ML11187A002

Review of the 2008 Steam Generator Tube Inspections During Refueling Outage 17 End of Cycle

ML11187A002
Person / Time
Site:	Catawba
Issue date:	07/11/2011
From:	Thompson J H Plant Licensing Branch II
To:	Morris J R Duke Energy Carolinas
Thompson J H, NRR/DORL/LPL2-1, 415-1119
References
TAC ME5751
Download: ML11187A002 (4)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 July 11, 2011 Mr. J. R. Morris Site Vice President Catawba Nuclear Station Duke Energy Carolinas, LLC 4800 Concord Road York, SC 29745 CATAWBA NUCLEAR STATION, UNIT 1 (CATAWBA 1) -REVIEW OF THE 2008 STEAM GENERATOR (SG) TUBE INSPECTIONS DURING REFUELING OUTAGE 17 END OF CYCLE (EOC 17) (TAC NO. ME5751)

Dear Mr. Morris:

By letter dated September 4,2008 (Agencywide Documents Access and Management System, Accession No. ML092750008), Duke Energy Carolinas.

LLC (the licensee).

submitted information summarizing the results of the 2008 SG tube inspections at Catawba 1. These inspections were performed during EOC 17. The Nuclear Regulatory Commission (NRC) staff conducted a conference call with the licensee on April 28. 2011, a summary of which is enclosed within, to clarify a few items in this letter. The NRC staff has completed its review of the submittal and concludes that the licensee provided the information required by the Catawba 1 Technical SpeCifications.

No additional follow up is required at this time. The NRC staff's review of the letter dated September 4, 2008. is enclosed.

If you have any questions, please call me at 301-415-1119.

Sincerely.

Jon Thompson, Project Manager Plant Licensing Branch 11-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No.

Staff cc w/encl: Distribution via UNITED NUCLEAR REGULATORY WASHINGTON, D.C. 20555-0001 STAFF EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO RESULTS OF 2008 STEAM GENERATOR TUBE INSPECTIONS PERFORMED DURING REFUELING OUTAGE 17 CATAWBA NUCLEAR STATION, UNIT 1 DOCKET NO. 50-413 By letter dated September 4, 2008 (Agencywide Documents Access and Management System, Accession No. ML092750008), Duke Energy Carolinas, LLC, (Duke, the licensee), submitted information summarizing the results of the 2008 steam generator (SG) tube inspections at Catawba Nuclear Station, Unit 1 (Catawba 1). The U.S. Nuclear Regulatory Commission (NRC) staff held a follow-up phone call on April 28, 2011, with the licensee to clarify a few minor pOints of information, the details of which are summarized below. Catawba 1 has four replacement model CFR 80 SGs, installed in 1996, designed and fabricated by Babcock and Wilcox International (BWI). Each SG has 6633 thermally treated Alloy 690 tubes that have an outside diameter of 0.6875 inch and a nominal wall thickness of 0.040 inch. The tubes were hydraulically expanded at each end for the full depth of the tubesheet.

The tubesheet is 27.1 inches thick with the clad. The tubes are supported by lattice grid tube supports and fan/connector bars. All supports are constructed from Type 410 stainless steel. The licensee provided the scope, extent, methods, and results of their SG tube inspections in the documents referenced above. In addition, the licensee described corrective actions (e.g., tube plugging) taken in response to the inspection findings.

On April 28, 2011, the licensee provided the following additional clarifying information via a phone conference with the NRC staff: A tube plug inspection was performed on each SG with no degradation noted. Secondary side inspections performed in each SG included: Sludge lancing in each SG. Top of tube sheet inspections at the hot and cold leg. 86 loose parts total were found in all four SGs. Twenty-eight loose parts were able to be removed. Of the remaining parts left in the SGs, three loose parts, believed to be flexatallic gasket pieces, were in SG C and SG D, required 23 total tubes to be preventatively plugged. An analysis performed by the SG vender determined that the remaining 58 parts left in the SGs would not challenge tube integrity during the next operating cycle. Enclosure

-The cumulative effective full power years since SG replacement for EOC16 and EOC17 are 9.19 and 10.52, respectively. The following tubes were plugged in SG C: Row Column Row Column 98 43 99 42 99 44 100 43 101 42 101 44 102 41 102 43 103 42 104 43 The following tubes were plugged in SG D: Row Row Column I Column 108 83 109 110 110 73 111 74 111 84 112 83 73 112 113 84 113 74 114 83 73 114 74 115 The nature of indications in the tube located in row 97, column 86, in SG C, was determined to be loose part wear with no part present at the time of inspection.

Based on a review of the information provided, the NRC staff concludes that the licensee provided the information required by the Technical Specifications.

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:

C. Hunt Date: July 11, 2011 July 11, 2011 Mr. J. R. Morris Site Vice President Catawba Nuclear Station Duke Energy Carolinas, LLC 4800 Concord Road York, SC 29745 CATAWBA NUCLEAR STATION, UNIT 1 (CATAWBA 1) -REVIEW OF THE 2008 STEAM GENERATOR (SG) TUBE INSPECTIONS DURING REFUELING OUTAGE 17 END OF CYCLE (EOC 17) (TAC NO. ME5751)

Dear Mr. Morris:

By letter dated September 4, 2008 (Agencywide Documents Access and Management System, Accession No. ML092750008), Duke Energy Carolinas, LLC (the licensee), submitted information summarizing the results of the 2008 SG tube inspections at Catawba 1. These inspections were performed during EOC 17. The Nuclear Regulatory Commission (NRC) staff conducted a conference call with the licensee on April 28, 2011, a summary of which is enclosed within, to clarify a few items in this letter. The NRC staff has completed its review of the submittal and concludes that the licensee provided the information required by the Catawba 1 Technical Specifications.

No additional follow up is required at this time. The NRC staff's review of the letter dated September 4, 2008, is enclosed.

If you have any questions, please call me at 301-415-1119.

Sincerely, IRA! Jon Thompson, Project Manager Plant Licensing Branch 11-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No.

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