ML20078K214
| ML20078K214 | |
| Person / Time | |
|---|---|
| Site: | Point Beach  |
| Issue date: | 02/03/1995 |
| From: | Link B WISCONSIN ELECTRIC POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| CON-NRC-95-008, CON-NRC-95-8 VPNPD-95-014, VPNPD-95-14, NUDOCS 9502090115 | |
| Download: ML20078K214 (3) | |
Text
.
i 1Altsctnisin
' Electnc
. POWER COMPANY
~
234 W Mich gon. PO Bos 2046. MAom W1532012046 (414)2202345 VPNPD-95-014 NRC 95-008
'Pebruary 3, 1995 Document Control Desk U.S. NUCLEAR REGULATORY COMMISSION Mail Station F1-137 Washington, DC 20555 Gentlemen:
DOCKETS 50-266 AND 50-301 ACTION PLAN SUBMITTAL SCHEDULE FOR RESOLUTION OF WESTINGHOUSE ALLOY 600 TT MECHANICAL PLUG FINDINGS POINT BEACH NUCLEAR PLANT, UNITS 1 AND 2 The following rcatus is provided as requested by the NRC staff in response to-rt, cent field experience with Westinghouse Alloy 600 Thermally Treated (TT) mechanical plugs.
This letter serves to provide the staff with our intended response schedule for submitting our action plan to the NRC.
Backaround In December 1994, Westinghouse notified Licensees of recent field experience with Alloy 600 mechanical steam generator tube plugs that necessitated a revision to the corrosion algorithm presented in WCAP-12244, " Steam Generator Tube Plug Integrity Summary Report," Revision 3.
This revision in the corrosion algorithm affects our previously developed schedule and action plan for addressing all remaining Alloy 600 TT mechanical plugs in service in our steam generators.
Westinghouse issued Addendum 3 to WCAP-12244, Revision 3, in late January 1995.
Until we thoroughly review Addendum 3, the original basis for the Justification for i
Continued Operation (JCO) provided to us by Westinghouse will continue to apply until appropriate actions (as set forth in the action plan) can be taken.
We believe that the issue is being effectively managed by the industry and that the issue does not pose an immediate safety concern to the health and safety of the public.
l;'{
9502090115 950203'
[
f
\\
- c. c, n n n e
' fg
/4 DR ADOCK 05000266 p
PDR uwsuwwee
\\0
o i
e r
Document Con, trol Desk February 3,-1995 Page 2 Wisconsin Electric Power Company Response We intend to comply with the recommendations set forth in Westinghouse Owners's Group Letter OG-94-107, dated December 30, 1994.
At present, Point Beach Nuclear Plant (PBNP) Unit 1 has a total of
'three Westinghouse Alloy 600 TT mechanical plugs in service in the steam generators which have not been repaired.
The three plugs are located in the cold legs.
Of these, two plugs are installed in tubes (Row 1 through Row 4) where plug top release may lead to tube perforation.
Point Beach Nuclear Plant Unit 1 utilizes Westinghouse Model 44F steam generators.
The next refueling outage for Unit 1 is scheduled to begin March 11, 1995.
No action is currently planned during this outage for the installed Unit 1 cold leg plugs.
However, this plan will be revised in accordance with the new corrosion algorithm.
No further notice of our action plan for Unit 1 will be given unless review of the addendum reveals that action is necessary this year.
Point Beach Nuclear Plant Unit 2 has a total of 364 Westinghouse Alloy 600 TT mechanical plugs in service in the steam generators which have not been repaired.
Of the total population, there i
are 88 hot leg plugs and 276 cold leg plugs.
None of these plugs are installed in tubes where plug top release may lead to tube l
perforation because Unit 2 utilizes Westinghouse Model 44 steam generators with partial depth tube roll expansion.
We plan to issue our detailed actions.regarding the remaining installed plugs on Unit 2 within 30 days prior to our next Unit 2 refueling outage, which is currently scheduled to begin on September 30, 1995.
In preparing our action plan, we will review Addendum 3 to WCAP-12244, Revision 3, to determine its impact on I
our previous response to NRC IE Bulletin 89-01, " Failure of Westinghouse Steam Generator Tube Mechanical Plugs."
We understand j
that our options are to repair or replace the plugs by the date calculated by the revised corrosion algorithm or to provide l
technical justification for deferral of actions beyond these dates.
During the interim period, continued safe operation is assured for PBNP Units 1 and 2.
We have validated the previously developed JCO presented in Section 3.0 of WCAP-12244, Revision 3, for PBNP.
Based on a current review of the plant configuration and operating conditions, we have concluded that the JCO is applicable to PBNP Units 1 and 2 during the time period between the plug calculated repair / replacement dates and the next scheduled refueling outage.
l j
o.. s
\\
o s
Document Con, trol Desk February 3, 1995 Page 3 Our bases for concluding that the JCO in WCAP-12244 is applicable to PBNP are summarized below (1)
There is a low probability of a Plug Top Release (PTR) event (2)
The population of tubes which may perforate as a result of PTR is limited.
(3)
Should perforation occur, the primary-to-secondary leakage consequences are limited.
(4)
There is a low likelihood that multiple plugs could be in a condition that would be capable of resulting in a PTR event.
(5)
The plant Emergency Operating Procedures, based on the Westinghouse Emergency Response Guidelines (ERG's), are adequate to bring the plant to a safe shutdown condition.
The above actions are consistent with the action plan defined in NRC IE Bulletin 89-01 and its supplements.
This action plan applies only to Alloy 600 TT mechanical plugs.
Repaired or welded plugs are not affected.
If you have any questions or concerns relative to this preliminary response, please contact 1(evin Crowley of my staff at (414)755-6284, or Tim Hanna at (414)755-6378.
Sincerely, M
Bob L Vice President Nuclear Power DAW /jg cc:
NRC Regional Administrator NRC Resident Inspector
)
i