ML19256C899
| ML19256C899 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 07/18/1979 |
| From: | Klingler G, Mckee P, Stone J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE) |
| To: | |
| References | |
| PNO-79-260, NUDOCS 7910150722 | |
| Download: ML19256C899 (1) | |
Text
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,..f PRELIMINARY _ NOTIFICATION
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July 18, 1979 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE--PNO-79-260 This preliminary notification constitutes EARLY notice of an event of POSSIBLE safety or public interest significance.
The infortnation presented is as initially received without verification or evaluation and is basically all that is known by IE staff on this date.
FACILITY: Tennessee Valley Authority '
Browns Ferry, Unit No. 3-Docket No. 50-296 Athens, Alabama SU3 JECT:
HYDR 0 GEN DETONATION IN OFF-GAS SYSTEM During power ascension on July 17 following a reactor scram from ic.w condenser vacuum, unstable recombiner operation resulted i increased hydrogen concen-tration and a subsequent detonation in the off-gas system.
The reactor was manually scramed from 40% power. Stack release rates stayed less than 1 per-cent of the Technical Specification limits.
No personnel injuries or contam-ination occurred.
Prior to the occurrence, hydrogen concentration in the off-gas system indicated a step increase from 0.2 to greater than five percent.
Faulty steam supply valves to the recombiner preheater are believed to be the cause of unstable operation.
Repairs to the steam supply valves and replacement of particulate filters have been completed and the plant was restarted on July 18.
Followup licensee investigation is in progress and is being followed by the IE Resident Inspector.
Local media interest is expected.
The licensee plans to issue a news release.
The NRC does not plan a news release.
The State of Alabama has been infomed.
Region II ( Atlanta) received notification of this occurrence by telephone from tne Resident Inspector at 4:15 p.m. on July 17.
This information is current as of 11:00 a.m. on July 18.
Contact:
P. McKee, IE x28019; J. S tone,
IE x28019; G. Klingler, IE x28019 Distribution:
Transmitted H St Cnairman Hendrie Commissioner Bradford S. J. Chil k, SECY Com.issioner Kennedy Commissioner Ahearne C. C. Kamerer, CA Co:Tr.issioner Gilinsky ACRS (For Distribution)
Transmi tted :
MNBB P. Bldg V. Stello, IE -
L. V. Gossick, EDO H. R. Denton, NRR Region T __
H. L. Ornstein, EDO R. C. DeYoung, NRR J. J. Fouchard, PA R. J. Mattson, NRR N. M. Haller, MPA D. Vassallo, NRR (MAIL)
R. G. Ryan, OSP D. Eisenhut, NRR J. J. Cummings, OIA H. K. Shapar,. ELD SS Bldg R. Minogue, SD
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W. J. Dircks, HMSS S. Levine, RES
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PRELIMIRARY NOTIFICATION
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