ML072910699
| ML072910699 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 10/25/2007 |
| From: | Chernoff H NRC/NRR/ADRO/DORL/LPLI-2 |
| To: | Pardee C Exelon Generation Co |
| Bamford, Peter J., NRR/DORL 415-2833 | |
| References | |
| TAC MD6701 | |
| Download: ML072910699 (9) | |
Text
October 25, 2007 Mr. Charles G. Pardee Chief Nuclear Officer and Senior Vice President Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555
SUBJECT:
PEACH BOTTOM ATOMIC POWER STATION, UNIT 2 - REQUEST FOR RELIEF FROM ASME OM CODE 5-YEAR TEST INTERVAL FOR SAFETY RELIEF VALVE/SAFETY VALVES, RELIEF REQUEST (RR) 01A-VRR-2 (TAC NO. MD6701)
Dear Mr. Pardee:
By letter dated September 10, 2007 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML072540439), as supplemented by letter dated October 5, 2007 (ADAMS Accession No. ML072820155), Exelon Generation Company, LLC (Exelon) submitted Relief Request (RR) 01A-VRR-2 requesting relief from the requirements of Title 10 of the Code of Federal Regulations (10 CFR), Part 50, Section 55a, concerning a requirement in the American Society of Mechanical Engineers, Code for Operation and Maintenance of Nuclear Power Plants (ASME OM Code). The RR involves an extension to the ASME OM Code 5-year test interval for Peach Bottom Atomic Power Station (PBAPS), Unit 2, valves 71G and 70B, and Unit 3, valves 71J and 70A. PBAPS withdrew its request for relief for Unit 3 valves 71J and 70A in the October 5, 2007, letter aforementioned.
The Nuclear Regulatory Commission (NRC) staff has reviewed the licensees analysis in support of the request for relief. The NRC staff has concluded that compliance with the ASME OM Code 5-year test interval for Unit 2 valves 71G and 70B is impractical. The NRC staff has determined that granting the relief requested for Unit 2 valves 71G and 70B pursuant to 10 CFR 50.55a(f)(6)(i) is authorized by law and will not endanger life or property or the common defense and security, and is otherwise in the public interest giving due consideration to the burden upon the licensee that could result if the requirements were imposed on the facility.
Relief is granted for Unit 2 valves 71G and 70B through September 2008.
C. Pardee If you have any questions, please contact the PBAPS Project Manager, Mr. John Hughey, at 301-415-3204.
Sincerely,
/ra/
Harold K. Chernoff, Chief Plant Licensing Branch I-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-277
Enclosure:
As stated cc w/encl: See next page
If you have any questions, please contact the PBAPS Project Manager, Mr. John Hughey, at 301-415-3204.
Sincerely,
/ra/
Harold K. Chernoff, Chief Plant Licensing Branch I-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-277
Enclosure:
As stated cc w/encl: See next page DISTRIBUTION:
PUBLIC RidsOgcRp LPLI-2 R/F RidsAcrsAcnwMailCenter RidsNrrPMJHughey RidsNrrLAABaxter RidsRgn1MailCenter RLaufer, OEDO, Region 1 RidsNrrDorlLpl1-2 RidsNrrDorlDpr STingen, NRR ADAMS Accession Number: ML072910699
- by memo dated OFFICE LPL1-2/PM LPL1-2/LA CPNB/BC*
LPL1-2/BC NAME JHughey ABaxter JMcHale MBaty HChernoff DATE 10/23/07 10/23/07 10/19/07 10/24/2007 10/25/2007 OFFICIAL RECORD COPY
Peach Bottom Atomic Power Station, Unit No. 2 cc:
Site Vice President Peach Bottom Atomic Power Station Exelon Generation Company, LLC 1848 Lay Road Delta, PA 17314 Plant Manager Peach Bottom Atomic Power Station Exelon Generation Company, LLC 1848 Lay Road Delta, PA 17314 Regulatory Assurance Manager Peach Bottom Atomic Power Station Exelon Generation Company, LLC 1848 Lay Road Delta, PA 17314 Resident Inspector U.S. Nuclear Regulatory Commission Peach Bottom Atomic Power Station P.O. Box 399 Delta, PA 17314 Regional Administrator, Region I U.S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406 Mr. Roland Fletcher Department of Environment Radiological Health Program 2400 Broening Highway Baltimore, MD 21224 Correspondence Control Desk Exelon Generation Company, LLC P. O. Box 160 Kennett Square, PA 19348 Director, Bureau of Radiation Protection Pennsylvania Department of Environmental Protection Rachel Carson State Office Building P.O. Box 8469 Harrisburg, PA 17105-8469 Board of Supervisors Peach Bottom Township 545 Broad Street Ext.
Delta, PA 17314-9203 Mr. Richard McLean Power Plant and Environmental Review Division Department of Natural Resources B-3, Tawes State Office Building Annapolis, MD 21401 Dr. Judith Johnsrud National Energy Committee Sierra Club 433 Orlando Avenue State College, PA 16803 Manager-Financial Control & Co-Owner Affairs Public Service Electric and Gas Company P.O. Box 236 Hancocks Bridge, NJ 08038-0236 Manager Licensing-Peach Bottom Atomic Power Station Exelon Generation Company, LLC 200 Exelon Way, KSA -3E Kennett Square, PA 19348 Vice President - Licensing and Regulatory Affairs Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555 Vice President-Operations Mid-Atlantic Exelon Generation Company, LLC 200 Exelon Way, KSA 3-N Kennett Square, PA 19348 Associate General Counsel Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555
Peach Bottom Atomic Power Station, Unit No. 2 cc:
Director-Licensing and Regulatory Affairs Exelon Generation Company, LLC 200 Exelon Way, KSA 3-E Kennett Square, PA 19348
Enclosure SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELIEF REQUEST 01A-VRR-2 RELIEF FROM 5-YEAR TEST INTERVAL FOR SAFETY RELIEF/SAFETY VALVES EXELON GENERATION COMPANY, LLC PEACH BOTTOM ATOMIC POWER STATION, UNIT 2 DOCKET NO. 50-277
1.0 INTRODUCTION
By letter dated September 10, 2007 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML072540439), as supplemented by letter dated October 5, 2007 (ADAMS Accession No. ML072820155), Exelon Generation Company, LLC (Exelon) submitted Relief Request (RR) 01A-VRR-2. The licensee requested relief from the requirements of Title 10 of the Code of Federal Regulations (10 CFR), Part 50, Section 55a, concerning a requirement in the American Society of Mechanical Engineers, Code for Operation and Maintenance of Nuclear Power Plants (ASME OM Code). The RR involves an extension to the ASME OM Code 5-year test interval for PBAPS Unit 2 valves 71G and 70B. The ASME Code-1990, is the Code of Record for the PBAPS Unit 2 inservice test (IST) program through August 14, 2008. The 2001 edition through 2003 addenda of the ASME OM Code will be the Code of Record for the PBAPS Unit 2 IST program beginning August 15, 2008.
2.0 REGULATORY EVALUATION
Section 50.55a(f) of 10 CFR, "Inservice Testing Requirements," requires, in part, that ASME Class 1, 2, and 3 components must meet the requirements of the ASME OM Code and applicable addenda, except where alternatives have been authorized or relief has been requested by the licensee and granted by the Commission pursuant to paragraphs (a)(3)(i), (a)(3)(ii), or (f)(6)(i) of 10 CFR 50.55a.
The licensee requested relief in accordance with 10 CFR 50.55a(f)(5)(iii) from the 5-year test requirements in (1) Appendix I, Section I-1.3.3 of the ASME OM Code-1990; and (2)
Mandatory Appendix I, Section I-1320(a) of the 2001 edition through 2003 addenda of the ASME OM Code. 10 CFR 50.55a(f)(5)(iii) requires that the licensee determine that conformance with the code requirement is impractical for the facility.
10 CFR 50.55a(f)(6)(i) authorizes the Commission to grant relief from ASME OM Code requirements upon making necessary findings.
The licensee is requesting relief from the 5-year test requirement for Unit 2 valves 71G and 70B because compliance with this ASME OM Code requirement is impractical. The NRC staff agrees that it is impractical to test the valves 71G and 70B because plant design does not allow the method utilized by the licensee to test its safety relief valves (SRVs) and safety valves (SVs) at power. At PBAPS, the unit must be shutdown to test the SRV and SVs. The NRCs findings, with respect to granting relief from the ASME OM Code 5-year test requirement, are given below.
3.0 TECHNICAL EVALUATION
FOR RELIEF REQUEST NO. 01A-VRR-2 The SRVs and SVs provide overpressure protection for the reactor coolant pressure boundary and are required by the ASME OM Code to be setpoint tested every 5 years. The licensee has proposed to extend the 5-year test interval specified by the ASME OM Code for Unit 2 valves 71G(SRV) and 70B(SV). The licensees analysis in support of its request for relief from the 5-year test requirement is described in the licensees letters dated September 10 and October 5, 2007. A description of the RR and the NRC staffs evaluation follows.
3.1 ASME OM Code Requirements ASME OM Appendix I, Section I-1.3.3(b), Subsequent 5-Years Periods, of the ASME OM Code-1990, requires that Class 1 pressure relief valves be tested at least once every 5 years.
ASME OM Code Mandatory Appendix I, Section I-1320(a), Test Frequencies, Class 1 Pressure Relief Valves, 2001 edition through 2003 addenda, requires that Class 1 pressure relief valves be tested at least once every 5 years.
ASME Code Interpretation 01-18, ASME OM Code-1995 with OMa ASME Code-1996 Addenda, Appendix I, dated June 26, 2003, clarifies the start of the 5-year test interval. The ASME OM Code Committee position is that the 5-year test interval starts when the valve is tested.
The licensee has requested relief from the ASME OM Code 5-year test interval requirement in (1) Appendix I, Section I-1.3.3(b) of the ASME OM Code-1990; and (2) Mandatory Appendix I, Section I-1320(a) of the 2001 edition through 2003 addenda of the ASME OM Code. Relief was requested for Unit 2 valves 71G and 70B.
3.2 Licensees Basis for Relief The test interval for Unit 2 valve 71G has already expired and the test interval for valve 70B will expire on October 29, 2007, because the licensee incorrectly applied the 5-year test requirement in the ASME OM Code. The licensees practice was to start the 5-year interval when an SRV/SV was installed and not to include storage time in the 5-year interval.
The licensee requested relief because testing Unit 2 valves 71G and 70B at power is impractical. The method utilized by the licensee to test its SRVs and SVs requires the plant to be shutdown. Testing the valves prior to the upcoming refueling outage scheduled for September 2008 would result in an unnecessary plant shutdown or an extension of a forced outage, unnecessary challenges to safety systems, and unnecessary cycling of equipment.
Normal practice at PBAPS was to remove and test six or seven of the thirteen SRV/SVs each refueling outage. Spare SRV/SVs that were previously refurbished and tested were installed in place of the SRV/SVs that were removed. The SRV/SVs removed from service were tested, refurbished, and then retested before being reinstalled during a future refueling outage. The licensee is proposing to remove the Unit 2 valves 71G and 70B during the September 2008 refueling outage for subsequent testing and refurbishment.
The licensee stated that an ASME OM Code-certified off-site vendor is used to perform as-found and as-left testing, inspection, and refurbishment of each SRV/SV that is removed from service in accordance with a licensee approved procedure. The procedure identifies the critical components that are required to be inspected for wear and defects, and the critical dimensions that are required to be measured during the inspection. Components are either reworked to within the specified tolerance or replaced if found to be worn or outside of specified tolerances.
The licensee stated that valve 71G was stored in a controlled environment for 32 months prior to installation, and will have been in service for 4 years prior to removal during the upcoming September 2008 refueling outage. Valve 70B was stored in a controlled environment for 23 months prior to installation, and will have been in service for 4 years prior to removal during the upcoming September 2008 refueling outage. The licensee also stated that the controlled environment was equipped to prevent condensation and corrosion.
3.3 Licensees Proposed Alternative Testing The licensee is proposing to extend the test interval for Unit 2 valves 71G and SV 70B beyond 5 years on a one-time basis. The requested interval extension for valve 71G is 20 months beyond the allowable 5-year interval. The requested interval extension for valve 70B is 11 months beyond the allowable 5-year interval. The 71G and 70B valves would be removed during the upcoming September 2008 refueling outage for subsequent testing.
3.4 NRC Staffs Evaluation of RR The NRC staff has reviewed the licensees basis for relief to determine if it is acceptable to extend the test interval for Unit 2 valves 71G and SV 70B beyond the allowable 5-year interval specified in the ASME OM Code. The test interval for SRV 71G would be extended to 80 months on a one-time basis, and the test interval for SV 70B would be extended to 71 months on a one-time basis. Both valves would be installed in Unit 2 for 48 months and were in storage for the remainder of the time (71G was stored for 32 months prior to installation and 70B was stored for 23 months prior to installation).
Although the ASME OM Code does not require that SRV/SVs be routinely refurbished, refurbishment every two operating cycles provides reasonable assurance that setpoint drift will be minimized. Test history provided by the licensee verifies that this is true because it shows that the SRV/SVs generally passed the Technical Specification (TS) as-found acceptance criteria of +/-1%. In some instances, unsatisfactory as-found tests were only slightly above the TS as-found acceptance criteria of +/-1%. In other instances, unsatisfactory SRV/SV as-found tests exceeded the TS acceptance criteria of +/-1% in a negative, or conservative, direction. Test results for SRV/SVs that were stored in a controlled environment indicate that the impact of storage in a controlled environment on the opening setpoint was minimal.
The NRC staff finds that the proposed alternative to extend the test interval for PBAPS Unit 2 valves 71G and SV 70B beyond the ASME OM Code 5-year test requirement is acceptable. The additional time beyond that required by the ASME Code should not impair the valves operational readiness.
3.5 Conclusion The NRC staff has concluded that compliance with ASME OM Code 5-year test interval for Unit 2 valves 71G and 70B is impractical because plant design does not allow the method utilized by the licensee to test its SRV/SVs at power. At PBAPS, the unit must be shutdown to test SRV/SVs. The additional time beyond that required by the ASME Code should not impair the valves operational readiness. The NRC staff has determined that granting the relief requested for Unit 2 valves 71G and 70B pursuant to 10 CFR 50.55a(f)(6)(i) is authorized by law and will not endanger life or property or the common defense and security, and is otherwise in the public interest giving due consideration to the burden upon the licensee that could result if the requirements were imposed on the facility. Relief is granted for Unit 2 valves 71G and 70B through September 2008.
Principal Contributor: Stephen G. Tingen Date: October 25, 2007