ML071230040
| ML071230040 | |
| Person / Time | |
|---|---|
| Site: | River Bend  |
| Issue date: | 05/17/2007 |
| From: | Hiltz T NRC/NRR/ADRO/DORL/LPLIV |
| To: | Burford F Entergy Operations |
| Vaidya B, NRR/DORL/LP4, 415-3308 | |
| References | |
| TAC MD3442 | |
| Download: ML071230040 (8) | |
Text
May 17, 2007 Mr. F. G. Burford Acting Director Nuclear Safety & Licensing Entergy Operations, Inc.
1340 Echelon Parkway Jackson, MS 39213-8298
SUBJECT:
RIVER BEND STATION, UNIT 1 - REQUEST FOR ALTERNATIVE RBS-ISI-005, RE: EXTENDING THE CURRENT INSERVICE INSPECTION INTERVAL IN ACCORDANCE WITH U.S. NUCLEAR REGULATORY COMMISSION INFORMATION NOTICE 98-44 (TAC NO. MD3442)
Dear Mr. Burford:
By letter dated November 1, 2006, as supplemented by letter dated February 14, 2007, Entergy Operations, Inc. (Entergy or the licensee), pursuant to Title 10 of the Code of Federal Regulations (10 CFR) 50.55a(a)(3)(i), submitted Request for Alternative RBS-ISI-005, which would extend the second inservice inspection (ISI) interval for Class 1 and 2 piping welds in Examination Categories B-J, C-F-1, and C-F-2 at River Bend Station, Unit 1 (RBS) to the end of its fifteenth refueling outage currently scheduled for spring 2009.
The Nuclear Regulatory Commission (NRC) staff has reviewed the subject request, and concluded that the proposed alternative provides an acceptable level of quality and safety.
Therefore, the NRC staff authorizes the proposed alternatives in accordance with 10 CFR 50.55a(a)(3)(i) and extends the second ISI interval for Class 1 and 2 piping welds in Examination Categories B-J, C-F-1, and C-F-2 at RBS to the end of its fifteenth refueling outage currently scheduled for spring 2009.
The NRC staff's Safety Evaluation is enclosed.
Sincerely,
/RA/
Thomas G. Hiltz, Chief Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-458
Enclosure:
Safety Evaluation cc w/encl: See next page
- No substantial change from SE Input Memo **Previously concurred OFFICE NRR/LPL4/PM NRR/LPL4/LA NRR/CPNB/BC OGC-NLO w/comments NRR/LPL4/BC NAME BVaidya JBurkhardt TChan*
BKlukan**
THiltz DATE 5/16/07 5/16/07 4/24/07 5/15/07 5/17/07
November 2006 River Bend Station cc:
Manager, Licensing Entergy Operations, Inc.
River Bend Station 5485 US Highway 61N St. Francisville, LA 70775 Director, Nuclear Safety & Licensing Entergy Operations, Inc.
1340 Echelon Parkway Jackson, MS 39213-8298 Louisiana Department of Environmental Quality Radiological Emergency Planning and Response Division P.O. Box 4312 Baton Rouge, LA 70821-4312 Louisiana Department of Environmental Quality Office of Environmental Compliance P.O. Box 4312 Baton Rouge, LA 70821-4312 Senior Resident Inspector P.O. Box 1050 St. Francisville, LA 70775 President of West Feliciana Police Jury P.O. Box 1921 St. Francisville, LA 70775 Regional Administrator, Region IV U.S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011-8064 Ms. H. Anne Plettinger 3456 Villa Rose Drive Baton Rouge, LA 70806 Executive Vice President and Chief Operating Officer Entergy Operations, Inc.
P.O. Box 31995 Jackson, MS 39286-1995 General Manager Plant Operations Entergy Operations, Inc.
River Bend Station 5485 US Highway 61N St. Francisville, LA 70775 Director, Nuclear Safety Assurance Entergy Operations, Inc.
River Bend Station 5485 US Highway 61N St. Francisville, LA 70775 Vice President, Operations Support Entergy Operations, Inc.
P.O. Box 31995 Jackson, MS 39286-1995 Mr. Jim Calloway Public Utility Commission of Texas 1701 N. Congress Avenue Austin, TX 78711-3326 Attorney General State of Louisiana P.O. Box 94095 Baton Rouge, LA 70804-9095 Brian Almon Public Utility Commission William B. Travis Building P.O. Box 13326 1701 North Congress Avenue Austin, Texas 78701-3326 Richard Penrod, Senior Environmental Scientist/State Liaison Officer Office of Environmental Services Northwestern State University Russsell Hall, Room 201 Natchitoches, LA 71497 Mr. Joseph E. Venable Vice President of Operations Entergy Operations, Inc.
River Bend Station 5485 US Highway 61N St. Francisville, LA 70775
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION REQUEST FOR ALTERNATIVE NO. RBS-ISI-005 TO EXTEND CURRENT INSERVICE INSPECTION INTERVAL ENTERGY OPERATIONS, INC. ET. AL.
RIVER BEND STATION, UNIT 1 DOCKET NO. 50-416
1.0 INTRODUCTION
By letter dated November 1, 2006 (Agencywide Documents Access and Management System (ADAMS) Accession Number ML063120415), as supplemented by letter dated February 14, 2007 (ADAMS Accession Number ML070520353), Entergy Operations, Inc. (Entergy or the licensee), pursuant to Title 10 of the Code of Federal Regulations (10 CFR) 50.55a(a)(3)(i),
requested an alternative to the requirements of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (the ASME Code); the requested alternative (RBS-ISI-005) would extend the second 10-year inservice inspection (ISI) interval for piping at River Bend Station (RBS) by approximately 5 months beyond the 1-year extension allowed by ASME Code,Section XI. The licensee requests to extend the second 10-year ISI interval for RBS to the end of its fifteen refueling outage, currently scheduled for spring 2009, on the basis that the alternative provides an acceptable level of quality and safety. The request does not involve Examination Category B-F piping welds, which are inspected in accordance with Generic Letter 88-01, NRC [Nuclear Regulatory Commission] Position on Intergranular Stress Corrosion Cracking (IGSCC) in BWR [Boiling-Water Reactor] Austenitic Stainless Steel Piping. The requested extension is approximately 5 months beyond the 1-year extension allowed by ASME Code,Section XI, Subsection IWB-2412(b).
2.0 REGULATORY EVALUATION
Pursuant to 10 CFR 50.55a(g), ISI of ASME Code Class 1, 2, and 3 components shall be performed in accordance with the requirements of Section XI of the ASME Code and applicable edition and addenda, except where specific written relief has been granted by the Commission pursuant to 10 CFR 50.55a(g)(6)(i). Paragraph 50.55a(a)(3) of 10 CFR states, in part, that alternatives to the requirements of paragraph (g) may be used, when authorized by the NRC, if the licensee demonstrates that: (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, 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 Inservice Inspection (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 test 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. The Code of record for the second 10-year ISI interval for RBS is the 1992 Edition with portions of the 1993 Addenda applicable to pressure testing of the ASME Code,Section XI. The components (including supports) may meet the requirements set forth in subsequent editions and addenda of the ASME Code incorporated by reference in 10 CFR 50.55a(b) subject to the limitations and modifications listed therein and subject to Commission approval.
Currently, RBS is in its second 10-year ISI interval. In its submission, as supplemented, the licensee stated that it plans to implement a risk-informed/safety-based ISI (RIS_B) program during the third inspection period of the current (second) 10-year ISI interval.
3.0 TECHNICAL EVALUATION
3.1 Description - Request No. RBS-ISI-005 3.1.1 ASME Code,Section XI Components Affected (As Submitted)
Components/Numbers: Piping Welds Code Class: 1 and 2 Examination Category: B-J, C-F-1, and C-F-2 Item Numbers: All
==
Description:==
Piping Welds Unit/Inspection Interval and Applicability:
River Bend Station (RBS) second (2nd) 10-year interval 3.1.2
Applicable Code Edition and Addenda
ASME Code,Section XI, 1992 Edition with portions of 1993 Addenda applicable to pressure testing. Subsection IWA-2430(d) requirements for component inspected under Program B.
ASME Code,Section XI, Table IWB-2412-1, defines an ISI interval to be 10 years in duration.
IWB-2412(b) allows extending the interval for 1 year to coincide with a plant outage.
3.1.3 Proposed Alternative (As Submitted)
Pursuant to 10 CFR 50.55a(a)(3)(i), Entergy Operations, Inc. (Entergy) requests authorization to extend the current ISI interval to include an additional refueling outage, which will be the fifteenth refueling outage (RF-15) currently scheduled for spring 2009
[approximately 5 months beyond the Code-allowed 1-year extension] for items in Examination Categories B-J, C-F-I, and C-F-2.
3.1.4 Licensee Basis for Alternative (As Submitted)
NRC Information Notice (IN) 98-44, Ten-Year Inservice Inspection Program Update for Licensees that Intend to Implement RI-ISI of Piping (Reference 2), states that the probabilistic risk assessment technology in NRC regulatory activities should be increased to the extent supported by state-of-the-art methods and data and in a manner that complements the NRC's deterministic approach. Basically, this information combined with risk assessment techniques and associated data provides for developing an effective approach to the ISI program. This approach provides an acceptable level of quality and safety, as required by 10 CFR 50.55a(a)(3)(i). IN 98-44 also states that the NRC staff will consider authorizing a delay of up to 2 years in implementing the next 10-year ISI program for piping only in order for the licensee to develop and obtain approval for the risk-informed ISI program for piping.
RBS is currently in the second ISI interval as defined by ASME Section XI Code for Inspection Program B. RBS is planning to submit to the NRC staff a request for alternative to implement a risk-informed/safety-based inservice inspection (RIS_B) program. Entergy plans to implement the RIS_B ISI program during RF-15 currently scheduled for the spring 2009. To accomplish this, Entergy requires approval of this request to extend the second ISI interval to the end of RF-15 (approximately 5 months beyond the Code-allowed [1]-year extension).
The RBS RIS_B process will be based upon ASME Code Case N-716, Alternative Piping Classification and Examination Requirements, Section Xl Division 1, which is founded in large part on the RI-ISI process as described in Electric Power Research Institute (EPRI) Topical Report (TR) 112657 [Revision] B-A, "Revised Risk-Informed Inservice Inspection Evaluation Procedure." The associated request for alternative will demonstrate a reduction in risk (or maintains risk neutrality) while substantially reducing worker exposure and undue burden. Because risk-informed ISI programs focus inspections (and inspection methods) on locations potentially susceptible to degradation while considering the consequence of piping failure, a more robust targeted inspection program can be defined.
3.2 Evaluation The NRC staff has reviewed the relief request alternative RBS-ISI-005 submitted in the licensees letter dated November 1, 2006, as supplemented by letter dated February 14, 2007, for the third period of the second 10-year ISI interval of RBS pertaining to Class 1 and 2 piping welds in Examination Categories B-J, C-F-1, and C-F-2. The licensee requested approval to extend its ISI interval for piping to the end of RBS's fifteenth refueling outage (RF-15), currently scheduled for spring 2009. The requested extension would extend approximately 5 months beyond the 1-year extension allowed by ASME Code,Section XI, Subsection IWA-2430(d).
NRC IN 98-44, Ten-Year Inservice Inspection (ISI) Program Update for Licensees that Intend to Implement Risk-Informed ISI of Piping, states that for licensees who intend to implement an RI-ISI program for piping per the guidance provided in IN 98-44, the staff will consider authorizing a delay of up to 2 years in the ISI interval for piping, so as to provide adequate time for the licensee to develop and obtain approval for the Risk-Informed ISI program regarding piping. RBS's second 10-year ISI interval began December 1997 and ends November 2007.
With the requested extension, the second interval would end following the completion of RBS's fifteenth refueling outage (RF-15), which is currently scheduled for the spring 2009 (approximately 5 months beyond the Code-allowed 1-year extension). RBS is currently in the third period of the second ISI interval. RBS has stated that it is planning to submit to the NRC staff, a request to implement a risk-informed/safety-based inservice inspection (RIS_B) program, to be implemented during RF-15. The RBS's RIS_B program will be based on Code Case N-716, which is similar to the RI-ISI process as described in the NRC-approved EPRI TR-112657, Revision B-A. It is expected that the alternative will demonstrate a reduction in risk (or maintain risk neutrality) while substantially reducing worker exposure and undue inspection burden. The RIS_B program will be designed to focus its inspections on locations that are potentially susceptible to degradation, while also considering the consequences of piping failure.
The licensee stated that by the end of the last refueling outage (RF-13), 75 percent of the piping weld examinations required by ASME Section Xl had been completed in the second ISI interval for Examination Categories B-F, B-J, C-F-I, and C-F-2. Therefore, RBS has met the minimum requirement specified in Table IWB-2412-1. If alternative RBS-ISI-005 is approved, the remaining percentage of the inspection locations necessary to ensure the 100 percent completion of examinations will be selected for examination per the RIS_B process in the third period of the ISI interval, and performed during RF-15. In the case that the licensees proposed RIS_B program using Code Case N-716 is not approved, the licensee plans to submit a different request for alternative to establish a risk-informed program based on EPRI TR-112657 and ASME Code Case N-578. The third 10-year ISI interval will include examination of the 100 percent of the inspection locations selected for examination per an approved RIS_B Program. Furthermore, the licensee will continue to perform required augmented inspection programs as committed to the staff in various correspondence. Augmented inspections pertaining to intergranular stress-corrosion cracking are scheduled to be performed during RF-14.
The NRC staff concludes that extending RBS's second 10-year ISI interval to the end of its RF-15, so as to provide adequate time for the licensee to develop and obtain approval for the Risk-Informed ISI program regarding piping, will provide an acceptable level of quality and safety because:
1.
A significant percentage of the required examinations for the second 10-year ISI interval have been completed and no problems thus far have been identified.
2.
Piping weld examinations will be performed in the third period of the interval regardless of whether the licensee's to-be-requested RIS_B program is approved by the NRC staff.
3.
The requested extension is consistent with the criteria identified in IN 98-44.
4.
The delay requested in alternative RBS-ISI-005 will be a one-time occurrence, for the purpose of developing a Risk-Informed ISI program for piping as outlined above, and should not affect future ISI intervals.
4.0 CONCLUSION
Based on the information provided in the licensees relief request for alternative RBS-ISI-005, dated November 1, 2006, as supplemented by letter dated February 14, 2007, and in light of the licensee's planned request for alternative RIS_B program, based on ASME Code Case N-716, the NRC staff has determined that extending RBSs second 10-year ISI interval to include an additional refueling outage (approximately 5 months beyond the Code-allowed 1-year extension) would provide an acceptable level of quality and safety. Therefore, pursuant to 10 CFR 50.55a(a)(3)(i), the NRC staff authorizes the licensee to extend RBS's second (current) 10-year ISI interval for piping in Examination Categories B-J, C-F-1, and C-F-2 to the end of its fifteenth refueling outage, currently scheduled for spring 2009.
All other requirements of the ASME Code,Section XI, for which relief was not specifically requested and authorized herein by the NRC staff, remain applicable, including third-party review by the Authorized Nuclear Inspector.
5.0 REFERENCES
1.
ASME Code,Section XI, 1992 Edition with portions of 1993 Addenda.
2.
NRC IN 98-44, Ten-Year Inservice Inspection (ISI) Program Update for Licensees that Intend to Implement Risk-Informed ISI of Piping.
Principal Contributors: A. Keim, CPNB Date: May 17, 2007