ML20248H946

PNO-78-087:on 780415,aluminum 24-inch Diameter Condensate Storage Tank Line Failed at Weld in Fabricated Y Junction Spilling 80,000 Gallons of Water to Reactor Bldg Basement Room

ML20248H946
Person / Time
Site:	Browns Ferry
Issue date:	04/19/1978
From:	Klingler G, Nolan F, Sniezek J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
To:
References
PNO-78-087, PNO-78-87, NUDOCS 9806080322
Download: ML20248H946 (1)

Text

_____ _ - _ _ _ _ _ _ _ _ _ _ _ _ _ _ - _ - _ _ _ _ _ _ _ _ _ _ - _ - _ _ _ _ - _ _ _ _ _ _ _ _ _ _ _ _ _ _

QQL MQbd C2'3 0% (.X' f W; PRELIMINARY NOTIFICATION I 2 O' #

April 19, 1978 g PRELIMINARY NOTIFICATION OF EVENT OR UNU5UAL OCCURRENCE = PNG-78-87 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 as of this date.

FACILITY: Tennessee Valley Authority Browns Ferry, Unit No. 3 Docket No. 50-296 Decatur, Alabama

SUBJECT:

CONDENSATE TANK EFFLUENT LINE FAILURE On April 15, an aluminum 24-inch diameter condensate storage tank line failed at a weld in a fabricated "Y" junction spilling 80,000 gallons of water to the reactor building basement room. This room houses one residual heat removal and one core spray pump. All safety-related systems remained operational. Spilled water was essentially free of radioactivity and was contained within the building.

Prior to the line failure, the reactor had tripped following' an inadvertent gei safety-relief valve opening (PN0 78-82). During the resultant transient, High Pressure Coolant Injection (HPCI) and Reactor Core Isolation Cooling (RCIC) automatically started on a low water level signal to refill the

(- reactor vessel using condensate storage tank water. Based on the safety analysis, the condensate storage tank is not required during accident conditions since the analysis assumes that the torus supplies adequate water for safety injection. The source of coolant water for the HPCI automatically switched from the condensate storage tank to the torus about the time the HPCI shut down, after refilling the reactor vessel.

Unit remains shutdown for repair of the failed line which is the second failure at this weld (PN0 77-211). Piping design is being modified prior to plant startup. Reactor restart is expected on April 20.

Media interest is not expected. A news release is not planned by the licensee nor the NRC. The State of Alabama has-been informed.

Region II (Atlanta) received notification of this occurrence by telephone ,

from the Assistant Plant Superintendent at 4:30 p.m. on April 18. This information is current as of 11:30 a.m. on April 19.

N'D)D .I Contact 1 GKlingler, IE x28019 FNgl a,r),, I E x28019 JSniezek, IE x28019 -

Distribution: Transmitted H St J.' 7 7 Chairman Hendrie Commissioner Bradford Commissioner Kennedy S. J. Chilk, SECY C. C. Kammerer, CA Commissioner Gilinsky (For Distribution)

Transmitted: MNBB T. P Bldg 3' N, E. Volgenn, n IE L. V. Gossick, EDO E. G. Case, NRR Region.jJ 3J 2 7 S. H. Hanauer, EDO .-

- J. J. Fouchard, PA . SSBldg3l29 (MAIL)

R. Hartfield, MIPC.. 1 ,- C. V. Smith, NMSS T. J. McTiernan, 01A R. G. Ryan, OSP R. Minogue., SD H. K. Shacar. ELD 9906000322 790419 g tie t w 2v unT ' e m ^*'