View source for PNO-II-88-001, on 880102,primary Containment Isolation Valves Drywell Equipment & Floor Drains Failed to Close Automatically After Receipt of Valid Group 2 Isolation Signal.Cause Under Investigation.Insp Team Dispatched

{{Adams
| number = ML20234F260
| issue date = 01/04/1988
| title = PNO-II-88-001:on 880102,primary Containment Isolation Valves Drywell Equipment & Floor Drains Failed to Close Automatically After Receipt of Valid Group 2 Isolation Signal.Cause Under Investigation.Insp Team Dispatched
| author name = Fredrickson P
| author affiliation = NRC OFFICE OF INSPECTION &amp; ENFORCEMENT (IE REGION II)
| addressee name = 
| addressee affiliation = 
| docket = 05000324
| license number = 
| contact person = 
| document report number = PNO-II-88-001, PNO-II-88-1, NUDOCS 8801110400
| document type = PRELIMINARY NOTIFICATION OF EVENT OR OCCURRENCE (PNO,, TEXT-INSPECTION &amp; AUDIT &amp; I&amp;E CIRCULARS
| page count = 1
}}
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PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE A 0 Y N This preliminary notification constitutes EARLY notice of events of POSSIBLE safety or public interest significance.        This information is as initially received without verification or evaluation, and is basically all that is known by the Region II staff on this date.
FACILITY:                             Licensee Emergency Classification:
Carolina Power & Light comoany             Notification of Unusual Event Brunswick Unit 2                           Alert Docket No. 50-324                          Site Area Emergency Southport, North Carolina                  General Emergency X    Not Applicable

==SUBJECT:==
REGION II DISPATCHES AUGMENTED INSPECTION TEAM (AIT) TO BRUNSWICK Following consultation with the' 0ffice of Nuclear Reactor Regulation (NRR) and the Office of Analysis and Evaluation of Operational Data ( AEOD), Region II is dispatching an Augmented Inspection Team to Carolina Power and Light Company's Brunswick nuclear power plant, located near Southport, North Carolina, to make an in-depth determination of why primary containment isolation valves for the Unit 2 drywell equipment drains and drywell floor drains failed to automatically close after receipt of valid Group 2 isolation signal on January 2, 1988.
A manual scram had oeen initiated at 12 : 17 a . m . (EST) on January 2, when condenser vacuum reached 22" Hg (decreasing) during an planned shutdown for a refueling outage.      Subsequently, a valid low level 1 signal (vessel level (162.5 inches) caused the group 2, 6 and 8 isolation signals. A total of four valves in both divisions failed to close as designed.
The two floor drains were subsequently closed from the cortrol room, but the eouioment drain vaives did not close. One equipment crain valve was found closed approximately 5 minutes after the event, and the other at approximately 10 minutes after tha event.      During this time, the auto close signal for the valve was sealed in.
The licensee cycled all four valves successfully later that morning when the drains had to be pumped. A licensee team has been investigating the event, but thus far no definitive cause has been found.
The NRC senior resident inspector responded to the site on January 3 and
,    $   continues to monitor the licensee's activities, augmented by regional staff.
O    Q.
Unit 2 will be in a scheduled refueling and maintenance outage until April, o    1988.
     'i' 8  to e uJc0 The State of North Carolina has been informed.
0 51
 ***     There was no injury to personnel, no release of radioactivity and no danger C7       to public health and safety as a result of this event. The NRC's AIT is being
 @@@     dispatched to the site to provide an in-depth regulatory analysis of the event (D o.cL to assure that its cause is fully understood prior to restart of the unit.
This information is current as of 4:00 p.m. (EST) on January 4      1988.
CONTACT
* P. FREDRICKSON - 242-5649 6p6A/3       J     - $l29 ' [ IIW' wfeef - T.O b                                   T4Sh E0                      re37 j}}

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