ML041470119

Issuance of License Amendment 175 Steam Generator Eddy Current Inspection Frequency

ML041470119
Person / Time
Site:	Kewaunee
Issue date:	06/18/2004
From:	Lyon C NRC/NRR/DLPM/LPD3
To:	Coutu T Nuclear Management Co
Lyon CF, NRR/DLPM, 415-2296
References
TAC MC0927, TAC MC1049
Download: ML041470119 (13)

Text

June 18, 2004 Mr. Thomas Coutu Site Vice President Kewaunee Nuclear Power Plant Nuclear Management Company, LLC N490 Highway 42 Kewaunee, WI 54216-9511

SUBJECT:

KEWAUNEE NUCLEAR POWER PLANT - ISSUANCE OF AMENDMENT RE: STEAM GENERATOR EDDY CURRENT INSPECTION FREQUENCY EXTENSION (TAC NOS. MC1049 AND MC0927)

Dear Mr. Coutu:

The U.S. Nuclear Regulatory Commission (NRC, Commission) has issued the enclosed Amendment No. 175 to Facility Operating License No. DPR-43 for the Kewaunee Nuclear Power Plant. This amendment revises the Technical Specifications (TSs) in response to your application dated October 8, 2003, as supplemented February 27 and May 3, 2004.

The amendment revises the TSs with a one-time change to allow a 40-month inspection interval after the first (post-replacement) steam generator inservice inspection, rather than after two consecutive inspections resulting in a C-1 classification.

The NRC staffs review of the proposed license amendment included a review of the information provided by you summarizing your 2003 steam generator tube inservice inspections. Information pertaining to the 2003 tube inspections, which were completed on April 19, 2003, was provided by you in the 2003 Inservice Inspection Report, dated August 6, 2003 (ML032250165), and 2003 Annual Operating Report, dated February 27, 2004 (ML040650370). Since this information was reviewed with the license amendment request, the NRC staffs Safety Evaluation also completes NRC review of your 2003 steam generator tube inspection reports conducted under TAC No. MC0927.

T. Coutu A copy of the Safety Evaluation is enclosed. The Notice of Issuance will be included in the Commissions next regular biweekly Federal Register notice.

Sincerely,

/RA/

Carl F. Lyon, Project Manager, Section 1 Project Directorate III Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket No. 50-305

Enclosures:

1. Amendment No. 175 to License No. DPR-43

2. Safety Evaluation cc w/encls: See next page

T. Coutu A copy of the Safety Evaluation is enclosed. The Notice of Issuance will be included in the Commissions next regular biweekly Federal Register notice.

Sincerely,

/RA/

Carl F. Lyon, Project Manager, Section 1 Project Directorate III Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket No. 50-305

Enclosures:

1. Amendment No. 175 to License No. DPR-43

2. Safety Evaluation cc w/encls: See next page Distribution:

PUBLIC PD3-1 R/F RidsNrrDlpmPdiii1 RidsNrrLATHarris RidsNrrPMFLyon RidsAcrsAcnwMailCenter RidsOgcRp PLouden (Region 3)

GHill (2)

KKarwoski TBoyce LLund ADAMS Accession Number: ML041470119 *No significant changes to SE OFFICE PDIII-1/PM PDIII-1/LA EMCB/SC IROB/SC OGC PDIII-1/SC NAME FLyon THarris LLund*

TBoyce TSmith LRaghavan DATE 06/03/04 06/03/04 5/13/04 06/07/04 06/17/04 06/17/04 OFFICIAL RECORD COPY

Kewaunee Nuclear Power Plant cc:

John Paul Cowan Executive Vice President &

Chief Nuclear Officer Nuclear Management Company, LLC 700 First Street Hudson, MI 54016 Plant Manager Kewaunee Nuclear Power Plant N490 Highway 42 Kewaunee, WI 54216-9511 Manager, Regulatory Affairs Kewaunee Nuclear Power Plant N490 Highway 42 Kewaunee, WI 54216-9511 David Molzahn Nuclear Asset Manager Wisconsin Public Service Corporation 600 N. Adams Street Green Bay, WI 54307-9002 Resident Inspectors Office U. S. Nuclear Regulatory Commission N490 Hwy 42 Kewaunee, WI 54216-9511 Regional Administrator Region III U. S. Nuclear Regulatory Commission 2443 Warrenville Road, Suite 210 Lisle, IL 60532-4352 Jonathan Rogoff Vice President, Counsel & Secretary Nuclear Management Company, LLC 700 First Street Hudson, WI 54016 Larry L. Weyers Chairman, President and CEO Wisconsin Public Service Corporation 600 North Adams Street Green Bay, WI 54307-9002 David Zellner Chairman - Town of Carlton N2164 County B Kewaunee, WI 54216 Mr. Jeffery Kitsembel Electric Division Public Service Commission of Wisconsin PO Box 7854 Madison, WI 53707-7854

NUCLEAR MANAGEMENT COMPANY, LLC DOCKET NO. 50-305 KEWAUNEE NUCLEAR POWER PLANT AMENDMENT TO FACILITY OPERATING LICENSEE Amendment No. 175 License No. DPR-43 1.

The U.S. Nuclear Regulatory Commission (the Commission) has found that:

A.

The application for amendment by Nuclear Management Company, LLC (NMC),

dated October 8, 2003, as supplemented February 27 and May 3, 2004, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act), and the Commissions rules and regulations set forth in 10 CFR Chapter I; B.

The facility will operate in conformity with the application, the provisions of the Act, and the rules and regulations of the Commission; C.

There is reasonable assurance (i) that the activities authorized by this amendment can be conducted without endangering the health and safety of the public, and (ii) that such activities will be conducted in compliance with the Commissions regulations; D.

The issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public; and E.

The issuance of this amendment is in accordance with 10 CFR Part 51 of the Commissions regulations and all applicable requirements have been satisfied.

2.

Accordingly, the license is amended by changes to the Technical Specifications as indicated in the attachment to this license amendment, and paragraph 2.C.(2) of Facility Operating License No. DPR-43 is hereby amended to read as follows:

(2) Technical Specifications The Technical Specifications contained in Appendix A, as revised through Amendment No. 175, are hereby incorporated in the license. The licensees shall operate the facility in accordance with the Technical Specifications.

3.

This license amendment is effective as of its date of issuance and shall be implemented within 30 days of the date of issuance.

FOR THE NUCLEAR REGULATORY COMMISSION

/RA/

L. Raghavan, Chief, Section 1 Project Directorate III Division of Licensing Project Management Office of Nuclear Reactor Regulation

Attachment:

Changes to the Technical Specifications Date of Issuance: June 18, 2004

ATTACHMENT TO LICENSE AMENDMENT NO. 175 FACILITY OPERATING LICENSE NO. DPR-43 DOCKET NO. 50-305 Replace the following page of the Appendix A Technical Specifications with the attached revised page. The revised page is identified by amendment number and contains marginal lines indicating the areas of change.

REMOVE INSERT TS 4.2-4 TS 4.2-4

TS 4.2-4 Amendment No. 175 Category Inspection Results C-1 Less than 5% of the total tubes inspected are degraded tubes, and non of the inspected tubes are defective.

C-2 Between 5% and 10% of the total tubes inspected are degraded tubes, or one or more tubes, but not more than 1% of the total tubes inspected, are defective.

C-3 More than 10% of the total tubes inspected are degraded tubes, or more than 1% of the inspected tubes are defective.

NOTE:

Fore all inspections, previously degraded tubes must exhibit significant

(>10%) added wall penetration to be included in the above percentage calculations.

3. Inspection Frequency In-service inspection of steam generator tubes shall be performed at the following intervals:

a. In-service inspections may be performed during refueling outages, but shall be performed at intervals not to exceed 24 calendar months, except that the inspection interval may be extended to a maximum of 40 months if:

1. two consecutive inspections following service under AVT conditions, not including the pre-service inspection, yield results that fall into the C-1 category, or

2. two consecutive inspections demonstrate that previously documented degradation sites have not continued to deteriorate and no new degradation is found.

NOTE:

A one-time inspection interval extension of a maximum of once per 40 months is allowed following the inspection performed during the Spring 2003 Outage. This is an exception to the Extension Criteria in that the inspection interval extension is based on the result of only one inspection result falling into the C-1 category.

b. If the result of a steam generator in-service inspection conducted in accordance with Table TS 4.2-2 falls into Category C-3, the inspection interval shall be reduced to 20 months. The 20 month interval shall apply until a subsequent inspection meets the conditions set forth in TS 4.2.b.3.a for extending the interval to 40 months.

SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATING TO AMENDMENT NO. TO FACILITY OPERATING LICENSE NO. DPR-43 NUCLEAR MANAGEMENT COMPANY, LLC KEWAUNEE NUCLEAR POWER PLANT DOCKET NO. 50-305

1.0 INTRODUCTION

By application dated October 8, 2003 (ADAMS Accession No. ML032901121), as supplemented February 27 (ML040720434) and May 3, 2004 (ML041320470), Nuclear Management Company, LLC (NMC, or the licensee), requested a one-time change to the Technical Specifications (TSs) for the Kewaunee Nuclear Power Plant. The proposed change revises the TS-required steam generator (SG) inspection interval to allow a 40-month inspection interval after one SG inspection, rather than after two inspections. The licensee requested the extension based upon the improved design of the replacement SGs (installed in 2001) and the results of the Spring 2003 SG inspections.

The supplements dated February 27 and May 3, 2004, provided additional information that clarified the application, did not expand the scope of the application as originally noticed, and did not change the Nuclear Regulatory Commission (NRC) staffs original proposed no significant hazards consideration determination as published in the Federal Register on January 20, 2004 (69 FR 2743).

Specifically, the proposed change would revise TS Surveillance Requirement 4.2.b.3.a, Inspection Frequency, to modify the exception to the Extension Criteria by adding the following:

Note: A one-time inspection interval extension of a maximum of once per 40 months is allowed following the inspection performed during the Spring 2003 Outage. This is an exception to the Extension Criteria in that the inspection interval extension is based on the result of only one inspection result falling into the C-1 category.

2.0 REGULATORY EVALUATION

The applicable NRC regulations and guidance for review of the licensees request to extend the operating interval between inspections include:

General Design Criterion (GDC) 14 of Appendix A to Title 10 of the Code of Federal Regulations (10 CFR) Part 50 requires that the reactor coolant pressure boundary be designed, fabricated, erected, and tested so as to have an extremely low probability of abnormal leakage, of rapidly propagating failure, and of gross rupture. SG tubes represent the majority of the reactor coolant pressure boundary.

GDC 30 of Appendix A to 10 CFR Part 50 requires, in part, that components which are part of the reactor coolant pressure boundary are designed, fabricated, erected, and tested to the highest quality standards practical and that means are provided for detecting and, to the extent practical, identifying the location of the source of reactor coolant leakage.

GDC 32 of Appendix A to 10 CFR Part 50 requires, in part, that components that are part of the reactor coolant pressure boundary be designed to permit the periodic inspection and testing of important areas and features to assess their structural and leakage integrity.

Appendix B to 10 CFR Part 50, Quality Assurance Criteria for Nuclear Power Plants and Fuel Reprocessing Plants, requires a quality assurance program to be applied to the design, fabrication, construction, and operation of structures, systems, and components in nuclear plants. The pertinent requirements of Appendix B apply to all activities affecting the safety-related functions of those structures, systems, and components. These activities include designing, purchasing, fabricating, handling, shipping, storing, cleaning, erecting, installing, inspecting, testing, operating, maintaining, repairing, refueling, and modifying.

Regulatory Guide (RG) 1.121, Bases for Plugging Degraded PWR [pressurized water reactor]

Steam Generator Tubes, provides guidance for determining minimum wall thickness, beyond which the degraded tube should be plugged (i.e., plugging limits). RG 1.121 also provides performance criteria that recommend that the margin of safety against tube rupture under normal operating conditions should not be less than 3 at any tube location where defects have been detected. The margin of safety against tube failure under postulated accidents, such as a loss-of-coolant accident, steam line break, or feedwater line break concurrent with the safe shutdown earthquake, should be consistent with the margin of safety determined by the stress limits specified in Section III of the American Society of Mechanical Engineers Code (ASME).

In summary, the review of the licensees request involves assessing whether the SG tube inspections performed at Kewaunee in 2003 will ensure the structural and leakage integrity of the SG tubes consistent with the design and licensing basis of the facility until the next scheduled SG tube inspection.

3.0 TECHNICAL EVALUATION

3.1 Background

The fundamental goal of the SG tube inspection and repair criteria is to ensure that the structural and leakage integrity of the SG tube bundle is maintained for the period of time between the inspections. Structural integrity involves demonstrating the tubes are capable of withstanding the loadings specified in the ASME Code and RG 1.121, "Bases for Plugging Degraded PWR Steam Generator Tubes." Leakage integrity involves demonstrating the dose consequences from SG tube leakage are acceptable per GDC 19 of 10 CFR Part 50, Appendix A, and 10 CFR Part 100. As a result, the NRC staffs review focused on whether the tube inspections performed by the licensee during their 2003 refueling outage are adequate in ensuring tube integrity for the period of time between inspections.

The licensees proposal involves a one-time extension of the 24 calendar month inspection frequency in TS Surveillance Requirement 4.2.b.3.a. to 40 calendar months. The licensees bases for the proposed TS amendment are the improved design features of the replacement SGs, the Spring 2003 tube inspection results, and related industry experience.

Information pertaining to the 2003 SG tube inspections, which were completed on April 19, 2003, was provided by the licensee in the 2003 Inservice Inspection Report, dated August 6, 2003 (ML032250165), and 2003 Annual Operating Report, dated February 27, 2004 (ML040650370).

3.2 SG Design Improvements The two SGs at Kewaunee Nuclear Power Plant were replaced during the refueling outage completed in the fall of 2001. The replacement SGs are Westinghouse model 54F SGs.

Improvements in the design of these SGs include:

The replacement SG tubing is made of thermally-treated Alloy 690 material, which has an increased resistance to stress corrosion cracking (SCC) over Alloy 600 material, which was used for the original Kewaunee SG tubing. Extensive industry testing has demonstrated that thermally-treated Alloy 690 material is superior to mill-annealed Alloy 600 material in its resistance to both primary and secondary system SCC, pitting, and general corrosion.

In addition to the thermal treatment process, additional stress relief was performed on all U-bends up to a 12-inch centerline radius. The additional stress relief on the low row U-bends was performed to relieve the residual stresses introduced by the tube bending process.

The replacement SG design uses tube support plates (TSP) fabricated from Type 405 stainless steel with broached quatrefoil tube holes. The stainless steel construction of the TSP virtually eliminates the potential for denting. The quatrefoil tube holes reduce the potential for dry-out and chemical concentration.

The replacement SG uses a flow distribution baffle (FDB) located between the top of the tubesheet and the lowest tube support plate fabricated from Type 405 stainless steel.

The FDB increases the flow velocity across the tubesheet surface, reduces sludge accumulation, and helps to mitigate corrosion.

The replacement SG utilizes three sets of anti-vibration bars in the U-bend region to stiffen the tube bundle, maintain proper tube spacing and alignment, and reduce tube vibration.

Full depth tube expansions eliminate the crevice in the tubesheet. Hydraulic expansion of the tubes into the tubesheet limits the residual stress in the SG tubes. Both these improvements reduce the susceptibility of the SG tube to corrosion.

3.3 Spring 2003 First Inservice Inspection During the refueling outage in the Spring of 2003, the licensee performed the first post-replacement SG tube inservice inspection at Kewaunee. The scope and results of this inspection are discussed in the licensee reports referenced above.

In summary, the licensee performed a bobbin inspection of 100 percent of the inservice tubes and performed rotating probe inspections on a sample of tubes at select locations. Rotating probe examinations were performed, in part, in the U-bend region of 20 percent of the Row 1 tubes, at the hot-leg expansion transition of 20 percent of the tubes, and at dings and dents that exceeded 5 volts.

No tube degradation due to wear or corrosion was detected in either of the Kewaunee SGs, and both SGs were classified as category C-1 (as defined in the plants TSs). Several possible loose part (PLP) indications were detected with a bobbin coil. All of these indications were inspected with a rotating probe, and there was no wear associated with any of the PLP indications. Visual examination confirmed three of these PLP indications were the result of loose parts. Of the three objects confirmed by visual examination, one small machine chip was removed. The licensee assessed the two loose parts left in service and concluded that they are not capable of causing significant damage to the Kewaunee SG tubes for the period of time between inspections. The staff concludes that the licensees operability assessment, which was based on analysis and experience with similar foreign objects, is reasonable.

3.4 Related Industry Experience To support its amendment request, the licensee reviewed industry operating experience with thermally-treated Alloy 690. Alloy 690 SG tubes are used at a number of plants world-wide. In addition, Alloy 690 has been used to fabricate sleeves used to repair degraded SG tubes. As a result of this review, the licensee concluded that the operating experience with Alloy 690 has been essentially flawless to-date (with wear-related degradation being the principal degradation mechanism).

Based on the 2003 inspection results and industry experience, the licensee assessed the effect of operating for a period of 40 calendar months between tube inspections and concluded that there is reasonable assurance that structural and leakage integrity will continue to be maintained until the next SG tube inspections. The staff concludes that the licensees assessment is reasonable.

3.5 Proposed Changes to the TSs TS Surveillance Requirement 4.2.b.3.a requires, in part, that two consecutive inspections result in a category C-1 classification before the inspection interval can be extended from a maximum of 24 calendar months to a maximum of 40 months. The licensee proposed to add a note to TS Surveillance Requirement 4.2.b.3.a which states:

A one-time inspection interval extension of a maximum of once per 40 months is allowed following the inspection performed during the Spring 2003 Outage. This is an exception to the Extension Criteria in that the inspection interval extension is based on the result of only one inspection result falling into the C-1 category.

The NRC staff finds that the proposed change is consistent with the technical basis of the proposed extension request.

3.6 Conclusion Based on a review of the information provided by the licensee, the NRC staff concludes that the replacement SGs incorporate both design and material improvements which are expected to improve the SG tubings resistance to all forms of service-induced corrosion, especially during the first several cycles of operation. In addition, based on a review of results of the Spring 2003 tube inspections, the operating experience with Alloy 690 SG tubes, and the licensees assessment of the results of the inspection, the staff concludes that there is reasonable assurance that the SGs can be safely operated for a 40-month operating interval between inspections, as proposed by the licensee. Therefore, the NRC staff has determined that the proposed TS changes are acceptable.

4.0 STATE CONSULTATION

In accordance with the Commission's regulations, the Wisconsin State official was notified of the proposed issuance of the amendment. The State official had no comments.

5.0 ENVIRONMENTAL CONSIDERATION

This amendment changes a surveillance requirement. The NRC staff has determined that the amendment involves no significant increase in the amounts, and no significant change in the types, of any effluent that may be released offsite and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that this amendment involves no significant hazards consideration and there has been no public comment on such finding (69 FR 2743). Accordingly, this amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the issuance of this amendment.

6.0 CONCLUSION

The staff has concluded, based on the considerations discussed above, that: (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public.

Principal Contributor: K. Karwoski Date: June 18, 2004