ML20217B298
| ML20217B298 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 10/06/1999 |
| From: | Hernan R NRC (Affiliation Not Assigned) |
| To: | Scalice J TENNESSEE VALLEY AUTHORITY |
| References | |
| GL-92-01, TAC-M92730, TAC-M92731, NUDOCS 9910120201 | |
| Download: ML20217B298 (5) | |
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NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555 4001
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.....p October 6, 1999 Mr. J. A. Scalice I
j Chief Nuclear Officer j
and Executive Vice President Tennessee Val ley Authority 6A Lookout Place
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1101 Market Street Chattanooga, Tennessee 37402-2801 j
SUBJECT:
CLOSEOUT OF GENERIC LETTER 32 01, REVISION 1, SUPPLEMENT 1,
- REACTOR VESSEL INTEGRITY," FOR SECUOYAH NUCLEAR PLANT, UNITS 1 AND 2 (TAC NOS. M92730 AND M92731)
Dear Mr. Scalice:
On May 19,1995, the U.S. Nuclear Regulato y Commission (NRC) issued Generic Letter 92-01, Revision 1, Supplement 1 (GL 92-01, Rev.1, Supp.1), " Reactor Vessel Structural Integrity," to holders of nuclear operating licenses. In issuing the GL, the staff required addressees to:
(1) identify, collect and report any new data pertinent to the analysis of structural integrity of the reactor pressure vessels (RPVs) at their nuclear plants, and (2)-
assess the impact of that data on their RPV integrity analyses relative to the requirements of Sections 50.60 and 50.61 to Part 50 of Title 10 of the Federal Code of Regulations (10 CFR 50.30 and 10 CFR 50.61), and to the requirements of Appendices G and H to Part 50 of Title 10 of the Federal Code of Regulations (Appendices G and H to 10 CFR Part 50).
On August 17,1995, and November 7,1995, the Tennessee Valley Authority (TVA) submitted responses to GL 92-01, Rev.1, Supp.1, and provided the requested information relativa to the structural integrity assessments for the Sequoyah Nuclear Plant, Units 1 and 2 (SON). The staff evaluated the responses to GL 92-01, Rev.1, Supp.1, and provided its conclusion relative to TVA's responses on July 26,1996. However, since the time of the staffs closure letter, the Combustion Engineering (CE) Owners Group and the Babcock and Wilcox (B&W) Owners Group have each submitted additiona! data regarding the alloying chemistries of beltline welds in Cs-and B&W-fabncated vessels. The additional alloying data were submitted in Topical Report Nos. CE NPSD-1039, Revision 2 and CE NPSD-1119, Revision 1 for CE-fabricated RPV welds, and in Topical Report No. BAW-2325, Revision 1 for B&W fabricated RPV welds.
In addition, Chicago Bri; ige and Iron (CB&l) BWR data were submitted in Topical Report BWRVIP-46. As a rescit of the efforts by CE and B&W, the staff determined that additional information was necessary relative to the structural integrity assessments for all operating plants.
In mid-1998, the staff issued a request for additional information (RAl) to all owners group plants
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ir..egard to the alloving chemistries of beltline welds, the assessment of surveillance data, v
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Mr. J. A. Scalice pressure-temperature (P-T) limits, and pressurized thermal shock (PTS) assessments for their plants. In the RAI, the staff requested that the licensees reassess the alloying chemistries for the beltline welds and surveillance welds of their RPV vessels relative to the chemistries provided in the topical reports mentioned above, and provide the impact of any changes to the best-estimate chemistries for the RPV beltline welds on the structural integrity assessments for their vessels relative to the requirements of 10 CFR 50.60,10 CFR 50.61, and /ppendices G and H to 10 CFR Part 50, as applicable to the licensing bases for their plants. An RA! was not issued in 1996 for SON because SON is not a member of any of the above owners groups.
However, additional NRC staff review and conference phone calls with your staff nave been conducted regarding the issues similar to those in the 1996 RAI for other plants.
As a result of the staff's review of the responses to GL 92-01, Revision 1, and GL 92-01, Rev.1, Supp 1. the staff has revised the information in the Reactor Vessel Integrity Database (RVID) and is releasing it as RVID Version 2. It should be noted that there are some variations in the data provided by the staff and the corresponding values reported in the responses to GL 92-01, Rev.1, Supp.1. The deviations between the data are explained in the reference sections for each unit, or the individual component screen notes (i.e., each forging, plate, and weld has a specific area for notes, which is a new feature of the database).
RVID deviations that affect SON are as follows:
l The staff determined that the best estimate chemistry data for the weld fabricated with e
weld wire heat number 25295 (Weld 25295)is 0.35% Cu and 0.13% Ni. The licensee's f
chemistry data for this weld is from one data point. The staff's chemistry data is from j
North Anna's subrrdtal (11/20/95), which reports the average of five data points for Weld
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25295, including the licensee's 0.33% Cu and 0.17% Ni and the value of 0.42% Cu and 0.08% Ni for an irradiated Charpy specimen, TW58, reported in WCAP-13333 (1992).
Weld 25295 and Forging 04 have surveillance data. However, one of the three surveillance data for Weld 25295 far exceeds the credibility criterion of RG 1.99, Rev. 2, j
and three of the six plate surveillance data are not credible. Consequently, Position 1.1 of NRC Regulatory Guide (RG) 1.99, Revision 2, should be used with full margin to calculate the chemistry factors for Weld 25295 and Forging 04. This approach is also i
supported by the fact that each set of surveillance data (weld or forging) are within the 2-sigma limits of the database used in the RG. This discussicr ir.cbJes the information l
in the surveillance report, WCAP-13333, dated June 1992.
The current P-T limits for SON Units 1 and 2 were approved by the NRC in 1991. At the time of approval, these limits did not consider the information regarding surveillance capsule data discussed in Westinghouse Topical Report WCAP-13333 (June 1992) or the more recent surveillance report, WCAP-15224 (June 1999). Appendix G of 10 CFR 50 requires that "..the values of RT, and Charoy unn9^ she?f energy must account for the effects of neutron radiation, including the results of the surveillance program of Appendix H of this Part." Appendix H also requires the licensees to submit their surveillance report within one year of the date of capsule withdrawal.
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Mr. 'J. A. S'calice'
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' TVA~ su'bmitted Westinghouse Topical Report WCAP-15224 for Surveillance Capsule Y to the I
NRC on September 13,1999. Capsule Y was removed in September 1998 and is the fourth surveillance capsule to be removed from the SON Unit i reactor vessel. TVA concluded, in the trcnsmittal letter for this report, that no changes to SON's P-T limits are required at this time.
The NRC staff has not had an opportunity to review this report.
In a telephone conversation with Mr. Jim Smith of your staff on October 5,1999, the staff was informed that TVA intends to submit a P_ressure-Temperaturc Limit Report by June 2000, similar
~ to those submitted or planned by other Westinghouse Owners Group members. It is our
. understanding that TVA will resolve the NRC concerns regarding the information in the two most recent capsule ' surveillance reports and the RVID, as discussed above. Therefore, this letter constitutes completion of the NRC staff's efforts for SON regarding GL 92-01, Rev.1, Supp.1.
The staff appreciates your efforts with regard to this matter.
The NRC_ also hereby solicits any written comments that TVA may have on the current RVID data for the SON plants by November 1,1999. Lack of comments on the RVID data will be construed as agreement with its contents. The new database diskettes are posted as a link on the world-wide-web NRC home page (http://www.nrc. gov /NRR/RVID/index.html ). Future submittals on P-T limits, PTS, or upper shelf energy (USE) should reference the most current RVID information.
Sincerely, I
h, C2JLW8e Ronald W. Hernan, Sr. Project Manager, Section 2 Project Directorate 11 Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket Nos. 50-327 and 50-328 cc: See next page 4
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~ Mr. J. A. Scalice -
SEQUOYAH NUCLEAR PLANT Tennes,see Valley Authority I
cc:
Mr. Karl W. Singer, Senior Vice President Mr. Pedro Salas, Manager Nuclear Operations Licensing and Industry Affairs Tennessee Valley Authority Sequoyah Nuclear Plant 6A Lookout Place Tennessee Valley Authority 1101 Market Street P.O. Box 2000 Chattanooga, TN -37402-2801 Soddy Daisy, TN 37379 l
l Mr. Jack A. Bailey.
Mr. D. L. Koehl, Plant Manager Vice President Sequoyah Nuclear Plant Engineering & Technical Services Tennessee Valley Authority Tennessee Valley Authority P.O. Box 2000 6A Lookout Place.
Soddy Daisy, TN 37379 1101 Market Street Chattanooga, TN 37402-2801 Mr. Melvin C. Shannon Senior Resident inspector Mr. Masoud Bajestani Sequoyah Nuclear Plant Site Vice President U.S. Nuclear Regulatory Commission Sequoyah Nuclear Plant.
2600 Igou Ferry Road Tennessee Valley Authority Soddy Daisy, TN 37379 P.O. Box 2000 o
Soddy Daisy, TN 37379 Mr. Michael H. Mobley, Director TN Dept. of Environment & Conservation
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General Counsel Division of Radiological Health Tennessee Valley Authority 3rd Floor, L and C Annex ET 10H 401 Church Street 400 West Summit Hill Drive Nashville, TN 37243-1532 Knoxville, TN 37902 County Executive Mr. N. C. Kazanas, General Manager Hamilton County Courthouse Nuclear Assurance Chattanooga, TN 37402-2801 Tennessee Valley Authority SM Lookout Place 1101 Market Street Chattanooga, TN 37402-2801 l
Mr. Mark J. Burzynski, Manager j
Nuclear Licensing i
Tennessee Valley Authority 4X Blue Ridge 1101 Market Street Chattanooga, TN 37402-2801 1
Mr. J. A. Scalice 3-TVA submitted Westinghouse Topical Report WCAP-15224 for Surveillance Capsule Y to the NRC on September 13,1999. Capsule Y waa removed in September 1998 and is the fourth surveillance capsule to be removed from the SQN Unit i reactor vessel. TVA concluded, in the transmittal letter for this report, that na changes to SON's P-T limits are required at this time.
The NRC staff has not had an opportunity to review this report.
In a telephone conversation with Mr. Jim Smith of your staff on October 5,1999, the staff was informed that TVA intends h) submit a Pressure-Temperature Limit Report by June 2000, similar to those submitted or planned by other Westinghouse Owners Group members. It is our understanding that TVA will resolve the NRC concerns regarding the information in the two most recent capsule surveillance reports and the RVID, as discussed above. Therefore, this letter constitutes completion of the NRC staff's efforts for SON regarding GL 92-01, Rev.1, Supp.1.
The staff appreciates your efforts with regard to this matter.
The NRC also hereby solicits any written comments that TVA may have on the current RVID data for the SON plants by November 1,1949. Lack of comments on the RVID data will be construed as agreement with its contents. The new database diskettes are posted as a link on the world-wide-web NRC home page (http://www.nrc. gov /NRR/RVID/index.html). Future submittals on P-T limits, PTS, or upper shelf energy (USE) should reference the most current RVID information.
Sincerely, Original signed by:
Ronald W. Hernan, Sr. Project Manager, Section 2 Project Directorate ll Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket Nos. 50-327 and 50-328 cc: See next page DISTRIBUTION:
Docket File OGC S. Black ACRS PUBLIC K. Wichman SON R/F W. Bateman H. Berkow P. Fredrickson, Rll S. Peterson S.Sheng B. Clayton R. Hernan A. Lee DOCUMENT NAME: G:\\PDil-2\\SQN\\ Generic Letter 92-01,R1S1 closecut.wpd To receive a copy of this document, Indicate in the box: "C" = Copy without attachment / enclosure "E" = Copy with attachment / enclosure "N" = No copy
- See previous concurrences OFFICE PDil-2/PMn PDll-2/LA lC EMCB/SC l
PDil-2/SQf>
l NAME RHernan k'u//C BClayton /)M/
KWichman*
SPetersorf '
DATE 70/f /99~
/d 6 /99 9/30/99*
\\O / (c /99 Official Record Copy