ML073110026

Second Request for Additional Information Regarding Inservice Inspection Request for Relief No. PDI-2

ML073110026
Person / Time
Site:	Watts Bar
Issue date:	11/09/2007
From:	Moroney B NRC/NRR/ADRO/DORL/LPLII-2
To:	Campbell W Tennessee Valley Authority
Moroney B, NRR/DORL, 415-3974
References
TAC MD4448
Download: ML073110026 (5)

Text

November 9, 2007 Mr. William R. Campbell, Jr.

Chief Nuclear Officer and Executive Vice President Tennessee Valley Authority 6A Lookout Place 1101 Market Street Chattanooga, TN 37402-2801

SUBJECT:

WATTS BAR NUCLEAR PLANT, UNIT 1 - SECOND REQUEST FOR ADDITIONAL INFORMATION REGARDING INSERVICE INSPECTION REQUEST FOR RELIEF NO. PDI-2 (TAC NO. MD4448)

Dear Mr. Campbell:

By letter dated February 7, 2007, the Tennessee Valley Authority (TVA) submitted Request for Relief (RR) No. PDI-2 for the second 10-year inservice inspection interval at Watts Bar Nuclear Plant, Unit 1. In RR No. PDI-2, TVA proposed to perform volumetric examinations on reactor pressure vessel nozzle-to-vessel welds at a reduced volume of one-half inch beyond the widest part of the boundary of the deposited weld material, in lieu of the requirements of the American Society of Mechanical Engineers Code,Section XI, Figures IWB-2500-7(a) and IWB-2500-7(b).

The staff has reviewed and evaluated the information provided by TVA in its letter dated July 25, 2007, which provided additional information in response to the staffs request for additional information (RAI) dated July 9, 2007. Based on this review, it was determined that additional information is required to complete the staffs evaluation for RR No. PDI-2. Based on discussions with your staff, we understand that you plan to respond to the enclosed RAI by December 14, 2007. If you have any questions regarding this issue, please feel free to contact me at (301) 415-3974.

Sincerely, RA/

Brendan T. Moroney, Project Manager Plant Licensing Branch II-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-390

Enclosure:

Second RAI cc w/enclosures: See next page

ML073110026 NRR-088 OFFICE LPL2-2/PM LPL2-2/PM LPL2-2/LA CVIB/BC LPL2-2/BC NAME MMitchell by JBowen BMoroney RSola SBailey for TBoyce memo DATE 11/07/07 11/07/07 11/07/07 09/1907 11/09/07 William R. Campbell, Jr. WATTS BAR NUCLEAR PLANT Tennessee Valley Authority cc:

Mr. Gordon P. Arent Ms. Beth A. Wetzel, Manager New Generation Licensing Manager Corporate Nuclear Licensing and Tennessee Valley Authority Industry Affairs 5A Lookout Place Tennessee Valley Authority 1101 Market Street 4X Blue Ridge Chattanooga, TN 37402-2801 1101 Market Street Chattanooga, TN 37402-2801 Mr. Ashok S. Bhatnagar Senior Vice President Mr. Masoud Bajestani, Vice President Nuclear Generation Development Watts Bar Unit 2 and Construction Watts Bar Nuclear Plant Tennessee Valley Authority Tennessee Valley Authority 6A Lookout Place P.O. Box 2000, EQB 1B 1101 Market Street Spring City, TN 37381 Chattanooga, TN 37402-2801 Mr. Michael K. Brandon, Manager Mr. James R. Douet Licensing and Industry Affairs Vice President Watts Bar Nuclear Plant Nuclear Support Tennessee Valley Authority Tennessee Valley Authority P.O. Box 2000 3R Lookout Place Spring City, TN 37381 1101 Market Street Chattanooga, TN 37402-2801 Mr. Michael J. Lorek, Plant Manager Watts Bar Nuclear Plant Mr. H. Rick Rogers Tennessee Valley Authority Vice President P.O. Box 2000 Nuclear Engineering & Technical Services Spring City, TN 37381 Tennessee Valley Authority 3R Lookout Place Senior Resident Inspector 1101 Market Street Watts Bar Nuclear Plant Chattanooga, TN 37402-2801 U.S. Nuclear Regulatory Commission 1260 Nuclear Plant Road Mr. Michael D. Skaggs, Site Vice President Spring City, TN 37381 Watts Bar Nuclear Plant Tennessee Valley Authority County Executive P.O. Box 2000 375 Church Street Spring City, TN 37381 Suite 215 Dayton, TN 37321 General Counsel Tennessee Valley Authority County Mayor 6A West Tower P. O. Box 156 400 West Summit Hill Drive Decatur, TN 37322 Knoxville, TN 37902 Mr. Lawrence E. Nanney, Director Mr. John C. Fornicola, Manager Division of Radiological Health Nuclear Assurance Dept. of Environment & Conservation Tennessee Valley Authority Third Floor, L and C Annex 3R Lookout Place 401 Church Street 1101 Market Street Nashville, TN 37243-1532 Chattanooga, TN 37402-2801 Mr. Larry E. Nicholson, General Manager Performance Improvement Tennessee Valley Authority 4X Blue Ridge 1101 Market Street Chattanooga, TN 37402-2801

SECOND REQUEST FOR ADDITIONAL INFORMATION SECOND 10-YEAR INSERVICE INSPECTION INTERVALREQUEST FOR RELIEF NO. PDI-2 WATTS BAR NUCLEAR PLANT, UNIT 1 TENNESSEE VALLEY AUTHORITY DOCKET NUMBER 50-390 Request for Relief (RR) No. PDI-2 is for the Second 10-year inservice inspection (ISI) interval, in which Watts Bar Nuclear Plant (WBN), Unit 1 adopted the 2001 Edition with addenda through the 2003 Addenda of the American Society of Mechanical Engineers (ASME) Code,Section XI as the ASME Code of record.

In its letter dated July 25, 2007, Tennessee Valley Authority (TVA) provided additional information regarding its proposal to perform volumetric examinations on reactor pressure vessel (RPV) nozzle-to-vessel welds at a reduced volume of 2 inch beyond the widest part of the boundary of the deposited weld material in lieu of the requirements of ASME Code,Section XI, Figures IWB-2500-7(a) and IWB-2500-7(b).

Question 1 In its request for additional information (RAI) dated July 9, 2007, the staff asked the licensee in Question 1(f): AHave the subject welds been previously ultrasonically examined using the examination volumes of ASME Code,Section XI, Figures IWB-2500-7(a) and (b)?@

TVA=s response to Question 1(f) is stated below:

Inservice examination of the eight RPV inlet and outlet nozzles was performed in 2005 by Southwest Research Institute to the requirements of ASME [Code,]

Section XI, 1995 Edition, 1996 Addenda, for a modified inspection volume including the weld plus 2" on both sides, in accordance with Request for Relief PDI-2. Utilizing the modified inspection volume, essentially 100% [percent]

coverage was not obtained for the outlet nozzles and Request for Relief 1-ISI-19 was submitted to the NRC [Nuclear Regulatory Commission] for approval. Relief was granted in a safety evaluation [SE] issued October 27, 2006 (Accession number ML062480232)...

In the staff=s SE dated October 27, 2006, Request for Relief (RR) 1-ISI-19 was evaluated based on the 1989 Edition of the ASME Code and Figure IWB-2500-7(b), and not for a modified inspection volume, nor to the 1995 Edition, 1996 Addenda of the ASME Code as implied in the RAI response above. In addition, based on the above RAI response, it appears to the staff that the RPV nozzle-to-vessel welds were examined at a reduced volume during the first 10-year WBN, Unit 1 ISI interval in lieu of the requirements of ASME Code,Section XI, Figure IWB-2500-7(b) prior to receiving authorization for the proposed alternative contained in RR PDI-2.

Please clarify prior response to RAI Question 1(f) regarding these points.

Enclosure

Question 2 For the second 10-year ISI interval in RR PDI-2, the licensee is requesting an alternative to the ASME Code requirements pursuant to Title 10 Code of Federal Regulations (10 CFR) 50.55a(a)(3)(i). In the licensee=s RAI response to Question 1(d), it was noted that 76 percent volumetric coverage was obtained for RPV Outlet Nozzles Weld Nos. N18, N17, N16, and N15 during the first 10-year ISI interval 2005 Refueling Outage (RFO) 6. For the closeout of the first 10-year ISI interval, the licensee submitted a request for relief under 10 CFR 50.55a(g)(5)(iii) because it was impractical to obtain essentially 100 percent coverage for the subject welds as required by the ASME Code. Relief was granted in a NRC SE dated October 27, 2006.

Since the proposed modified area to be examined in RR PDI-2 is an alternative to the ASME Code requirements; 10 CFR 50.55a(g)(5)(iii) does not have provisions to allow subsequent relief based on impracticality for authorized alternatives to the ASME Code. If the licensee expects that it will obtain less than essentially 100% volumetric coverage of the proposed modified area during the second 10-year ISI interval examination, it should include a discussion of that reduced examination volume in RR PDI-2.

Please clarify the percent of the reduced examination volume (assuming RR PDI-2 is authorized) that you expect to be able to examine. If this examination will be Aless than essentially 100%@ of the reduced volume, justify in the context of RR PDI-2 why obtaining less than Aessentially 100%@

coverage of the reduced examination volume still provides for an adequate examination.