ML071380183
| ML071380183 | |
| Person / Time | |
|---|---|
| Site: | Duane Arnold  |
| Issue date: | 06/12/2007 |
| From: | Travis Tate NRC/NRR/ADRO/DORL/LPLIII-1 |
| To: | Vanmiddlesworth G Nuclear Management Co |
| Feintuch K, NRR/DORL/LPL3-1, 415-3079 | |
| References | |
| TAC MD2520, TAC MD2523 | |
| Download: ML071380183 (12) | |
Text
June 12, 2007 Mr. Gary Van Middlesworth Site Vice President Duane Arnold Energy Center 3277 DAEC Road Palo, IA 52324-9785
SUBJECT:
DUANE ARNOLD ENERGY CENTER - SAFETY EVALUATION OF RELIEF REQUESTS NDE-R004 AND NDE-R007 FOR THE FOURTH 10-YEAR INTERVAL OF THE INSERVICE INSPECTION PROGRAM (TAC NOS. MD2520 AND MD2523)
Dear Mr. Van Middlesworth:
By letter dated June 30, 2006, as supplemented by letters (2) dated December 21, 2006, FPL Energy Duane Arnold, LLC (FPL Energy) submitted requests for relief from the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (Code),Section XI requirements for the Duane Arnold Energy Center (DAEC). The subject relief requests are for the fourth 10-year inservice inspection (ISI) interval at DAEC, which began on November 1, 2006. The letter of June 30, 2006, addressed relief requests NDE-R001, NDE-R002, NDE-R003, NDE-R004, NDE-R005, NDE-R006, NDE-R007, and NDE-R008.
The U.S. Nuclear Regulatory Commission (NRC) staff has completed its review of relief requests NDE-R004 and NDE-R007, as documented in the enclosed safety evaluation (SE),
and concludes the following:
1)
With respect to relief request NDE-R004, regarding the proposed alternative to use ASME Code Case N-700 for welded attachments on vessels provides an acceptable level of quality and safety. Therefore, the licensees proposed alterative is authorized pursuant to 10 CFR 55.55a(a)(3)(i) for the fourth 10-year ISI interval at DAEC or until ASME Code Case N-700 is approved for general use by reference in Regulatory Guide 1.147 Inservice Inspection Code Case Acceptability, ASME Section XI, Division 1, whichever event occurs first. If and when ASME Code Case N-700 is so approved, the licensee must follow the conditions, if any are specified, in Regulatory Guide 1.147 to continue the use of Code Case N-700.
2)
With respect to relief request NDE-R007, regarding the examination of the buried portion of service water piping, compliance with the Code requirement to perform a test that determines the rate of pressure loss or the change in flow would result in hardship to FPL Energy without a compensating increase in the level of quality and safety. FPL Energys proposed alternative provides reasonable assurance of operational readiness.
Therefore, pursuant to 10 CFR 50.55a(a)(3)(ii), the proposed alternative is authorized for the fourth 10-year ISI interval at DAEC.
G. Van Middlesworth All other ASME Code,Section XI requirements for which relief was not specifically requested and approved in these relief requests remain applicable, including third-party review by the authorized Nuclear Inservice Inspector.
Previously, in its letter of January 31, 2007 (ADAMS Accession No. ML070090357), the NRC staff completed its review of relief requests NDE-R001, NDE-R002, NDE-R005, NDE-R006, and NDE-R008, contained in FPL Energys letter dated June 30, 2006, as supplemented by a letter dated December 21, 2006.
In addition, as noted in your letter dated June 30, 2006, relief request NDE-R003 was approved as relief request NDE-R047 by the NRC staff in a SE dated January 6, 2005. Your letter stated that the content of relief request NDE-R003 was editorially updated, was included for completeness, and that FPL Energy was not requesting NRC approval of this request.
Accordingly, the NRC did not review relief request NDE-R003.
If you have any questions regarding this matter, please contact Mr. Karl Feintuch at (301) 415-3079.
Sincerely,
/RA/ Patrick Milano for Travis L. Tate, Acting Chief Plant Licensing Branch III-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-331
Enclosure:
Safety Evaluation cc w/encl: See next page
ML070090357), the NRC staff completed its review of relief requests NDE-R001, NDE-R002, NDE-R005, NDE-R006, and NDE-R008, contained in FPL Energys letter dated June 30, 2006, as supplemented by a letter dated December 21, 2006.
In addition, as noted in your letter dated June 30, 2006, relief request NDE-R003 was approved as relief request NDE-R047 by the NRC staff in a SE dated January 6, 2005. Your letter stated that the content of relief request NDE-R003 was editorially updated, was included for completeness, and that FPL Energy was not requesting NRC approval of this request.
Accordingly, the NRC did not review relief request NDE-R003.
If you have any questions regarding this matter, please contact Mr. Karl Feintuch at (301) 415-3079.
Sincerely,
/RA/ Patrick Milano for Travis L. Tate, Acting Chief Plant Licensing Branch III-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-331
Enclosure:
Safety Evaluation cc w/encl: See next page DISTRIBUTION:
PUBLIC RidsAcrsAcnwMailCenter RidsNrrDorlLpl3-1 LPL3-1 Reading RidsRgn3MailCenter TBloomer, EDO Region 3 RidsNrrPMKFeintuch RidsNrrLATHarris PPatnaik RidsOgcRp TMcLellan ADAMS Accession No. ML071380183 OFFICE LPL3-1/PM LPL3-1/LA CPNB/BC CSGB/BC OGC LPL3-1/(A)BC NAME KFeintuch THarris
- MMitchell
- AHiser BKlukan TTate PM for DATE 06/12/07 06/07/07 05/21/07 05/23/07 06/05/07 06/12/07
Duane Arnold Energy Center cc:
Mr. J. A. Stall Senior Vice President, Nuclear and Chief Nuclear Officer Florida Power & Light Company P. O. Box 14000 Juno Beach, FL 33408-0420 Mr. M. S. Ross Managing Attorney Florida Power & Light Company P. O. Box 14000 Juno Beach, FL 33408-0420 Marjan Mashhadi Senior Attorney Florida Power & Light Company 801 Pennsylvania Avenue, NW Suite 220 Washington, DC 20004 Mr. W. E. Webster Vice President, Nuclear Operations South Region Florida Power & Light Company P. O. Box 14000 Juno Beach, FL 33408-0420 John Bjorseth Site Director Duane Arnold Energy Center 3277 DAEC Road Palo, IA 52324 Steven R. Catron Manager, Regulatory Affairs Duane Arnold Energy Center 3277 DAEC Road Palo, IA 52324 U. S. Nuclear Regulatory Commission Resident Inspectors Office Rural Route #1 Palo, IA 52324 Regional Administrator, Region III U.S. Nuclear Regulatory Commission Suite 210 2443 Warrenville Road Lisle, IL 60532-4351 Mr. M. Warner Vice President, Nuclear Operations, North Region Florida Power & Light Company P. O. Box 14000 Juno Beach, FL 33408-0420 Mr. D. A. Curtland Plant Manager Duane Arnold Energy Center 3277 DAEC Rd.
Palo, IA 52324-9785 Mr. R. S. Kundalkar Vice President, Technical Services Florida Power & Light Company P. O. Box 14000 Juno Beach, FL 33408-0420 Daniel K. McGhee Iowa Department of Public Health Bureau of Radiological Health 321 East 12th Street Lucas State Office Building, 5th Floor Des Moines, IA 50319-0075 Chairman, Linn County Board of Supervisors 930 1st Street SW Cedar Rapids, IA 52404 May 4, 2007
ENCLOSURE SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO RELIEF REQUESTS FOR THE FOURTH 10-YEAR INTERVAL OF THE INSERVICE INSPECTION PROGRAM FPL ENERGY DUANE ARNOLD, LLC DUANE ARNOLD ENERGY CENTER DOCKET NO. 50-331
1.0 INTRODUCTION
By letter dated June 30, 2006 (Reference 1), as supplemented by a letter dated December 21, 2006 (Reference 2), FPL Energy Duane Arnold, LLC (FPL Energy, the licensee) submitted requests for relief from the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (Code),Section XI requirements for the Duane Arnold Energy Center (DAEC). The subject relief requests are for the fourth 10-year inservice inspection (ISI) interval at DAEC, which began on November 1, 2006.
In relief request NDE-R004 the licensee proposed to use ASME Code Case N-700 Alternative Rules for Selection and Class 1, 2, and 3 Vessel Welded Attachments for Examinations,Section XI, Division 1 in lieu of the requirements specified in the ASME Code,Section XI for Class 1, 2, and 3 vessel welded attachments. ASME Code Case N-700 was approved by the ASME Code Committee on November 18, 2003.
In relief request NDE-R007, the licensee requested relief from performing the ASME-required pressure test of the buried portion of service water piping that consisted of either the measurement of the rate of the pressure loss or the measurement of the change in flow between the ends of the buried components. The licensee stated that the isolation valves that are used for measuring rate of pressure loss are not suitable for performing pressure isolation function and there is no flow instrumentation upstream of the buried piping. Alternatively, the licensee proposed a test that will confirm that flow during operation is not impaired. The integrity of the buried piping will be verified during quarterly pump testing under the inservice testing program for pumps and valves. In addition, the licensee proposed to perform visual examination of the ground surface immediately above each buried section, after the subject piping has been in operation for at least 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, once per refueling cycle.
2.0 REGULATORY EVALUATION
The ISI of the ASME Code Class 1, 2, and 3 components is to be performed in accordance with Section XI of the ASME Code and applicable edition and addenda as required by Title 10 of the Code of Federal Regulations (10 CFR) Section 50.55a(g), except where specific written relief has been granted by the U.S. Nuclear Regulatory Commission (NRC) pursuant to 10 CFR 50.55a(g)(6)(i). Pursuant to 10 CFR 50.55a(a)(3), 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, and 3 components (including supports) must 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 of Nuclear Power Plant Components, to the extent practical within the limitations of design, geometry, and materials of construction of the components. The regulation requires 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) 12 months prior to the start of the 120-month interval, subject to the limitations and modifications listed therein.
The applicable ASME Code of record for the fourth 10-year ISI interval at DAEC is the ASME Code,Section XI, 2001 Edition with Addenda through 2003.
3.0 TECHNICAL EVALUATION
3.1 Relief Request NDE-R004 3.1.1 Components for Which Relief NDE-R004 is Requested ASME Code Class 1, 2, and 3: Vessel Welded Attachments
References:
(1)
Table IWB-2500-1, Examination Category B-K, Footnote 4; (2)
Table IWC-2500-1; Examination Category C-C, Footnote 4; and (3)
Table IWD-2500-1, Examination Category D-A, Footnote 3 of the 2001 Edition, 2003 Addenda of ASME Code,Section XI ASME Code Examination Categories: B-K, C-C, D-A ASME Code Item Numbers: B10.10, C3.10, D1.10 3.1.2 ASME Code Requirements Pertaining to NDE-R004 ASME Code,Section XI, Table IWB-2500-1, Examination Category B-K, Footnote 4 and Table IWC-2500-1, Examination Category C-C, Footnote 4 state that for multiple vessels of similar design, function, and service, only one of the multiple vessels shall be selected for a surface examination.
ASME Code,Section XI, Table IWD-25001, Examination Category D-A, Footnote 3 states that selected samples of welded attachments shall be examined each inspection interval. All welded attachments selected for examination shall be those most subject to corrosion, as determined by the owner, such as the welded attachments of the service water or emergency service water (ESW) systems. For multiple vessels of similar design, function, and service, the welded attachments of only one of the multiple vessels shall be selected for examination. For welded attachments of piping, pumps, and valves, a 10 percent sample shall be selected for examination. This percentage sample shall be proportional to the total number of nonexempt welded attachments connected to the piping, pumps, and valves in each system subject to these examinations.
3.1.3 Licensees Proposed Alternative Examination The licensee proposed to use ASME Code Case N-700, Alternative Rules for Selection and Class 1, 2, and 3 Vessel Welded Attachments for Examinations,Section XI, Division 1 in lieu of the requirements specified in the ASME Code,Section XI for Class 1, 2, and 3 vessel welded attachments. ASME Code Case N-700 was approved by the ASME Code Committee on November 18, 2003.
3.1.4 Licensees Basis for Relief Request NDE-R004 (As provided by the licensee)
[ASME] Code Case N-509, Alternative Rules for the Selection and Examination of Class 1, 2, and 3 Integrally Welded Attachments,Section XI, Division 1, was incorporated in the 1995 Edition, 1995 Addenda of ASME Section XI. The technical basis for development of [ASME] Code Case N-509 concluded that operational transients/water hammers [were] the major potential for welded attachment failures ([the] possibility exists for corrosion related failures). The technical basis of [ASME] Code Case N-509 also concluded that welded attachment failures have been identified as a result of connected support member deformation and had not been identified by the [ASME Code] Section XI examinations. This is the basis for [ASME] Code Case N-509 and the 1995 Addenda, and later addenda, which require welded attachments to be examined whenever component support deformation is identified. In addition, a sampling plan for welded attachments was maintained. [ASME Code Case N-509 and the ASME Code, Section XI]
2001 Edition through 2003 Addenda require in Examination Categories B-K and C-C that For multiple vessels of similar design, function and service, only one welded attachment of only one of the multiple vessels shall be selected for examination. There is no criterion for selection of the one welded attachment that must be examined. [ASME]
Code Case N-509 and the [ASME Code,Section XI 2001 Edition through] 2003 Addenda do not specifically address selection criteria for single vessels.
[ASME] Code Case N-700 utilizes the basis for development of [ASME] Code Case N-509 to provide criteria for selection of [ASME Code] Class 1, 2, and 3 [vessel] welded attachments for examination. [ASME] Code Case N-700 requires that for multiple vessels of similar design, function and service, only one welded attachment of only one of the multiple vessels shall be selected for examination. [ASME Code Case N-700]
requires that only one welded attachment on a single vessel be examined. However,
[ASME Code Case N-700] also requires that the attachment selected for examination on one of the multiple vessels or the single vessel, as applicable, be an attachment under continuous load during normal system operation if such an attachment exists or an attachment subject to a potential intermittent load during normal system operation if an attachment under continuous load does not exist.
3.1.5 NRC Staffs Evaluation of Relief Request NDE-R004 The 2001 Edition through the 2003 Addenda of ASME Code,Section XI, Table IWB-2500-1, Examination Category B-K, Footnote 4; Table IWC-2500-1, Examination Category C-C, Footnote 4; and Table IWD-2500-1, Examination Category D-A, Footnote 3. Footnote 4 and Footnote 3 requirements are as cited in Section 3.1.1 of this safety evaluation.
As an alternative to the ASME Code requirements, the licensee proposed to invoke ASME Code Case N-700 for the selection of Class 1, 2, and 3 vessel welded attachments for examination.
ASME Code Case N-700 requires that for multiple vessels of similar design, function, and service, only one welded attachment of only one of the multiple vessels shall be selected for examination. In addition, ASME Code Case N-700 requires that only one welded attachment on a single vessel is to be examined. The attachment selected for examination on one of multiple vessels or a single vessel, as applicable, is to be an attachment under continuous load during operation.
ASME Code Case N-700 utilizes the basis for development of ASME Code Case N-509. ASME Code Case N-509 was incorporated in the ASME Code Section XI, 1995 Edition, 1995 Addenda.
The technical basis for development of ASME Code Case N-509 concluded that operational transients and water hammers are the major potential causes for welded attachment failures (the possibility for corrosion related failures also exists). Industry experience found that welded attachment failures have been identified as a result of connected support member deformation and have not been identified by prior ASME Code examinations. ASME Code,Section XI, 1995 Addenda, and later addenda, requires welded attachments to be examined whenever component support deformation is identified.
ASME Code Case N-700 maintains the same sampling philosophy for welded attachments on vessels as does ASME Code Case N-509, and most of the ASME Code examination requirements. The sampling philosophy ensures the detection of service-induced degradation:
For multiple vessels, the ASME Code Case N-700 sampling plan requires that only one welded attachment of only one of multiple vessels be selected for examination; for a single vessel, only one welded attachment is to be examined. ASME Code Case N-700 also requires that the attachment selected for examination is to be an attachment under continuous load during normal system operation, or an attachment subject to potential intermittent load (seismic, water hammer, etc.) during normal system operation, if an attachment under continuous load does not exist. Per the foregoing, the staff determined that ASME Code Case N-700 provides an acceptable level of quality and safety for use at DAEC during the fourth ISI interval.
3.2 Relief Request NDE-R007 3.2.1 System/Component(s) for Which Relief NDE-R007 is Requested Buried Class 3 components are subject to system pressure testing in sections of the River Water Supply, the ESW system, and the Residual Heat Removal Service Water (RHRSW) system.
3.2.2 ASME Code Requirements Pertaining to NDE-R007 The 2001 Edition through the 2003 Addenda of ASME Code,Section XI, Table IWD-2500-1, Examination Category D-B, Item Number D2.10 requires a system leakage test and visual examination. For buried components where a VT-2 visual examination cannot be performed, the examination requirement is satisfied by the following: the system pressure test for buried components that are isolable by means of valves shall consist of a test that determines the rate of pressure loss; alternatively, the test may determine the change in flow between the ends of the buried components.
The acceptable rate of pressure loss or flow shall be established by the Owner.
3.2.3 Licensees Request for Relief NDE-R007 Relief is requested from performing the system leakage test for buried portions that are isolable by means of valves by measuring rate of pressure loss or the change in flow between the ends of buried components.
In lieu of performing a system pressure test in accordance with the requirements specified in IWA-5244(b)(1), DAEC proposes to use the provisions of IWA-5244(b)(2) to confirm that flow during operation is not impaired. The integrity of the buried piping for the river water supply and RHRSW system will be verified during quarterly service water pump testing. Trending of pressure drop across each pump will indicate leakage through the buried piping assuming no degradation of the pump. Should the pump test results fall in the required action range of the Code, additional testing and evaluations will be performed accordingly to determine whether the unsatisfactory test results are due to side-stream leakage past butterfly valves, degraded pump performance, or through-wall leakage. For the ESW system, the integrity of the buried piping will be verified by quarterly pump testing and by verification that adequate flow is supplied to cooling loads as provided by installed instrumentation. In addition, DAEC proposes to perform visual examination of the ground surface area immediately above each buried section of the River Water Supply, ESW, and RHRSW systems on a refuel cycle basis in lieu of performing the test required by IWA-5244(b)(1). The visual examination will be performed only after the subject piping has been in operation at nominal operating conditions for a minimum of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
3.2.4 Licensees Basis for Requesting Relief NDE-R007 (As provided by the licensee)
IWA-5244(b)(1) requires either a pressure loss test or a test that determines the change in flow between the ends of the buried components for isolable sections of buried piping. The acceptable rate of pressure loss or flow shall be established by the Owner. Sections of River Water Supply, [ESW system], and the [RHRSW system] buried piping were not designed with consideration for isolation valves adequate for performing a pressure loss type test or do not contain instrumentation adequate for measuring changes in flow between the ends of the buried piping.
The River Water Supply System contains large diameter buried piping (24-inch diameter) that runs from the river intake structure to the pump house and is greater than 1500 feet in length.
The ESW system and the RHRSW system contain large diameter buried piping (16-inch diameter for RHRSW and 8-inch and 6-inch diameter for ESW) that runs from the pump house to the turbine building and is greater than 500 feet in length. The subject design for these systems did not provide for isolation valves that are capable of supporting a pressure loss type test considering the volume of the piping and the available capacity of the test pumps. The system isolation valves were only intended to provide isolation for maintenance activities with only static system pressure.
River Water Supply and ESW systems were designed with a single flow element per train located in the pump house. ESW has some additional flow instrumentation on some downstream components, but not for every branch on a train. RHRSW was designed with a single flow element per train located in the reactor building before the Residual Heat Removal System Heat Exchanger. Therefore, the installed instrumentation is inadequate for measuring the flow difference at each end of the buried piping. The use of ultrasonic flow was considered, but the piping configurations do not provide for the straight runs of piping required for accurate flow measurement.
Both the River Water Supply and RHRSW systems include four pumps each with two pumps designated to each of two independent trains. The River Water Supply pumps and RHRSW pumps have installed excess capacity. Therefore, each of the independent trains of both the River Water and RHRSW systems can accommodate a leak and still satisfy the accident analysis requirements. ESW system has one pump per train. The ESW system supplies various plant heat exchangers, which have flow margin due to heat transfer requirements.
3.2.5 NRC Staffs Evaluation of Relief Request NDE-R007 The Code of Record requires a system pressure test for the buried portion of service water piping that will determine either a rate of pressure loss or a change in flow at the ends of the buried piping. The buried service water piping at DAEC uses butterfly valves at the ends, which were not designed for pressure isolation and, therefore, are unsuitable to determine meaningful rate of pressure loss. One end of buried piping is not instrumented for flow measurement and thus does not permit measurement of change in flow. Therefore, the Code-required test cannot be performed. The Code, however, permits the methodology, for nonisolable buried components, to confirm that flow during operation is not impaired. The NRC staff agrees with licensees approach that unimpaired flow in the buried piping can be qualitatively assessed during the quarterly service water pump test. Using the downstream flow instrument, a reference flow would correspond to a target pump head. As the pump degrades, the developed head decreases at the reference flow. However, a decrease in pump head may also indicate increase in flow due to any through-wall leakage in the buried piping. From trending of head loss (pressure drop) during a pump test at the reference flow, an assessment can be made on the integrity of buried piping. The licensee has stated that should the pump test results fall in the required action range of the Code, additional testing and evaluations will be performed accordingly to determine whether the unsatisfactory test results are due to degraded pump performance, or through-wall leakage in the buried portion of piping. For portions of buried piping supplying to cooling loads such as the emergency diesel generator coolers, control building chillers, and the residual heat removal and core spray room coolers, there is flow instrumentation on the supply line to each cooling load. Any marked decrease in supplied flow would be indicative of significant through-wall leakage in the buried piping. The licensee states that trending of the instrumented critical load flow rates in relation to the upstream set reference flow will ensure integrity of the buried piping. The NRC staff agrees that the methodology would provide a qualitative assessment of any significant leakage in the buried piping supplying cooling water to these components. In addition, DAEC also proposes to perform a visual examination of the ground surface immediately above each buried section of ESW piping, after the subject piping has been in operation for at least 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, once per refueling cycle. The NRC staff believes that trending of head produced by the pump from the results of quarterly test and ensuring adequate flow through each instrumented critical load, along with the visual examination of ground surface in the proximity of the buried piping, will provide reasonable assurance of integrity of the buried piping in lieu of the Code required test in accordance with IWA-5244(b)(1) of the ASME Code,Section XI. The NRC staff has further determined that compliance with the Code requirement, which would require installation of an additional flow measuring device at the inlet end of the buried piping, would result in hardship to the licensee without a compensating increase in the level of quality and safety.
4.0 CONCLUSION
4.1 Conclusion for NDE-R004 The NRC staff concludes that the licensees proposed alternative to use ASME Code Case N-700 for welded attachments on vessels provides an acceptable level of quality and safety.
Therefore, the licensees alterative is authorized pursuant to 10 CFR 55.55a(a)(3)(i) for the licensees fourth 10-year ISI interval or until ASME Code Case N-700 is approved for general use by reference in Regulatory Guide 1.147 Inservice Inspection Code Case Acceptability, ASME Section XI, Division 1, whichever event occurs first. If and when ASME Code Case N-700 is so approved, the licensee must follow the conditions, if any are specified, in Regulatory Guide 1.147 to continue the use of Code Case N-700.
All other requirements of the ASME Code,Section XI, for which relief has not been specifically requested, remain applicable, including third party review by the Authorized Nuclear Inservice Inspector.
4.2 Conclusion for NDE-R007 The NRC staff concludes that, for the buried portion of service water piping, compliance with the Code requirement to perform a test that determines the rate of pressure loss or the change in flow would result in hardship to the licensee without a compensating increase in the level of quality and safety. The licensees proposed alternative provides reasonable assurance of operational readiness. Therefore, pursuant to 10 CFR 50.55a(a)(3)(ii), the proposed alternative in relief request NDE-R007 is authorized for the licensees fourth 10-year ISI interval.
All other requirements of the ASME Code,Section XI, for which relief has not been specifically requested, remain applicable, including a third party review by the Authorized Nuclear Inservice Inspector.
5.0 REFERENCES
1.
Letter from G. V. Middlesworth (FPL Energy) to NRC, Duane Arnold Energy Center, Fourth Ten-Year Inservice Inspection Plan, dated June 30, 2006.
2.
Letter from G. V. Middlesworth, (FPL Energy) to NRC, Duane Arnold Energy Center, Responses to Requests for Additional Information and Revised Relief Requests NDE-R005 and NDE-R007 - Fourth 10-Year Inservice Inspection Program, dated December 21, 2006.
Principal Contributors: T. McLellan P. Patnaik K. Feintuch Date: June 12, 2007