ML19256C680
| ML19256C680 | |
| Person / Time | |
|---|---|
| Site: | Trojan File:Portland General Electric icon.png |
| Issue date: | 09/07/1979 |
| From: | Bryan S, Mckee P, Stone J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE) |
| To: | |
| References | |
| PNO-79-402, NUDOCS 7910110661 | |
| Download: ML19256C680 (2) | |
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PRELIMINARY NOTIFICATION
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Septembei 7, 1979 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE--PNO-79-402 This oreliminary notification constitutes EARLY notice of events of POSSIBLE safety or public interest sionificance.
The information presented is as initially received without verification or evaluation and is basically all that is known by IE staff on this date.
Facility:
Portland General Electric Company Trojan Nuclear Plant Rainier, Oregon DN 50-344
Subject:
REACTOR TRIP, SAFETY INJECTION, AND VALVE FAILURE The Trojan nuclear plant tripped from full power at 1:07 a.m. on 9/5/79 due to a ground fault trip of the "D" reactor coolant pump (RCP).
The fault was traced to an insulation weakness near the inboard connector of the containment penetration.
The fault was apparently related to fabrication or installation, not to environ-mental conditions.
The licensee inspected all other high voltage penetrations and found no other discrepancies.
While the plant was shut down, licensee reviews being conducted pursuant to IE Bulletin 79-14 disclosed a missing pipe support on the suction piping of the "B" containment spray pump (the support was apparently not installed during initial construction).
The licensee installed the missing support, repaired the insulation faust associated with "D" RCP, ?nd proceeded with plant restart.
At 0507 on 9/6/79, following reactor startup, the licensee experienced difficulties in the turbine control system.
While maintenance personnel were troubleshooting the control system, the turbine control valves opened rapidly.
This caused a reactor trip, a high steam flow / low Tavg safety injection, and main steam line isolation.
Minimum reactor coolant system (RCS) temperature during the transient was 530 degrees F.
All ECC1 components functioned properly upon initiation of the safety injection.
However, the four main steam line bypass valves (one 3" air-operated valve by-passes each main steam isolation valve) did not close as required on a main steam isolation signal.
The licensee is still investigating the cause of this failure.
The plant is currently at 540 degrees F. ~Tavg.
In view of the valve problem still being investigated and the need to re-establish required boron concentration in the RCS, the licensee does not foresee plant startup earlier than 9/7/79.
A news release by Region V is not olanned.
The above information was received by the Region V office in telephone calls from the NRC resident inspector at 9 a.m. on 9/S/79 and 8 a.m. on 9/6/79.
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September 7, 1979 PNO-79-402 Continued
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Contact:
JStone, IE x28019 PMcKee, IE x28019 SBryan, IE x28019 Distribution:
Transmitt'd H St Chairman Hendrie Commissioner Bradford S. J. Chilk, SECY Commissioner Kennedy Commissioner Ahearne C. C. Kammerer, CA Commi,ssioner Gilinsky ACRS (For Distribution) g. q.2-Transmitted:
MNBB P. Bldg V. Stello, IE L. V. Gossick, EDO H. R. Denton, NRR Region N/
H. L. Ornstein, E00 R. C. DeYoung, NRR J. J. Fouchard, PA R. J. Mattson, NRR Landow N. M. Haller, MPA D. Vassallo, NRR J. J. Cummings, DIA R. G. Ryan, OSP D. Eisenhut, NF-H. K. Shapar, ELD SS Bldg (MAIL)
W. J. Dircks, NMSS R. Minogue, SD
- S. Levine, RES PECTNTfMRT11011ricWTT5s ~
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