ML19210D793
| ML19210D793 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 11/16/1979 |
| From: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Crouse R TOLEDO EDISON CO. |
| References | |
| NUDOCS 7911280079 | |
| Download: ML19210D793 (1) | |
Text
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UNITED STATES
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NUCLEAR REGULATORY COMMISSION 3 k ",'/ ' fE REGION 111 o,
799 ROOSEVELT ROAD g, s.,-,/
cLEN E LLYN. lLLINOIS 60137 Docket No. 50-346 Toledo Edison Company ATTN:
Mr. Richard P. Crouse Vice President Energy Supply Edison Plaza 300 hadison Avenue Toledo, OH 43652 Gentlemen:
The enclosed IE Information Notice No. 79-27 provides information with regard to the sequence of events that followed incidents involving steam generator tube ruptures at two PWR units.
Sincerely, hb James G. Keppler Director
Enclosures:
1.
IE Information Notice No. 79-27 2.
Recently Issued IE Information Notices cc w/encls:
Mr. T. Murray, Station Superintendent Central Files Director, NRR/DPM Director, NRR/ DOR PDR Local PDR NSIC TIC Harold W. Kohn, Power 1435
$25 Siting Commission Helen W. Evans, State of Ohio 7911280 O
SSINS No.:
6870 Accession No.:
7910250488 UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON D.C.
20555 November 16, 1979 IE Information Notice No. 79-27 STEAM GENERATOR TUBE RUPTURES AT TWO PWR PLANTS Description of Circumstances:
In recent t.?cnths two incidents involving steam generator tube ruptures have occurred.
In both instances, the units were cooled down and placed in the residual heat removal mode with existing procedures.
Event of June 25, 1979 at the Doel 2 Nuclear Power Plant in Belgium s
The first event occurred on June 25, 1979, at the Doel 2.'uclear power plant in Belgium.
The Doel unit is a 390 Mwe Westinghouse two-loop reactor.
The event consisted of a rupture of several tubes in the loop B steam generator.
The resultant leakage between the primary and secondary systems was estimated to be 125 gpm.
The event started when the plant was heated up after a shutdown caused by a malfunction of the main steam isolation valve.
At the time of the incident the primary coolant pressure was:
2233 psi and the temperature:
491 F.
The reactor remained subtritical throughout the event.
The first indication of abr.ormal behavior was a rapid decrease of the primary system pressure (approximately:
28 psi / min.).
This was followed by the sequence of events listed below:
1435 526 Time, min.
1.
Increase of charging flow demand, requiring startup of a second 1.8 charging pump.
2.
Automatic isolation of the CVCS 3.
Shut off of the pressurizer hea DUPLICATE DOCUMENT pressurizer.
Entire document previously entered into system under:
h ANO J
No. of pages: