ML19327A621
| ML19327A621 | |
| Person / Time | |
|---|---|
| Site: | La Crosse File:Dairyland Power Cooperative icon.png |
| Issue date: | 07/03/1980 |
| From: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Linder F DAIRYLAND POWER COOPERATIVE |
| References | |
| NUDOCS 8008060505 | |
| Download: ML19327A621 (1) | |
Text
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UNITED STATES hb 8
NUCLEAR REGULATORY COMMISSION o
REGION ill e
799 ROOSEVELT ROAD o
GLEN ELLYN. ILLINOIS 60137 JUL 3 E00~
Docket No. 50-409 Dairyland Power Cooperative ATTN:
Mr. F. W. Linder General Manager 2615 East Avenue - South La Crosse, WI 54601 Gentlemen:
This enclosed IE Bulletin No. 80-17, is forwarded to you for informa-tion. No written response is required.
If you desire additional information regarding this matter, please contact this office.
Sincerely,
%M James G. Keppl Director
Enclosure:
IE Bulletin No. 80-17 cc w/ encl:
Mr. R. E. Shimshak, NSIC Plant Superintendent TIC Central Files Mr. John J. Duffy, Chief Director, KRR/DPM Boiler Inspector, Department Director, NRR/ DOR of Industry, Labor and Human PDR Relations Local PDR 8008060'
SSINS No.:
6820 Accession No.:
8005050076 UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT JULY 3, 1980 IE BULLETIN NO. 80-17 FAILURE OF 76 0F 185 CONTROL RODS TO FULLY INSERT DURING A SCRAM AT A BWR Description of Circumstances:
On June 28, 1980, 76 of the 185 control rods failed to fully insert during a routine shutdown at TVA's Browns Ferry Unit No. 3 located at Athens, Alabama.
The reactor was manually scrammed from about 30 percent power in accordance with routine shutdown procedures.
The shutdown was initiated to repair the feedwater system.
The 76 control rods that failed to fully insert were all on the east side of the core.
Following scram discharge volume (SDV) high level bypass and a short drain period of the SDV, a second manual scram was initiated and all partially inserted rods were observed to drive inward, but 59 remained partially withdrawn. A third manual scram was made, again following high level in the SDV and bypassing for another short drain of the SDV, with the result that 47 rods remained partially withdrawn.
Following a longer drain of the SDV, an automatic scram occurred that was initiated by a scram discharge volume tank high water level signal when the scram reset switch was placed in " Normal"; with this scram all ruaining rods fully inserted.
The total time elapse from the initial scram to the time that all rods were inserted was approximately 15 minutes.
Core coolant flow, temperature and pressure remained normal for plant conditions. The unit is now shutdown and additional testing indicates that a possible cause of the malfunction was the retention of a significant amount of water in the east bank scram discharge volume.
In view of these interim findings and pending results of continued investigation, the following actions are to be taken.
Actions To Be Taken By Licensees:
All General Electric Boiling Water Reactors with operating licenses which are operating at any power on the date of this Bulletin shall perform the
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