ML063390103

Relief Requests 13R-01 for Alignment of Inservice Inspection and Containment Inservice Inspection

ML063390103
Person / Time
Site:	Limerick
Issue date:	01/24/2007
From:	Richard Guzman NRC/NRR/ADRO/DORL/LPLI-1
To:	Crane C Exelon Generation Co, Exelon Nuclear
Kim J, NRR/ADIP/NRLPO, 415-4125
References
TAC MD2727, TAC MD2728
Download: ML063390103 (7)

Text

January 24, 2007 Mr. Christopher M. Crane President and Chief Nuclear Officer Exelon Nuclear Exelon Generation Company, LLC 200 Exelon Way, KSA 3-E Kennett Square, PA 19348

SUBJECT:

LIMERICK GENERATING STATION, UNITS 1 AND 2 - RELIEF REQUESTS I3R-01 FOR ALIGNMENT OF INSERVICE INSPECTION AND CONTAINMENT INSERVICE INSPECTION (TAC NOS. MD2727 AND MD2728)

Dear Mr. Crane:

By letter dated August 4, 2006, as supplemented on October 31, 2006, Exelon Generation Company, LLC (EGC or the licensee) proposed relief from the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code),Section XI, Rules for Inservice Inspection of Nuclear Power Plant Components. Specifically, relief is being sought to reduce the duration of the Limerick Generating Station (LGS), Unit 2 second inservice inspection (ISI) interval in order to create a common ISI interval for LGS, Units 1 and 2. In addition, relief is requested to reduce the first containment ISI (CISI) interval for LGS, Unit 2, which will permit subsequent CISI interval dates to be synchronized with the future ISI intervals for both units.

The net effect of this request is to establish one common interval for both the ISI and CISI programs at LGS, Units 1 and 2. The Nuclear Regulatory Commission (NRC) staff review addresses the ability of the licensee to maintain an acceptable level of quality and safety after altering its ISI programs, and to ensure integrity of the containment.

The NRC staff has reviewed Relief Request I3R-01, and has determined that the licensees proposed alternative to the requirements of ASME Code,Section XI, IWA-2432 is acceptable because it will provide an acceptable level of quality and safety. Therefore, pursuant to Title 10 of the Code of Federal Regulation, Section 50.55a(a)(3)(i) the alternative is authorized for the Limerick Generating Station, Units 1 and 2. The staffs Safety Evaluation is enclosed.

If you have any questions regarding this matter, please contact James Kim at (301) 415-4125.

Sincerely,

/RA/

Richard V. Guzman, Project Manager Plant Licensing Branch I-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-352 and 50-353

Enclosures:

As stated cc w/encls: See next page

January 24, 2007 Mr. Christopher M. Crane President and Chief Nuclear Officer Exelon Nuclear Exelon Generation Company, LLC 200 Exelon Way, KSA 3-E Kennett Square, PA 19348

SUBJECT:

LIMERICK GENERATING STATION, UNITS 1 AND 2 - RELIEF REQUESTS I3R-01 FOR ALIGNMENT OF INSERVICE INSPECTION AND CONTAINMENT INSERVICE INSPECTION (TAC NOS. MD2727 AND MD2728)

Dear Mr. Crane:

By letter dated August 4, 2006, as supplemented on October 31, 2006, Exelon Generation Company, LLC (EGC or the licensee) proposed relief from the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code),Section XI, Rules for Inservice Inspection of Nuclear Power Plant Components. Specifically, relief is being sought to reduce the duration of the Limerick Generating Station (LGS), Unit 2 second inservice inspection (ISI) interval in order to create a common ISI interval for LGS, Units 1 and 2. In addition, relief is requested to reduce the first containment ISI (CISI) interval for LGS, Unit 2, which will permit subsequent CISI interval dates to be synchronized with the future ISI intervals for both units.

The net effect of this request is to establish one common interval for both the ISI and CISI programs at LGS, Units 1 and 2. The Nuclear Regulatory Commission (NRC) staff review addresses the ability of the licensee to maintain an acceptable level of quality and safety after altering its ISI programs, and to ensure integrity of the containment.

The NRC staff has reviewed Relief Request I3R-01, and has determined that the licensees proposed alternative to the requirements of ASME Code,Section XI, IWA-2432 is acceptable because it will provide an acceptable level of quality and safety. Therefore, pursuant to Title 10 of the Code of Federal Regulation, Section 50.55a(a)(3)(i) the alternative is authorized for the Limerick Generating Station, Units 1 and 2. The staffs Safety Evaluation is enclosed.

If you have any questions regarding this matter, please contact James Kim at (301) 415-4125.

Sincerely,

/RA/

Richard V. Guzman, Project Manager Plant Licensing Branch I-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-352 and 50-353

Enclosures:

As stated cc w/encls: See next page DISTRIBUTION:

PUBLIC LPL1-2 R/F RidsNrrDorlLpl1-2 RidsNrrPMRGuzman RidsOgcRp GHill (4) RidsNrrDirsItsb RidsNrrPMJKim RidsDeEgca RidsDciCvib RidsNrrLACRaynor RidsRgn1MailCenter ADAMS Accession Number: ML063390103 OFFICE LPL1-2/PE LPL1-1/PM LPL1-2/LA EGCA/BC CVIB/BC OGC LPL1-2/BC NAME JKim RGuzman CRaynor SSamaddar MMitchell MBarkman HChernoff DATE 1/03/07 1/03/07 1/03/07 1/04/07 1/03/07 1/16/07 1/24/07 OFFICIAL RECORD COPY

Limerick Generating Station, Unit Nos. 1 and 2 cc:

Site Vice President Assistant General Counsel Limerick Generating Station Exelon Generation Company, LLC Exelon Generation Company, LLC 200 Exelon Way P.O. Box 2300 Kennett Square, PA 19348 Sanatoga, PA 19464 Correspondence Control Desk Plant Manager Exelon Generation Company, LLC Limerick Generating Station P.O. Box 160 Exelon Generation Company, LLC Kennett Square, PA 19348 P.O. Box 2300 Sanatoga, PA 19464 Regional Administrator, Region I U.S. Nuclear Regulatory Commission Regulatory Assurance Manager - Limerick 475 Allendale Road Exelon Generation Company, LLC King of Prussia, PA 19406 P.O. Box 2300 Sanatoga, PA 19464 Senior Resident Inspector U.S. Nuclear Regulatory Commission Senior Vice President - Nuclear Services Limerick Generating Station Exelon Generation Company, LLC P.O. Box 596 4300 Winfield Road Pottstown, PA 19464 Warrenville, IL 60555 Library Vice President - Operations, Mid-Atlantic U.S. Nuclear Regulatory Commission Exelon Generation Company, LLC Region I 200 Exelon Way, KSA 3-N 475 Allendale Road Kennett Square, PA 19348 King of Prussia, PA 19406 Vice President Director, Bureau of Radiation Protection Licensing and Regulatory Affairs Pennsylvania Dept. of Environmental Exelon Generation Company, LLC Protection 4300 Winfield Road Rachel Carson State Office Building Warrenville, IL 60555 P.O. Box 8469 Harrisburg, PA 17105-8469 Director Licensing and Regulatory Affairs Chairman Exelon Generation Company, LLC Board of Supervisors of Limerick Township 200 Exelon Way, KSA 3-E 646 West Ridge Pike Kennett Square, PA 19348 Linfield, PA 19468 Manager Licensing Dr. Judith Johnsrud Limerick Generating Station National Energy Committee Exelon Generation Company, LLC Sierra Club 200 Exelon Way, KSA 3-E 433 Orlando Avenue Kennett Square, PA 19348 State College, PA 16803

SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION REQUEST FOR RELIEF I3R-01 ALIGNMENT OF INSERVICE INSPECTION AND CONTAINMENT INSERVICE INSPECTION LIMERICK GENERATING STATION, UNITS 1 AND 2 DOCKET NOS. 50-352 AND 50-353

1.0 INTRODUCTION

By letter dated August 4, 2006, as supplemented on October 31, 2006, Exelon Generation Company, LLC (EGC or the licensee) proposed relief from the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code),Section XI, Rules for Inservice Inspection of Nuclear Power Plant Components. Specifically, relief is being sought to reduce the duration of the Limerick Generating Station (LGS), Unit 2 second inservice inspection (ISI) interval in order to create a common ISI interval for LGS, Units 1 and 2. In addition, relief is requested to reduce the first containment ISI (CISI) interval for LGS, Unit 2, which will permit subsequent CISI interval dates to be synchronized with the future ISI intervals for both units.

The net effect of this request is to establish one common interval for both the ISI and CISI programs at LGS, Units 1 and 2. The Nuclear Regulatory Commission (NRC) staff review addresses the ability of the licensee to maintain an acceptable level of quality and safety after altering its ISI programs, and to ensure integrity of the containment. The LGS, Unit 1 conversion to the common ISI interval start date would occur during the Unit 2 refueling outage in February 2007.

2.0 REGULATORY EVALUATION

Title 10 of the Code of Federal Regulations (10 CFR ) Section 50.55a(g) specifies that ISI of nuclear power plant components shall be performed in accordance with the requirements of the ASME Code,Section XI, except where specific written relief has been granted by the Nuclear Regulatory Commission (NRC or the Commission) pursuant to 10 CFR 50.55a(g)(6)(i).

Section 50.55a(a)(3) of 10 CFR states that alternatives to the requirements of paragraph (g) may be used, when authorized by the NRC, if (i) the proposed alternatives would provide an acceptable level of quality and safety, or (ii) compliance with the specified requirements would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety. Section 50.55a(g)(5)(iii) of 10 CFR states that if the licensee has determined that conformance with certain ASME Code requirements is impractical for its facility, the licensee shall notify the Commission and submit, as specified in 10 CFR 50.4, information to support the determinations.

Pursuant to 10 CFR 50.55a(g)(4), ASME Code Class 1, 2, and 3 components (including supports) shall meet the requirements, except the design and access provisions and preservice examination requirements, set forth in the ASME Code,Section XI, to the extent practical within

the limitations of design, geometry, and materials of construction of the components. The regulations require that ISI of components and system pressure tests conducted during the first 10-year interval, and subsequent intervals, comply with the requirements in the latest edition and addenda of Section XI of the ASME Code incorporated by reference in 10 CFR 50.55a(b) 12 months prior to the start of the 120-month interval, subject to the limitations and modifications listed therein.

3.0 TECHNICAL EVALUATION

3.1 Components for Which Relief is Requested All Class 1, 2, 3, MC and CC components.

3.2 Applicable Code Edition and Addenda The current LGS, Units 1 and 2 code of record for the second 10-year ISI interval is the ASME Code,Section XI, 1989 Edition. The code of record for the LGS Units 1 and 2 first 10-year CISI program is the ASME Code,Section XI, 1992 Edition through the 1992 Addenda.

After modification of the 10-year interval dates as proposed, the common ASME Code of record will be the 2001 Edition through the 2003 Addenda of ASME Code,Section XI.

3.3 Applicable ASME Code Requirement ASME Code,Section XI, IWA-2432 requires that each inspection interval consist of a 10-year duration, except as modified by IWA-2430(d), which permits the inspection interval to be reduced or extended by as much as 1 year, provided that successive intervals are not altered by more than 1 year from the original pattern of intervals.

3.4 Licensee Proposed Alternative and Basis for Use Currently, the LGS Unit 1 second ISI Interval is scheduled to end on January 31, 2007, and the same LGS Unit 2 interval will end on January 7, 2010. This creates about a 3-year gap between the two units ISI programs. LGS proposes to reduce the duration of the second ISI interval for LGS Unit 2 by approximately 3 years to permit the commencement of its third ISI interval to coincide with the start of the third ISI interval for LGS Unit 1; and, hence, will establish a joint interval with common start and end dates, and ensure use of the same ASME Code Edition and Addenda for the next and successive intervals. Any examination methods unique to, and specifically required in, the remainder of the LGS, Unit 2 third period under the previous ISI interval ASME Code (i.e., ASME Code Section XI, 1989 Edition), will be scheduled and completed in the first period of the subsequent interval. The above method of scheduling will maintain the original sequence of examination and, thus, will not affect the frequency of examination.

EGC also requested to similarly affect the CISI program interval dates by reducing the duration of the first CISI interval for LGS Unit 2 by approximately 3 years, and to permit commencement of the second CISI interval for Class MC and CC components to coincide with the start of the joint third ISI interval for Class 1, 2, and 3 components as previously described. This will result in both the ISI and CISI programs being under the same ASME Code edition and addenda for

the next and successive intervals. For the rolling 5-year IWL frequency applicable to Class CC components that are subject to Subsection IWL requirements, the inspection will be conducted in accordance with the ASME Code of record for LGS at the time of examination.

The licensee stated that 10 CFR 50.55a(g)(4)(ii) does not prohibit licensees from updating to a later Edition and Addenda of the ASME Code midway through a 10-year IWE and IWL examination interval. The licensee further stated that using the common interval date justified above and based on the current Unit 1 ISI program dated February 1, 2007, the ASME Code of record for the third interval ISI and second interval CISI programs is to be set on January 31, 2006. The latest edition and addenda of the ASME Code incorporated by reference in 10 CFR 50.55a(b)(2) of the regulation was the 2001 Edition through the 2003 Addenda. Thus, LGS will utilize the 2001 Edition through the 2003 Addenda of Section XI to develop the ISI program update for the third ISI interval and second CISI interval.

The licensee asserts that the proposed alternative, as described above, provides an acceptable level of quality and safety, and does not adversely impact the health and safety of the public.

3.5 Evaluation In the subject relief request the licensee proposed an alternative to the ASME Code,Section XI, IWA-2432 requirements. The proposed alternative will reduce the duration of the second 10-year ISI interval of the LGS Unit 2 by about 3 years and the duration of the first 10-year CISI interval of the LGS Unit 2 by about 3 years. However, the ASME Code allows only a year change to the original pattern of the 10-year ISI interval. Therefore, to determine whether the proposed alternative will provide an acceptable level of quality and safety, the NRC staffs review will focus on its effect on the implementation of the ASME Code-required ISI.

Currently, LGS Units 1 and 2 have different 10-year ISI interval dates due to different commercial operating dates. This may result in different governing code editions in subsequent ISI intervals which may require the implementation of different code requirements at different units. In addition, the 10-year interval dates for CISI are different from that of the ISI because the CISI program was not implemented until 1996. The proposed alternative will synchronize the 10-year ISI interval between Units 1 and 2 and align the 10-year CISI intervals of Units 1 and 2 with the synchronized ISI interval. This will establish a common interval for both the ISI and the CISI programs at LGS Units 1 and 2, and allow the use of a common ASME Code of record. The common code of record will be 2001 Edition through the 2003 Addenda of ASME Code,Section XI. There are distinct advantages in implementing the same code requirements at both units in a common interval. The advantages include the reduction of administrative burden of maintaining different sets of procedures and requirements, and, thus, reducing chances of applying the wrong requirements.

The licensee also stated that the examination and tests required by the CISI program have been implemented in accordance with the established schedule, and the examination and tests performed to date have satisfied the acceptance standards contained within Articles IWE-3000 and IWL-3000 without exception.

In the supplementary information contained in Section 2.2 of the Final Rule (67 FR 60520) dated September 26, 2002, the NRC staff stated that 10 CFR 50.55a(g)(4)(ii) does not prohibit

licensees from updating to a later edition and addenda of the ASME Code midway through a 10-year IWE or 5-year IWL examination interval. Additionally, the staff advised that licensees wishing to synchronize their 120-month intervals may submit a request in accordance with 10 CFR 50.55a(a)(3) to obtain authorization to extend or reduce 120-month intervals.

Based on the above, the NRC staff has determined that the licensees proposed alternative will make the implementation of the ISI and CISI programs at LGS Units 1 and 2 more efficient and effective with no change to the frequency of required examinations. Therefore, the staff finds that the licensees proposed alternative will provide an acceptable level of quality and safety.

4.0 CONCLUSION

Based on the information provided in the licensees submittal, the NRC staff concludes that the licensees proposed alternative to the requirements of ASME Code,Section XI, IWA-2432 is acceptable because it will provide an acceptable level of quality and safety. Therefore, pursuant to 10 CFR 50.55a(a)(3)(i) the alternative is authorized for the LGS Units 1 and 2.

Principal Contributors: D. Jeng R. Jackson Allison K. Black Date: January 24, 2007