ML19211C066
| ML19211C066 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 11/16/1979 |
| From: | Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | Cavanaugh W ARKANSAS POWER & LIGHT CO. |
| References | |
| NUDOCS 8001100037 | |
| Download: ML19211C066 (1) | |
Text
bec to DAC:ADM:
CENTRAL FILES pa arc UNITED STATES PDR:HQ
,4 uq'o, NUCLEAR REGULATORY COMMISSION LPDR W
REGloN IV y
n l
o 611 RYAN PLAZA DRIVE, SUITE 1000 4j ARLINGTON, TEXAS 76012 NSIC o
'g Y ' ' ' %D November 16, 1979 Docket Nos.
50-313 50-368 Arkansas Power and Light Company
' ATTN:
Mr. William Cavanaugh III Vice President of Generation and Construction F. O. Box 551 Little Rock, Ark ansas 72203 Gentlemen:
The enclosed IE Infor=ation Notice provides information with regard to the sequence of events that followed incidents involving steam generator tube ruptures at two PWR units.
Sincerely, Karl V. {}eyfrit
'sC E
Director
Enclosures:
1.
IE Information Notice 79-27 2.
Recently Issued IE Information Notices cc: Janes P. O'Hanlon, Plant Manager Arkansas Nuclear One P. O. Box 608 Russellville, Arkansas 72801 1739 062
^
8001100 bh3
SSINS No.:
6870 Accession No.:
7910250488 UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON D.C.
20555 IE Information Notice No. 79-27 Date: November 16, 1979 Page 1 of 7 STEAM GENERATOR TU3E RUPIURES 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 b'y 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 letdown line.
2.4 3.
Shut off of the pressurizer heaters due to low liquid level in the 2.4 pressurizer.
4.
Closing of block valves in the pressurizer relief line.
4.6 5.
Rapid increase of water level in The steam generator was isolated.
DUPLICATE DOCUMENT 6.
Startup of the third charging pum Entire document previously all charging pumps from the CV ta entere to syst un er ANO 1739 063 e
No. of pages:
O
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