RS-07-137, Response to Request for Additional Information Related to Clinton Power Station Unit 1 Relief Request 2209
| ML072740030 | |
| Person / Time | |
|---|---|
| Site: | Clinton  |
| Issue date: | 09/28/2007 |
| From: | Hansen J AmerGen Energy Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| RS-07-137 | |
| Download: ML072740030 (5) | |
Text
AmerGen Energy Company, LLC 4300 Winfield Road Warrenviile, f L 60555 RS-07-137 September 28, 2007 U. S. Nuclear Regulatory Commission ATTN : Document Control Desk Washington, DC 20555-0001
References:
1.
Subject:
www.exeloncorp.com Clinton Power Station, Unit 1 Facility Operating License No. NPF-62 NRC Docket No. 50-461
- 2.
10 CFR 50.55a Letter from P. R. Simpson (Exelon Generation Company, LLC) to U. S. NRC, " Requests for Relief from ASME OM Code 5-year Test Interval for Safety Relief Valves (Relief Requests 2208 and 2209),"
dated August 30, 2007 erG m
An Exelon Company Letter from S. P. Sands (U.S. NRC) to C. M. Crane (AmerGen Energy Company, LLC), "Request for Additional Information Related to Request for Relief from ASME OM Code 5-year Test Interval for Safety Relief Valves (Relief Requests 2208 and 2209)," dated September 25, 2007 Response to Request for Additional Information Related to Clinton Power Station Unit 1 Relief Request 2209 In Reference 1, AmerGen Energy Company, LLC (AmerGen) requested relief from the American Society of Mechanical Engineers/American National Standards Institute, "Code for Operation and Maintenance of Nuclear Power Plants," 1987 Edition through 1988 Addenda, Appendix I, "Inservice Testing of Pressure Relief Devices in Light-Water Reactor Nuclear Power Plants," Section 1.3.3, "Test Frequency, Class 1 Pressure Relief Devices." Specifically, AmerGen requested NRC approval of proposed Relief Request 2209 to extend the five-year test interval, on a one-time basis, for eight Safety Relief Valves (SRVs) at Clinton Power Station (CPS) Unit 1. In Reference 2, the NRC transmitted a Request for Additional Information to AmerGen concerning the requested relief. The response to Reference 2 is provided in the Attachment to this letter.
As stated in Reference 1, AmerGen requests approval of CPS Unit 1 Relief Request 2209 by November 15, 2007, to enable plant start-up following the eleventh CPS Unit 1 refueling outage (C1 R11).
September 28, 2007 U. S. Nuclear Regulatory Commission Page 2 There are no regulatory commitments contained within this letter.
If you have any questions concerning this letter, please contact Mr. John L. Schrage at (630) 657-2821.
Jefye~VV Hdnfsen Manager - Licensing
Attachment:
Response to NRC Request for Additional Information, Clinton Power Station Unit 1, Relief Request 2209
Attachment Response to NRC Request for Additional Information Clinton Power Station, Unit 1 Relief Request 2209
By letter dated August 30, 2007, AmerGen Energy Company, LLC (AmerGen) requested relief from the American Society of Mechanical Engineers (ASME)/American National Standards Institute (ANSI), "Code for Operation and Maintenance of Nuclear Power Plants," 1987 Edition through 1988 Addenda, (ASME OM Code), Appendix I, "Inservice Testing of Pressure Relief Devices in Light-Water Reactor Nuclear Power Plants,"
Section 1.3.3, "Test Frequency, Class 1 Pressure Relief Devices" (Reference 1). The relief request proposed to extend the five-year test interval, on a one-time basis, for eight Safety Relief Valves (SRVs) at Clinton Power Station (CPS), Unit 1. In Reference 2, the NRC requested the following additional information to complete its review.
NRC Request 1 Attachment Response to NRC Request for Additional Information Clinton Power Station, Unit 1 Relief Request 2209 The relief request states that the vendor manual for the safety relief valves indicates that in general, there is no degradation in the valves when stored in a controlled environment for a period of up to five years before actual installation. Please provide test results for Dikkers Model G-471 safety relief valves (SRVs) that were maintained in a controlled environment for an extended period of time and setpoint tested prior to actual installation. (Similar test results were summarized in an Exelon Generation Company, LLC letter to the NRC dated July 3, 2007, however, these test results were for Dresser valves.) As an alternative, provide the as-found set-pressure test results for SRVs (Dikkers Model G-471) that were stored in a controlled environment similar to the controlled environment at Clinton for an extended period of time, installed for approximately 4 years, and then tested.
AmerGen Response AmerGen has identified results from pressure lift tests for two Dikkers Model G-471 SRVs that were conducted prior to installation, following an extended storage period.
These two SRVs were tested and certified, stored in a controlled environment for a period of 6 years and 7 months, and then retested and recertified, prior to installation.
The two sets of test results, summarized in the table below, confirmed that storage of Dikkers Model G-471 SRVs for an extended period of time has minimal impact upon the ability of the SRVs to satisfy the ASME as-found acceptance criteria of plus or minus 3%, and thus does not reduce the level of quality or safety.
Table CPS Unit 1 Dikkers Model G-471 SRV Test Results Valve S/N Tested Pressure Dec 1978 Storage Period Tested Pressure Jul 1985
% Deviation 160535 1167 psig 6 years, 7 months 1176 psig
+0.8%
160785 1199 psig 6 years, 7 months 1199 psig 0.0%
NRC Request 2 Attachment Response to NRC Request for Additional Information Clinton Power Station, Unit 1 Relief Request 2209 Please verify that relief is not being requested for the Code requirement that a minimum of 20% of the valves be tested within any 24-month interval.
AmerGen Response The requested relief in Reference 1 only pertains to the five-year test interval. AmerGen will continue to comply with the Code requirement to test a minimum of 20% of the CPS Unit 1 SRVs within any 24-month interval.