westinghouse Steam Generator Tube hicchanical Plugs,* G.S. Thomas to USNRC
Subject:
Response to NRC Ilulletin 89 01, Supplement 2:
Failure of Westinghouse Steam Generator Tube hicchanical Plugs Gentlemen:
1
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1 This letter provides information requested by NRC llulletin 89-01, Supplement 2 regarding steam generator tube mechanical plugs supplied to Seabrook Station by Westinghouse Electric Corporation.
As initially reported in Reference (d), there are currently a total of twelve mechanical plugs installed in the tubes of the four steam generators at Seabrook Station Unit 1.
These twelve mechanical plugs were fabricated from Alloy 600, llent Number NX2387, a " group 2*
heat as defined by the llulletin, Supplement 2.
In response to NRC Bulletin 89 01, Supplement 2, NRC-requested Action No. 1.,
New llampshire Yankee (NilY) has verified that the information contained in Table 2 oi Reference (c) is correct with respect to Seabrook Station. We note that the value of EFPD gmr hiultiplication Factor used for Seabrook Station in Table 2 (0.90) is slightly higher than the k;$
actual capacity factor it represents; however, the calculation using the value 0.90 predicts a
$8 conservatively earlier
- year to repair plugs.*
5$
information from Table 2 of Reference (c) indicates that the most limiting mechanical 3d plugs (those installed in the hot legs of the Seabrook Station steam generators) should be
$8 repaired or replaced by 1995. New llampshire Yankee does not plan to repair or replace QC any of its currently installed mechanical plugs at the first refueling outage which commenced 5
on July 26, 1991, llowever, following completion of the first refueling outage, NHY will 38 determine the remedial action to be taken by 1995 for the most limiting mechanical plugs.
N Currently-installed Westinghouse mechanical plugs, if removed, will be examined for indications of primary water stress cor don cracking (PWSCC) on a sample basis, The
/8/
New Hampshire Yonkee Division of Public Service Company of New Hampshire P.O. Box 300
- Seabrook, NH 03874
- Telephone (603) 474 9521 O
s
'.
- United States Nuclear Regulatory Commission July 30,1991 Attention: Document Control Desk Page two results of these examinations.will be retained as part of the steam generator records and the applicable information will be provided to Westinghouse.
NRC requested Action No. 2.c) of NRC Bulletin 89 01 Supplement 2 regarding
- mechanical plugs fabricated from Alloy 600,11 cat No. NX5222 is not applicable to Seabrook Station si4ce all mechanical plugs installed in Seabrook Station Unit 1 steam generators were fabricated from Heat No. NX2387 material. The Westinghouse recommended long term action plan specifies tha: Alloy 600 mechanical plugs be repaired or replaced with Alloy 690 plugs.
New Hampshire Yankee currently plans to utilize Alloy 690 material for required replacement of mechanical plugs in the steam generators at Seabrook Station.
If you have any questions regarding this matter, please contact Mr. Geoffrey Kingston ut(603)474-9521, extension 3371.
Very truly yours, W
Ted C. Fe*,enbaum cc:
Mr. Thomas T. Martin -
Regional Administrator United States-Nuclear Regulatory Comrnission Region I 475 Allendale Road King of Prussir., PA 19406 Mr. Gordon E. Edison, Sr. Project Manager Project Directorate 13 Division of Reactor Project-United States Nuclear Regulatory Commission Washington, DC 20555 Mr. Noel Dudley NRC Senior Resident inspector P.O. Box 1149 Seabrook Station, NH 03874 STATE OF NEW IIAMPSIIIRE Rockingham, ss.
July 30,1991 Then personally appeared before tv, the above named Ted C. Feigenbaum, being duly sworn, did state that he is President 1-Chief Executive Officer of the New llampshire g
Yankee Division of Public Service Conipany of New Hampshire, that he is duly authorized s
to execute and ' file the foregoing inf ormation in the name and on the behalf of New Hampshire Yankee Division of the Public Scryice Company and that the statements therein are true to the best of his knowledge and belief.
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