ML20151Y180

From kanterella
Jump to navigation Jump to search
PNO-77-130:on 770717,excessive Temp in Offgas Charcoal Filter Occurred.Hydrogen Recombiner Operation Erratic Prior to Occurrence.Unit Operation Continues with Filters Bypassed.Region II Inspectors Enroute to Browns Ferry Site
ML20151Y180
Person / Time
Site: Browns Ferry Tennessee Valley Authority icon.png
Issue date: 07/18/1977
From: Constable G, Sniezek J, Whitt K
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE)
To:
References
PNO-77-130, NUDOCS 9809180141
Download: ML20151Y180 (1)


Text

'fM UAMom/' W (b{ U l' @ie 3 l

,~

PRELIMINARY NOTIFICATION .

1 July 18, 1977 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE This preliminary notification constitutes EARLY notice of an event of POSSIBLE safety or public interest significance. The information '

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 Athens, Alabama

> $UBJECT:

_ EXCESSIVE TEMPERATURE IN OFFGAS CHARC0AL FILTER During operation at 600 mwe on July 17, 1977, an apparent ignition took place at 4:00 p.m. in the offgas system's "B" charcoal filter, as evidenced by high temperature (greater than 700 degrees F recombiner operation was erratic prior to the occurrence.). The Thehydrogen filters were bypassed by isolating them from the offgas system at S:00 p.m. and a nitroger, purge was' initiated on all charcoal filters. Unit operation con-tinues with the filters bypassed.

Subsequent analysis of samples of the stack effluent indicated I-131 concentration of 8.63 E-12 uci/cc (0.08% of technical specification

. m.

limit) and I-133 Additional concentration sampling of 1.05 E-11 uci/cc (0.15% of T.S. limit)..

is in progress.

m Temperatures in the "B" filter have stabilized at about 1000 degrees F based on copper constantan thermocouple readings. Licensee is removing a wall to perform a visual inspection of the filter unit to aid in determining cause of the event.

The licensee has informed the State of Alabama and plans to make a g press release.

,/

Region II received notification of this event at 5:15 a.m. on July 18,

/

1977. Region II inspectors are enroute to the Browns Ferry site. ~

Contact:

KWhitt, IE x27451 GLConstable, IE x27451 JHSniezek, IE 27451 b

p Distribution: Transmitted H St / 2. 7 ;

Commissioner Kennedy C. C. Kammerer, CA g G. F. Murphy, JCAE Commissioner Gilinsky S. J. Chi 1F, SECY H.H.Whiteside,SCtd s

H. R. Myers, HCEE Transmitted: MNBB_/ j P Bldg l l 3 L- 55 Bldg ll3 c/

L. V. Gossick, ED0 E. G. Case, NRR C. V. Smith, NMSS S. H. Hanauer, ED0 J. A. Harris, PA W. G. Mcdonald, MIPC Luge (MAIL) E. Volgenau, IE R. G. Ryan, OSP T. J. McTiernan, OIA -

Region @ Q3_(o

( H. K. Shapar, ELD -

1 7,, c 1 1 PRELIMIN4RYNOTIFICATION 9809180141 770718 --

PDR I&E -

PNO-77-130 PDR