ML19209A444
| ML19209A444 | |
| Person / Time | |
|---|---|
| Site: | Point Beach  |
| Issue date: | 09/27/1979 |
| From: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Burstein S WISCONSIN ELECTRIC POWER CO. |
| References | |
| NUDOCS 7910040065 | |
| Download: ML19209A444 (1) | |
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UNITED STATES 8
't NUCLEAR RFGULATORY COMMISSION q
.E REGION 111 i,
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799 ROOSEVELT ROAD e
g atEu Ettvu. ittinois scia 7 SEP 2 71979 Docket No. 50-266 Docket No. 50-301 Wisconsin Electric Power Company ATTN:
Mr. Sol Burstein Executive Vice President Power Plants 231 West Michigan Milwaukee, WI 53201 Gentlemen:
The enclosed IE Bulletin No. 79-24 is forwarded to you for action. Written responses are required.
If you desire additifaal information regarding this matter, please contact this office.
Sincerely,
$ fr=u=uAn ames G. Keppler Director
Enclosures:
1.
Designated Applicants for Operating Licenses cc w/ encl:
Mr. G. A. Reed, Plaut Manager Central Files Director, NRR/DPM Director, NRR/ DOR C. M. Trammell, ORB /NRR PDR Local PDR NSIC TIC Sandra A. Bast, Lakeshore
, Citizens for Safe Energy 1089
'81 7 910 040 s O (o[
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Accession No. 7908220114 SSINS No:
6820 UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
20555 September 27, 1979 IE Bulletin No. 79-24 FR0 ZEN LINES Summary:
On January 3, 1979, an unusual event occurred at Davis-Besse, Unit 1.
The event involved the freezing of the water in a portion of the high pressure coolant injection (HPCI) system recirculation line that is common to both high pressure coolant injection pumps.
The line was not thawed until January 5, 1979, and the event was not reported to NRC until March 12, 1979.
In addition, over the past five years, there have been several events involving frozen instrument ar.d sampling lines.
Description of Circumstances:
The condition was discovered on January 3,1979, while the reactor was operating at apprcximately 96 percent power.
During a monthly surveillance test of the HPCI pumps, there was no flow through the recirculation line from the pump di; charge to the Borated Water Storage Tank (BWST).
Investigation revealed that water in a portion of the line exposed to the outside weather was frozen.
lnis portion of the line to 'the BWST is common to both HPCI pumps.
The line has redundant heat tracing (a heated wire to prevent freezing); it is insulated; and it has a low-temperature alarm system to warn of freezing conditions.
Water in the line froze apparently because of prolonged sub-freezing temperatures and a defect in the insulation.
There was no apparent malfunct!on of the heat tracing or temperature alarm circuits, although the temperature sensing elements are located in an area not exposed to the coldest temperature conditions.
This recirculation line serves two purposes:
One is to provide a flow path for surveillance testing, and the other is to provide a minimum flow path to prevent possible damage to the pump in the event it is operated against a closed discharge valve or a reactor coolant system pressure greater than the maximum discharge pressure of the pump (approximately 1600 psig).
In the initial review of the event on January 3,1979, the licensee concluded that the pumps were still operable with the recirculation line frozen.
Therefore, no immediate action was taken to thaw the frozen section of the line. On January 5, 1979, the line was thawed and the surveillance test of the pumps qwas successfully completed.
DUPLICATE DOCUMENT Entire document previously entered L.
into system under:
1089 1 {
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