ML072220350

Review of Cycle 14 Steam Generator Tube Inservice Inspection Summary Reports

ML072220350
Person / Time
Site:	Catawba
Issue date:	08/14/2007
From:	Stang J NRC/NRR/ADRO/DORL/LPLII-1
To:	Morris J Duke Power Co
Stang J, NRR/DORL, 415-1345
References
TAC MD3419
Download: ML072220350 (6)

Text

August 14, 2007 Mr. J. R. Morris Site Vice President Catawba Nuclear Station Duke Power Company LLC 4800 Concord Road York, SC 29745

SUBJECT:

CATAWBA NUCLEAR STATION, UNIT 2 - REVIEW OF CYCLE 14 STEAM GENERATOR TUBE INSERVICE INSPECTION REPORTS (TAC NO. MD3419)

Dear Mr. Morris:

By letter to the Nuclear Regulatory Commission (NRC) dated August 31, 2006, as supplemented by letter dated May 31, 2007, Duke Power Company LLC (the licensee) submitted the Cycle 14 steam generator (SG) tube inservice inspection reports for Catawba Nuclear Station (Catawba), Unit 2, in accordance with Technical Specification (TS) Section 5.6.8, and as required by the American Society of Mechanical Engineers, Boiler and Pressure Vessel Code,Section XI, Paragraph IWA-6230, for the SG tube inspections performed during the end of cycle (EOC) 14 refueling outage (March 2006).

A summary of the NRC staffs evaluation of the EOC 14 refueling outage SG tube inspection results is enclosed. The NRC staff concludes that the licensee provided the information required by the Catawba Unit 2 TSs, and that no additional follow-up is required at this time.

Sincerely,

/RA/

John F. Stang, Senior Project Manager Plant Licensing Branch II-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-414

Enclosure:

EOC 14 Refueling Outage SG Tube Inspection Results cc w/encl: See next page

August 14, 2007 Mr. J. R. Morris Site Vice President Catawba Nuclear Station Duke Power Company LLC 4800 Concord Road York, SC 29745

SUBJECT:

CATAWBA NUCLEAR STATION, UNIT 2 - REVIEW OF CYCLE 14 STEAM GENERATOR TUBE INSERVICE INSPECTION REPORTS (TAC NO. MD3419)

Dear Mr. Morris:

By letter to the Nuclear Regulatory Commission (NRC) dated August 31, 2006, as supplemented by letter dated May 31, 2007, Duke Power Company LLC (the licensee) submitted the Cycle 14 steam generator (SG) tube inservice inspection reports for Catawba Nuclear Station (Catawba), Unit 2, in accordance with Technical Specification (TS) Section 5.6.8, and as required by the American Society of Mechanical Engineers, Boiler and Pressure Vessel Code,Section XI, Paragraph IWA-6230, for the SG tube inspections performed during the end of cycle (EOC) 14 refueling outage (March 2006).

A summary of the NRC staffs evaluation of the EOC 14 refueling outage SG tube inspection results is enclosed. The NRC staff concludes that the licensee provided the information required by the Catawba Unit 2 TSs, and that no additional follow-up is required at this time.

Sincerely,

/RA/

John F. Stang, Senior Project Manager Plant Licensing Branch II-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-414

Enclosure:

EOC 14 Refueling Outage SG Tube Inspection Results cc w/encl: See next page DISTRIBUTION:

PUBLIC RidsAcrsAcnwMailCenter LPL2-1 R/F RidsNrrDorlLpl2-1(EMarinos) RidsNrrPMJStang(hard copy) RidsOgcRP RidsRgn2MailCenter(JMoorman) RidsNrrLAMOBrien(hard copy) SCampbell,EDO Region II J. Burke, NRR RidsNrrDciCsgb(AHiser)

ADAMS: ML072220350 OFFICE LPL2-1/PM LPL2-1/LA DCI/CSGB LPL2-1/BC NAME JStang MOBrien MYoder for AHiser EMarinos DATE 8/14/07 8/13/07 8/14/07 8/14/07 OFFICIAL RECORD COPY

OFFICE OF NUCLEAR REACTOR REGULATION REVIEW OF CYCLE 14 STEAM GENERATOR TUBE INSPECTION REPORTS CATAWBA NUCLEAR STATION, UNIT 2 DOCKET NO. 50-414 By letter to the Nuclear Regulatory Commission (NRC) dated August 31, 2006 (Agencywide Documents Access and Management System (ADAMS), Accession No. ML062550112), as supplemented by letter dated May 31, 2007 (ADAMS Accession No. ML071630231), Duke Power Company LLC (the licensee), submitted the Cycle 14 steam generator (SG) tube inservice inspection reports for Catawba Nuclear Station (Catawba), Unit 2, in accordance with Technical Specification (TS) Section 5.6.8, and as required by the American Society of Mechanical Engineers, Boiler and Pressure Vessel Code,Section XI, Paragraph IWA-6230, for the SG tube inspections performed during the end of cycle (EOC) 14 refueling outage (March 2006).

Catawba Unit 2 has four Westinghouse Model D5 SGs, which are designated 2A through 2D.

All four SGs were inspected During EOC 14 refueling outages. Each SG has 4,570 thermally treated Alloy 600 tubes with an outside diameter of 0.750-inch and a nominal wall thickness of 0.043-inch. The tubes are hydraulically expanded for the full-depth of the tubesheet at each end. The tubes are supported by Type 405 stainless steel support plates with quatrefoil-shaped holes. The U-bend region of the tubes installed in Rows 1 through 9 was thermally treated after bending in order to reduce stress.

The licensee provided the scope, extent, methods, and results of the Catawba Unit 2 SG tube inspections in the documents referenced above. In addition, the licensee described corrective actions (i.e., tube plugging) taken in response to the inspection findings.

The staff has the following notes/observations as a result of reviewing the information provided by the licensee.

During the EOC 14 outage, additional crack-like indications were found near the tube end in all four SGs. All of these indications were left in service since they were located in a region of the tubesheet where flaws are not required to be removed from service in accordance with the TSs.

C The licensee performed secondary side inspections of the pre-heater baffle plate and pre-heater water-boxes for erosion and wear as a follow-up to industry events at other plants with the same model of SG. As a result of the inspection of the baffle plate in EOC 14, a total of 202 objects were identified in the four SGs. Of these 202 objects, 133 were removed. All of the remaining objects were evaluated by the licensee for Enclosure

acceptability to leave in place for one cycle of operation. The waterbox cap plate region of all four SGs were inspected during the EOC 14 outage. Since SGs 2A did not have a cap plate cutout (as confirmed during the EOC 13 outage), it was not reinspected during the EOC 14 outage. The EOC 13 inspection showed the welds associated with the cap plate cutout region were structurally sound. The inspections of the waterbox cap plate region during the EOC 14 outage in SGs 2B, 2C, and 2D did not show any change in condition in these welds. No unusual wear was found.

C An inspection of the primary moisture separator region is planned for EOC 15 in 2007.

C The licensee indicated that certain wear indications were not sized during the outage, but that they were determined to meet structural and TS tube repair limits and left in service (i.e., < 40% through-wall).

Based on a review of the information provided, the NRC staff concludes that the licensee provided the information required by their TSs. In addition, the NRC staff concludes that there are no technical issues that warrant follow-up action at this time since the inspections appear to be consistent with the objective of detecting potential tube degradation and the inspection results appear to be consistent with industry operating experience at similarly designed and operated units.

Principal Contributor: J. Burke Date: August 14, 2007

Catawba Nuclear Station, Units 1 & 2 Page 1 of 2 cc:

Site Vice President Senior Resident Inspector Catawba Nulcear Station U.S. Nuclear Regulatory Commission Duke Power Company, LLC 4830 Concord Road 4800 Concord Road York, South Carolina 29745 York, SC 29745 Assistant Director Associate General Counsel and Managing Division of Waste Management Attorney Bureau of Land and Waste Management Duke Energy Carolinas, LLC Dept. of Health and Environmental Control 526 South Church Street - EC07H 2600 Bull Street Charlotte, North Carolina 28202 Columbia, South Carolina 29201-1708 Regulatory Compliance Manager Duke Energy Corporation Nuclear Regulatory Issues 4800 Concord Road and Industry Affairs York, South Carolina 29745 Duke Energy Corporation 526 South Church Street North Carolina Municipal Power Mail Stop EC05P Agency Number 1 Charlotte, North Carolina 28202 1427 Meadowwood Boulevard P.O. Box 29513 Saluda River Electric Raleigh, North Carolina 27626 P.O. Box 929 Laurens, South Carolina 29360 County Manager of York County York County Courthouse Vice President York, South Carolina 29745 Customer Relations and Sales Westinghouse Electric Company Piedmont Municipal Power Agency 6000 Fairview Road 121 Village Drive 12th Floor Greer, South Carolina 29651 Charlotte, North Carolina 28210 Assistant Attorney General Owners Group (NCEMC)

North Carolina Department of Justice Duke Energy Corporation P.O. Box 629 4800 Concord Road Raleigh, North Carolina 27602 York, South Carolina 29745 NCEM REP Program Manager Senior Counsel 4713 Mail Service Center Duke Energy Carolinas, LLC Raleigh, North Carolina 27699-4713 526 South Church Street - EC07H Charlotte, NC 28202 North Carolina Electric Membership Corp.

P.O. Box 27306 Raleigh, North Carolina 27611

Catawba Nuclear Station, Units 1 & 2 Page 2 of 2 cc:

Division of Radiation Protection NC Dept. of Environment, Health, and Natural Resources 3825 Barrett Drive Raleigh, North Carolina 27609-7721 Group Vice President, Nuclear Generation and Chief Nuclear Officer P.O. Box 1006-EC07H Charlotte, NC 28201-1006