ML20151S159

Event Followup Rept 87-150

ML20151S159
Person / Time
Site:	Wolf Creek
Issue date:	11/11/1987
From:	Nicole Fields NRC
To:
Shared Package
ML20151S148	List: ML20151S145 ML20151S159
References
FOIA-88-68 NUDOCS 8804280216
Download: ML20151S159 (2)

Text

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NOV i ! C.'.

SUCJECT EVENT FOLLOWUP REPORT NO.87-150 50.72 EVENT NOS. 10320, 1C331/345/347-0CTOBER 10-16, 1967 PLANT - I!OLF CREEK UNIT '

PROJECT ltANAGER - P. O'CONNOR COGNIZANT - N. FIELDS 00BLEP!

Fersonnel contamination, hydrogen burn, ddath, lake water purrped into steam generators.

CAUSE Apparent lack of centrol over outage activities.

SIGNIFICANCE 5eries of events which creates a cencern that procedural or personnel in-adequacies exist at the plant.

DISCUSSION While the llclf Creek facility was engaged in a refueling outage (reactor in mode 6),

several events occurred which collectively indicate a lack of administrative contrcl over activities at the plant.

On October 10, 1987 contract personnel were contaminated when they brcke a vent valve fittirs from the top of a desireralizer which as pressurized.

At the time they were attecptir.9 to unclos a transfer pipe which was being used to renove resin beads from the deminerel'izer. Twc workers received a 260 rrrad skin dcse and resin beads were strewn over the ceilir.q, the floor ano equiprent in the room.

On October 14, 1987, there was a trspected hydrogen burn in the pressurizer when a workman, atter.pting te weld a valvt. essociated with a pressurizer level transmitter, reported hearing a levd coise for several seconds. A temporary cover which had been placed on the flange of a code safety valve was blown off. There were nc injuries reported as e result of this incideni; however, the lives of several workers were placed at unusuel risk (IE Ir. formation Fetice No.82-26 discus:es the issue cf inadequate degassing and purging).

• On October 14, 1987, a contract electrician was killed >( en he made contact ,

i with an energized 4160 ESF bus section while cleaning a potential transformer.

The cubicle in which he was killed was not identified as containing energized equipment. A nearby cubicle containing another section of bus was tagged as energized.

l The tagging systen used to mark the equiprent was not under formal plant

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control. There was an assumption among werkers that everyone knew" the state of each piece of equipment being raintained.

On October 15, 1987, with the reactor nearly defueled, control room, fuel building and containetrt purge isolation signals and an auxiliary feedwater j initiation signal were generated (the train "B' AFW rump was locked cut),

j These actuations occurred due to the failure of the 125Y DC battery supply for one of twe trein "B" ESF AC inverters. The two train "B" battery banks had been supplying power to the two AC inverters for over 8804200216 800330 PDR FOIA PDR LYKINS08-68 , g,

.p.

24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, since the start of maintenance on the 4160V bus. About two hours (cllowing tFt initiel battery failure, the secerv battery bank failed resulting in the start cf an essential service water (ESil) pump and e switchover of AFW suction from the condensatt storage tank (CST) to the ESW systen. The emergency diesel generator also started and loaded to the bus. (Shutdown cooling was icst for about 30 seconds cs the RHR and spent fuel pool cooling pumps were shed anc reloaded).

Since the E3W system takes its suction from the ecoling lake, lake water was subsequently pumed into the secondary system, incluoing 7,500 to 10,000 gallons (calculated) into the steam generators. Eceause of an inferral tagging procedure used in the control room, operators incorrectly assured that AFW pump suction and discharge lines were isolated and therefore did not manually shut the ESW pump down. Operators further neglected tc secure the train "A" AFW pump. It is assumed that this pump contributed to the inventory of lakewater puged into the reactor.

The pumping continued for over ? 1/? hours. The steam generators were already in wet "le>vp" (nearly full) and this added water filled the steam generator and steam lines up to the closed main stear isolation valves.

FOLLOWUP A connection was rade from the "A" train bus to a spare train "B" charger to provide power to the train 'B' batteries, making the associated 120 VAC inverter busses operable.

Licensee has clearet lake water from the steen generators, condens&te storage tank and other secendary water systems.

Licenset is voluntarily placing a hold on outage activites while root cause determination is attemped.

', Licensee has established four task forces, one for each of the four ever.ts.

• Region is following, talking with licensee regarding apparent loss of administrative certrol during outage and apparent leek of obiectivity of task force membership.

Region has issued several Prelimintry Notificatiens.

Region is contemplating other actions including increased monitoring of the licensee's practices.

STATUS OF REVIEW This review is closed.

Nick Fields FWR Section Events Assessment Brarch i

cc: P. O'Connor C. E. Rossi j

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