ML070580333

Authorization of Relief Request No. ISI-33 for Second 10-Year and Third 10-Year ISI Interval

ML070580333
Person / Time
Site:	Callaway
Issue date:	03/15/2007
From:	Terao D NRC/NRR/ADRO/DORL/LPLIV
To:	Naslund C D Union Electric Co
Donohew J N, NRR/DORL/LP4, 415-1307
References
ISI-33, TAC MD2033
Download: ML070580333 (7)

Text

March 15, 2007Mr. Charles D. NaslundSenior Vice President and Chief Nuclear Officer Union Electric Company Post Office Box 620 Fulton, MO 65251

SUBJECT:

CALLAWAY PLANT, UNIT 1 - AUTHORIZATION OF RELIEF REQUESTNO. ISI-33 FOR THE SECOND AND THIRD 10-YEAR INSERVICE INSPECTION INTERVALS (TAC NO. MD2033)

Dear Mr. Naslund:

By letters dated May 18 and December 12, 2006 (ULNRC-05291 and -05351), the UnionElectric Company (the licensee) submitted Relief Request (RR) No. ISI-33, which proposed analternative to certain requirements of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (the ASME Code) at the Callaway Plant, Unit 1. Specifically, the licensee proposed using a root mean square error criterion for sizing flaws that is greater than the ASME Code,Section XI, Appendix VIII, Supplements 2 and 10 acceptance criteria forexaminations performed from the inside surface of pressure boundary piping. The request is for the second 10-year inservice inspection (ISI) interval, which ended on December 18, 2005, and the third 10-year ISI interval, which began on December 19, 2005.Based on the enclosed safety evaluation, the Nuclear Regulatory Commission (NRC) staff hasdetermined that (1) the ASME Code-required examination coverage requirements are impractical for the subject weld listed in RR No. ISI-33, and (2) the requested relief from the ASME Code is authorized by law and will not endanger life or property or the common defense and security, and is otherwise in the public interest giving due consideration to the burden upon the licensee that could result if the requirements were imposed on the facility. Therefore, pursuant to paragraph 50.55a(g)(6)(i) of Title 10 of the Code of Federal Regulations, the NRCstaff grants the relief in RR No. ISI-33 for the second 10-year ISI interval and third 10-year ISI interval at Callaway. All other ASME Code,Section XI, requirements for which relief was not specifically requested and approved in this relief request remain applicable, including third-partyreview by the Authorized Nuclear Inservice Inspector.Sincerely,/RA/David Terao, ChiefPlant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor RegulationDocket No. 50-483

Enclosure:

Safety Evaluation cc w/encl: See next page

ML070580333NRR -028 Subject to EditOFFICENRR/LPL4/PMNRR/LPL4/LACPNB/BCOGCNloNRR/LPL4/BCNAMEJDonohewLFeizollahiTChanJCampbellDTerao DATE3/7/073/15/072/7/073/13/073/15/07 June 2006Callaway Plant, Unit 1 cc:Professional Nuclear Consulting, Inc.

19041 Raines Drive Derwood, MD 20855John O'Neill, Esq.Pillsbury Winthrop Shaw Pittman LLP 2300 N. Street, N.W.

Washington, D.C. 20037Mr. Keith A. Mills, Supervising EngineerRegional Regulatory Affairs/Safety Analysis AmerenUE P.O. Box 620 Fulton, MO 65251U.S. Nuclear Regulatory CommissionResident Inspector Office

8201 NRC Road Steedman, MO 65077-1302Mr. Les H. KanuckelManager, Quality Assurance AmerenUE P.O. Box 620 Fulton, MO 65251Missouri Public Service CommissionGovernor Office Building 200 Madison Street Jefferson City, MO 65102-0360Regional Administrator, Region IVU.S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011-4005Mr. H. Floyd GilzowDeputy Director for Policy Missouri Department of Natural Resources P.O. Box 176 Jefferson City, MO 65102-0176Mr. Rick A. MuenchPresident and Chief Executive Officer Wolf Creek Nuclear Operating Corporation P.O. Box 411 Burlington, KA 66839Mr. Dan I. Bolef, PresidentKay Drey, Representative Board of Directors Coalition for the Environment 6267 Delmar Boulevard University City, MO 63130Mr. Lee Fritz, Presiding CommissionerCallaway County Court House 10 East Fifth Street Fulton, MO 65151Mr. David E. Shafer Superintendent, Licensing Regulatory Affairs AmerenUE P.O. Box 66149, MC 470 St. Louis, MO 63166-6149Manager, Regulatory AffairsAmerenUE P.O. Box 620 Fulton, MO 65251Mr. Keith G. Henke, PlannerDivision of Community and Public Health Office of Emergency Coordination 930 Wildwood P.O. Box 570 Jefferson City, MO 65102Certrec Corporation4200 South Hulen, Suite 630 Fort Worth, TX 76109Director, Missouri State Emergency Management Agency P.O. Box 116 Jefferson City, MO 65102-0116 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATIONRELATED TO RELIEF REQUEST NO. ISI-33UNION ELECTRIC COMPANYCALLAWAY PLANT, UNIT 1DOCKET NO. 50-48

31.0INTRODUCTION

By letters dated May 18 and December 12, 2006 (Agencywide Documents Access andManagement System (ADAMS) Accession Nos. ML061460043 and ML063530466, respectively), the Union Electric Company (the licensee) submitted Relief Request (RR)No. ISI-33, which proposed an alternative to certain requirements of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (the ASME Code) at the Callaway Plant, Unit 1. Specifically, the licensee proposed using a root mean square (RMS) error criterion for depth-sizing flaws that is greater than the ASME Code,Section XI, Appendix VIII,Supplements 2 and 10 acceptance criteria for examinations performed from the inside surface of reactor coolant system pressure boundary piping. The licensee's request is for the second 10-year inservice inspection (ISI) interval, which ended on December 18, 2005, and the third 10-year ISI interval, which began on December 19, 2005.

2.0REGULATORY EVALUATION

In accordance with Paragraph 50.55a(g)(4) of Title 10 of the Code of Federal Regulations(10 CFR), ASME Code Class 1, 2, and 3 components must meet the requirements set forth in ASME Code,Section XI, "Rules for Inservice Inspection of Nuclear Power Plants Components,"

to the extent practical within the limitations of design, geometry, and materials of construction of the components. The regulations require that all inservice examinations 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 ASME Code,Section XI, incorporated by reference in 10 CFR 50.55a(b) 12 months prior to the start of the 10-year interval.For Callaway, the licensee stated that the code of record for the second 10-year ISI interval isthe 1989 Edition of Section XI of the ASME Code. For the third 10-year ISI interval, the Code of record is the 1998 Edition through the 2000 Addenda of Section XI of the ASME Code.Alternatives to requirements may be authorized or relief granted by the Nuclear RegulatoryCommission (NRC) pursuant to 10 CFR 50.55a(a)(3)(i), 10 CFR 50.55a(a)(3)(ii), or 10 CFR 50.55a(g)(6)(i). In proposing alternatives or requesting relief, the licensee must demonstrate that: (1) the proposed alternatives would provide an acceptable level of safety; (2) compliance would result in hardship or unusual difficulty without a compensating increase in the level of 1NRC Safety Evaluation dated April 7, 2004, which the letter authorizing relief request ISI-27, ADAMS Accession No. ML0410005162.quality and safety; or (3) conformance is impractical for the facility. Pursuant to 10 CFR50.55a(g)(4)(iv), ISI items may meet the requirements set forth in subsequent editions and addenda of the ASME Code that are incorporated by reference in 10 CFR 50.55a(b), subject to the limitations and modifications listed therein, and subject to Commission approval. Portions of editions and addenda may be used provided that related requirements of the respective editions and addenda are met.

3.0TECHNICAL EVALUATION

FOR RR NO. ISI-333.1Affected ComponentsThe licensee stated that the relief request is specific to pipe weld 2-BB-01-F302.

3.2Applicable CodeAs stated in the application, for the second 10-year ISI interval, the ISI code of record is the1989 Edition with no Addenda, ASME Code,Section XI, Appendix VIII, Supplement s 2 and 10,Paragraph 3.2(b) (for both supplements) which states that the RMS error for flaw depths estimated by ultrasonic testing (UT) shall not exceed 0.125 inches.For the third 10-year ISI interval, the ISI Code of record is the 1998 Edition with 2000 Addenda,ASME Code,Section XI, Appendix VIII, Supplements 2 and 10, Paragraph 3.2(b).3.3Proposed InspectionThe licensee proposed using the Electric Power Research Institute (EPRI) PerformanceDemonstration Initiative (PDI) program for the implementation of Appendix VIII, Supplement 2in coordination with Supplement 10 1, Paragraph 3.2(b), 0.245-inch RMS criterion in lieu of theASME Code-required 0.125-inch RMS criterion because of the impracticality in the licensee achieving the ASME Code-required criterion. At this time, no vendor has been able to achieve the 0.125-inch RMS criterion with the transducer applied on the pipe inside diameter (ID). The licensee would use the qualifications of Appendix VIII, Supplement 10, as administrated by thePDI, as described in its RR ISI-27, which was authorized by NRC in its letter dated April 17, 2004.The difference between the 0.245-inch RMS error and the ASME Code-required 0.125-inchRMS error (i.e., 0.82-inch difference) will be added to the measured flaw size for the purpose of flaw evaluation.3.4Licensee's Basis for ImpracticalityThe licensee's vendor performed a combined Appendix VIII, Supplements 2 and 10 (identifiedin the licensee's submittal of May 18, 2006, as Supplement 14) performance demonstration that 2Summary of Public Meeting Held May 24 and 25, 2005 with EPRI-PDI Representatives,dated September 8, 2005, ADAMS Accession No. ML052580257.did not satisfy the ASME Code-required 0.125-inch RMS depth-sizing error criterion. Thevendor actually demonstrated a 0.245-inch RMS depth-sizing error for the combined Supplements 2 and 10. Currently, no vendor has been able to achieve the 0.125-inch RMS criterion with the transducer applied on the pipe ID, and it is, therefore, impractical at this time to require the licensee to meet this criterion.3.5EvaluationThe licensee's ISI code of record for the second 10-year ISI interval is the 1989 Edition with noaddenda. The regulation 10 CFR 50.55a(g)(6)(ii)(C)(2) requires that licensees with the 1989 Edition and earlier editions and addenda ISI code of record use the 1995 Edition with 1996 Addenda of Section XI, Appendix VIII for UT examinations. For the third 10-year ISI interval,the licensee is using the 1998 Edition with 2000 Addenda. The licensee's vendor performed a coordinated Supplements 2 and 10 (licensee's Supplement 14) performance demonstration as implemented by the PDI program.The ASME Code requires that the maximum error for flaw-depth measurements, whencompared to the true flaw depth, must not exceed 0.125-inch RMS error. The nuclear power industry is in the process of qualifying personnel and procedures with a coordinated Appendix VIII, Supplement 2 and Supplement 10 performance demonstration as implementedby the PDI program. However, to date, no personnel or procedure has yet achieved the ASME Code-required 0.125-inch RMS maximum error criterion for performance demonstrations performed from the pipe ID. The difficulties are associated with the surface roughness of the field welds. As licensees perform ID UT examinations, they are taking profilometry measurements which can be used to assess the representativeness of the test specimens used to establish the vendor's RMS error criterion

2. At this time, achieving a 0.125-inch RMS errorcriterion is impractical because no vendor has been able to achieve the 0.125-inch RMS criterion with the transducer applied on the pipe ID. The licensee has stated that the vendor has achieved a 0.245-inch RMS error for the coordinated Supplement 2 and Supplement 10 performance demonstrations. The licensee proposed adding the depth-sizing difference between the performance demonstrated error of 0.245-inch and the Code-required error of 0.125-inch to the measured flaw size. Based on its evaluation, the NRC staff finds that compliance with the ASME Code-requiredRMS error criterion is impractical at this time and that adding the difference between the demonstrated depth sizing RMS error and the ASME Code-required depth sizing RMS error when determining acceptance to the standards specified in ASME Code,Section XI, IWB-3500, provides reasonable assurance of structural integrity.3.6ConclusionBased on the above evaluation, the NRC staff concludes that compliance with the ASMECode-required RMS depth-sizing error value is impractical because no vendor has been able to achieve the 0.125-inch RMS criterion with the transducer on the pipe ID, and that the proposed inspection, as implemented by the PDI program in a coordinated performance demonstration, provides reasonable assurance of structural integrity. Therefore, based on its evaluation, theNRC staff concludes that the relief is authorized by law and will not endanger life or property, or the common defense and security and is otherwise in the public interest, given the consideration of the burden upon the licensee. Therefore, pursuant to 10 CFR 50.55a(g)(6)(i),

the relief is granted for Callaway for the second 10-year ISI interval and third 10-year ISI interval for the subject weld.All other requirements of the ASME Code,Section XI, for which relief has not been specificallyrequested remain applicable, including third-party review by the Authorized Nuclear Inservice Inspector. Principal Contributor: Don Naujock Date: March 15, 2007