ML21153A176

Issuance of Amendment No. 201 Revision of Technical Specifications Related to Steam Generator Tube Inspection, and Repair Methods

ML21153A176
Person / Time
Site:	Beaver Valley
Issue date:	06/30/2021
From:	Sujata Goetz Plant Licensing Branch 1
To:	Grabnar J Energy Harbor Nuclear Corp
Goetz S
References
EPID L-2020-LLA-0140
Download: ML21153A176 (22)

Text

June 30, 2021 Mr. John J. Grabnar Site Vice President Energy Harbor Nuclear Corp.

Beaver Valley Power Station Mail Stop P-BV-SSB P.O. Box 4, Route 168 Shippingport, PA 15077-0004

SUBJECT:

BEAVER VALLEY POWER STATION, UNIT NO. 2 - ISSUANCE OF AMENDMENT NO. 201 RE: REVISION OF TECHNICAL SPECIFICATIONS RELATED TO STEAM GENERATOR TUBE INSPECTION AND REPAIR METHODS (EPID L-2020-LLA-0140)

Dear Mr. Grabnar:

The U.S. Nuclear Regulatory Commission (NRC or Commission) has issued the enclosed Amendment No. 201 to Renewed Facility Operating License No. NPF-73 for the Beaver Valley Power Station, Unit No. 2. The amendment is in response to your application dated June 25, 2020 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML20177A272), as supplemented by letters dated January 22, 2021 (ADAMS Accession No. ML21022A133), February 16, 2021 (ADAMS Accession No. ML21048A082), and May 12, 2021 (ADAMS Accession No. ML21132A242).

The license amendment revises the technical specification (TS) requirements related to methods of inspection and service life for Alloy 800 steam generator tubesheet sleeves. The proposed TS changes also remove a note about sleeve inspection that would no longer be applicable.

J. Grabnar A copy of the related safety evaluation is also enclosed. Notice of Issuance will be included in the Commissions monthly Federal Register notice.

Sincerely,

/RA/

Sujata Goetz, Project Manager Plant Licensing Branch I Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-412

Enclosures:

1. Amendment No. 201 to NPF-73

2. Safety Evaluation cc: Listserv

ENERGY HARBOR NUCLEAR CORP.

ENERGY HARBOR NUCLEAR GENERATION LLC DOCKET NO. 50-412 BEAVER VALLEY POWER STATION, UNIT NO. 2 AMENDMENT TO RENEWED FACILITY OPERATING LICENSE Amendment No. 201 Renewed License No. NPF-73

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

A. The application for amendment by Energy Harbor Nuclear Corp*. (the licensee) acting on its own behalf and as agent for Energy Harbor Nuclear Generation LLC, dated June 25, 2020, as supplemented by letters dated January 22, 2021, February 16, 2021, and May 12, 2021, 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.

• Energy Harbor Nuclear Corp. is authorized to act as agent for Energy Harbor Nuclear Generation LLC and has exclusive responsibility and control over the physical construction, operation, and maintenance of the facility.

Enclosure 1

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 Renewed Facility Operating License No. NPF-73 is hereby amended to read as follows:

(2) Technical Specifications The Technical Specifications contained in Appendix A, as revised through Amendment No. 201, and the Environmental Protection Plan contained in Appendix B, both of which are attached hereto are hereby incorporated in the license. Energy Harbor Nuclear Corp. shall operate the facility in accordance with the Technical Specifications and the Environmental Protection Plan.

3. This license amendment is effective as of its date of issuance and shall be implemented within 60 days.

FOR THE NUCLEAR REGULATORY COMMISSION James G. Digitally signed by James G. Danna Danna Date: 2021.06.30 15:19:07 -04'00' James G. Danna, Chief Plant Licensing Branch I Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation

Attachment:

Changes to the Renewed Facility Operating License and Technical Specifications Date of Issuance: June 30, 2021

ATTACHMENT TO LICENSE AMENDMENT NO. 201 BEAVER VALLEY POWER STATION, UNIT NO. 2 RENEWED FACILITY OPERATING LICENSE NO. NPF-73 DOCKET NO.50-412 Replace the following pages of the Renewed Facility Operating License with the attached revised pages. The revised pages are identified by amendment number and contain vertical lines indicating the areas of change.

Renewed Facility Operating License No. NPF-73 Remove Insert Page 4 Page 4 Replace the following pages of the Appendix A, Technical Specifications, with the attached revised pages. The revised pages are identified by amendment number and contain marginal lines indicating the areas of change.

Appendix A, Technical Specifications Remove Insert 5.5-10 5.5-10 5.5-11 5.5-11 5.5-12 5.5-12

C. This renewed operating license shall be deemed to contain and is subject to the conditions specified in the following Commission regulations set forth in 10 CFR Chapter 1 and is subject to all applicable provisions of the Act and to the rules, regulations, and orders of the Commission now or hereafter in effect; and is subject to the additional conditions specified or incorporated below:

(1) Maximum Power Level Energy Harbor Nuclear Corp. is authorized to operate the facility at a steady state reactor core power level of 2900 megawatts thermal.

(2) Technical Specifications The Technical Specifications contained in Appendix A, as revised through Amendment No. 201, and the Environmental Protection Plan contained in Appendix B, both of which are attached hereto are hereby incorporated in the license. Energy Harbor Nuclear Corp. shall operate the facility in accordance with the Technical Specifications and the Environmental Protection Plan.

Amendment No. 201 Beaver Valley Unit 2 Renewed Operating License NPF-73

Programs and Manuals 5.5 5.5 Programs and Manuals 5.5.5.2 Unit 2 SG Program (continued)

NDE = 95-percent cumulative probability allowance for nondestructive examination uncertainty (i.e., a value of 20-percent has been approved by NRC). The NDE is the value provided by the NRC in GL 95-05 as supplemented.

Implementation of these mid-cycle repair limits should follow the same approach as in Specifications 5.5.5.2.c.4.a through 5.5.5.2.c.4.d.

5. The F* methodology, as described below, may be applied to the expanded portion of the tube in the hot-leg or cold-leg tubesheet region as an alternative to the 40% depth based criteria of Specification 5.5.5.2.c.1:

a) Tubes with no portion of a lower sleeve joint in the hot-leg or cold-leg tubesheet region shall be repaired or plugged upon detection of any flaw identified within 3.0 inches below the top of the tubesheet or within 2.22 inches below the bottom of roll transition, whichever elevation is lower. Flaws located below this elevation may remain in service regardless of size.

b) Tubes which have any portion of a sleeve joint in the hot-leg or cold-leg tubesheet region shall be plugged upon detection of any flaw identified within 3.0 inches below the lower end of the lower sleeve joint. Flaws located greater than 3.0 inches below the lower end of the lower sleeve joint may remain in service regardless of size.

c) The F* methodology cannot be applied to the tubesheet region where a laser or TIG welded sleeve has been installed.

d. Provisions for SG Tube Inspections Periodic SG tube inspections shall be performed. The number and portions of the tubes inspected and methods of inspection shall be performed with the objective of detecting flaws of any type (e.g., volumetric flaws, axial and circumferential cracks) that may be present along the length of the tube, from the tube-to-tubesheet weld at the tube inlet to the tube-to-tubesheet weld at the tube outlet, and that may satisfy the applicable tube plugging or repair criteria. The tube-to-tubesheet weld is not part of the tube. In tubes repaired by sleeving, the portion of the original tube wall between the sleeves joints is not an area requiring re-inspection. In addition to meeting the requirements of d.1, d.2, d.3, d.4 and d.5 below, the inspection scope, inspection methods, and inspection intervals shall be such as to ensure that SG tube integrity is maintained until the next SG inspection. A degradation assessment shall be performed to determine the type and location of flaws to which the tubes may be susceptible and, based on this assessment, to determine which inspection methods need to be employed and at what locations.

Beaver Valley Units 1 and 2 5.5 - 10 Amendments 296 / 

Programs and Manuals 5.5 5.5 Programs and Manuals 5.5.5.2 Unit 2 SG Program (continued)

1. Inspect 100% of the tubes in each SG during the first refueling outage following SG installation.

2. After the first refueling outage following SG installation, inspect each steam generator at least every 24 effective full power months or at least every refueling outage (whichever results in more frequent inspections).

In addition, inspect 100% of the tubes at sequential periods of 60 effective full power months beginning after the first refueling outage inspection following SG installation. Each 60 effective full power month inspection period may be extended up to 3 effective full power months to include a SG inspection outage in an inspection period and the subsequent inspection period begins at the conclusion of the included SG inspection outage. If a degradation assessment indicates the potential for a type of degradation to occur at a location not previously inspected with a technique capable of detecting this type of degradation at this location and that may satisfy the applicable tube plugging or repair criteria, the minimum number of locations inspected with such a capable inspection technique during the remainder of the inspection period may be prorated. The fraction of locations to be inspected for this potential type of degradation at this location at the end of the inspection period shall be no less than the ratio of the number of times the SG is scheduled to be inspected in the inspection period after the determination that a new form of degradation could potentially be occurring at this location divided by the total number of times the SG is scheduled to be inspected in the inspection period.

3. Indications left in service as a result of application of the tube support plate voltage-based plugging or repair criteria (Specification 5.5.5.2.c.4) shall be inspected by bobbin coil probe during all future refueling outages.

Implementation of the steam generator tube-to-tube support plate plugging or repair criteria requires a 100-percent bobbin coil inspection for hot-leg and cold-leg tube support plate intersections down to the lowest cold-leg tube support plate with known outside diameter stress corrosion cracking (ODSCC) indications. The determination of the lowest cold-leg tube support plate intersections having ODSCC indications shall be based on the performance of at least a 20-percent random sampling of tubes inspected over their full length.

4. When the F* methodology has been implemented, inspect 100% of the inservice tubes in the hot-leg tubesheet region with the objective of detecting flaws that may satisfy the applicable tube plugging or repair criteria of Specification 5.5.5.2.c.5 every 24 effective full power months or one interval between refueling outages (whichever is less).

Beaver Valley Units 1 and 2 5.5 - 11 Amendments 296 / 

Programs and Manuals 5.5 5.5 Programs and Manuals 5.5.5.2 Unit 2 SG Program (continued)

5. For Alloy 800 sleeves: The parent tube, in the area where the sleeve-to-tube hard roll joint and the sleeve-to-tube hydraulic expansion joint will be established, shall be inspected prior to installation of the sleeve. Sleeve installation may proceed only if the inspection finds these regions free from service induced indications.

e. Provisions for monitoring operational primary to secondary LEAKAGE

f. Provisions for SG Tube Repair Methods Steam generator tube repair methods shall provide the means to reestablish the RCS pressure boundary integrity of SG tubes without removing the tube from service. For the purposes of these Specifications, tube plugging is not a repair. All acceptable tube repair methods are listed below.

1. ABB Combustion Engineering TIG welded sleeves, CEN-629-P, Revision 02 and CEN-629-P Addendum 1.

2. Westinghouse laser welded sleeves, WCAP-13483, Revision 2.

3. Westinghouse leak-limiting Alloy 800 sleeves, WCAP-15919-P, Revision 2.

Beaver Valley Units 1 and 2 5.5 - 12 Amendments 296 / 

SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 201 TO RENEWED FACILITY OPERATING LICENSE NO. NPF-73 ENERGY HARBOR NUCLEAR CORP.

BEAVER VALLEY POWER STATION, UNIT NO. 2 DOCKET NO. 50-412

1.0 INTRODUCTION

By letter dated June 25, 2020 (Reference 1), and as supplemented by letters dated January 22, 2021 (Reference 2), February 16, 2021 (Reference 3), and May 12, 2021 (Reference 4), Energy Harbor Nuclear Corp. (the licensee), submitted a license amendment request (LAR) to change the technical specifications (TSs) for Beaver Valley Power Station, Unit No. 2 (Beaver Valley).

The proposed TS changes would revise requirements related to methods of inspection and service life for Alloy 800 steam generator (SG) tubesheet sleeves. The proposed amendment would also remove a note stating that the inspection objective of detecting flaws of any type along the tube wall does not apply to the portion of the tube adjacent to the nickel band on the sleeve at the lowest sleeve/tube joint.

The proposed TS changes are based on development of a qualified inspection technique for the SG tube behind the nickel band, as described in the license amendment request. The licensee provided additional information in response to NRC staff questions in References 2 to 4. The supplemental letters, dated January 22, February 16, and May 12, 2021, provided additional information that clarified the application, did not expand the scope of the application as originally noticed, and did not change the U.S. Nuclear Regulatory Commission (NRC) staffs original proposed no-significant-hazards-consideration determination as published in Volume 85 of the Federal Register, page 55514, on September 8, 2020 (85 FR 55514).

2.0 REGULATORY EVALUATION

2.1 System Description The SG tubes function as an integral part of the reactor coolant pressure boundary and, in addition, serve to isolate radiological fission products in the primary coolant from the secondary coolant and the environment. For the purpose of this safety evaluation (SE), SG tube integrity means that the tubes are capable of performing this safety function in accordance with the plant design and licensing basis.

Enclosure 2

2.2 Regulatory Requirements and Guidance Title 10 of the Code of Federal Regulations (10 CFR) Part 50, Domestic Licensing of Production and Utilization Facilities. The general design criteria (GDCs) in Appendix A, General Design Criteria for Nuclear Power Plants, to 10 CFR Part 50, were published in July 1971. The construction permit for Beaver Valley Unit 2 was issued in May 1974, based, in part, on conformance with the standards set forth in the GDCs. The GDCs provide regulatory requirements that state the reactor coolant pressure boundary shall be designed, fabricated, erected, and tested to have an extremely low probability of abnormal leakage ... and of gross rupture (GDC 14, Reactor coolant pressure boundary); shall be designed with sufficient margin to assure that the design conditions of the reactor coolant pressure boundary are not exceeded during ... normal operation, including operational occurrences, and under postulated accident conditions (GDC 15, Reactor coolant system design, and GDC 31, Fracture prevention of reactor coolant pressure boundary); shall be designed, fabricated, erected, and tested to the highest quality standards practical (GDC 30, Quality of reactor coolant pressure boundary); and shall be designed to permit periodic inspection and testing to assess structural and leaktight integrity (GDC 32, Inspection of reactor coolant pressure boundary).

The regulation, 10 CFR 50.36, requires that each license authorizing operation of a utilization facility (e.g., a nuclear power reactor) include TSs derived from the analyses and evaluation included in the safety analysis report, and amendments thereto. Specifically, 10 CFR 50.36(c) requires that TSs include, among other things, administrative controls. Administrative controls are defined by 10 CFR 50.36(c)(5), in part, as provisions necessary to ensure operation of the facility in a safe manner.

Beaver Valley TS 5.5, Programs and Manuals, which is in TS Section 5.0, Administrative Controls, requires that certain programs be established, implemented and maintained.

TS 5.5.5.2 requires a Unit 2 SG Program be established and implemented to ensure that SG tube integrity is maintained. In addition, the sleeves must also satisfy the structural and leakage integrity requirements in the Beaver Valley TSs. TS 5.5.5.2 requires that an SG program be established and implemented to ensure that SG tube integrity is maintained. TS 5.5.5.2.b.1 and TS 5.5.5.2.b.2 specify the structural integrity and accident induced leakage performance criteria that are to be met to maintain tube integrity.

3.0 TECHNICAL EVALUATION

3.1 Background

Before a plant is approved to operate, applicants for pressurized-water reactor licenses are required to analyze the consequences of postulated design-basis accidents, such as a SG tube rupture and a main steam line break. These analyses consider primary-to-secondary leakage that may occur during these events and must show that the offsite radiological consequences do not exceed the applicable limits of the 10 CFR 100.11 accident source term, GDC 19 for control room operator doses (or some fraction thereof as appropriate to the accident), or the plant-specific accident analysis limits contained in the Updated Final Safety Analysis The three SGs at Beaver Valley are Westinghouse Model 51 SGs. Each SG contains 3,376 mill-annealed Alloy 600 tubes. Each tube has a nominal outside diameter of 0.875 inches and a nominal wall thickness of 0.050 inches. The tubes are supported by a number of carbon steel tube support plates and Alloy 600 anti-vibration bars. The tubes were roll expanded at both ends for the full depth of the tubesheet. The inner diameter portion of the tubes from about

3 inches above the top-of-the tubesheet to about 1 inch above the tube ends (on both the hot-leg and cold-leg side of the SG) was shot-peened prior to operation. Shot peening is a method of increasing resistance to degradation driven by tensile stress, including stress corrosion cracking, by imparting compressive stress. In addition, the U bend region of the small radius tubes were in-situ stress relieved prior to operation.

Beaver Valley received previous amendments related to installation of SG tube sleeves. The U.S. Nuclear Regulatory Commission (NRC) issued an amendment in 2009 (Reference 5) that allowed SG sleeves to remain in service until 2017. Subsequent SG sleeve license amendments issued in 2015 (Reference 6) and 2018 (Reference 7) limited the sleeves service life to five operating cycles and eight operating cycles, respectively. In each case, the NRC issued TSs with limits on the SG tube service life primarily due to challenges with inspecting the SG tube behind the nickel band on the sleeve. The TS limit on the number of operating cycles and the note that excluded the tube area behind the nickel band from the flaw detection method requirements applicable to the tube length were based, in part, on the lack of a qualified inspection method in that location.

Westinghouse leak-limiting Alloy 800 SG tube repair sleeves are new tube segments that are inserted into a flawed parent SG tube to allow the tube to remain in service. Two versions of these sleeves have been approved for use in Beaver Valley SGs. The tube support plate sleeve design has been approved for permanent use; however, none have been installed to date, therefore, the support plate sleeve design is not discussed in this SE.

Tubesheet transition zone sleeves (see Figure 1) have been installed over multiple refueling outages at Beaver Valley. These sleeves allow tubes with flaws located near the secondary face of the tubesheet to remain in service by changing the pressure boundary from the parent tube to the inserted sleeve at the flaw location. The tubesheet transition zone sleeve upper joint is formed with a series of hydraulic expansions and the lower joint is formed using a mechanical roll expansion within the tubesheet. The lower roll joint sleeve outside diameter contains a thermally sprayed band of nickel alloy on the upper portion of the roll joint and a nickel band in the lower portion of the joint. The thermal spray band provides a rough surface that enhances the mechanical strength of the joint to resist tube pull-out. The nickel band layer provides enhanced leakage resistance between the sleeve and the parent tube.

The design, installation, analysis, and qualification tests of these sleeves were previously submitted in the Westinghouse topical report, WCAP-15919-P, Revision 2, Steam Generator Tube Repair for Westinghouse Designed Plants with 7/8 inch Inconel 600 Tubes Using Leak Limiting Alloy 800 Sleeves, January 2006 (proprietary). The non-proprietary version of the report is WCAP-15919-NP, Revision 2, dated January 2006 (Reference 9).

Figure 1. Schematic of Tubesheet Zone Leak Limiting Sleeve (Reference 9) 3.2 Previous NRC Technical Evaluations for the Use of Westinghouse Leak-Limiting Alloy 800 Sleeves at Beaver Valley Unit 2 On September 2009, by amendment 170 (Reference 5), the use of Alloy 800 sleeves in the tubesheet region of the Beaver Valley SGs was first approved as a repair method under TS 5.5.5.2.f.3. This amendment permitted the use of Westinghouse leak-limiting sleeves, WCAP-15919-P, Revision 2. It also revised some associated TS inspection and reporting requirements. Due to the challenges of inspecting the portion of the parent tube behind the nickel band in the lower sleeve joint, the 2009 license amendment required all tubesheet region sleeves to be removed from service by the spring 2017 refueling outage (2R19).

On December 2015, the NRC issued Amendment Nos. 296 and 184 (Reference 6) which approved changes to TS 5.5.5.2.f.3 to allow sleeves in the tubesheet region to remain in service for up to five fuel cycles of operation. Amendment Nos. 296 and 184 allowed the licensee to modify the sleeves from previous calendar year limitation to an equivalent operating cycle basis

that recognized that sleeves were not immediately installed following the 2009 amendment approval.

On February 2019, the NRC issued Amendment No. 193 (Reference 7) which permitted SG sleeves to remain in service for up to eight cycles of operation. The 2019 amendment revised the TSs to include additional technical information supporting longer term sleeve use and allowed up to eight fuel cycles for the leak limiting Alloy 800 SG tubesheet zone sleeves.

Historically, SG sleeve inspections have been performed using +PointTM probe. As stated in the 2019 amendment, due to uncertainties associated with the model assisted probability of detection simulation, performed by the licensee and associated with detection of potential flaws behind the nickel band with the +Point' probe, TS 5.5.5.2.d contains the following note specific to sleeve inspection in the lower tubesheet joint:

The requirement for methods of inspection with the objective of detecting flaws of any type (e.g., volumetric flaws, axial and circumferential cracks) that may be present along the length of the tube does not apply to the portion of the original tube wall adjacent to the nickel band (the lower half) of the lower joint for the repair process that is discussed in Specification 5.5.5.2.f.3. However, the method of inspection in this area shall be a rotating plus point (or equivalent) coil.

The SG tube plugging criterion of Specification 5.5.5.2.c.3 is applicable to flaws in this area.

The 2019 NRC staff SE also noted that a qualified inspection technique would be needed to approve the leak-limiting Alloy 800 tubesheet zone sleeves on a permanent basis.

In addition to sleeve inspection, the SEs in References 5 to 7 found sleeve material, design, and installation process to be acceptable, which are necessary to demonstrate that a sleeve can provide adequate structural and leakage integrity to allow the flawed parent tube to remain in service. The staff finds that the previous qualification testing remains valid since the licensee has not proposed to modify the sleeve design, material, or installation process.

In the current LAR, the licensee details the development of a new inspection method for the nickel band region of the lower joint of tubesheet zone sleeves using a new probe called Ghent Version 2. Therefore, the focus of this SE is on the ability of the modified eddy current probe to detect flaws in the parent tube behind the nickel band and why flaws that may not be reliably detected are acceptable.

3.3 Proposed Changes In support of its LAR, the licensee submitted two documents related to development of an eddy current technique for inspection behind the nickel band in the tubesheet zone sleeve:

x SG-CDMP-19-17-P/NP, Qualification of an Examination Technique to Inspect Parent Tube Flaws Adjacent to the Nickel Band of an Alloy 800 Sleeve at Beaver Valley Unit 2, April 2020.

x SG-CDMP-19-19-P/NP, Probability of Flaw Detection in the Alloy 800 Mechanical Sleeve Lower Tubesheet Joint Using the Ghent Version 2 Eddy Current Probe, April 2020.

SG-CDMP-19-17-P/NP describes the methodology and processes used to qualify the Beaver Valley eddy current technique used to detect flaws in the parent tubing adjacent to the nickel band region of the Alloy 800 sleeve assembly. SG-CDMP-19-19-P/NP provides the results from inspection of tubing samples containing stress corrosion cracking and evaluates the probability of flaw detection in the lower tubesheet zone of the sleeve using the Ghent Version 2 eddy current probe. Non-proprietary versions of the Beaver Valley Unit 2 SG Sleeve LAR enclosures are available in Energy Harbor Nuclear Corp, Non-Proprietary versions of LAR Appendices A, B, C, D, and F, April 2020 (Reference 10).

Based on the new probe inspection capability for the nickel band, combined with the continued use of +PointTM probe, the LAR proposes two changes to the TS to remove the limitation on the number of cycles of operation an Alloy 800 sleeve can remain in service in the tubesheet region.

The licensee proposed to delete the note in TS 5.5.5.2.d that describes inspection requirements specific to the lower sleeve joint in the region of the nickel band, including the requirement to use a rotating +Point' (or equivalent) coil in that region because SG tube plugging criterion of TS 5.5.5.2.c.3 is applicable to the flaws in the portion of the original tube wall adjacent to the nickel band region (i.e., the lower half) of the tubesheet joint. The licensee stated that this requirement is redundant to the requirement specified in TS 5.5.5.2.c.3.

5.5.5.2.d Provisions for SG Tube Inspections

-NOTE-The requirement for methods of inspection with the objective of detecting flaws of any type (e.g., volumetric flaws, axial and circumferential cracks) that may be present along the length of the tube does not apply to the portion of the original tube wall adjacent to the nickel band (the lower half) of the lower joint for the repair process that is discussed in Specification 5.5.5.2.f.3. However, the method of inspection in this area shall be a rotating plus point (or equivalent) coil. The SG tube plugging criterion of Specification 5.5.5.2.c.3 is applicable to flaws in this area.

The Licensee also proposed to delete the sentence in TS 5.5.5.2.f.3 limiting Alloy 800 sleeves installed in the tubesheet region to no more than eight fuel cycles. The licensees proposed TS revisions, with the deletions shown with strike-through font, are as follows:

5.5.5.2.f Provisions for SG Tube Repair Methods

3. Westinghouse leak-limiting Alloy 800 sleeves, WCAP-15919-P, Revision 2. An Alloy 800 sleeve installed in the hot-leg or cold-leg tubesheet region shall remain in service for no more than eight fuel cycles of operation starting from the outage when the sleeve was installed.

3.4 Evaluation of Proposed Changes The Beaver Valley Updated Final Safety Analysis states that there are approximately 570 leak limiting Alloy 800 tubesheet zone sleeves in-service. Historically, the inspection program for the Alloy 800 sleeves were performed with a +Point' eddy current probe. Due to previous TS limitations on sleeve life and uncertainty about flaw detection thresholds behind the nickel band

in the parent tubing, the licensee determined that a different inspection technique was required that improves detection through the masking effects created by the nickel band.

After a feasibility study, the licensee determined that a modified Version 2 Ghent Probe produced the most promising detection improvement (Reference 11). The Version 2 Ghent Probe modifications include a magnet to saturate the sleeves ferromagnetic nickel band and probe coil positioning to enhance circumferential crack detection. The Version 2 probe also contains a +PointTM coil to improve inspection efficiencies since the +PointTM is qualified to inspect the non-nickel band region of the tube and sleeve assembly.

The licensee performed a site-specific qualification of the Version 2 Ghent Probe using the Electric Power Research Institute (EPRI) Examination Guidelines, Appendix H (Reference 12).

The licensee also used the Version 2 Ghent Probe for supplemental information during the Beaver Valley 2R21 refueling outage in spring 2020 to collect data on all in-service sleeved tubes at the lower tubesheet joint. The Version 2 Ghent Probe detected scratches that were present in two sleeves at the interface between the sleeve nickel band and tube inner diameter surface. Since these two surfaces are rolled into intimate contact, it was not possible from the data to determine if the scratches were in the nickel band of the sleeve or the tube inner diameter.

The licensee provided responses, as detailed References 2 - 4, regarding the modified Version 2 Ghent Probe design in order to evaluate its ability to detect flaws in the parent tube behind the nickel band.

The NRC staff asked the licensee how the sleeve nickel band thickness (within the specified tolerance limit) would affect the probability of crack detection, since the nickel band effects are not totally removed by the Version 2 Ghent Probe. In response, the licensee performed a nickel thickness study that is described in Reference 3. Based on the electrical discharge machining notch response over a range of conditions from no nickel to the maximum sleeve nickel band thickness, the licensee developed a relationship between nickel thickness and the change in flaw amplitude. The licensee applied this relationship to the outer diameter of sample flaw amplitudes to show how different nickel thickness values affect the eddy current signal amplitude from a crack. Although the relationship between nickel thickness and reduction in flaw amplitude may not be identical for electrical discharge machining notches and cracks, the NRC staff concluded, based on the nickel thickness study data, that deep cracks will be detected in the parent tube behind the nickel band, even if the sleeve nickel band thickness is at the upper specification limit.

The staff also asked about the ability of the Version 2 Ghent Probe to detect stress corrosion cracking, as compared to electrical discharge machining notches, located in the parent tube behind the nickel band. Because stress corrosion cracking affects less tube volume compared to electrical discharge machining notches, it is more challenging to detect.

The sample flaws used for the Beaver Valley probe site were created with electrical discharge machining. As documented in the SG-CDMP-19-19-P/NP, the licensee evaluated probe performance with stress corrosion cracking by performing a probability of detection study with the Version 2 Ghent Probe. Alloy 800 sleeves were inserted into tube samples containing the outer diameter stress corrosion cracking of various depths (Reference 2) that were obtained from EPRI. The tubes were positioned such that the cracks were centered about the middle of the nickel band on the sleeve to simulate the most challenging inspection scenario. Following eddy current testing, the cracked tube samples were destructively examined in a laboratory and

the crack depths were measured to support development of probability of detection for the Version 2 Ghent Probe.

Using results from the cracked sleeve-parent tube assembly inspections and destructive examinations, the licensee created probability of detection curves using three different methods:

(1) a simple hit-miss probability of detection, (2) an unadjusted model assisted probability of detection , and (3) an optimized model assisted probability of detection that provided a crack amplitude adjustment to account for the nickel bands influence on crack signals. The 95th percentile probability of detection values for the three methods varied. The licensee considered the hit-miss probability of detection curve to provide the best representation of the actual flaw detection as the LAR stated that the full effect of the nickel band is inherent in this curve.

Given the limited number of detected cracks for the hit-miss curve, the NRC staff determined that the more conservative model assisted probability of detection curves would better represent plant inspections. Therefore, the NRC staff hypothesized that for the more challenging to detect circumferential crack orientation, a 60 percent through-wall (TW) parent tube crack behind the nickel band in the sleeve, would not be detected. The staff also hypothesized that the probability of detection will increase with increasing crack depth and that a deep crack (e.g.,

85-90 percent TW) would be detected with high probability. Version 2 Ghent Probe was able to detect the scratches at the nickel band-parent tube interface during the 2R21 refueling outage at Beaver Valley.

The NRC staff also hypothesized that a parent tube could contain a crack less than 85 percent TW behind the nickel band that was not detected, which is a conservative assumption since operating experience and analysis suggest this location will not be susceptible to cracking. As discussed in the NRC staffs 2019 SE (Reference 7), operating experience and previous analytical modeling indicate cracking will not occur in this location.

More than 10,000 tubesheet zone sleeves have been installed worldwide for various lengths of time and no cracking behind the nickel band has ever been detected. Even though the eddy current probes used for those inspections may have a reduced probability of crack detection compared to the Version 2 Ghent Probe, the staff expects that cracking would have been detected in some sleeve assemblies if cracking behind the nickel band was occurring.

In addition, the absence of detected cracks behind the nickel band in tubesheet zone sleeves is consistent with previous analysis provided by the licensee (Reference 13) indicating (absent localized geometry discontinuities) that the inner surface of the parent tube behind the nickel band would be in compression, and therefore unlikely to crack.

Before the sleeve is installed, the licensee is required by TS 5.5.5.2.d to inspect the parent tube to verify the local tube condition is acceptable free from flaws and anomalies before making the bottom sleeve roll joint. Creating a compressive residual stress (as opposed to a tensile residual stress) on the inner diameter surface of the tubes makes the tubes resistant to primary water stress corrosion-cracking. In addition, the inside surface of the tubes installed in Beaver Valley were shot-peened in the tubesheet region of interest to induce a residual compressive residual stress. The reduced susceptibility to primary water stress corrosion cracking from pre-service shot peening alone is demonstrated by the small fraction of tubes in Beaver Valley that have experienced primary water stress corrosion cracking at the top-of-the tubesheet location compared to similar designed SGs with the same tubing alloy but were not shot-peened.

Despite the conservative assumption that tube cracking could occur in the parent tube behind the sleeves nickel band and be undetected, previous licensee testing and analysis reviewed and accepted by the NRC staff (Reference 7) demonstrated that the sleeve assembly meets structural and leakage integrity requirements. Although this SE discusses the results of previous tests, the previous staff SEs (References 5 to 7) provide greater detail concerning previous testing and analysis demonstrating that the Alloy 800 leak limiting sleeve assembly meets the structural and leakage integrity requirements. Previous testing of axially slotted tube samples showed that axial cracks have little impact on the axial load bearing capability of the sleeve roll joint.

In addition, previous mechanical tests also simulated a 100 percent TW circumferential crack by testing circumferentially separated tubes at the intersection of the microlok and nickel band region. The separated tube condition was shown to meet all structural requirements and bounds any postulated circumferential cracking in the parent tube behind the nickel band.

Previous laboratory testing has also demonstrated that sleeve-to-tube joint leakage will be small, even for limited length roll expansions of approximately one half the design roll expanded length. Thus, the leakage test results showed that postulated degradation behind the nickel band, even if undetected, will not lead to excessive leakage beyond that currently allotted to each sleeve in Beaver Valley.

The LAR also provided the results from three fully probabilistic operational assessment runs for one cycle assuming that three cracks are present but not detected in the tubing behind the nickel band within the sleeved tube population. The three analyses were performed using undetected flaw depth distributions determined from the hit-miss probability of detection curve, the optimized model assisted probability of detection curve, and the unadjusted model assisted probability of detection curve (the most conservative). The operational assessment was performed for one cycle since eddy current inspections will be performed with the Version 2 Ghent Probe each refueling outage. A uniform flaw length distribution was assumed from a short crack up to the full length of the nickel band. The industry maximum depth crack growth distribution (Reference 14) was applied to beginning-of-cycle flaw distribution. The results from all three fully probabilistic analyses met the probability of burst and probability of leakage acceptance criteria while conservatively assuming that the bottom sleeve joint was in the tubing free-span and not within the tubesheet. The operational assessment adds further support that the tubesheet zone sleeve joint will maintain tube integrity, even if a crack is present in the parent tube behind the nickel band but was not detected.

3.5 Technical Conclusion In Reference 7, the NRC staff previously found the tubesheet zone sleeve acceptable for service on a limited basis and consistent with the design, testing, and inspection requirements for the reactor coolant pressure boundary in GDC 14, 15, 30, 31 and 32 of Appendix A to 10 CFR Part 50. Based on the information provided in the LAR, the NRC staff finds the licensee tubesheet zone sleeve acceptable for service without any limitation on service life since (a) the licensee will be inspecting the parent tube at the location where the sleeve joints will be established to ensure the region is free of detectable flaws and anomalies prior to sleeving, (b) cracks are unlikely to form in the parent tube behind the nickel band due to a favorable stress state, (c) if cracks were to develop in this location, the Version 2 Ghent Probe will detect the crack with high probability once the cracks become deep (e.g., 85 percent TW), and (d) even if deep cracks are present in the parent tube behind the nickel band but were not detected, the sleeve joint still meets all structural and leakage requirements. Thus, the NRC staff concludes

that the licensee demonstrated that the tubesheet sleeve design and inservice inspections will maintain SG tube structural and leakage integrity over the full range of normal operating conditions, anticipated transients, and accident conditions.

The NRC staff finds that deleting the note in TS 5.5.5.2.d, which would remove the exception for applying the inspection requirement objective to the original tube wall adjacent to the nickel band of the lower sleeve joint, is acceptable. Deleting this portion of the note restores the more stringent requirement that the method of inspection has the objective of detecting flaws of any type that may be present along the length of the tube per TS 5.5.5.2.d. The licensees development of a site-specific qualified eddy current inspection technique with the Ghent V2 Probe supports the deletion of the first portion of this note.

NRC staff also finds it acceptable to delete the requirement that the SG tube plugging criterion of TS 5.5.5..2.c.3 be applied because this requirement is also specified in TS 5.5.5.2.c.3 and thus need not be restated in TS 5.5.5.2.d.

NRC staff also finds it acceptable to delete the Notes reference to TS 5.5.5.2.f.3, which restricts the operating service life of tubesheet zone sleeves to eight fuel cycles, and to delete the last sentence in TS 5.5.5.2.f.3, since the licensee has demonstrated that the Ghent Version 2 probe has the ability to detect flaws in the sleeve and parent tube wall that would challenge tube integrity. In addition, the licensee operational assessment demonstrated that tube structural and leakage integrity will be maintained to the next inspection even if cracks were not detected. Therefore, there is reasonable assurance that the tubesheet zone sleeves sleeves can remain in service beyond eight cycles and maintain tube integrity without a service life restriction.

In sum, the NRC staff finds that the proposed changes licenseesatisfy the 10 CFR 50.36(c)(5) requirement for administrative controls because the TSs, as revised, include sufficient provisions to ensure the operation of the facility with the tube sleeves in a safe manner.

4.0 STATE CONSULTATION

In accordance with the Commissions regulations, the Pennsylvania State official was notified of the proposed issuance of the amendment on May 24, 2021. The State official had no comments.

5.0 ENVIRONMENTAL CONSIDERATION

The amendment changes a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20. The NRC staff has determined that the amendment involves no significant increase in the amounts, and no significant change in the types, of any effluents 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 the amendment involves no significant hazards consideration, and there has been no public comment on such finding (85 FR 55514). Accordingly, the amendments meet 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 the amendment.

6.0 CONCLUSION

The Commission 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) there is reasonable assurance that such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.

7.0 REFERENCES

1. Penfield, Rod, Energy Harbor Nuclear Corp., letter to U.S. Nuclear Regulatory Commission, License Amendment Request to Revise Technical Specification Requirements Related to Inspection Method and Service Life for Alloy 800 Steam Generator Tubesheet Sleeves, dated June 25, 2020, ADAMS Accession No. ML20177A272.

2. Grabnar, John J., Energy Harbor Nuclear Corp., letter to U.S. Nuclear Regulatory Commission, Response to Request for Additional Information Regarding Steam Generator Tube Sleeve License Amendment Request, dated January 22, 2021, ADAMS Accession No. ML21022A133.

3. Grabnar, John J., Energy Harbor Nuclear Corp., letter to U.S. Nuclear Regulatory Commission, Response to Request for Additional Information for Question RAI #1c, dated February 16, 2021, ADAMS Accession No. ML21048A082.

4. Grabnar, John J., Energy Harbor Nuclear Corp., letter to U.S. Nuclear Regulatory Commission, Response to Request for Additional Information Regarding Steam Generator Tube Sleeve License Amendment Request (EPID L-2020-LLA-0140), dated May 12, 2021, ADAMS Accession No. ML21132A242.

5. Morgan, Nadiyah, U.S. Nuclear Regulatory Commission, letter to Peter P. Sena, III, Sena, FirstEnergy Nuclear Operating Company, Beaver Valley Power Station, Unit No. 2 - Issuance of Amendment Re: The Use of Westinghouse Leak-Limiting Alloy 800 Sleeves for Steam Generator Tubes [sic] Repair, dated September 30, 2009, ADAMS Accession No. ML092590189.

6. Lamb, Taylor A., U.S. Nuclear Regulatory Commission, letter to Eric A. Larson, FirstEnergy Nuclear Operating Company, Beaver Valley Power Station, Unit Nos. 1 and 2 - Issuance of Amendments Re: License Amendment Request to Revise Steam Generator Technical Specifications, dated December 16, 2015 ADAMS Accession No. ML15294A439.

7. Parker, Carleen J., U.S. Nuclear Regulatory Commission, letter to Ricard D. Bologna, FirstEnergy Nuclear Operating Company, Beaver Valley Power Station, Unit 2 -

Issuance of Amendment No. 193 Re: Revise Steam Generator Technical Specifications, dated February 25, 2019, ADAMS Accession No. ML18348B206.

8. U.S. Nuclear Regulatory Commission, Regulatory Guide (RG) 1.121, Bases for Plugging Degraded PWR Steam Generator Tubes, August 1975, ADAMS Accession No. ML003739366.

9. Westinghouse Electric Company, LLC, WCAP-15919-NP, Revision 2, Steam Generator Tube Repair for Westinghouse Designed Plants with 7/8 Inch Inconel 600 Tubes Using Leak Limiting Alloy 800 Sleeves, January 2006, ADAMS Accession No. ML082890824.

10. Energy Harbor Nuclear Corp., Non-Proprietary versions of LAR Appendices A, B, C, D, and F, April 2020, ADAMS Accession No. ML20177A273.

11. Energy Harbor Nuclear Corp., Ghent Version 2 Probe License Amendment Request, dated May 26, 2020, ADAMS Accession No. ML20143A035.

12. Electric Power Research Institute, EPRI Report 3002007572, Revision 8, "Steam Generator Management Program: Pressurized Water Reactor Steam Generator Examination Guidelines, June 2016.

13. Bologna, Richard, FirstEnergy Nuclear Operating Company, letter to U.S. Nuclear Regulatory Commission, Beaver Valley Power Station, Unit No. 2, Steam Generator Technical Specification Amendment Request, dated March 28, 2018, ADAMS Accession No. ML18087A293.

14. EPRI Technical Report 3002007571 , "Steam Generator Management Program: Steam Generator Integrity Assessment Guidelines: Revision 4," June 2016, ADAMS Accession No. ML16208A272.

Principal Contributors: P. Klein, NRR G. Makar, NRR Date: June 30, 2021

J. Grabnar

SUBJECT:

BEAVER VALLEY POWER STATION, UNIT NO. 2 - ISSUANCE OF AMENDMENT NO. 201 RE: REVISION OF TECHNICAL SPECIFICATIONS RELATED TO STEAM GENERATOR TUBE INSPECTION AND REPAIR METHODS (EPID L-2020-LLA-0140) DATED JUNE 30, 2021 DISTRIBUTION:

Public PM File Copy RidsNrrDnrlNcsg Resource RidsNrrDssStsb Resource RidsRgn1MailCenter Resource RidsACRS_MailCTR Resource RidsNrrDorlLpl1 Resource RidsNrrLAKZeleznock Resource RidsNrrLAJBurkhardt Resource RidsNrrPMBeaverValley Resource PKlein, NRR SBloom, NRR GMakar, NRR ADAMS Accession No.: ML21153A176 OFFICE NRR/DORL/LPL1/PM NRR/DORL/LPL1/LAiT NRR/DORL/LPL1/LA NRR/DSS/STSB/BC(A)

NAME SGoetz KZeleznock JBurkhardt NJordan DATE 6/10/2021 6/04/2021 6/09/2021 6/7/2021 OFFICE NRR/DNRL/NCSG/BC OGC - NLO NRR/DORL/LPL1/BC NRR/DORL/LPL1/PM NAME SBloom MYoung JDanna SGoetz DATE 5/26/2021 6/29/2021 6/30/2021 6/30/2021