ML20127C234
| ML20127C234 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 12/30/1992 |
| From: | Sieber J DUQUESNE LIGHT CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| TAC-M77638, TAC-M77639, NUDOCS 9301140069 | |
| Download: ML20127C234 (4) | |
Text
- - - _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.
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s%n,,m r A mn rxxu December 30, 1992 re o se v i e Presamt bwe G%r, M M $ $/%
U.
S.
Nuclear Regulatory Commission Attn:
Document Control Desk Washington, DC 20555
Subject:
Beaver Valley Power Station, Unit No. 1 and No. 2 BV-1 Docket No. 50-334, Licenso No. DPR-66 DV-2 Docket No. 50-412, Licenso No. NPF-73 Revision to SER for Amendments 165 and 47 (TAC Nos. M77638 and M77639)
In the Safety Evaluation Report (SER) provided by the Nuclear Regulatory Commission (NRC) for the subject amendments, references number 5
(Unit 1) and 6
(Unit
- 2) titled " Containment Liner Test Channels at Beaver Valley Power Station" were used to make the determination that the corrosion rates inside the test channels with missing vent plugs are not large enough to significantly degrade the containment.
After further evaluation, it was concluded that the above referenced reports contain some non-conservative assumptions with regard to the effect of electrolyte oxygen concentration on the corrosion rates in the test channels.
NRC approval of the amendments was
- based, in
- part, on an expected worst case corrosion rate of 88 mils over a forty-year lifetime.
Subsequent assessments of corrosion rates indicate
- that, with proper corrective actions, the expected corrosion rates will range between 6.8 and 15.6 mils over a
forty-year lifetime.
The information contained in Attachment 1 provides a summary of our remedial action plan for each Unit which will ensure that the corrosion rates inside the test channels which were found with missing vent plugs remain within these assumptions.
The remaining information in the referenced reports on the capability of the test channels to withstand all
- loads, which might be imposed on them during normal test and upset conditions without impairing the performance of the containment liner
- itself, is still valid and should continue to be referenced.
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9301140069 921230
}1 PDR ADOCK 05000334 J
I P
. Revision to SER for Amendments 165 and 47 6 r Page 2 If you have any questions, please contact Mr. Steve Sovick at (412) 393-5211.
Sincerely,
(.Y
^
J.
D.
Sieber Attachment ec: Mr.
L.
W.
Rossbach, Sr. Resident Inspector Mr. T.
T.
Martin, NRC Region I Administrator Mr.
A.
W.
De Agazio, Project Manager Mr.
T.
M. Gerusky, Director BRP/ DER Mr.
R. Janati, BRP/ DER Mr.
M.
L.
Bowling (VEPCO) i
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ATTACllMENT 1
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Zncloned is a summary of our remedial action plan for the containment liner tent channelo which were previously found to have missing vent plugs.
')
e Containment Isiner Wnt I' lug itemedial Action I'lan Unit i Actions-Unit 2 Actions-During 8th Refueling Outage During the 3rd Refueling Outage l.
Identify all accessible plugs 1.
Identify all accessible plugs 2.
Verify that two (2) accessible vent plugs 2.
Verify that two (2) accessible vent plugs can be found for each channel segment can be found for each channel segment found to have previously missing plugs.
found to have pteviously missing plugs.
3.
Replace all accessible carbon steel plugs 3.
Replace all accessible cartun steel plugs with stainless steel plugs (as time permits).
with stainless steel plugs (as time permits).
4 4.
Attempt to flush and inert one channel 4.
Flush and inert compromised channel segment to prove feasibility of approach.
segments per 2!WT02.47.04.
5.
Temporarily seal tia channels to be inerted 5.
Seal all compromised charmels following in 9R.
inerting.
During 9th Refueling Outage During 4th Refueling Outage 1.
perform the Type A test with all channel 1.
perform the Type A test.
se;tments found to have previously missing plugs included within the test boundary.
2.
Following successful Type A testing, open one channel, filled with Argon gas in 3R, 2.
Following successful Type A testing, all and test for the presence of corrosion by-compromised channels are to be evacuated product gases or ilushed, filled with Argon gas, and sealed.
3.
If no corrosion by-product gases are found, 3.
No further actions are required, provided re-inert and seal the channel the Unit 2 4R Activity 2 is successful.
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