PNO-III-86-150, on 861218,licensee Entered Mode 4 from Mode 3 to Investigate 861215 Failure of MSIV to Close Per Tech Specs.Leak in Pressurizer Level Sensing Line Isolation Valve Will Be Repaired.Investigation Continuing
| ML20212C001 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 12/18/1986 |
| From: | Defayette R, Guldemond W NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| References | |
| PNO-III-86-150, NUDOCS 8612290363 | |
| Download: ML20212C001 (1) | |
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hY PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL: OCCURRENCE--PNO-III--86-150 Data 12/18/86 This preliminary notification constitutes EARLY notice of events of POSSIBLE safety or!public interest significance. The information is as initially received without verification or evaluation, and is basically all that is known by the Region III staff on this date.
. Facility: Toledo Edison Company--
Licensee Emergency Classification:
Davis-Besse Nuclear Plant Notification of an Unusual Event Oak Harbor, OH '43449-Alert Site Area Emergency,
JVgg 1
General Emergency X Not Applicable Subj:ct:
MSIV REPAIR At7:30a.m.(CST), December 18, 1986, the licensee entered Mode 4 (hot shutdown) from Mode 3 (hot standby) to investigate the continuing failure of'a Main Steam Isolation Valva (MSIV) to close within technical specification limits.
1 On D:cember 15, the licensee performed closing time tests on the MSIV, and found that the valve continually closed in about 6.5 seconds. Technical Specifications requires the
'. valve to close within 5 seconds.
Tha licensee adjusted the closing mechanism, but the adjustment had little effect. The licensee then declared the MSIV inoperable, and on December 16, disassembled the closing mechanism, cleaned it, and reassembled it. The MSIV still fails to close within the required time.
j ' In an unrelated matter the licensee discovered a small leak in a pressurizer level sensing
. lins isolation valve which also will be repaired. Resolution of the MSIV problem remains
.the pacing item for plant startup.
i Tha unit is expected to be in Mode 4 for about 3 days while the licensee's investigation continues..The plant has been shutdown since June 9, 1985, and cannot go critical (Mode
- 2) without NRC authorization.
An augmented inspection team from Region III (Chicago) and headquarters is on site n observing the licensee's activities. Region III continues to follow the licensee's
~
course of action.
' Tha State of Ohio will be notified.
- Thisinformationiscurrentasof11
- 00a.m.(CST), December 18, 1986.
fkl
. CONTACT:
R. DeFayette W. Guldemond l-FTS 388-5767 FTS 388-5574 8612290363 861218 PDR I&E
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If Region III Rev. Nove62r 19A m '~ 39
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