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 Union Electric Co
Donohew J N, NRR/DORL/LP4, 415-1307
References
ISI-33, TAC MD2033
Download: ML070580333 (7)

Text

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

SUBJECT:

CALLAWAY PLANT, UNIT 1 - AUTHORIZATION OF RELIEF REQUEST NO. 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 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 error criterion for 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 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 has determined 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 NRC staff 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-party review by the Authorized Nuclear Inservice Inspector.

Sincerely,

/RA/

David Terao, Chief Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-483

Enclosure:

Safety Evaluation cc w/encl: See next page

ML070580333 NRR -028 Subject to Edit OFFICE NRR/LPL4/PM NRR/LPL4/LA CPNB/BC OGC Nlo NRR/LPL4/BC NAME JDonohew LFeizollahi TChan JCampbell DTerao DATE 3/7/07 3/15/07 2/7/07 3/13/07 3/15/07 Callaway Plant, Unit 1 cc:

Professional Nuclear Consulting, Inc. Mr. Dan I. Bolef, President 19041 Raines Drive Kay Drey, Representative Derwood, MD 20855 Board of Directors Coalition for the Environment John ONeill, Esq. 6267 Delmar Boulevard Pillsbury Winthrop Shaw Pittman LLP University City, MO 63130 2300 N. Street, N.W.

Washington, D.C. 20037 Mr. Lee Fritz, Presiding Commissioner Callaway County Court House Mr. Keith A. Mills, Supervising Engineer 10 East Fifth Street Regional Regulatory Affairs/Safety Analysis Fulton, MO 65151 AmerenUE P.O. Box 620 Mr. David E. Shafer Fulton, MO 65251 Superintendent, Licensing Regulatory Affairs U.S. Nuclear Regulatory Commission AmerenUE Resident Inspector Office P.O. Box 66149, MC 470 8201 NRC Road St. Louis, MO 63166-6149 Steedman, MO 65077-1302 Manager, Regulatory Affairs Mr. Les H. Kanuckel AmerenUE Manager, Quality Assurance P.O. Box 620 AmerenUE Fulton, MO 65251 P.O. Box 620 Fulton, MO 65251 Mr. Keith G. Henke, Planner Division of Community and Public Health Missouri Public Service Commission Office of Emergency Coordination Governor Office Building 930 Wildwood P.O. Box 570 200 Madison Street Jefferson City, MO 65102 Jefferson City, MO 65102-0360 Certrec Corporation Regional Administrator, Region IV 4200 South Hulen, Suite 630 U.S. Nuclear Regulatory Commission Fort Worth, TX 76109 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011-4005 Director, Missouri State Emergency Management Agency Mr. H. Floyd Gilzow P.O. Box 116 Deputy Director for Policy Jefferson City, MO 65102-0116 Missouri Department of Natural Resources P.O. Box 176 Jefferson City, MO 65102-0176 Mr. Rick A. Muench President and Chief Executive Officer Wolf Creek Nuclear Operating Corporation P.O. Box 411 Burlington, KA 66839 June 2006

SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO RELIEF REQUEST NO. ISI-33 UNION ELECTRIC COMPANY CALLAWAY PLANT, UNIT 1 DOCKET NO. 50-483

1.0 INTRODUCTION

By letters dated May 18 and December 12, 2006 (Agencywide Documents Access and Management 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 licensees 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.

2.0 REGULATORY 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 is the 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 Regulatory Commission (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

quality and safety; or (3) conformance is impractical for the facility. Pursuant to 10 CFR 50.55a(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.

3.0 TECHNICAL EVALUATION

FOR RR NO. ISI-33 3.1 Affected Components The licensee stated that the relief request is specific to pipe weld 2-BB-01-F302.

3.2 Applicable Code As stated in the application, for the second 10-year ISI interval, the ISI code of record is the 1989 Edition with no Addenda, ASME Code,Section XI, Appendix VIII, Supplements 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).

3.3 Proposed Inspection The licensee proposed using the Electric Power Research Institute (EPRI) Performance Demonstration Initiative (PDI) program for the implementation of Appendix VIII, Supplement 2 in coordination with Supplement 101, Paragraph 3.2(b), 0.245-inch RMS criterion in lieu of the ASME 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 the PDI, 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-inch RMS error (i.e., 0.82-inch difference) will be added to the measured flaw size for the purpose of flaw evaluation.

3.4 Licensees Basis for Impracticality The licensees vendor performed a combined Appendix VIII, Supplements 2 and 10 (identified in the licensees submittal of May 18, 2006, as Supplement 14) performance demonstration that 1

NRC Safety Evaluation dated April 7, 2004, which the letter authorizing relief request ISI-27, ADAMS Accession No. ML0410005162.

did not satisfy the ASME Code-required 0.125-inch RMS depth-sizing error criterion. The vendor 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.

3.5 Evaluation The licensees ISI code of record for the second 10-year ISI interval is the 1989 Edition with no addenda. 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 licensees vendor performed a coordinated Supplements 2 and 10 (licensees Supplement 14) performance demonstration as implemented by the PDI program.

The ASME Code requires that the maximum error for flaw-depth measurements, when compared 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 implemented by 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 vendors RMS error criterion2. At this time, achieving a 0.125-inch RMS error criterion 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-required RMS 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.

3.6 Conclusion Based on the above evaluation, the NRC staff concludes that compliance with the ASME Code-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, 2

Summary of Public Meeting Held May 24 and 25, 2005 with EPRI-PDI Representatives, dated September 8, 2005, ADAMS Accession No. ML052580257.

provides reasonable assurance of structural integrity. Therefore, based on its evaluation, the NRC 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 specifically requested remain applicable, including third-party review by the Authorized Nuclear Inservice Inspector.

Principal Contributor: Don Naujock Date: March 15, 2007