ML040780557

Request for Additional Information Concerning License Amendment Request for a One-Time Increase in Steam Generator Inspection Interval

ML040780557
Person / Time
Site:	Harris
Issue date:	03/12/2004
From:	Chandu Patel NRC/NRR/DLPM/LPD2
To:	Scarola J Carolina Power & Light Co
Patel C P, NRR/DLPM, 415-3025
References
TAC MC1633
Download: ML040780557 (6)

Text

March 12, 2004 Mr. James Scarola, Vice President Shearon Harris Nuclear Power Plant Carolina Power & Light Company Post Office Box 165, Mail Code: Zone 1 New Hill, North Carolina 27562-0165

SUBJECT:

SHEARON HARRIS NUCLEAR PLANT, UNIT 1 - REQUEST FOR ADDITIONAL INFORMATION CONCERNING THE LICENSE AMENDMENT REQUEST FOR A ONE-TIME INCREASE IN STEAM GENERATOR INSPECTION INTERVAL (TAC NO. MC1633)

Dear Mr. Scarola:

By letter dated December 8, 2003, Carolina Power & Light Company proposed a change to Technical Specification 4.4.5.3a, Steam Generator Surveillance Requirements, for the Shearon Harris Nuclear Power Plant. The proposed one-time change would revise the Steam Generator inspection frequency requirements to allow a 40-month inspection interval after the completion of the first inservice inspection following steam generator replacement, rather than after two consecutive inspections resulting in C-1 classification.

Based on our review of the information provided by you, we have determined that additional information is required to complete our review. The details about the required information are provided in the enclosure. This information was discussed with your staff during a conference call on March 11, 2004. As discussed during the conference call, we request that you provide your response as soon as possible but no later than April 15, 2004.

Sincerely,

/RA/

Chandu P. Patel, Project Manager, Section 2 Project Directorate II Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket No. 50-400

Enclosure:

Request for Additional Information cc w/encl: See next page

ML040780557 NRR-088 OFFICE PM:PDII/S2 LA:PDII/S2 SC:PDII/S2 NAME CPatel EDunnington WBurton (A)

DATE 3/12/04 3/12/04 3/12/04 COPY Yes/No Yes/No Yes/No REQUEST FOR ADDITIONAL INFORMATION FOR CAROLINA POWER & LIGHT COMPANY SHEARON HARRIS NUCLEAR PLANT UNIT NO. 1 DOCKET NUMBER 50-261 TAC. NO. MC1633

1. The amendment request dated December 8, 2003, states that a 100% inspection of all open tubes was conducted during the first outage (RFO-11) following steam generator (SG) replacement. In the RFO-11 summary report dated July 20, 2003 (ADAMS No.

ML032680868), it was stated that: (1) 100% of the open steam generator tubing (all three steam generators) was inspected using a bobbin probe, (2) rotating coil exams were conducted on a sample of benign indications recorded from the preservice inspection, and (3) rotating coil exams were conducted on a sample of benign indications newly found during RFO-11. In the description for the preservice inspection dated April 1, 2002 (ADAMS No. ML020990567), it was stated that the following eddy current inspections were conducted: (1) 100% of all open tubes with a bobbin coil, (2) 100% of all manufacturing dents $ 2.0 volts with a rotating coil probe, (3) 100% of all open tubes with rotating coil and pancake coil at the hot leg top-of-tubesheet transitions

+/- 2-in., and (4) 100% of the Row 1 U-bend region from the upper hot leg to cold leg support with a rotating coil.

a. Discuss whether any tubes were identified that were not expanded for the full depth of the tubesheet. If some tubes were not fully expanded, provide the number of tubes affected, the length of the expansion (include the tubesheet thickness), the tube identification, and any corrective actions taken (or planned).

If any tubes are currently in service that were not fully expanded, discuss whether these tubes will retain adequate integrity until the next scheduled inspection. Include in the response your technical basis for your conclusion.

The staff notes that a crevice between the tube and tubesheet can result in a corrosive environment (i.e., the crevice region may lead to tube degradation in shorter time periods than what would be observed for nominal tubing).

b. Discuss whether any tubes were identified that were expanded above the top of the tubesheet or whether any tubes were identified with bulges. If such tubes were identified, provide the number of tubes affected, the size of the bulge, the tube identification, and any corrective actions taken (or planned). If any such tubes are currently in service, discuss whether these tubes will retain adequate integrity until the next scheduled inspection. Include in the response your technical basis for your conclusion. The staff notes that a bulge (i.e.,

overexpansion) can result in increased stresses in the tube which may lead to degradation in shorter time periods than what would be observed for nominal tubing.

c. With respect to the benign indications identified during RFO 11, discuss the nature of these indications (e.g., manufacturing burnish mark) and the number of indications in each grouping. Discuss whether these indications could be traced ENCLOSURE

to the baseline inspection. If any of the indications could not be traced back to baseline, discuss the cause of these indications and your technical basis for leaving them in service.

2. It was indicated that some of the preservice inspection benign indications displayed a slight signal phase rotation upon eddy current examination during RFO-11, and that phase rotation after the first cycle of plant operation has been observed by the eddy current analysis at other plants with replacement steam generators with similar tubing.

It was noted that signal phase rotation was not evidence of tube degradation.

Discuss the cause of this phase rotation and whether the phase rotation observed at Harris was caused by the same mechanism as that which caused the phase rotation at the other plants. That is, provide a basis for the conclusion that no service-induced degradation is occurring in the benign indications that experienced signal phase rotation. Include in your response a discussion of why all of the benign indications did not have a slight phase rotation.

3. It was noted in the amendment request that no indications of mechanical wear were noted in areas where the tubes contact with the anti-vibration bars (AVBs). It is also stated that the Westinghouse Delta 75 steam generators are designed in such a way that the potential for tube wear is reduced.

Clarify whether any service-induced AVB wear has been observed in Westinghouse Delta Series steam generators. If wear has been observed, discuss the maximum growth rate observed and whether tube integrity will be maintained for the operating interval between inspections.

4. Describe what actions, if any, were taken to verify that the steam generator tubes were manufactured (i.e., processing, heat treatment, etc.) as specified so as to exhibit optimal resistance to degradation (refer to NRC Information Notice 2002-21 dated April 1, 2003). If tubes with non-optimal tube processing have been identified, discuss the implications of these findings with respect to tube integrity for the proposed 40-month interval between inspections.

5. Provide the following general design information regarding the steam generators:

a. Schematic that depicts the tube supports and the tube support naming conventions

b. Tubesheet map that depicts the rows and columns of the tubes

c. Tube manufacturer

d. Tube outside diameter and wall thickness

e. Tube pitch and orientation (i.e., 1.1-in. triangular)

f. Any other noteworthy design characteristics, not included in your amendment request, that could be a factor regarding tube integrity

g. Measurement scheme when reporting eddy current analysis results (i.e., points of reference for measurements: the bottom of a support, middle of support, etc.)

h. Tube support (including AVB) thickness

6. Clarify what will be required under your proposed technical specifications if the next inspection is classified as C-2 or C-3. For example, would NRC approval be required to continue with 40-month inspection intervals? If not, modify the proposed wording such that if the next inspection is not C-1, NRC approval would be required to continue with a 40-month inspection interval.

7. A primary-to-secondary leak was observed at a plant that recently replaced their steam generators. In reviewing the eddy current data for the leaking tube (both preservice and inservice inspection data), the licensee noticed an anomalous dent signal. Although the leak was attributed to this dent signal, there was no clear indication of a 100%

through-wall flaw based on the rotating probe data (the leak was attributed to this location based on visual and non-destructive examination data).

Given that your steam generators contain dents/dings, discuss the potential for a through-wall or near through-wall flaw to exist at these locations (e.g., are there anomalous dent/ding signals?). Please discuss your primary-to-secondary leakage history since installation of the steam generators. Discuss whether the hydrostatic test and/or other pressure tests performed during fabrication would have been able to detect small leaks through the tubes. Discuss whether any other inspection data could represent through-wall or near through-wall flaws (e.g., do other types of indications exhibit anomalous signals?).

Mr. James Scarola Shearon Harris Nuclear Power Plant Carolina Power & Light Company Unit 1 cc:

Steven R. Carr Mr. Robert J. Duncan II Associate General Counsel - Legal Director of Site Operations Department Shearon Harris Nuclear Power Plant Progress Energy Service Company, LLC Carolina Power & Light Company Post Office Box 1551 Post Office Box 165, Mail Zone 1 Raleigh, North Carolina 27602-1551 New Hill, North Carolina 27562-0165 Resident Inspector/ Harris NPS Mr. Robert P. Gruber c/o U. S. Nuclear Regulatory Commission Executive Director 5421 Shearon Harris Road Public Staff NCUC New Hill, North Carolina 27562-9998 4326 Mail Service Center Raleigh, North Carolina 27699-4326 Ms. Margaret A. Force Assistant Attorney General Chairman of the North Carolina State of North Carolina Utilities Commission Post Office Box 629 Post Office Box 29510 Raleigh, North Carolina 27602 Raleigh, North Carolina 27626-0510 Public Service Commission Mr. Herb Council, Chair State of South Carolina Board of County Commissioners Post Office Drawer 11649 of Wake County Columbia, South Carolina 29211 P. O. Box 550 Raleigh, North Carolina 27602 Ms. Beverly Hall, Section Chief Division of Radiation Protection Mr. Tommy Emerson, Chair N.C. Department of Environment Board of County Commissioners and Natural Resources of Chatham County 3825 Barrett Drive P. O. Box 87 Raleigh, North Carolina 27609-7721 Pittsboro, North Carolina 27312 Mr. James W. Holt Mr. Terry C. Morton, Manager Manager Support Services Performance Evaluation and Shearon Harris Nuclear Power Plant Regulatory Affairs PEB 7 Carolina Power & Light Company Progress Energy P. O. Box 165, Mail Zone 1 Post Office Box 1551 New Hill, North Carolina 27562-0165 Raleigh, North Carolina 27602-1551 Mr. John R. Caves, Supervisor Mr. Benjamin C. Waldrep Licensing/Regulatory Programs Plant General Manager Shearon Harris Nuclear Power Plant Shearon Harris Nuclear Power Plant Carolina Power & Light Company Carolina Power & Light Company P. O. Box 165, Mail Zone 1 P. O. Box 165, Mail Zone 3 New Hill, NC 27562-0165 New Hill, North Carolina 27562-0165 Mr. John H. ONeill, Jr.

Shaw, Pittman, Potts & Trowbridge 2300 N Street, NW.

Washington, DC 20037-1128