ML071790511

Supplemental Information Regarding License Amendment Request 05-0009- Steam Generator Tube Integrity

ML071790511
Person / Time
Site:	Davis Besse
Issue date:	06/27/2007
From:	Bezilla M FirstEnergy Nuclear Operating Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
3346, TAC MD2145
Download: ML071790511 (7)

Text

FENOC oC 5501 North State Route 2 FirstEnergyNuclear Operating Company Oak Harbor, Ohio 43449 Mark B. Bezilla 419-321-7676 Vice President - Nuclear Fax: 419-321-7582 Docket Number 50-346 License Number NPF-3 Serial Number 3346 June 27, 2007 United States Nuclear Regulatory Commission Document Control Desk Washington, D. C. 20555-0001

Subject:

Supplemental Information Regarding License Amendment Request 05-0009 -

Steam Generator Tube Integrity (TAC No. MD2145)

Ladies and Gentlemen:

By letter dated May 30, 2006 (Serial No. 3231), the FirstEnergy Nuclear Operating Company (FENOC) submitted License Amendment Request (LAR) No. 05-0009 to revise steam generator tube integrity Technical Specifications for Davis-Besse Nuclear Power Station (DBNPS), Unit No. 1. Subsequently, by letter dated April 24, 2007 (Serial No. 3338), FENOC provided a response to an NRC request for additional information regarding the LAR. As a result of follow-up discussions with the NRC staff regarding the April 24 letter, FENOC agreed to propose modifications to the proposed Technical Specification (TS) Section 6.8.4.g wording. Attachment 1 provides a revised markup of TS Section 6.8.4.g showing the proposed modifications.

FENOC has determined that the revisions proposed by this supplement do not affect either the original evaluation of proposed changes or the No Significant Hazards Consideration Determination provided in the May 30, 2006 submittal.

Attachment 2 identifies that there are no commitments contained in this submittal.

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Docket Number 50-346 License Number NPF-3 Serial Number 3346 Page 2 If there are any questions or if additional information is required, please contact Mr. Thomas A. Lentz, Manager - FENOC Fleet Licensing, at (330) 761-6071.

I declare under penalty of perjury that the foregoing is true and correct. Executed on June SL.), 2007.

Very truly yours, Mark B. Bezilla, Vic/resident - Nuclear MKL Attachments cc: Regional Administrator, NRC Region III NRC/NRR Project Manager NRC Senior Resident Inspector Utility Radiological Safety Board

Docket Number 50-346 License Number NPF-3 Serial Number 3346 UPDATED PROPOSED MARKUPS OF TECHNICAL SPECIFICATION SECTION 6.8.4.g (3 pages attached)

NOTE The revision bars shown on the following pages indicate changes to the proposed markup provided in the April 24, 2007 letter. Additions are double-underlined and deletions are struck through.

6.0 ADMINISTRATIVE CONTROLS 6.8.4 (Continued)

g. Steam Generator (SG) Program A Steam Generator Program shall be established and implemented to ensure that SG tube integrity is maintained. In addition, the Steam Generator Program shall include the following provisions:

I) Provisions for condition monitoring assessments: Condition monitoring assessment means an evaluation of the "as found" condition of the tubing with respect to the performance criteria for structural integrity and accident induced leakage. The "as found" condition refers to the condition of the tubing during a SG inspection outage, as determined from the inservice inspection results or by other means, prior to the plugging or repair of tubes. Condition monitoring assessments shall be conducted during each outage during which the SG tubes are inspected, plugged, or repaired to confirm that the performance criteria are being met.

2) Performance criteria for SG tube integrity: SG tube integrity shall be maintained by meeting the performance criteria for tube structural integrity, accident induced leakage, and operational leakage.

a. Structural integrity performance criterion: All in-service SG tubes shall retain structural integrity over the full range of normal operating conditions (including startup, operation in the power range, hot standby, and cooldown and all anticipated transients included in the design specification) and design basis accidents. This includes retaining a safety factor of 3.0 against burst under normal steady state full power operation primary to secondary pressure differential and a safety factor of 1.4 against burst applied to the design basis accident primary to secondary pressure differentials. Apart from the above requirements, additional loading conditions associated with the design basis accidents, or combination of accidents in accordance with the design and licensing basis, shall also be evaluated to determine if the associated loads contribute significantly to burst or collapse. In the assessment of tube integrity, those loads that do significantly affect burst or collapse shall be determined and assessed in combination with the loads due to pressure with a safety factor of 1.2 on the combined primary loads and 1.0 on axial secondary loads.

b. Accident induced leakage performance criterion: The primary to secondary accident induced leakage rate for any design basis accident, other than a SG tube rupture, shall not exceed the leakage rate assumed in the accident analysis in terms of total leakage rate for all SGs and leakage rate for an individual SG.

Leakage is not to exceed 1 gpm per SG, except during a SG tube rupture.

c. The operational leakage performance criterion is specified in LCO 3.4.6.2, "Reactor Coolant System Operational Leakage."

DAVIS-BESSE, UNIT I 6-10 Amendment No.

6.0 ADMINISTRATIVE CONTROLS 6.8.4.g (Continued)

3) Provisions for SG tube repair criteria

a. Tubes found by inservice inspection to contain flaws, in a region of the tube that contains no repair, with a depth equal to or exceeding 40% of the nominal tube wall thickness shall be plugged or repaired.

b. Sleeves found by inservice inspection to contain flaws, in a region of the sleeve that contains no sleeve joint, with a depth equal to or exceeding 40% of the nominal sleeve wall thickness shall be plugged.

c. Tubes with a flaw, in either the parent tube or the sleeve, within a sleeve-to-tube joint shall be plugged.

d. Tubes with a flaw in a repair roll shall be plugged.

4) 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 repair criteria. The tube-to-tubesheet weld is not part of the tube.

For tubes that have undergone repair rolling, the tube and tube roll, outboard of the new roll area in the tube sheet, can be excluded from inspections because it is no longer part of the pressure boundary once the repair roll is installed. For tubes that have undergone sleeving repairs, the segment of the parent tube between the bottom of the upper-most sleeve roll and the top of the middle sleeve roll can be excluded from inspection because it is no longer part of the pressure boundary once the sleeve is installed.For- tubes that have undergone sleeving repairs, sections of the parent tmube above the upper- most sleeve rcell and between the upper-most sleeve roll and the lowMer mcSt Sleeve roll can be exeluded from inspections beeauase they are no longer part of the pr.essu.r.e boundai.y on. e the sleeve is installed. In addition to meeting the requirements of 4.a through 4.e 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. An assessment of degradation 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.

a. Inspect 100% of the tubes in each SG during the first refueling outage following SG replacement.

b. Inspect 100% of the tubes at sequential periods of 60 effective full power months. The first sequential period shall be considered to begin after the first inservice inspection of the SGs. No SG shall operate for more than 24 effective full power months or one interval between refueling outages (whichever is less) without being inspected.

DAVIS-BESSE, UNIT 1 6-11 Amendment No.

6.0 ADMINISTRATIVE CONTROLS 6.8.4.g.4 (Continued)

c. If crack indications are found in any SG tube, then the next inspection for each SG for the degradation mechanism that caused the crack indication shall not exceed 24 effective full power months or one interval between refueling outages (whichever is less). If definitive information, such as from examination of a pulled tube, diagnostic non-destructive testing, or engineering evaluation indicates that a crack-like indication is not associated with a crack(s), then the indication need not be treated as a crack.

d. During each periodic SG tube inspection, inspect 100% of the tubes that have been repaired by the repair roll process.Inspect 100-% of the tbes that have been repird by the repair roll proceess dur-ing each periodic SG tube inispection. This special inspection shall be limited to the repair roll joint and the roll transitions of the repair roll.

e. Inspect peripheral tubes in the vicinity of the secured internal auxiliary feedwater header between the upper tube sheet and the 15th tube support plate during each periodic SG tube inspection. The tubes selected for inspection shall represent the entire circumference of the steam generator and shall total at least 150 peripheral tubes.

5) Provisions for monitoring operational primary to secondary leakage.

6) 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.

a. Sleeving in accordance with Topical Report BAW-2120P.

b. Repair rolling in accordance with Topical Report BAW-2303P, Revision 4. The new roll area must be free of flaws in order for the repair to be considered acceptable.

7) Special visual inspections: Visual inspections of the secured internal auxiliary feedwater header, header to shroud attachment welds, and the external header thermal sleeves shall be performed on each SG through the auxiliary feedwater injection penetrations. These inspections shall be performed during the third period of each ten-year Inservice Inspection Interval (ISI).

DAVIS-BESSE, UNIT I 6-12 Amendment No.

Docket Number 50-346 License Number NPF-3 Serial Number 3346 Page 1 of 1 COMMITMENT LIST The following list identifies those actions committed to by the Davis-Besse Nuclear Power Station (DBNPS) in this document. Any other actions discussed in the submittal represent intended or planned actions by the DBNPS. They are described only for information and are not regulatory commitments. Please contact Mr. Thomas A. Lentz, Manager - FENOC Fleet Licensing, at (330) 761-6071 of any questions regarding this document or any associated regulatory commitments.

COMMITMENT DUE DATE None N/A