ML20033F445
| ML20033F445 | |
| Person / Time | |
|---|---|
| Site: | Hatch  |
| Issue date: | 02/16/1990 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20033F444 | List: |
| References | |
| GL-88-01, NUDOCS 9003210069 | |
| Download: ML20033F445 (3) | |
Text
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A, UNITED STATES g,
g NUCLEAR REGULATORY COMMISSION r.
l WASHINGTON, D. C. 20555 k...+,/ SAFETY EVALUATION BY TFE OFFICE OF NUCLEAR REACTOR RESPONSE TO idC GENERIC LETTER 88-01 GEORGIA POWER COMPANY OGLETHORPE POWER CCRFORATION HUNICIPAL ELECTRIC AUTHORITY OF GEORGIA CITY OF DALTON, CEORGIA m
EDWIN I. HATCH NUCLEAR PLANT UNITS 1 AND 2 DOCKET NOS. 50-321 and 50-366
1.0 INTRODUCTION
Georgia Power Company (the liccnsee) submitted its respense to NRC Generic Letter 88-01, "NRC Pesition on 10500 in BWR Austenitic Stainless Steel Pipirg," for hatch Units 1 ano 2 by letter dated June 30, 1988.. Additional information as requested by the NRC staff was provided by letters dated Stpterter 27, 1568, and October 19, 1008. Generic Letter 88-01 (GL 88-01) requested licensees and construction permit holders to resolve the intergranular stress corrosion cracking (IGSCC) issues for boiling water reactor (BWR) piping made of austenitic stainless steel that is 4 inches or i
larger in nominal diameter and containing reactor coolant at a temperature 1
above 200 degrees Fahrenheit during power operation regardless of ASME Boiler and Pressure Vessel Code classification. The licensee was requested to provide the following:
1.
The current plans regarding pipe replacenent and/or other measures taken or to be taken to mitigate 1G500 and provide assurance of continued long term integrity and reliability.
2.
The Inservice Inspection (ISI) Program to be implenented at the next i
refueling outage, j
1 3.
A Technical Specification (TS) chanSe to include a statenent in the section on ISI that the ISI Prograi.1 for piping covered by the sco3e of GL 88-01 will be in conformance with the NRC staff positions on scledule, methods and personnel, and sanple expansion included in GL 88-01 (See nodel BWR Standard Technical Specification enclosed in GL 88-01).
4.
Confirmation of licensee plans to ensure that the TSs related to L
leakage detection will be in conformance with the NRC staff position on 3
leak detection included in GL 88-01.
5.
Plans to notify the NRC in accordance with 10 CFR 50.55a(g) of ary flaws identified that do not meet IWB-3500 criteria of Section XI of the Code for continued operation without evaluation, or a change found in the condition of the welds previously known to be cracked, and plans for evaluation of the flaws for continued operation and/or repair.
9003210069 900216 PDR ADOCK 05000321 F
PDC i
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, 2.0 DISCUSSION The licensee's response to Generic Letter 88-01 has been reviewed by the NRC staff with the assistance of its contractor, Viking Systerns International (VSI).
The Technical Evaluation Reports (TERs) provided as Attachments 1 and 2 are VSI's evaluation of the licensee's response to GL 88-01 for Hatch Units 1 and 2.
The staff has reviewed the TERs ano concurs with the evaluations, conclusions and recommendations contained therein.
The licensee's proposals to average the 4-hour interval leakage measurements over a 24-hour period (TER i
Section 2.8) and to not incorporate the piping ISI requirements in the unit Technical Specifications (TSs) (TER Section 3.3) are denied.
Section E.12 of Enclosure 1 to the licensee's June 30, 1988, letter stated that GPC interpreted the leakage ironitoring requirements as allowing averaging of the unidentified leatase limits over a 24-hour period.
This is not in accordance with the IRC staff position on leak detection as stated in Attachment A to Generic Letter 88-01.
However, the staff has reconsidered the frequency for leakage monitoring and has concluded that monitoring at 4-hour intervals inposes an unnecessary administrative burden on plant operators.
Accordingly, the staff has revised its position to require leakage monitoring every 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> instead of every 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />.
However, as noted above, this 8-hour
-interval lealage tray not be averaged over a 24-hour period.
l Section F.1 of Enclosure I to the ifcensee's June 30, 1988, letter stated that it would not modify the Unit I and Unit 2 TSs to specify conformance to GL 88-01, but would incorporate such confor:rance specification in alternative plant documents.
This position is unacceptable.
The staff has determined that confornance to the guidelines of GL 88-01 will be required to be included in the TSs even after implementation of the Technical Specification Iraprovement Program.
Pending inclusion of the requirements in the improved l
TSs, the requirements should be incorporated in the existing ISs for Hatch Units I and 2.
3.0 CONCLUSION
Based on its review of the licensee's response to GL 88-01, the NRC staff l
concludes that the response is acceptable except as noted above.
The staff also concludes that the proposed IGSCC inspection and mitigation program will provide reasonable assurance of maintaining the long-term structural integrity of the austenitic stainless steel piping at Hatch Units 1 and 2.
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3 The licensee is requested to incorporate the leakage monitoring requirements and a statenent requiring the perfornance of the piping ISI requirenents in accorder.ce with GL 08-01 in the existing TSs and in the Improved TSs submitted as part of the Technical Specification improvement Program, Further, while it
-is acceptable to conduct reactor coolant system leakage measuretients at inter-vals of up to 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> (revised from the 4-hour intervals specified in GL 88-01),- these measurements may not be averaged.
Principal Contributors:
T. McLellan W. Koo L. Crocker Cated:
February 16, 1990 I
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