ML19327A619
| ML19327A619 | |
| Person / Time | |
|---|---|
| Site: | Zimmer |
| Issue date: | 07/03/1980 |
| From: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Borgmann E CINCINNATI GAS & ELECTRIC CO. |
| References | |
| NUDOCS 8008060501 | |
| Download: ML19327A619 (1) | |
Text
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UNITED STATES 8*
1, NUCLEAR REGULATORY COMMISSION 71 10 REGION lli t
.e 799 ROOSEVELT ROAD g
GLEN ELLYN. ILLINOIS 6o137 o
N 3O Docket No. 50-358 Cincinnati Gas and Electric Company ATTN:
Mr. Earl A. Borgmann Senior Vice President Engineering Services and Electric Production 139 East 4th Street Cincinnati, OH 45201 Jentlemen:
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, a
,,b James G. Kepp e'r Director
Enclosure:
IE Bulletin No. 80-17 cc w/ enc 1:
Mr. J. R. Schott, Plant Superintendent Central Files Director, NRR/DPM Director, NRR/ DOR PDR Local PDR NSIC TIC Harold W. Kohn, Power Siting Commission Citizens Against a Radioactive Environment Helen W. Evans, State of Ohio 800806 50/3 h
8, 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manual scram was initiated and all partially inserted rods were observed to drive inward, but 59 remained partially withdrawn.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high level in the SDV and bypassing for another short drain of the SDV, with the result that 47 rods remained partially withdrawn.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 remaining 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 following steps in the time stated.
Thrwp that are nresentiv shutdown shall perform the following steps prior tr DUPLICATE DOCUMENT 1.
Within3daysfromthedateof[j tests to verify that there is b DischargeVolume(SDV)andassej Entire document previously entered into system under:
are' operable and vent system i>;
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