ML20082E910
| ML20082E910 | |
| Person / Time | |
|---|---|
| Site: | Point Beach  |
| Issue date: | 07/25/1991 |
| From: | Fay C WISCONSIN ELECTRIC POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| CON-NRC-91-073, CON-NRC-91-73 IEB-89-001, IEB-89-1, VPNPD-91-241, NUDOCS 9108020121 | |
| Download: ML20082E910 (4) | |
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Wisconsin Electnc POWER COMPANY 231 w Mcwn eo ikw 20a Muusee w 53201 Im! 2212m VPNPD 241 NRC 07 3 July 25, 1991 Document Control Desk U.S.
NUCLEAR REGULATORY COMMISSION Mail Station P1-137 Washington, D.C.
20555 Gentlemen:
DOCKET NOS. 50-266 AND 50-301 NRC BULLETIN NO. 89-01. SUPPLEMENT 2 FAILURE OF WESTINGHOUSE STEAM GENERATOR TUBE MECHANICAL PLUGS POINT BEACH NUCLEAR PLANT. UNITS 1 AND 2 This letter is in response to NRC Bulletin No. 89-01, Supplement 2, regarding potential degradation of Westinghouse supplied mechanical plugs for steam generator tubes.
Supplement 2 was issued on June 28, 1991, and received by Wisconsin Electric on July 1, 1991.
Wisconsin Electric (WE) has installed mechanical plugs supplied by Westinghouse in the four steam generators at Point Beach Nuclear Plant (PBNP) beginning in 1980.
Wisconsin Electric has also been following and proactively responding to the issue of potential degradation of these plugs since 1988.
Based on the recent information from Sequoyah, Unit 1, and North Anna, Unit 2, and in response to NRC Bulletin 89-01, Supplement 2, action has been taken to address the " group 2" plug heats similar to the action taken for the " group 1" plug heats.
With respect to the specific actions requested under Bulletin 89-01, Supplement 2, our responses are pr;vided as follows.
1.
Verification of Information The information contained in Table 2 of WCAP-12244, Addendum 2, Revision 3, pertinent to Point Beach Units 1 and 2 has been verified by review of the outage eddy current final report files.
The " INSTALLATION" and " STATUS" portions of Table 2 were reviewed against the heat numbers in " group 2" of NRC 89-01, Supplement 2.
Table 2 was also reviewed for information pertaining to unrepaired " group 1" heat numbers installed in the steam generator cold legs.
The following is a summary of the WEP(UNIT 1) and WIS(UNIT 2) installation data which was re-verified:
9108020121 910727, gM/
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l Document Control Desk July 25, 1991 Page 2 Outaae Month / Year No. of Pluas lleat Number S.G.
& Leg WEP 01/84 1
2387 B HL 01/84 1
2387 B CL WIS 31/88 18 5222 A HL 11/88 5
5222 B HL 11/88 2
5222 B HL 04/80 2
9789 A HL 04/81 24 85C4 A HL 04/81 16 85C4 B HL 04/82 6
1989 B HL 04/8?
10 1989 A HL 06/83 3
1989 A HL i
06/83 1
1989 B HL l
06/83 1
2205 A HL 10/84 3
2387 B HL 10/84 14 2387 A HL 10/85 10 2387 A HL 10/85 10 3962 B CL 10/86 14 3962 A CL 10/86 58 3962 B CL 10/87 14 4523 B CL 10/87 30 4523 A CL 10/87 2
3513 B CL 11/88 18 5222 A CL 11/88 5
5222 B CL 11/88 2
5222 B CL 04/81 25 85C4 A CL 04/81 16 85C4 B CL 04/82 6
1989 B CL 04/82 10 1989 A CL
~
06/83 4
1989 A CL 06/83 1
1989 B CL 10/84 14 2387 A CL 10/84 3
2387 B CL 10/85 10 2387 A CL 10/85 34 2387 B CL This information agrees with the documentation records reviewed in WCAP-12244, Addendum 2, Revision 3, and is correct as shown.
e I
Document Control Desk July 25, 1991 Page 3 A review of the " STATUS" information for these plugs showed that a correction is necessary for the WEP(UNIT 1) data in the status heading.
All of the mechanical plugs in steam generator B installed prior to 1991 have been repaired using the plug-in-a-plug " PIP" repair process.
The table incorrectly shows that only the hot leg plugs were repaired.
The plug operating temperatures were compared with plant calorimetric data for both units and were verified to be correct.
2.
CORRECTIVE ACTIONS a)
Plugs requiring repair or replacement have been repaired during previous outages.
Hot leg plugs with heat NX-5222 were repaired or replaced as a conservative approach during the initial " PIP" project.
b)
No adjustment is necessary as a result of the corrections noted in Item 1 above.
c)
All hot leg plugs from the NX-5222 heat lot have been repaired using the " PIP" process.
Per WCAP 12244, Addendum 2, Revision 3, cold leg plugs fabricated from heat NX-5222 do not require repair until 2019.
d)
INCONEL 690 mechanical plugs have been usbd at Point Beach since 1989.
INCONEL 600 plugs are no longer used at Point Beach.
e)
Based on our response to Items 2a through 2d, no alternative plan for insuring mechanical plug integrity.is necessary.
Our 1998 refueling outage has been targeted for the next
" PIP" project barring Unit 2 steam generator replacement.
f)
ALARA considerations will be used in the event of necessary plug repairs or replacements.
I Document Control Desk July 25, 1991 Page 4 Please contact us if you have any question concerning our responses to this bulletin supplement.
Very truly yours, S
.o.
GYv C.
W.
Payd Vice President Nuclear Power Copy to:
NRC Resident Inspector NRC Regional Administru m Subscribed and sworn to before me this oat': day of
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