ML19327A606
| ML19327A606 | |
| Person / Time | |
|---|---|
| Site: | Vermont Yankee File:NorthStar Vermont Yankee icon.png |
| Issue date: | 07/03/1980 |
| From: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | Rich Smith VERMONT YANKEE NUCLEAR POWER CORP. |
| References | |
| NUDOCS 8008060466 | |
| Download: ML19327A606 (1) | |
Text
(LDutt9 UufJutU noeuq'o, NUCLEAR REGULATCRY COMMISSION g
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KING OF PRUS$1 A, PENNSYLVA il A 1940s Docket No. 50-271 July 3, 1980 Vermont Yankee Nuclear Power Corpor1 tion ATTN:
Mr. Robert L. Smith Licensing Engineer 25 Research Drive Westborough, Massachusetts 01581 Gentlemen:
The enclosed IE Bulletin No. 80-17, is forwarded for action.
Prepare to perform the scram tests contained in tha Bulletin; however, the 20-day time clock for completing will begin upon notification by telephone from the IE Regional Office.
The testing shall be performed as directed unless shutdown would severely impact the power reliability in your area as shcwn by appropriate and timely documentation to the Director of the Office of Inspection and Enforcement.
A written response to the Bulletin is required. If you desire additional informa-tion regarding this matter, please contact this office.
Sincerely, W.
m o
- H. Grier virector
Enclosures:
1.
List of Recently Issue'd IE Bulletins CONTACT:
D. L. Caphton (215-337-5266) i 8008060 %
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Vermont Yankee Nuclear Power 2
Corporation cc w/encls:
Mr. Warren P. Murphy, Plant Superintendent Ms. J. Abbey, Technical Secretary Mr. J. E. Griffin, President Mr. L. H. Heider, Vice President 4
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ENCLOSURE 1 SSINS No.: 682t.
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 thic Bulletin shall perform the followinn steps in the time stated. Those t!"+r7 i
following steps prior to operating D PLICATE DOCUMENT 1.
Within 3 days from the date of tests to verify that there is i
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