View source for PNO-I-97-072, on 971123,operators Initiated Plant Shutdown When Main Steam Isolation Valves AO-203-1C & AO-203-2B Were Declared Inoperable During Surveillance Test

{{Adams
| number = ML20199H189
| issue date = 11/24/1997
| title = PNO-I-97-072:on 971123,operators Initiated Plant Shutdown When Main Steam Isolation Valves AO-203-1C & AO-203-2B Were Declared Inoperable During Surveillance Test
| author name = Conte R, Laura R
| author affiliation = NRC OFFICE OF INSPECTION &amp; ENFORCEMENT (IE REGION I)
| addressee name = 
| addressee affiliation = 
| docket = 05000293
| license number = 
| contact person = 
| document report number = PNO-I-97-072, PNO-I-97-72, NUDOCS 9711260045
| 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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Novembor 24, 1997 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE PNO-I-97-072 Thio preliminary notification constitutes EARLY notice of events of POSSIBLE cofoty or public interest significance. The information is as initially rocoived without verification or evaluation, and is basically all that is known by Region I staff in King of Prussia, Pennsylvania on this date.
Easility                                                      Licensee Emeraency Classification                                        l Bo ton Edison Co.                                               Notification of Unusual Event                                         I Pilgrim 1                                                       Alert                                                               y Plymouth, Massachusetts                                         Site Area Emergency                                                   6 Dockots: 50-293                                                 General Emergency X Not Applicable

==Subject:==
UNPLANNED SHUTDOWN GREATER THAN 72 MURS - EN NO. 33303 On November 23, 1997, operators initiated a plant shutdown when main steem isolation valves (MSIVs) AO-203-1C and AO-203-2B were declared inoparable during a surveillance test.               The MSIVs are Atwood Morell, 20 inch Y-globe valves, air to open with air and spring to close. The two MSIVe stroke time tested properly within the prescribed 3 to 5 second full close criteria using the control panel switch. However, the valves failed to fully seat during a full-stroke, fail-safe test (Inservice Test Program Requirement) when actuator air was removed allowing valve closure with spring force only.             Initial troubleshooting on AO-203-2B (located in the steam tunnel) revealed that the main disc was approximately 3/4 inch off of its seat during slow closure using the push-button, Decause AO-203-1C is located inside the drywell, no similar measuremants were taken. As a result, operators entered technical specification (TS) for inoperable Primary Containment Isolation Valves which requires a shutdown within 24 hours. Boston Edison Company (BECo) formed an MSIV investigation team including the use of Atwood Morrel and General Electric personnel to identify the root cause and implement corrective cetions, as needed.
At 04:01 a.m. on November 23, 1997. BECo commenced a normal shutdown of the Pilgriu reactor. The turbine was secured at 10:25 a.m., and the mode cwitch turned to the " Shutdown" position at 6:27 p.m. later that same day. As of 8:30 a.m. on November 24, 1997, the reactor was in Cold Shutdown with a primary coolant temperature of approximately 110 degrees Fahrenheit. No significant safety related problems were experienced during the plant shutdown and subsequent cooldown.
The resident inspector staff responded to the site on November 23 to monitor _a portion of the shutdown activities and will monitor outage activities.       BECo did not issue a press release but plans to informally notify members of the local media. This PN is current as of 2:30 p.m. on November 24, 1997. The Region I-Public Affairs Officer is prepared to recpond to media inquiries. The Commonwealth of Massachusetts has been notified.

==Contact:==
. Richard Laura                    Richard Conte (508)747-0565                 (610)337-5183 l          g12g45971124                                                              g*g}p PNO-I-97-072           PDR          i                              , o             '
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