ML20059H067
| ML20059H067 | |
| Person / Time | |
|---|---|
| Site: | Clinton  |
| Issue date: | 08/24/1990 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20058K124 | List: |
| References | |
| GL-88-01, GL-88-1, NUDOCS 9009140219 | |
| Download: ML20059H067 (2) | |
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3, SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION i
EVALUATION OF NRC GENERIC LETTER 88-01 RESPONSE ILLIN0IS POWER COMPANY CLINTON POWER STATION 1
DOCKET N0. 50-461
1.0 INTRODUCTION
Illinois Power Company, the licensee, submitted its response to NRC Generic Letter (GL) 88-01, "NRC Position,on IGSCC in BWR Austenttic Stainless Steel Piping" for Clinton Power Station by letter dated July 29, 1988, and additional information requested by the staff was provided by letter dated September 21 i
1989. GL-88-01 requested licensees and construction permit holders to resolv,e theintergranularstresscorrosioncracking(IGSCC)issueforBWRpipingmade
' 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. The licensee was i
requested to address the following:
1.
The current plans regarding pipe replacement and/or other measures taken l
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 I$1 that the la Program for piping covered by the scope of this letter will be in ss
' positions on schedule, methods and personnel, and sample expansion included in GL-88-01 (See model BWR Standard Technical SpecificationenclosedinGL-88-01).
It is recognized that the inservice i
Inspection and Testing sections may be removed from the Technical 4
S)ecifications Improvement programs.
In this case, this requirement-i siall remain with ISI section when it is included in an alternative document.
'4.
The confirmation of your plans to ensure that the Technical Specifications l
related to leakage detection will be in conformance with the staif positions f
on leak detection including in GL-88-01.
U 9009140219 900&c4 PDR ADOCK 05000461 P
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The p7ans 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 i
Code for continued operation without evaluation, or a' change found in the condition of the welds previously known to be r. racked and your evaluation of the flaws for continued operation and/or yr.ur repair plans.
2.0 DISCUSSION The licensee's response to NRC GL-88-01 has been reviewed by the staff with the assistance of its contractor, Viking Systems International (VSI). The attiched Technical Evaluation Report Report (TER). is VSI's evaluation of the licensee's response to NRC GL-88-01. The staff has reviewed the TER and concurs with the evaluations, conclusions, and recommendations contained in the TER.
In the review of the licensee's GL-88-01 submittal..the-staff has 1
found the following positions to be unacceptable:
1.
The licsnsee's position with regard to the classification of 50 Category 1
A welds that contain non-resistant materials and have not been nitigated.
s 2.
The licensee's position to monitor leakage every 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> instead of GL-88-01 requirement to monitor leakage every 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />, j
For a detailed discussion of these items, see sections 2.0 and 3.0 of the attached TER.
The staff has re-evaluated the frequency of leakage monitoring. After discussions with several BWR operators, the staff concluded that monitoring i
every 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> creates'an unnecessary administrative hardship to the plant operators. Thus, RCS leakage measurements may be taken 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 /> as required th GL-88-01.
3.0 CONCLUSION
i Based on the review of the licensee's NRC GL-88-01 response, the staff concludes that the response as evaluated is acce stable with the exception of 1
the licensee's positions as identified above. T1e licensee is requested to submit a TS change that would require monitoring of unidentified leakage every 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> as required in GL-88-01 or the licensee may take measurements 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 as required in GL-88-01. Furthermore the licensee
'should reclassify the 50 Category A welds that contain non-resistant materials and have not been mitigated and modify the inspection plan accordingly.
The staff also. concludes that the proposed IGSCC inspection and mitigation
. program will provide reasonable assurance of maintaining the long-term
-structural integrity of austenitic stainless piping in the Clinton Power Station.
Attachment:
VSI Technical Evaluation Report Date: 3 August 24, 1990
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