ML080980311
| ML080980311 | |
| Person / Time | |
|---|---|
| Site: | Dresden, Peach Bottom, Oyster Creek, Limerick, Clinton, Quad Cities, LaSalle |
| Issue date: | 04/30/2008 |
| From: | Russell Gibbs NRC/NRR/ADRO/DORL/LPLIII-2 |
| To: | Pardee C AmerGen Energy Co, Exelon Generation Co |
| gratton c | |
| References | |
| TAC MD5352, TAC MD5353, TAC MD5354, TAC MD5355, TAC MD5356, TAC MD5357, TAC MD5358, TAC MD5359, TAC MD5360, TAC MD5361, TAC MD5362, TAC MD5363 | |
| Download: ML080980311 (24) | |
Text
April 30, 2008 Mr. Charles G. Pardee Chief Nuclear Officer and Senior Vice President Exelon Generation Company, LLC Chief Nuclear Officer AmerGen Energy Company, LLC 4300 Winfield Road Warrenville, IL 60555
SUBJECT:
CLINTON POWER STATION, UNIT NO. 1; DRESDEN NUCLEAR POWER STATION, UNITS 2 AND 3; LASALLE COUNTY STATION, UNITS 1 AND 2; LIMERICK GENERATING STATION, UNITS 1 AND 2; OYSTER CREEK NUCLEAR GENERATING STATION; PEACH BOTTOM ATOMIC POWER STATION, UNITS 2, AND 3; AND QUAD CITIES NUCLEAR POWER STATION, UNITS 1 AND 2 - RELIEF REQUEST TO USE BOILING WATER REACTOR VESSEL AND INTERNALS PROJECT GUIDELINES IN LIEU OF SPECIFIC ASME CODE REQUIREMENTS (TAC NOS. MD5352 THRU MD5363)
Dear Mr. Pardee,
By letter dated April 19, 2007, as supplemented by letters dated October 5, 2007, January 8 and April 4, 2008, Exelon Generation Company, LLC, and AmerGen Energy Company, LLC, (the licensee), submitted a request for relief from the requirements of Section XI of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code), Rules for Inservice Inspection [ISI] of Nuclear Power Plant Components, that apply to reactor vessel internal components for the subject nuclear reactor units. The licensee proposed to use Boiling Water Reactor Vessel and Internal Project (BWRVIP) guidelines as alternatives to certain ASME Code,Section XI requirements.
The Nuclear Regulatory Commission (NRC) staff has completed its review of the licensees submittal. The NRC staff concludes that the proposed alternatives to the ASME Code,Section XI requirements specified in Attachment 1 of the enclosure to this letter, provide an acceptable level of quality and safety. The NRC staff authorizes the proposed alternatives for the subject plants applicable 10-year interval ISI programs pursuant to Title 10 of the Code of Federal Regulations (10 CFR), Section 50.55a(a)(3)(i), with one exception. Guideline BWRVIP-41, Revision 1, BWR Jet Pump Assembly Inspection and Flaw Evaluation Guidelines, had been under review by the NRC staff but was withdrawn from NRC review on July 18, 2007, to allow for revision. The proposed alternatives based on BWRVIP-41, Revision 1, are, therefore, not authorized. As a result, the licensee must continue to implement the ASME Code,Section XI, ISI requirements for the jet pump components for which this proposed alternative was requested.
The new inspection plans should be documented in the respective ISI program plan for the applicable 10-year interval for each of the subject units. The use of the proposed alternatives is authorized until the end of the applicable 10-year ISI interval for each unit, a summary of which is provided in Attachment 2 to the enclosure to this document.
C. Pardee If you have any questions regarding this authorization, please contact Christopher Gratton at (301) 415-1055.
Sincerely,
/RA/
Russell Gibbs, Chief Plant Licensing Branch III-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-461, 50-237, 50-249, 50-373, 50-374, 50-352, 50-353, 50-219, 50-277, 50-278, 50-254 and 50-265
Enclosure:
As stated cc w/encl: See next page
C. Pardee If you have any questions regarding this authorization, please contact Christopher Gratton at (301) 415-1055.
Sincerely,
/RA/
Russell Gibbs, Chief Plant Licensing Branch III-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-461, 50-237, 50-249, 50-373, 50-374, 50-352, 50-353, 50-219, 50-277, 50-278, 50-254 and 50-265
Enclosure:
As stated cc w/encl: See next page DISTRIBUTION:
PUBLIC LPL3-2 R/F RidsNrrDorlLpl3-2 RidsNrrLAEWhitt LPL1-2 R/F RidsNrrDorlLpl1-2 RidsNrrLAABaxter RidsNrrPMCGratton RidsOgcRp RidsRgn3MailCenter RidsRgn1MailCenter RidsNrrDorlDpr RidsNrrPMPBamford RidsNrrPMSSands RidsNrrPMJWiebe RidsNrrPMJHughey RidsNrrPMEMiller RidsNrrPMMDavid RidsAcrsAcnw&mMailCenter RidsNrrDciCvib GCheruvenki, NRR ADAMS Accession Number: ML080980311 NRR-028 OFFICE LPL3-2/PM LPL3-2/LA DCI/CVIB/BC OGC LPL3-2/BC NAME CGratton EWhitt MMitchell P. Moulding RGibbs DATE 4/30/08 4/30/08 4/11/08 4/17/2008 4/30/08 OFFICIAL RECORD COPY
Clinton Power Station, Unit No. 1 cc:
Corporate Distribution Exelon Generation Company, LLC Via e-mail Clinton Distribution Exelon Generation Company, LLC Via e-mail Clinton Resident Inspector U.S. Nuclear Regulatory Commission Via e-mail Illinois Emergency Management Agency Division of Disaster Assistance &
Preparedness Via e-mail J. W. Blattner, Project Manager Sargent & Lundy Engineers Via e-mail Chairman of DeWitt County c/o County Clerks Office Via e-mail
Dresden Nuclear Power Station, Units 2 and 3 cc:
Corporate Distribution Exelon Generation Company, LLC Via e-mail Dresden Distribution Exelon Generation Company, LLC Via e-mail Dresden Resident Inspector U.S. Nuclear Regulatory Commission Via e-mail Chairman Grundy County Board Via e-mail Illinois Emergency Management Agency Division of Disaster Assistance &
Preparedness Via e-mail
LaSalle County Station, Units 1 and 2 cc:
Corporate Distribution Exelon Generation Company, LLC Via e-mail LaSalle Distribution Exelon Generation Company, LLC Via e-mail LaSalle Resident Inspector U.S. Nuclear Regulatory Commission Via e-mail Phillip P. Steptoe, Esquire Sidley and Austin Via e-mail Assistant Attorney General Chicago, IL 60603 Via e-mail Chairman LaSalle County Board Via e-mail Attorney General Via e-mail Chairman Illinois Commerce Commission Via e-mail Illinois Emergency Management Agency Division of Disaster Assistance &
Preparedness Via e-mail Robert Cushing, Chief, Public Utilities Division Illinois Attorney General's Office 100 W. Randolph Street Chicago, IL 60601
Limerick Generating Station, Unit Nos. 1 and 2 cc:
Christopher Mudrick Site Vice President Limerick Generating Station Exelon Generation Company, LLC 3146 Sanatoga Road Sanatoga, PA 19464 Ed Callan, Plant Manager Limerick Generating Station Exelon Generation Company, LLC 3146 Santoga Road Sanatoga, PA 19464 Manager Regulatory Assurance - Limerick Generating Station Exelon Generation Company, LLC 3146 Sanatoga Road Sanatoga, PA 19464 Senior Vice President - Mid-Atlantic Operations Exelon Generation Company, LLC 200 Exelon Way, KSA 3-N Kennett Square, PA 19348 Chief Operating Officer-Exelon Nuclear Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555 Senior Vice President -Operations Support Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555 Vice President Licensing and Regulatory Affairs Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555 Director, Licensing and Regulatory Affairs Exelon Generation Company, LLC Correspondence Control P.O. Box 160 Kennett Square, PA 19348 Manager Licensing Exelon Generation Company, LLC Correspondence Control P.O. Box 160 Kennett Square, PA 19348 Correspondence Control Desk Exelon Generation Company, LLC 200 Exelon Way, KSA 1-N-1 Kennett Square, PA 19348 Regional Administrator, Region I U.S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406 Senior Resident Inspector U.S. Nuclear Regulatory Commission Limerick Generating Station P.O. Box 596 Pottstown, PA 19464 Library U.S. Nuclear Regulatory Commission Region I 475 Allendale Road King of Prussia, PA 19406 Director, Bureau of Radiation Protection Pennsylvania Dept. of Environmental Protection Rachel Carson State Office Building P.O. Box 8469 Harrisburg, PA 17105-8469 Chairman Board of Supervisors of Limerick Township 646 West Ridge Pike Linfield, PA 19468 Dr. Judith Johnsrud National Energy Committee Sierra Club 433 Orlando Avenue State College, PA 16803
Limerick Generating Station, Unit Nos. 1 and 2 J. Bradley Fewell, Esquire Associate General Counsel Exelon Generation Company, LLC 4300 Winfield Road Kennett Square, PA 19348 Mr. Charles G. Pardee Chief Nuclear Officer and Senior Vice President Exelon Generation Company, LLC 200 Exelon Way Kennett Square, PA 19348
Oyster Creek Nuclear Generating Station Site Vice President - Oyster Creek Nuclear Generating Station AmerGen Energy Company, LLC P.O. Box 388 Forked River, NJ 08731 Senior Vice President-Operations Support AmerGen Energy Company, LLC 4300 Winfield Road Warrenville, IL 60555 Kathryn M. Sutton, Esquire Morgan, Lewis, & Bockius LLP 1111 Pennsylvania Avenue, NW Washington, DC 20004 Patrick Mulligan, Chief Bureau of Nuclear Engineering New Jersey Department of Environmental Protection 25 Arctic Parkway Ewing, NJ 08638 Vice President - Licensing and Regulatory Affairs AmerGen Energy Company, LLC 4300 Winfield Road Warrenville, IL 60555 Regional Administrator, Region I U.S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406-1415 Mayor of Lacey Township 818 West Lacey Road Forked River, NJ 08731 Manager Regulatory Assurance Oyster Creek Generating Station AmerGen Energy Company, LLC P.O. Box 388 Forked River, NJ 08731 Senior Resident Inspector U.S. Nuclear Regulatory Commission P.O. Box 445 Forked River, NJ 08731 Director - Licensing and Regulatory Affairs AmerGen Energy Company, LLC Correspondence Control P.O. Box 160 Kennett Square, PA 19348 Manager Licensing - Oyster Creek Exelon Generation Company, LLC Correspondence Control P.O. Box 160 Kennett Square, PA 19348 Ron Bellamy, Region I U.S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406-1415 Correspondence Control Desk AmerGen Energy Company, LLC 200 Exelon Way, KSA 1-NB1 Kennett Square, PA 19348 Plant Manager Oyster Creek Nuclear Generating Station AmerGen Energy Company, LLC P.O. Box 388 Forked River, NJ 08731 Associate General Counsel Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555 Chief Operating Officer (COO)
AmerGen Energy Company, LLC 4300 Winfield Road Warrenville, IL 60555 Senior Vice President - Mid-Atlantic Operations AmerGen Energy Company, LLC 200 Exelon Way, KSA 3-N Kennett Square, PA 19348
Peach Bottom Atomic Power Station, Unit Nos. 2 and 3 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 Chief Operating Officer (COO)
Exelon Nuclear Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555 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 200 Exelon Way, KSA 1N1 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 P.O. Box 160 Kennett Square, PA 19348 Vice President - Licensing and Regulatory Affairs Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555
Peach Bottom Atomic Power Station, Unit Nos. 2 and 3 cc:
Senior Vice President-Mid-Atlantic Operations Exelon Generation Company, LLC 200 Exelon Way, KSA 3-N Kennett Square, PA 19348 Senior Vice President - Operations Support Exelon Generation Company, LLC 200 Exelon Way, KSA 3-N Kennett Square, PA 19348 Director - Licensing and Regulatory Affairs Exelon Generation Company LLC Correspondence Control P.O. Box 160 Kennett Square, PA 19348 Associate General Counsel Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555
Quad Cities Nuclear Power Station, Units 1 and 2 cc:
Corporate Distribution Exelon Generation Company, LLC Via e-mail Quad Cities Distribution Exelon Generation Company, LLC Via e-mail Quad Cities Resident Inspector U.S. Nuclear Regulatory Commission Via e-mail David C. Tubbs MidAmerican Energy Company Via e-mail Managing Senior Attorney MidAmerican Energy Company Via e-mail Chairman Rock Island County Board of Supervisors Via e-mail Illinois Emergency Management Agency Division of Disaster Assistance & Preparedness Via e-mail
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION REQUEST FOR RELIEF FROM INSERVICE INSPECTION REQUIREMENTS FOR BOILING WATER REACTOR VESSEL AND INTERNALS EXELON GENERATION COMPANY, LLC AMERGEN ENERGY COMPANY, LLC CLINTON POWER STATION, UNIT NO. 1 DRESDEN NUCLEAR POWER STATION, UNITS 2 AND 3 LASALLE COUNTY STATION, UNITS 1 AND 2 LIMERICK GENERATING STATION, UNITS 1 AND 2 OYSTER CREEK NUCLEAR GENERATING STATION PEACH BOTTOM ATOMIC POWER STATION, UNITS 2 AND 3 QUAD CITIES NUCLEAR POWER STATION, UNITS 1 AND 2 DOCKET NOS. 50-461, 50-237, 50-249, 50-373, 50-374, 50-352, 50-353, 50-219, 50-277, 50-278, 50-254 and 50-265
1.0 INTRODUCTION
By letter to the Nuclear Regulatory Commission (NRC, the Commission) dated April 19, 2007 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML071140082), as supplemented by letters dated October 5, 2007 (ADAMS Accession No. ML072820584), January 8 (ADAMS Accession No. ML080150430), and April 4, 2008 (ADAMS Accession No. ML080980056), Exelon Generation Company, LLC, and AmerGen Energy Company, LLC (the licensee), submitted a relief request (RR) for the following reactor plants: Clinton Power Station, Unit No. 1 (CPS); Dresden Nuclear Power Station, Units 2 and 3 (DNPS); LaSalle County Station, Units 1 and 2 (LSCS); Limerick Generating Station, Units 1 and 2 (Limerick); Oyster Creek Nuclear Generating Station (Oyster Creek); Peach Bottom Atomic Power Station, Units 2 and 3 (PBAPS); and Quad Cities Nuclear Power Station, Units 1 and 2 (QCNPS). The RR proposed an alternative to the requirements of Title 10 of the Code of Federal Regulations (10 CFR), Section 50.55a. The licensee proposed to use Boiling Water Reactor Vessel and Internals Project (BWRVIP) guidelines as an alternative to certain requirements of Section XI of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code) for inservice inspection (ISI) of reactor vessel internal (RVI) components.
2.0 REGULATORY REQUIREMENTS ISI of ASME Code Class 1, 2, and 3 components is performed in accordance with Section XI of the ASME Code as required by 10 CFR 50.55a(g), except where specific relief has been granted by the Commission pursuant to 10 CFR 50.55a(g)(6)(i). Section 50.55a(a)(3) states that alternatives to the requirements of 10 CFR 50.55a(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.
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 the pre-service examination requirements, set forth in the ASME Code,Section XI, "Rules for ISI of Nuclear Power Plant Components," to the extent practical within the limitations of design, geometry, and materials of construction of the components. The regulations require that inservice examination 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),
twelve months prior to the start of the 120-month interval, subject to the limitations and modifications listed therein. The ASME Code of Record for the applicable 10-year ISI interval for each unit in the Exelon BWR fleet is shown in the Attachment A of the licensees submittal dated April 19, 2007, and is included as Attachment 2 to this enclosure.
3.0 LICENSEES EVALUATION 3.1 The Components for Which an Alternative is Requested ASME Code,Section XI, Class 1, Examination Categories B-N-1 and B-N-2, Code Item Numbers B13.10, Vessel Interior, B13.20, Interior Attachments within Beltline Region, B13.30, Interior Attachments Beyond Beltline Region, and B13.40, Core Support Structures.
3.2 Examination Requirements From Which an Alternative is Requested ASME Code, Section Xl requires the visual examination (VT) of certain RVI components. These examinations are included in Table IWB-2500-1, Categories B-N-1 and B-N-2, and identified with the following item numbers:
B13.10 - Examine accessible areas of the RV interior each period using a technique which meets the requirements for a VT-3 examination, as defined in paragraph IWA-2213 of the ASME Code,Section XI.
B13.20 - Examine interior attachment welds within the beltline region each interval using a technique which meets the requirements for a VT-1 examination as defined in paragraph IWA-2211 of the ASME Code,Section XI.
B13.30 - Examine interior attachment welds beyond the beltline region each interval using a technique which meets the requirements for a VT-3 examination, as defined in paragraph IWA-2213 of the ASME Code,Section XI.
B13.40 - Examine surfaces of the core support structures each interval using a technique which meets the requirements for a VT-3 examination, as defined in paragraph IWA-2213 of the ASME Code,Section XI.
These examinations are performed to assess the structural integrity of the RVI components.
3.3 Licensees Basis for Requesting an Alternative and Justification for Granting Relief The licensee concluded that the alternative examinations (described below) will maintain an adequate level of quality and safety of the affected welds and components and will not adversely impact the health and safety of the public. As part of its justification for the relief, the licensee stated that BWRs now examine RVI components in accordance with BWRVIP inspection guidelines. The licensee stated that these guidelines have been written to address the examination of safety significant RVI components using appropriate methods and reexamination frequencies. The licensee also noted that the NRC has agreed with the BWRVIP approach in principle and has issued safety evaluations (SEs) for these guidelines. Relief from examinations in Table IWB-2500-1 of the ASME Code is requested pursuant to 10 CFR 50.55a(a)(3)(i).
3.4 Alternative Examination In lieu of the requirements of the applicable ASME Code, Section Xl, edition and addenda, the licensee proposed to examine the RVI components in accordance with BWRVIP inspection guidelines for the subject plants. The particular proposed guidelines that are applicable to the various RVI components are:
BWRVIP-18-A, BWRVIP Core Spray Internals Inspection and Flaw Evaluation Guidelines" BWRVIP-25, BWRVIP Core Plate Inspection and Flaw Evaluation Guidelines BWRVIP-26-A, BWRVIP Top Guide Inspection and Flaw Evaluation Guidelines BWRVIP-27-A, BWRVIP BWR Standby Liquid Control System/Core Plate Delta P Inspection and Flaw Evaluation Guidelines BWRVIP-38, BWRVIP Shroud Support Inspection and Flaw Evaluation Guideline BWRVIP-41, Revision 1, BWRVIP Jet Pump Assembly Inspection and Flaw Evaluation Guidelines BWRVIP-47-A, BWR Lower Plenum Inspection and Flaw Evaluation Guidelines BWRVIP-48-A, Vessel ID Attachment Weld Inspection and Flaw Evaluation Guidelines BWRVIP-76, BWR Core Shroud Inspection and Flaw Evaluation Guidelines BWRVIP-138, BWRVIP Updated Jet Pump Beam Inspection and Flaw Evaluation Guidelines The licensee stated that where guidance in existing BWRVIP documents has been supplemented or revised by subsequent correspondence approved by the BWRVIP Executive Committee, the most current approved guidance will be implemented.
In its submittal dated April 19, 2007, the licensee provided a table comparing the ASME Code,Section XI, Category B-N-1 and B-N-2 examination requirements to the current BWRVIP Guideline examination criteria. In Attachment B of the April 19, 2007, submittal, the licensee provided a discussion comparing the requirements in ASME Code Item Nos. B13.10, B13.20, B13.30, and B13.40 in Table IWB-2500-1 to the examination criteria in the BWRVIP for the following RVI components:
Core Spray Internals Jet Pump Core Shroud Core Shroud Support and Core Support Structure The licensee stated that these examples demonstrated that the inspection techniques that are recommended by the BWRVIP inspection guidelines are superior to the inspection techniques mandated by the ASME Code,Section XI ISI program. Additionally, according to the licensee, these examples proved that the BWRVIP inspection guidelines call for more frequent inspections of the RVI components than do the corresponding ASME Code,Section XI ISI program. The licensee claimed that by implementing the BWRVIP inspection guidelines, the aging degradation of the RVI components can be identified in a timely manner so that proper corrective action can be taken to restore the integrity of the applicable RVI component.
Therefore, the licensee concluded that implementation of the BWRVIP inspection guidelines provides an acceptable level of quality and safety. The licensees proposed alternatives for the RVI components and subcomponents covered under the scope of this alternative request are summarized in Attachment 1 of this SE.
4.0 NRC STAFF EVALUATION The NRC staff reviewed the licensees letter dated April 19, 2007, containing the BWRVIP inspection guidelines that the licensee proposed as alternatives to the ISI requirements of the ASME Code. The NRC staff has previously reviewed and issued SEs on several BWRVIP guidelines. The NRC staff reviewed those BWRVIP inspection guidelines the licensee proposed as alternatives in its April 19, 2007, letter and found that the NRC staff has previously issued SEs approving each of the referenced generic BWRVIP inspection guidelines, with the exception of BWRVIP-41, Revision 1. The NRC staff also verified that any conditions identified in the approved staff SEs for use of the BWRVIP inspection guidelines were satisfactorily addressed by the licensee in its application for this request for relief. References to the NRC staff SEs approving the generic BWRVIP inspection guidelines are contained in Section 6.0 of this SE. Due to the proprietary content of the applications, some of the SEs are not publically available.
During its review of the licensees request for relief, the NRC staff identified some issues which required additional information from the licensee. By letter dated September 5, 2007, the NRC staff requested additional information on certain inspection requirements and inspection frequencies that formed the basis for the relief requests. In its letters dated October 5, 2007, January 8 and April 4, 2008, the licensee responded to the information requests. The NRC staff reviewed the licensees responses and found them to be acceptable. In one instance, however, additional clarification, as documented below, was needed.
Request for additional information (RAI) (9) addressed future inspection strategies for the top guide grid beams that are prone to irradiation-assisted stress corrosion cracking (IASCC). The threshold neutron (n) fluence limit for the occurrence of IASCC in RVI components is 5 x 1020 n/cm2 (E > 1 MeV). Top guide grid beams are more susceptible to IASCC when exposed to a neutron fluence value greater than the threshold limit. In its letter dated October 5, 2007, the licensee stated in responding to RAI (9) that future inspection strategies for the top guide grid beams that are prone to IASCC will be based on the criteria currently being developed by the BWRVIP. In Table 3-2 of the BWRVIP-26 report, the BWRVIP states that a single top guide grid beam failure where neutron fluence exposure exceeds the threshold limit does not have a safety consequence, hence, no inspection is considered necessary. However, as a result of IASCC, multiple cracks were discovered in top guide grid beams at Oyster Creek.
Therefore, the NRC staff is concerned that multiple failures of the top guide grid beams are possible when they are exposed to a neutron fluence value greater than 5 x 1020 n/cm2 (E > 1 MeV), resulting in potential safety consequences. To ensure that cracking in top guide grid beams due to IASCC will be identified in a timely manner, the NRC staff recommends that licensees inspect certain locations of the top guide grid beams during the applicable ISI interval when their exposure exceeds the threshold limit.
The following BWR units have renewed their operating licenses. To address the issue of IASCC of top guide grid beams, the licensee has already made the following commitments that have been documented in NRC staff-approved license renewal SEs:
Commitment # 9 - NUREG-1875, Safety Evaluation Report Related to the License Renewal of Oyster Creek Generation Station (Oyster Creek), (ADAMS Accession Nos.
ML071290023 and ML071310246)
Commitment # 9 - NUREG-1796, Safety Evaluation Report Related to the License Renewal of Dresden Nuclear Power Station (DNPS), Units 2 and 3 and Quad Cities Nuclear Power Station (QCNPS), Units 1 and 2, (ADAMS Accession Nos.
ML043060582 and ML043060584)
Commitment # 8 - NUREG-1769, Safety Evaluation Report Related to the Peach Bottom Atomic Power Station (PBAPS), (ADAMS Accession Nos. ML031010042, ML031010053, and ML031010127)
To maintain consistency regarding the top guide grid beam inspections, the NRC staff determined that similar inspections at the licensees other BWR units (i.e., CPS, LSCS, and Limerick) should be conducted during the current ISI interval when their top guide grid beams exposure exceeds the IASCC threshold limit. In a letter dated April 4, 2008, the licensee stated that it will perform inspections on the top guide grid beams at CPS, LSCS, and Limerick when their exposure exceeds the IASCC threshold limits. For LSCS and Limerick, the licensee proposes to inspect 10 percent of the top guide grid beams every 12 years with at least 5 percent to be inspected within six years once the limit is reached. For the CPS unit, inspection of the rim areas containing the weld and the heat affected zone from the top surface of the top guide and two cells in the same axis/plane as the weld will be performed every 6 years. The inspection method will be either enhanced visual examination (EVT-1) or ultrasonic examination (UT). The NRC staff reviewed the licensees response and agrees that the inspection methods and the frequency of inspections are consistent with the aforementioned commitments made in
the NRC staff-approved SEs for the license renewals of Oyster Creek, DNPS, QCNPS, and PBAPS, and will identify IASCC of the top guide grid beams in a timely manner. The NRC staff, therefore, considers that its concern regarding the RAI (9) is resolved.
In summary, the NRC staff has verified that an NRC-staff SE has been issued for each of the BWRVIP inspection guidelines referenced as a proposed alternative for this relief request except for BWRVIP-41, Revision 1, and that, in each case, the NRC staff SE determined that the BWRVIP inspection guideline criteria would identify degradation of the RVI components in a timely manner. Therefore, the NRC staff concludes that the proposed alternatives will ensure that the integrity of the RVI components will be maintained with an acceptable level of quality and safety.
It should be noted that the BWRVIP executive committee withdrew its request to have the NRC staff review the BWRVIP-41, Revision 1 report so that it could update the document to include additional guidance related to jet pump component inspections (See ADAMS Accession No. ML072010091). Therefore, the NRC staff cannot authorize those portions of the licensees request for which the proposed alternative is based on BWRVIP-41, Revision 1. For the jet pump components where this alternative was proposed, the licensee must continue to implement the ASME Code,Section XI ISI requirements. BWRVIP-138 was also mentioned by the licensee in its letter dated October 5, 2007, but the licensee did not cite the inspection guideline as a proposed alternative for any specific Section XI ISI requirement. Accordingly, while the BWRVIP executive committee also withdrew this report from NRC consideration, that action does not affect the NRC staffs conclusions concerning the present RR.
of this SE summarizes the BWRVIP inspection guidelines authorized by the NRC staff as proposed alternatives for ASME Code-required inspections, identifying the RVI components, the applicable ASME Code,Section XI examination requirements, and BWRVIP inspection guideline criteria authorized as alternatives.
In the event the licensee wishes to take exceptions to, or deviations from, the NRC staff-approved BWRVIP inspection guidelines authorized as proposed alternatives, the licensee must revise and resubmit its request for authorization to use the proposed alternative under 10 CFR 50.55a.
The NRC staff acknowledges that the BWRVIP executive committee periodically revises the BWRVIP guidelines to include enhancements in inspection techniques and flaw evaluation methodologies. While the licensee may choose to implement enhancements described in a revised version of a BWRVIP inspection guideline, the licensee must continue to also meet the requirements of the version of the BWRVIP inspection guideline that forms the safety basis for an NRC-authorized proposed alternative to the requirements of 10 CFR 50.55a, until the end of the NRC-approved alternatives authorized duration, or until it is superseded by a new NRC-approved alternative. The license may, of course, also choose to return to complying with the inspection requirements of the ASME Code of Record for any or all units.
5.0 CONCLUSION
Based on the information provided in the licensee's submittals, the NRC staff concludes that the proposed alternatives summarized in Attachment 1 to this SE will ensure that the integrity of the RVI components are maintained with an acceptable level of quality and safety. However, the
NRCs conclusion does not include authorization of the requested alternatives which apply to the inspection of jet pump assembly components based on the provisions of BWRVIP-41, Revision 1 and BWRVIP-138. The licensees requested alternatives based on these topical reports are not authorized.
Pursuant to 10 CFR 50.55a(a)(3)(i), the NRC staff authorizes the licensees proposed alternatives described in Attachment 1, for CPS, DNPS, LSCS, Limerick, Oyster Creek, PBAPS, and QCNPS, on the basis that they provide an acceptable level of quality and safety. The alternatives authorized herein are effective for a duration that coincides with the applicable 10-year inspection intervals for each unit that is specified in Attachment 2. All other requirements of the ASME Code,Section XI for which an alternative has not been specifically requested and approved by the NRC remain applicable, including third party review by the Authorized Nuclear Inservice Inspector.
6.0 PREVIOUSLY ISSUED NRC STAFF SAFETY EVALUATIONS Final Safety Evaluation of BWR Core Spray Internals Inspection and Flaw Evaluation Guidelines (BWRVIP-18), December 2, 1999 (ADAMS Accession No. ML081160166, non-public).
Final Safety Evaluation of BWRVIP Vessel and Internals Project, BWR Core Plate Inspection and Flaw Evaluation Guidelines (BWRVIP-25), December 19, 1999 (ADAMS Accession Nos.
ML993620267 and ML993620274, non-public).
Final Safety Evaluation of BWR Vessel and Internals Project, BWR Top Guide Inspection and Flaw Evaluation Guidelines (BWRVIP-26), September 29, 1999 (ADAMS Accession No. ML081160165, non-public).
Safety Evaluation of the BWRVIP Vessel and Internals Project, BWR Standby Liquid Control System / Core Plate Inspection Delta-P and Flaw Evaluation Guidelines (BWRVIP-27), June 9, 2004 (ADAMS Accession No. ML081160167, non-public).
Final Safety Evaluation of the BWR Vessel And Internals Project, BWR Shroud Support Inspection and Flaw Evaluation Guidelines (BWRVIP-38), July 24, 2000 (ADAMS Accession No. ML003735498).
Final Safety Evaluation of the BWRVIP Vessel and Internals Project, BWR Vessel and Internals Project, LPCI Coupling Inspection and Flaw Evaluation Guidelines (BWRVIP-42),
May 26, 2000 (ADAMS Accession No. ML003719695).
Final Safety Evaluation of BWR Vessel and Internals Project, BWR Lower Plenum Inspection and Flaw Evaluation Guidelines (BWRVIP-47), October 13, 1999 (ADAMS Accession No. ML081160164, non-public).
Final Safety Evaluation of BWR Vessel and Internals Project, Vessel ID Attachment Weld Inspection and Flaw Evaluation Guidelines (BWRVIP-48), September 29, 1999 (ADAMS Accession No. ML081160163, non-public).
Safety Evaluation of Proprietary EPRI Report, "BWR Vessel and Internals Project, BWR Core Shroud and Inspection and Flaw Evaluation Guidelines (BWRVIP-76)," July 28, 2006 (ADAMS Accession No. ML062140594, non-public).
Principle Contributor: G. Cheruvenki, NRR Date: April 30, 2008
ATTACHMENT 1 Summary of ASME Category B-N-1 and B-N-2 Requirements With BWRVIP Guidance Requirements (1)
ASME Item No.
Table IWB-2500-1 Component ASME Exam Scope ASME Exam ASME Frequency Authorized Alternative BWRVIP Exam Scope BWRVIP Exam BWRVIP Frequency B13.10 Reactor Vessel Interior Accessible Areas (Non-specific)
VT-3 Each period BWRVIP-18-A, 25, 26-A, 27-A, 38, 42-A, 47-A, 48-A, and 76 Overview examinations of components during BWRVIP examinations satisfy Code VT-3 inspection requirements.
Interior Attachments Within Beltline - Jet Pump Riser Braces BWRVIP-48-A Table 3-2 Riser Brace Attachment EVT-1 100% in first 12 years (with 50% to be inspected in the first 6 years); 25% during each subsequent 6 years B13.20 Lower Surveillance Specimen Holder Brackets Accessible Welds VT-1 Each 10-year Interval BWRVIP-48-A Table 3-2 Bracket Attachment VT-1 Each 10-year Interval
ATTACHMENT 1 (cont.)
ASME Item No.
Table IWB-2500-1 Component ASME Exam Scope ASME Exam ASME Frequency Authorized Alternative BWRVIP Exam Scope BWRVIP Exam BWRVIP Frequency Interior Attachments Beyond Beltline - Steam Dryer Hold-down Brackets BWRVIP-48-A Table 3-2 Bracket Attachment VT-3 Each 10-year Interval Guide Rod Brackets BWRVIP-48-A Table 3-2 Bracket Attachment VT-3 Each 10-year Interval Steam Dryer Support Brackets BWRVIP-48-A Table 3-2 Bracket Attachment EVT-1 Each 10-year Interval Feedwater Sparger Brackets BWRVIP-48-A Table 3-2 Bracket Attachment EVT-1 Each 10-year Interval Core Spray Piping Brackets BWRVIP-48-A Table 3-2 Bracket Attachment EVT-1 Every 4 Refueling Cycles Upper and Middle Surveillance Specimen Holder Brackets BWRVIP-48-A Table 3-2 Bracket Attachment VT-3 Each 10-year Interval Shroud Support (Weld H9) including gussets where applicable BWRVIP-38, 3.1.3.2 Figures 3-2 and 3-5 Weld H9 EVT-1 or UT Maximum of 6 years for one sided EVT-1, Maximum of 10 years for UT B13.30 Weld H12 Shroud Support Legs Accessible Welds Rarely Accessible VT-3 Each 10-year Interval BWRVIP-38, 3.2.3 Weld H12 Per BWRVIP-38 NRC SER (7-24-2000) inspect with appropriate method (4)
When accessible
ATTACHMENT 1 (cont.)
ASME Item No.
Table IWB-2500-1 Component ASME Exam Scope ASME Exam ASME Frequency Authorized Alternative BWRVIP Exam Scope BWRVIP Exam BWRVIP Frequency Integrally Welded Core Support Structure - Shroud Support BWRVIP-38 3.1.3.2, Figures 3-2 and 3-5 Shroud Support and Leg Welds including Gussets as applicable EVT-1 or UT Based on as found conditions, to a maximum 6 years for one-sided EVT-1, 10 years for UT Shroud Horizontal Welds BWRVIP-76 2.2.1 Welds H1-H7 as applicable EVT-1 or UT Based on as found conditions, to a maximum 6 years for one-sided EVT-1, 10 years for UT Shroud Vertical Welds BWRVIP-76 2.3, Figure 3-3 Vertical and Ring Segment Welds as applicable EVT-1 or UT Maximum 6 years for one-sided EVT-1, 10 years for UT B13.40 Shroud Repairs (3)
Accessible Surfaces VT-3 Each 10-year Interval BWRVIP-76 Section 3.5 Tie-Rod Repair VT-3 Per designer recommendations per BWRVIP-76 Note (1) This Table provides only an overview of the requirements. For more details, refer to the ASME Code,Section XI, Table IWB-2500-1, and the appropriate BWRVIP document.
Note (2) In accordance with Appendix A of BWRVIP-38, a site specific evaluation will determine the minimum required weld length to be examined.
Note (3) Shroud repairs are currently installed on both units at Dresden and Quad Cities, and on single units at Oyster Creek and Clinton.
Note (4) When inspection tooling and methodologies are available, they will be utilized to establish a base line inspection of these welds.
ATTACHMENT 2 APPLICABLE CODE EDITION AND ADDENDA PLANT INTERVAL EDITION START END Clinton Power Station Second 1989 Edition, no addenda January 1, 2000 December 31, 2010 Dresden Nuclear Power Station, Units 2 and 3 Fourth 1995 Edition, though 1996 Addenda January 20, 2003 January 19, 2013 LaSalle County Station Units 1 and 2 Third 2001 Edition, through 2003 Addenda October 1, 2007 September 30, 2017 Limerick Generating Station, Units 1 and 2 Third 2001 Edition, through 2003 Addenda February 1, 2007 January 31, 2017 Oyster Creek Generating Station Fourth 1995 Edition, though 1996 Addenda October 15, 2002 October 14, 2012 Peach Bottom Atomic Power Station Unit 2 Fourth 2001 Edition, through 2003 Addenda (Final edition to be determined)
November 5, 2008 November 4, 2018 Peach Bottom Atomic Power Station Unit 3 Fourth 2001 Edition, through 2003 Addenda (Final edition to be determined)
August 15, 2008 August 14, 2018 Quad Cities Nuclear Power Station, Units 1 and 2 Fourth 1995 Edition, though 1996 Addenda March 10, 2003 March 9, 2013