PNO-IV-85-062, on 851206,plant Offgas Sys Experienced Transient Upon Automatic Switchover from Dryer a to Dryer C. Caused by Failure of Discharge Valve on Dryer C to Open Resulting in Back Pressure Blowing Out Water Loop Seals

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PNO-IV-85-062:on 851206,plant Offgas Sys Experienced Transient Upon Automatic Switchover from Dryer a to Dryer C. Caused by Failure of Discharge Valve on Dryer C to Open Resulting in Back Pressure Blowing Out Water Loop Seals
ML20137Z192
Person / Time
Site: River Bend Entergy icon.png
Issue date: 12/06/1985
From: Johnson E
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
To:
References
PNO-IV-85-062, PNO-IV-85-62, NUDOCS 8512110243
Download: ML20137Z192 (1)


December 6,1985 PRELIf11 NARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE -- PNO-IV-85-62 This preliminary notification constitutes EARLY notice of events of POSSIBLE safety or public interest significance. The infomation is as initially received without verification or evaluation, and is basically all that is known by the Regicn IV staff on this date.

FACILITY:

Gulf States Utilities Licensee Emergency Classification:

River Bend Nuclear Generating Station Notification of Unusual Event St. Frcncisville, Louisiana Alert Docket: 50-458 Site Area Emergency General Emergency X Not Applicable

SUBJECT:

SMALL RELEASE OF N0BLE GAS ACTIVITY WITHIN THE OFF-GAS BUILDING At approximately 8:20 a.m. on Friday, December 6,1985, the plant off-gas system experienced a transient upon the automatic switchover f rom dryer "A" to dryer "C" . This transient occurred when the discharge valve on dryer "C" failed to open and resulted in a back pressure which blew out all of the water loop seals of the system. One of the water loop seals discharges to the p radwaste dirty waste sump in the off-gas building condensate demineralizer

, room. As a result, some noble gases were released into this room.

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g There were construction painters and insulators working in this room and F 37 people were detected with contamination upon exiting the radiological

$ control area. Ten people had some body contamination and 27 people had only clothing contamination. This contamination was due to noble gas daughter 6 products and decays off in a relatively short period of time. Perscnnel were held for approximately 20-30 minutes and subsequent body counting revealed no discernable contamination. NRC and license are investigating the incident.

Neither the licensee nor the NRC plans to issue a press release, i The state of Louisiana has been informed, g Region IV received notification of this occurrence by the SRI at 12:53 p.m. on

.g December 6,1985.

'b CONTACT: E. H. Johnson, FTS 728-8106 DISTRIBUTION:

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PDR LICENSEE:

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