ML011290479

Inservice Inspection Relief Request ISI-12

ML011290479
Person / Time
Site:	Nine Mile Point
Issue date:	05/31/2001
From:	Correia R NRC/NRR/DLPM/LPD1
To:	Mueller J Niagara Mohawk Power Corp
Tam P
References
ISI-12, TAC MA9662
Download: ML011290479 (6)

Text

May 31, 2001 Mr. John H. Mueller Chief Nuclear Officer Niagara Mohawk Power Corporation Nine Mile Point Nuclear Station P.O. Box 63 Lycoming, NY 13093

SUBJECT:

NINE MILE POINT NUCLEAR STATION, UNIT NO. 1 - INSERVICE INSPECTION RELIEF REQUEST ISI-12 (TAC NO. MA9662)

Dear Mr. Mueller:

By letter dated October 30, 1999, as supplemented by letter dated May 12, 2000, Niagara Mohawk Power Corporation (NMPC) requested relief for Nine Mile Point Nuclear Station, Unit No. 1, from the requirements of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code)Section XI, 1989 Edition, Article IWF-5000, for the third 10-year inservice inspection (ISI) interval. By letter dated October 5, 2000, the NRC staff authorized a number of reliefs, but stated that Relief Request ISI-12 was still under review. By letter dated September 28, 2000, NMPC submitted a revised Relief Request ISI-12. Additional information was provided in a letter dated April 23, 2001. Relief Request ISI-12 is concerned with relief from augmented inspection of twenty-one (21) austenitic stainless steel welds which are susceptible to intergranular stress-corrosion cracking.

Based on the conclusion set forth in the enclosed supplemental safety evaluation, the staff determines that the Code requirements are impractical and NMPCs proposed alternatives provide reasonable assurance of structural integrity of the subject welds. Therefore, relief is granted pursuant to 10 CFR 50.55a(g)(6)(i) for the third interval. The staff has determined that granting relief pursuant to 10 CFR 50.55a(g)(6)(i) 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 would result if the requirements were imposed on the facility.

Please contact the project manager, Mr. Peter Tam (301-415-1451, electronic mail at pst@nrc.gov) if you have any questions.

Sincerely,

/RA/

Richard P. Correia, Acting Chief, Section 1 Project Directorate I Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket No. 50-220

Enclosure:

Safety Evaluation cc w/encl: See next page

Mr. John H. Mueller May 31, 2001 Chief Nuclear Officer Niagara Mohawk Power Corporation Nine Mile Point Nuclear Station P.O. Box 63 Lycoming, NY 13093

SUBJECT:

NINE MILE POINT NUCLEAR STATION, UNIT NO. 1 - INSERVICE INSPECTION RELIEF REQUEST ISI-12 (TAC NO. MA9662)

Dear Mr. Mueller:

By letter dated October 30, 1999, as supplemented by letter dated May 12, 2000, Niagara Mohawk Power Corporation (NMPC) requested relief for Nine Mile Point Nuclear Station, Unit No. 1, from the requirements of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code)Section XI, 1989 Edition, Article IWF-5000, for the third 10-year inservice inspection (ISI) interval. By letter dated October 5, 2000, the NRC staff authorized a number of reliefs, but stated that Relief Request ISI-12 was still under review. By letter dated September 28, 2000, NMPC submitted a revised Relief Request ISI-12. Additional information was provided in a letter dated April 23, 2001. Relief Request ISI-12 is concerned with relief from augmented inspection of twenty-one (21) austenitic stainless steel welds which are susceptible to intergranular stress-corrosion cracking.

Based on the conclusion set forth in the enclosed supplemental safety evaluation, the staff determines that the Code requirements are impractical and NMPCs proposed alternatives provide reasonable assurance of structural integrity of the subject welds. Therefore, relief is granted pursuant to 10 CFR 50.55a(g)(6)(i) for the third interval. The staff has determined that granting relief pursuant to 10 CFR 50.55a(g)(6)(i) 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 would result if the requirements were imposed on the facility.

Please contact the project manager, Mr. Peter Tam (301-415-1451, electronic mail at pst@nrc.gov) if you have any questions.

Sincerely,

/RA/

Richard P. Correia, Acting Chief, Section 1 Project Directorate I Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket No. 50-220

Enclosure:

Safety Evaluation cc w/encl: See next page Distribution:

PUBLIC PDI-1 Reading W. Koo Bplatchek, RGI R. Correia S. Little P. Tam OGC G. Hill (2), T-5 C3 ACRS Accession No. ML011290479 OFFICE PM:PDI-1 LA:PDI-1 SC:EMCB OGC ASC:PDI 1 NAME PTam SLittle KWichman* RHoefling RCorreia DATE 5/18/01 5/17/01 5/3/01 5/24/01 5/31/01 Official Record Copy

• Memo of 5/3/01 used essentially as-is.

Nine Mile Point Nuclear Station Unit No. 1 Regional Administrator, Region I U.S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406 Resident Inspector U.S. Nuclear Regulatory Commission P.O. Box 126 Lycoming, NY 13093 Charles Donaldson, Esquire Assistant Attorney General New York Department of Law 120 Broadway New York, NY 10271 Mr. Paul D. Eddy Electric Division NYS Department of Public Service Agency Building 3 Empire State Plaza Albany, NY 12223 Mr. F. William Valentino, President New York State Energy, Research, and Development Authority Corporate Plaza West 286 Washington Avenue Extension Albany, NY 12203-6399 Mark J. Wetterhahn, Esquire Winston & Strawn 1400 L Street, NW Washington, DC 20005-3502 Gary D. Wilson, Esquire Niagara Mohawk Power Corporation 300 Erie Boulevard West Syracuse, NY 13202 Supervisor Town of Scriba Route 8, Box 382 Oswego, NY 13126

SUPPLEMENTAL SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION THIRD 10-YEAR INTERVAL INSERVICE INSPECTION (ISI)

REQUEST FOR RELIEF ISI-12 NINE MILE POINT NUCLEAR STATION, UNIT NO. 1 NIAGARA MOHAWK POWER CORPORATION DOCKET NUMBER 50-220

1.0 INTRODUCTION

By letter dated October 30, 1999, as supplemented by letter dated May 12, 2000, Niagara Mohawk Power Corporation (NMPC) requested relief for Nine Mile Point Nuclear Station, Unit No. 1, from the requirements of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code)Section XI, 1989 Edition, Article IWF-5000, for the third 10-year inservice inspection (ISI) interval. By letter dated October 5, 2000, the NRC staff authorized a number of reliefs, but stated that Relief Request ISI-12 was still undergoing review.

By letter dated September 28, 2000, NMPC submitted a revised Relief Request ISI-12.

Additional information was provided in a letter dated April 23, 2001. ISI-12 is concerned with relief from augmented inspection of twenty-one (21) austenitic stainless steel welds which are susceptible to intergranular stress-corrosion cracking (IGSCC).

2.0 EVALUATION 2.3 Relief Request ISI-12 Part 50 of Title 10 of the Code of Federal Regulations (10 CFR Part 50), paragraph 55a(g)(6)(ii)(C) requires accelerated implementation of the ASME Code,Section XI, 1995 Edition with 1996 Addenda, Appendix VIII, Performance Demonstration for Ultrasonic Examination Systems. 10 CFR 50.55a(b)(2)(xv)(A), 10 CFR 50.55a(b)(2)(xv)(G) and 10 CFR 50.55a(b)(2)(xvi) define new requirements for examination coverage and qualification demonstration. These requirements affect austenitic steel piping. Generic Letter (GL) 88-01, NRC Position on Intergranular Stress Corrosion Cracking in Boiling Water Reactor Austenitic Stainless Steel Piping, provides guidance regarding augmented volumetric examination of nonconforming service-sensitive piping welds. The welds covered by NMPCs ISI-12 consist of five (5) Category D welds(40-WD-005, 40-WD-006, 40-WD-011, 40-WD-051, and 37-WD-003)

Enclosure

and sixteen (16) Category G welds (40-WD-050-A, 40-WD-010-A, 39-09R-WD-001, 39-10R-WD-001, 39-WD-194, 39-WD-194A, 39-WD-226, 39-WD-226A, 38-WD-007, 38-WD-008, 38-WD-087, 38-WD-088, 33-WD-014, 33-WD-036, 33-WD-035 and 33-WE-015). Category D welds are welds made of non-resistant materials and are required to be inspected every two refueling cycles. Category G welds are welds made of non-resistant materials and are not ultrasonically inspected. These welds are located in the reactor core spray system (six welds),

emergency condenser system (six welds), shutdown cooling system (four welds), reactor clean-up system (4 welds), and the reactor drain line (one weld).

The sixteen Category G welds are located inside penetrations and, therefore, are inaccessible for ultrasonic inspection. For the five Category D welds, only partial ultrasonic inspection can be performed since access to these welds is either obstructed by the presence of permanent pipe hanger or limited by component configuration. Due to these access limitations, the full ultrasonic inspection of these welds cannot be achieved. Therefore, in lieu of the full ultrasonic inspection, the NMPC proposed to perform the following alternate examinations:

(1) Perform ultrasonic examination to the extent practical on the five Category D welds with a frequency of once every other refueling outage and, (2) Perform a visual (VT-2) examination on all twenty-one welds every refueling outage for evidence of leakage.

NMPC indicated that similar inspection relief for the subject Category G welds was granted by NRC in the previous ISI program for the second 10-year interval (reference letter, R. A. Capra of NRC to B. R. Sylvia of NMPC, April 6, 1994). In the current relief request, in addition to the sixteen Category G welds, NMPC added the five Category D welds. This is due to the consideration that the requirement of full ultrasonic inspection (100 percent volume of the weld) based on the Performance Demonstration Initiative (PDI) pertaining to Appendix VIII, Performance Demonstration for Ultrasonic Examination Systems of ASME Code,Section XI cannot be implemented on these Category D welds. As stated above in the first paragraph of this safety evaluation, Appendix VIII was incorporated into the ASME Code,Section XI.

The staff has reviewed the GL 88-01 guidelines that are applicable to IGSCC inspection. The staff notes that note (3) to Table 1, Summary of Inspection Schedules for BWR [Boiling-Water Reactor] Piping Weldments of GL 88-01 provides some mitigation and inspection guidelines for welds that are not ultrasonic-inspectable. The subject note stated that these welds should be replaced, sleeved, or local leak detection applied. In addition, radiographic testing (RT) or visual inspection for leakage may also be considered.

For these 21 welds, NMPC proposed to perform ultrasonic testing and/or surface examinations to the extent practical. Based on review of NMPCs submittal, the staff finds NMPCs ISI Relief Request ISI-12 acceptable because the proposed alternate examinations of the subject welds meet the guidelines in GL 88-01.

3.0 CONCLUSION

The staff concludes that for Request for Relief ISI-12, the Code requirements are impractical and NMPCs proposed alternatives provide reasonable assurance of structural integrity of the subject welds. Therefore, relief is granted pursuant to 10 CFR 50.55a(g)(6)(i). The staff has

determined that granting relief pursuant to 10 CFR 50.55a(g)(6)(i) is authorized by law and willnot 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 would result if the requirements were imposed on the facility.

Principal Contributor: W. Koo Date: May 31, 2001