ML19210D809
| ML19210D809 | |
| Person / Time | |
|---|---|
| Site: | Trojan File:Portland General Electric icon.png |
| Issue date: | 11/16/1979 |
| From: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | Goodwin C PORTLAND GENERAL ELECTRIC CO. |
| References | |
| NUDOCS 7911280103 | |
| Download: ML19210D809 (1) | |
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UNITED STATES NUCLEAR REGULATORY COMMISSION 7
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,e SUITE 202. WALNUT CREEK PLAZA WALNUT CREEK, CALIFORNI A 94596 flovember 16, 1979 Docket No. 50-344 Portland General Electric Cccpar.y 121 S. W. Salmon Street Portland, Oregon 97204 Attention: Mr. Charles Goodwia, Jr.
Assistant Vice President Gentlemen:
The enclosed IE Information Notice provides information with regard to the sequence of events that followed incidents involving steam generator tube ruptures at two PWR units.
Sincerely, L
s R. H. Engelken Director
Enclosures:
1.
IE Information Notice 79-27 2.
Recently Issued IE Information Notices cc w/ enclosures:
C. P. Yundt, PGE F. C. Gaidos, PGE
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h47 79112 8 0 t o3
SSINS Mo.:
6870 Accession No.:
7910250488 IPlITEn STATES MUCLEAR REGULATORY r.ntmISSInal 0FFICE OF INSPECTION APID ENFnRCE'dErlT WASHINGTON D.C.
20555 November 16, 1979 IE Infomation Notice No. 79-27 STEAM GENERATOR TUBE RUPTURES AT TWO PWR PLAtlTS Descriotion of Circumstances:
In recent months two incidents involvina stean generator tube ruptures have occurred.
In both instances, the units were cooled down and placed in the residual heat removal mode with existing oracedures.
Event of June 25, 1979 at the Doel 2 Nuclear Power Plant in Belgium The first event occurred on June 25, 1979, at the Doel 2 nuclear oower olant in-Belgium. The Doel unit is a 390 %e Westinghouse two-loco reactor. The event consisted of a rupture of several tubes in the 1000 B steam generator. The resultant leakage between the orinary ano secondary systems was estinated to be 125 gom. The event started when the plant was heated uo after a shutdown caused by a malfunction of the main stean isolation valve. At the time of tge incident the primary coolant pressure was:
2233 psi and the temperature: 491 F.
The reactor remained subcritical throughout the event.
The first indication of abnomal behavior was a raoid decrease of the crimary system pressure (accroximately: 28 osi/nin.). This was followed by the sequence of events listed below:
Time, min.
1.
Increase of charaina flow demand, reauirina startup of a second 1.8 charging pump.
2.
Automatic isolation of the CVCS letdown line.
2.4 3.
Shut off of the pressurizer heaters due to low liquid level in the 2.4 pressurizer.
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