ML20034B094
| ML20034B094 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 04/17/1990 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20033G848 | List: |
| References | |
| GL-88-01, GL-88-1, NUDOCS 9004250326 | |
| Download: ML20034B094 (3) | |
Text
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UNITED STATES NUCLEAR REGULATORY COMMISSION i
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L ENCLOSURE SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION EVALUATION OF NRC GENERIC LETTER 88-01 RESPONSE:
1 GPU NUCLEAR CORPORATION OYSTER CREEK NUCLEAR GENERATING STATION
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DOCKET NO. 50-219
1.0 INTRODUCTION
GPU Nuclear Corporation, the licensee, submitted its response to NRC Generic-Letter (GL) 88-01, "NRC Position on IGSCC in BWR Austenitic Stainless Steel
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t Piping" for Oyster Creek Nuclear Generating Station by letters dated August 12,_1988,. and January 31, 1989. Additional.information was provided by letters dated November 16, 1989-and February. 21, 1990.
GL-88-01 requested Licensees and construction permit holders to resolve the IGSCC issue.for BWR piping made of austenitic stainless steel that is 4 inches or larger in nominal diameter, and contains reactor coolant at a temperature above 200 degrees Fahrenheit during power operation regardless of Code" classification.
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The licensee was requested to address the following:
1.
The current plans regarding pipe replacement and/or other measures taken to mitigate IGSCC and provide assurance of continued long-term integrity and reliability.
2.
The Inservice Inspection (ISI) Program to be implemented at the next refueling outage for austenitic stainless steel piping covered under the scope of this letter that conforms to the staff positions on inspection schedules, methods and personnel, and sample expansion included in GL-88-01.
3.
The Technical Specification change to include a statement;in the section on ISI that the ISI Program for piping covered by the scope of'this letter will be in staff positions on schedule, methods and personnel, and sample expansion included in GL-88-01 (See model BWR Standard Technical i
Specification enclosed in GL-88-01).
It is recognized that'the= Inservice Inspection and Testing Sections may be removed from the. Technical Specifications Improvement programs.
In this case, this requirement shall remain with the ISI Section v: hen it is included in an alternative.
document.
4.
The confirmation of your plans to ensure that the Technical Specifications related to leakage detection will'be in conformance with the staff positions on leak detection included in GL-88-01.
9004250326 900417 DR ADOCK 05000219 PDC
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The plans to notify the NRC in accordance with 10 CFR 50.55a(g) of any 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 l
condition of.the welds < previously known to be cracked and GPUN's evaluation-of the flaws for continued operation and/or repair plans.
2.0 DISCUSSION The. licensee's response to GL-88-01 has been reviewed by the staff with the assistance of its contractor, Viking Systems International (VSI).
The.
i attachedTechnicalEvaluationReport(TER)isVSI'sevaluationofthe-licensee's response to GL-88-01.
The staff has reviewed the TER and concurs with the evaluations, conclusions, and reconnendations contained in j
the TER.
In the review of the licensee's GL-88-01 submittal, the. staff has found the following positions to be unacceptable:
1.
The licensee's position not to amend the Technical Specification (TS) to include a statement on ISI as required in GL-88-01.
2.
The licensee's position to reduce the frequency of piping inspections based on the implementation of hydrogen water chemistry;(HWC). The staff has learned through reports that piping weld-cracking has occurred at two nuclear. power generating facilities which.have been operating-with HWC.
The staff has some concerns regarding the effectiveness of HWC in mitigating IGSCC.
Therefore, the staff is not granting inspection credit based on the implementation of HWC at this time until the staff's.
concerns are resolved.
3.
The licensee's position to reduce the frequency of inspections on SI-treated welds.
4.
The licensee did not justify the reduction in the frequency of inspection of wilds classified as IGSCC Categories C, D, E, and G.
The licensee should revise the inspection schedules for these welds in accordance with GL-88-01 and all IGSCC Category G welds should be inspected during the i
nextscheduledrefuelingoutage(13R).
5.
The licnesee's position concerning classifying five casting-to-casting-welds in the Recirculation System as uninspectable. There are techniques available in the industry to inspect castings and the castings should be inspected in accordance with GL-88-01.
6.
The licensee's position concerning classifying five casting-to-casting welds in the Recirculation System as uninspectable.
There are techniques available in the industry to inspect castings and the castings should be inspected in accordance with GL-88-01.
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The licensee's position of considering flaw evaluation having no constraint on plant restart. The licensee should revise its position and follow the staff's position in G-88-01 reporting requirements which l-requires NRC approval of flaw evaluations and/or repairs-in accordance t
with IWB 3640 and IWA 4130 before resumption of operation.
8.
The licensee's position of not ultrasonically inspecting =the RWCU welds outboard ofL the secondary Containment Isolation Valves (CIV) piping after I
13R refueling outage.
The-licensee should ultrasonically inspect at l-least 10% of the welds outboard of the. secondary CIV during each refueling ou tage. -
For a detail discussion of these items, see. Sections.2.0 and 3.0 of TER attached-to the SE.
1 The staff has re-evaluated the frequency of leakage monitoring.
After discus -
sions with several BWR operators the staff concluded that monitoring every <
four hours creates an unnecessary administrative hardship to the )lant operators. Thus, RCS leakage measurements may be taken every eig1t-hours instead of every four hours as required in GL-88-01.
3.0 CONCLUSION
Based on the review of the licensee's GL-88-01 response the st'aff conclud'es that the response as evaluated is acceptable with the exception of the licensee's positions as identified above. The licensee:is requested-to submit a TS change that would incorporate as ISI-statement per GL-88-01 and revise.their. inspection t
plans as discussed above.
The staff also concludes that the proposed IGSCC inspection and mitigation program will provide reasonable assurance of maintaining the long-term-struc-tural integrity of austenitic stainless steel piping in the Oyster Creek Nuclear Generating Plant.
Principal Contributors:
T. McLellan and W. Koo Dated April 17,1990 y
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