ML19210D786
| ML19210D786 | |
| Person / Time | |
|---|---|
| Site: | Clinton  |
| Issue date: | 11/16/1979 |
| From: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Gerstner W ILLINOIS POWER CO. |
| References | |
| NUDOCS 7911280069 | |
| Download: ML19210D786 (1) | |
Text
&
e no 4
/
uq'o, UNITED STATES l'
NUCLEAR REGULATORY COMMISSION
$,., c '
'n T'
E REGION lil o,k N,' [e[
799 ROOSEVE LT ROAD GLE N E L LYN, lL LINOIS 60137 l
Docket No. 50-461 Docket No. 50-462 Illinois Power Company ATTN:
Mr. W. C. Gerstner Executive Vice President 500 South 27th Street Decatur, IL 62525 Gentlemen:
The enclosed IE Informition 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,
.~ [b.
ames G. Keppler Director
Enclosures:
1.
IE Information Notice No. 79-27 2.
Recently Issued IE Information Notices cc w/encls:
Central Files Director, NRR/DPM Director, hRR/ DOR PDR Local PDR NSIC TIC Mr. Dean Hansell, Office of Assistant Attorney General 1435 Sly 0
1on280
4 SSINS No.:
6870 Accession No.:
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 months 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 The first event occurred on June 25, 1979, at the Doel 2 nuclear 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 subcritical throughout the event.
The first indication of abnormal behavior was a rapid decrease of the primary system pressure (approximately:
28 psi / min.).
This was followed by the sequence of events listed below:
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 DOCUMdNd'5 55 l 6 pressurizer.
Entire document previously entered into system under:
[h No, pages: