ML100750034
| ML100750034 | |
| Person / Time | |
|---|---|
| Site: | Watts Bar  |
| Issue date: | 03/19/2010 |
| From: | John Lamb Watts Bar Special Projects Branch |
| To: | Krich R Tennessee Valley Authority |
| Lamb John G./NRR/DORL, 415-3100 | |
| References | |
| Download: ML100750034 (3) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555*0001 March 19, 2010 Mr. R. M. Krich Vice President, Nuclear Licensing Tennessee Valley Authority 3R Lookout Place 1101 Market Street Chattanooga, TN 37402-2801
SUBJECT:
WAITS BAR NUCLEAR PLANT, UNIT 1 - REQUEST TO VOLUNTARILY SUPPLY DRAWINGS REGARDING THE REPLACEMENT STEAM GENERATORS
Dear Mr. Krich:
Over the past several years, the Office of Nuclear Regulatory Research (RES) has been studying the potential for severe accident induced system failures as part of the U.S.
Nuclear Regulatory Commission (NRC) Steam Generator (SG) Action Plan. The NRC RES staff work involves a study of the severe accident induced natural circulation flows and mixing in the primary loops of pressurized-water reactors with special attention paid to the SG inlet plenum (channel head) region.
The work has focused on the Zion Nuclear Power Plant and its associated Model 51 SG design. Over the past 20 years, many of the Westinghouse SGs have been replaced.
The NRC RES staff is interested in considering the extent of the geometric variations in the replacement SG designs to gauge the potential impact (a sensitivity study) on their existing results. Specifically, the NRC RES staff is focused on the SG inlet plenum (channel head) geometry.
To study this effect, the NRC RES staff needs drawings of the SGs for a few replacement SG designs that might be geometrically different from the Model 51 design that were studied in detail. Specifically, the NRC staff is requesting drawings for the hot leg nozzle region, the inlet plenum (channel head) region, and the tubesheet be voluntarily submitted by licensees. The results of the study will most likely be documented in a NUREG, but the detailed design and dimensions of the inlet plenum/channel head will most likely not be released.
The replacement SGs at Watts Bar Nuclear Plant (WBN), Unit 1 represent one of the SG designs of potential interest.
The NRC staff is requesting that Tennessee Valley Authority (TVA) voluntarily provide replacement SG drawings for the hot leg nozzle region, the inlet plenum (channel head) region, and the tubesheet for WBN Unit 1. There is no requirement for TVA to provide this information. Should TVA seek to have the documentation, or a portion of it, withheld from public disclosure because it contains trade secrets, privileged, or confidential,
R.M. Krich
- 2 commercial information, TVA, or the owner of the documents, needs to request withholding and follow the procedlures in Section 2.390, "Public inspections, exemptions, requests for withholding," of Title 10 of the Code of Federal Regulations.
If you have any questions related to the NRC RES work, please contact Chris Boyd at (301) 251-7525. If you have any other questions, please contact me at (301) 415-3100.
G. Lamb, Senior Project Manager tts Bar Special Projects Branch vision of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No.: 50-390 cc: Distribution via Listserv
R.M. Krich
- 2 commercial information, TVA, or the owner of the documents, needs to request withholding and follow the procedures in Section 2.390, "Public inspections, exemptions, requests for withholding," of Title 10 of the Code of Federal Regulations.
If you have any questions related to the NRC RES work, please contact Chris Boyd at (301) 251-7525. If you have any other questions, please contact me at (301) 415-3100.
Sincerely, IRAI John G. Lamb, Senior Project Manager Watts Bar Special Projects Branch Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No.: 50-390 cc: Distribution via Listserv PUBLIC RidsOgcRp Resource LPWB Reading RidsOpaMail Resource RidsAcrsAcnw_MailCTR Resource RidsRgn2MailCenter Resource DDiaz-Toro,OEDO RidsNrrDssScrb RidsNrrPMWattsBar1 Resource RidsNrrLABClayton Resource RidsNrrDorl Resource KKarwoski, t\\lRR RidsNrrDorlLp-Wb Resource CBoyd, RES RidsNrrDciCsgb Resource RTaylor, NRR Accession No'.. ML100750034 OFFICE DORLIWBSP/PM DORLIWBSP/LA DCI/CSGB/BC DORLIWBSP/BC NAME JLamb BClayton RTaylor LRaghavan DATE 03/16/10 03/16/10 03/16/10 03/19/10 OFFICIAL RECORD COPY