ML18033B510
| ML18033B510 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 09/14/1990 |
| From: | Ross T Office of Nuclear Reactor Regulation |
| To: | Kingsley O TENNESSEE VALLEY AUTHORITY |
| Shared Package | |
| ML18033B511 | List: |
| References | |
| TAC-R00155, TAC-R00156, TAC-R00157, TAC-R155, TAC-R156, TAC-R157, NUDOCS 9009250055 | |
| Download: ML18033B510 (6) | |
Text
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September 14, 1990 Docket Nos. 50-259, 50-260 and 50-296 UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 Mr. Oliver D. Kingsley, Jr.
Senior Vice President, Nuclear Power Tennessee Valley Authority 6N 38A Lookout Place 1101 Market Street Chattanooga, Tennessee 37401-2802
Dear Mr. Kingsley:
SUBJECT:
SAFETY EVALUATION OF THE EFFECT OF ACCIDENTAL RELEASES OF HAZARDOUS CHEMICALS TRANSPORTED BY BARGES ON CONTROL ROOM HABITABILITY(TAC NOS.
- R00155, R00156, AND R00157)
The NRC staff has reviewed an analysis by the Tennessee Valley Authority (TVA) regarding the probable effects of accidental releases of hazardous chemicals, transported down the Tennessee River by barges, upon control room habitability at the Browns Ferry Nuclear (BFN) plant.
TVA provided their analysis and conclusions to the staff by submittals dated May 31, 1990 and August 16, 1990.
Based on our own independent evaluation of this analysis, as detailed in the enclosure, we concur with TVA's conclusion that out of the twenty chemicals transported by barges past BFN, only six could adversely affect habitability of the control room.
Furthermore, the staff also concurs with TVA that of these six chemicals, chlorine poses the greatest potential threat because the other five chemicals slowly build up to toxic concentrations.
In tact, the rate of buildup is slow enough (i.e. longer than two minutes) to meet the criteria of Regulatory Guide (RG) 1.78, "Assumptions for Evaluating the Habitability of a Nuclear Power Plant Control Room During a Postulated Hazardous Chemical Release,"
for allowing control room operators sufficient time to don protective gear.
Only chlorine builds up toxic levels much faster than operators could be expected to recognize and respond to.
- However, TVA demonstrated by a probabilistic argument that the chances of an accident resulting in releases of enough chlorine to affect habitability of the control room is less than the level of probability specified by the NRC's Standard Review Plan (SRP) for requiring an accident to
'e included as part of a plant's safety analysis.
The staff finds TVA's analysis and arguments acceptable for concluding that hazardous chemicals being barged on the Tennessee River by BFN do not pose a
significant safety concern to control room habitability, provided that TVA institutes the appropriate compensatory measures (i.e.
emergency procedures and training) outlined by RG 1.78 for the five toxic chemicals which build up slowly.
Although, as an alter native to these compensatory
- measures, TVA could submit additional analysis, for staff evaluation, to demonstrate that the combined contribution of all six potentially threatening chemicals would have an aggre-gate probabilistic risk of creating a toxic environment in the control room from an accidental chemical release of less than the SRP threshold.
PDR IIIIDOCK OSQOPNU P
Mr. Oliver D. Kingsley, Jr.
"2-In order to satisfactorily resolve this issue prior to restart of Unit 2, we would expect to receive a response from you within the next thirty days that either (1) confirms that appropriate compensatory measures exist at BFN to accomodate accidental chemical
- releases, or (2) provides additional analysis concluding that these measures are unwarranted because the level of probabi-listic risk is sufficiently low. If you have any questions concerning this letter, please do not hesitate to contact me at (301) 492-1313.
Sincerely, Original signed by Thierry M. Ross, Project Manager Project Directorate II-4 Division of Reactor Projects - I/II Office of Nuclear Reactor Regulation
Enclosure:
As stated cc w/enclosure:
See next page OFC: PDII-4/LA:PDII-4/PM: NR EMCB: PDII 4/0 a
NAME:MKrebsQg: TRoss g,: Kfar wake: PHe don DATE:9/f$ /90:9//Q /90:9/ /:9/ lQ /90 OFFICIAL RECORD COPY Document Name:
BFFERRYl
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Mr. Oliver D. Kingsley, Jr.
"3" CC:
Mr. Marvin Runyon, Chairman Tennessee Valley Authority ET 12A 7A 400 West Summit Hill Drive Knoxville, Tennessee 37902 Mr. Edward G. Wallace
- Manager, Nuclear Licensing and Regulatory Affairs Tennessee Valley Authority 5N 1578 Lookout Place Chattanooga, Tennessee 37402-2801 Mr. John B. Waters, Director Tennessee Valley Authority ET 12A 9A 400 West Summit Hill Drive Knoxville, Tennessee 37902 Mr.
W.
F. Millis Chief Operating Officer ET 12B 16B 400 Mest Summit Hill Drive Knoxville, Tennessee 37902 General Counsel Tennessee Valley Authority 400 Mest Summit Hill Drive ET 11B 33H Knoxville, Tennessee 37902 Mr. Dwight Nunn Vice Pr esident, Nuclear Engineering Tennessee Valley Authority 6N 38A Lookout Place 1101 Market Street Chattanooga, Tennessee 37402-2801 Dr. Mark 0. Medford Vice President and Nuclear Technical Director Tennessee Valley Authority 6N 38A Lookout Place Chattanooga, Tennessee 37402-2801 Mr. 0. J. Zeringue, Site Director Browns Ferry Nuclear Plant Tennessee Valley Authority P.
0.
Box 2000
- Decatur, Alabama 35602 Mr.
P. Carier, Site Licensing Manager Browns Ferry Nuclear Plant Tennessee Valley Authority P.
0.
Box 2000
- Decatur, Alabama 35602 Mr.
L.
M. Myers, Plant Manager Browns Ferry Nuclear Plant Tennessee Valley Authority P.
0.
Box 2000
- Decatur, Alabama 35602
- Chairman, Limestone County Commission P.
0.
Box 188
- Athens, Alabama 35611 Claude Earl Fox, M.D.
State Hea'Ith Officer State Department of Public Health State Office Building Montgomery, Alabama 36130 Regional Administrator, Region II U. S. Nuclear Regulatory Commission 101 Marietta Street, N.M.
Atlanta, Georgia 30323 Mr. Charles Patterson Senior Resident Inspector Browns Ferry Nuclear Plant U.S. Nuclear Regulatory Commission Route 12, Box 637
- Athens, Alabama 35611 Tennessee Valley Authority Rockville Office 11921 Rockville Pike Suite 402 Rockville, Maryland 20852
Dieteigution
'ocket-File NRC PDR Local PDR S.
Varga G.
Lainas F.
Hebdon S.
Black B. Milson P.
Kellogg C. Patterson M. Krebs T.
Ross OGC E. Jordan K. Parczewski ACRS (10)
BFN Rdg. File 14"E"4 14-H-3 R"II R-II R-II MNBB-3302 7-D-4
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