ML20196G116
| ML20196G116 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 11/03/1998 |
| From: | Berkow H NRC (Affiliation Not Assigned) |
| To: | Ohanlon J VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| Shared Package | |
| ML20196G120 | List: |
| References | |
| GL-90-05, GL-90-5, TAC-MA1222, TAC-MA1223, NUDOCS 9812070253 | |
| Download: ML20196G116 (4) | |
Text
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1 UNITED STATES g
j NUCLEAR REGULATORY COMMISSION t
WASHINGTON, D.C. 2006H001 e%
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November 3, 1998 l
l Mr. J. P. O'Hanlon Senior Vice President - Nuclear Virginia Electric and Power Company 5000 Dominion Blvd.
l Glen Allen, Virginia 23060 l
l
SUBJECT:
NORTH ANNA POWER STATION UNIT 1 AND UNIT 2 - ASME SECTION XI RELIEF REQUEST, REVISION TO NDE SERVICE WATER SYSTEM (SWS)
LEAKS (TAC NOS. MA1222 AND MA1223) i
Dear Mr. O'Hanlon:
On February 24,1997, you submitted a request for relief for the stainless steel lines of the SWS l
because the failure mechanism of the previously identified leaks was determined to be microbiologically induced corrosion (MIC) and on August 8,1997, supplemented the relief request by identifying each and every line for which the relief would be applied. The purpose of the request was to avoid the submittal of a specific relief request to the NRC for each additional pin leak or location with possible evidence of previous leakage that may be identified during routine SWS piping walkdowns. The MIC monitoring program required walkdowns of the accessible portions of the stainless steal SW piping to identify, monitor and quantify leakage.
l When a leak or evidence of previous leakage was identified, structural analysis and increased monitoring of the affected welds was implemented. Further, the program included provisions for evaluating continued system operability in accordance with GL 90-05 until appropriate Code repairs can be completed. The NRC approved this relief request on November 24,1997.
By your letter dated February 24,1998, as supplemented November 2,1998, you submitted a revision to the original relief request NDE-32 of February 24,1997. This revision contained certain enhancements that were made to the original program. The specific changes contained in this revision are:
- 1. Performance of a Code repair in 14 days after discovery of the MIC-induced leaks, in place of a structural analysis.
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- 2. The use of an alternate non-destructive examination technique based on a report on the l
correlation between Radiography (RT) and Ultrasonic (UT) examination techniques. The i
revised relief request would permit the use of either RT or UT to evaluate the MIC-affected
)
locations in the SWS.
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- 3. Minor program scope changes to correct discrepancies in the listing of the SW lines.
0700/3 i
The NRC staff has evaluated the revision to inservice inspection program relief request NDE-
}(Og 32, submitted on February 24,1998, and based on the evaiuation of relief request NDE-32, it is concluded that the performance of an immediate Code repair after each and every newly discovered flaw caused by MIC would have constituted an undue burden (create undue hardship) upon Virginia Electric and Power Company (VEPCO) since the repair may exceed the time limits imposed by the goveming Technical Specification. This would necessitate the j
isolation of portions of the SWS that are otherwise structurally sound and capable of performing 9812070253 981103 PDR ADOCK 05000338 p
l gg H1I CEUM- {a eaa
2 their intended safety function. Isolating portions of the SWS to perform a Code repair is not in the best interest of plant safety, given the magnitude of the flaw and your alternative program.
Your alternative program for this r eriod includes evaluation of the flaws consistent with the guidelines and acceptance criter a of GL 90-05. Upon discovery, each flaw detected will be documented in the corrective action system by deviation report. Identification of a structurally inadequate weld will result in associated piping to be declared inoperable and an appropriate Technical Specification action statement to be taken. The through-wall flaws and leakage rates will be monitored. An augmented inspection program will be performed on a quarterly basis on a sample of a minimum of 10 welds in the SWS for augmented radiographic inspections. You have further stated that all the flaws will be repaired within 18 months from the day of the identification of the flaws and the documentation of the SWS inspection, monitoring program and repair of identified flaws will be maintained on site, available for inspector review, and in accordance with the quality records retention requirements. This alternative to the Code requirement will be followed for the remainder of the second 10-year inspection interval. The Unit 1 second 10-year interval will end on December 24,1998, and the Unit 2 second 10-year interval will end on December 14,2000.
The staff finds the VEPCO position on l} the structuralintegrity and operability assessments as well as the proposed actions to meet the Code requirements, ii) the proposed UT examination technique to be used for the detection of MIC in the stainless steel SWS piping which is as effective as the currently followed RT examination technique, iii) performing a Code repair in 14 days after discovery of the MIC-induced leaks, in place of a structural analysis, and iv) the additions / deletions contained in the revised piping list which are within the bounds of the original relief request to be acceptable and this request to be reasonable.
The staff finds that the alternative is authorized pursuant to 10 CFR 50.55a(a)(3)(ii) because compliance with the requirement would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety. The proposed alternative is authorized for the remainder of the second 10-year inspection interval for each unit. The staffs evaluation and conclusions are contained in the Enclosure.
l The staff has completed its evaluation of the relief request and we are, therefore, closing out l
TAC Nos. MA1222 and MA1223.
Sincerely, GnqwA msn ec) &*
Herbert N. Berkow, Director Project Directorate 11-2 Division of Reactor Projects - 1/11 Office of Nuclear Reactor Regulation Docket Nos. 50-338 and 50-339
Enclosure:
As stated cc w/ encl: See next page Distribution:
Docket File Public PDil-2 RF ACRS j
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OFFICE PM:PDil-2 g7 l_A:PDil-2g PDhlK NRR:DE:ECGB* OGC*
NAME NKalyard l EDunnington HberMw/
GBagchi DATE d / 3 /98 M / 3 /98
- )_/ y/98
/
/98
/
/98 COPY Yes/No h No YepfNo/
Yes/No Yes/No
_ =-.
2 their intended safety function. Isolating portions of the SWS to perform a Code repair is not in the best interest of plant safety, given the magnitude of the flaw and your altemative program.
You. alternative program for this period includes evaluation of the flaws consistent with the guidelines and acceptance criteria of GL 90-05. Upon discovery, each flaw detected will be documented in the corrective action system by deviation report. Identification of a structurally l
inadequate weld will result in associated piping to be declared inoperable and an appropriate Technical Specification action statement to be taken. The through-wall flaws and leakage rates will be monitored. An augmented inspection program will be performed on a quarterly basis on I
a sample of a minimum of 10 welds in the SWS for augmented radiographic inspections. You have further stated that all the flaws will be repaired vethin 18 months from the day of the identification of the flaws and the documentation of the SWS inspection, monitoring program and repair of identified flaws will be maintained on site, available for inspector review, and in accordance with the quality records retention requirements. This altemative to the Code requirement will be followed for the remainder of the second 10-year inspection interval. The Unit 1 second 10-year interval will end on December 24,1998, and the Unit 2 second 10-year interval will end on December 14,2000.
The staff finds the VEPCO position on l) the structural integrity and operability assessments as well as the proposed actions to meet the Code requirements, ii) the proposed UT examination technique to be used for the detection of MIC in the stainless steel SWS piping which is as effective as the currently followed RT examination technique, iii) performing a Code repair in 14 i
days after discovery of the MIC-induced leaks, in place of a structural analysis, and iv) the i
additions / deletions contained in the revised piping list which are within the bounds of the original l
relief request to be acceptable and this request to be reasonable.
1 The staff finds that the attemative is authorized pursuant to 10 CFR 50.55a(a)(3)(ii) because compliance with the requirement would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety. The proposed altemative is authorized for the remainder of the second 10-year inspection interval for each unit. The staff's evaluation and conclusions are contained in the Enclosure.
{
l The staff has completed its evaluation of the relief request and we are, therefore, closing out TAC Nos. MA1222 and MA1223.
Sincerel,
I H
rt N. Berkow, irector Project Directorate 11-2 Division of Reactor Projects - 1/11 Office of Nuclear Reactor Regulation Docket Nos. 50-338 and 50-339
Enclosure:
As stated s
cc w/ encl: See ne.xt page
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L Mr. J. P. O'Hanlon North Anna Power Station Virginia Electric & Power Company Units 1 and 2 cc:
- Mr. J. Jeffrey Lunsford Regional Administrator, Region il CountyAdministrator U.S. Nuclear Regulatory Commission Louisa County Atlanta Federal Center P.O. Box 160 61 Forsyth St., SW, Suite 23T85 Louisa, Virginia 230g3 Atlanta, Georgia 30303 l
Mr. Donald P. Irwin, Esquire Mr. W. R. Matthews Hunton and Williams Site Vice President Riverfront Plaza, East Tower North Anna Power Station 951 E. Byrd Street P. O. Box 402 Richmond, Virginia 2321g Mineral, Virginia 23117 Dr. W. T. Lough Mr. R. C. Haag Virginia State Corporation U.S. Nuclear Regulatory Commission
' Commission Atlanta Federal Center Division of Energy Regulation 61 Forsyth St., SW, Suite 23T85 P. O. Box 11g7 Atlanta, Georgia 30303 Richmond, Virginia 2320g Mr. E. S. Grecheck Old Dominiori Electric Cooperative Site Vice President 4201 Dominion Blvd.
Surry Power Station Glen Allen, Virginia 23060 Virginia Electric and Power Company 5570 Hog Island Road Mr. J. H. McCartny, Manager Surry, Virginia 23883 Nuclear Licensing & Operations l
Support Robert B. Strobe, M.D., M.P.H.
l Virginia Electric and Power Company State Health Commissioner Innsbrook Technical Center Office of the Commissioner 5000 Dominion Blvd.
-Glen Allen, Virginia 23060 P.O. Box 2448 a
l.
Richmond, Virginia 23218 Office of the Attorney General i
Commonwealth of Virginia
- 900 East Main Street l_
Richmond, Virginia 2321g Senior Resident inspector i
North Anna Power Station U.S. Nuclear Regulatory Commission 1024 Haley Drive Mineral, Virginia 23117 l
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