ML19290E404
| ML19290E404 | |
| Person / Time | |
|---|---|
| Site: | Dresden, Byron, Braidwood, Quad Cities, Zion, LaSalle  |
| Issue date: | 02/08/1980 |
| From: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Reed C COMMONWEALTH EDISON CO. |
| References | |
| NUDOCS 8003110092 | |
| Download: ML19290E404 (1) | |
Text
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UNITED STATES NUCLEAR REGULATORY COMMISSION
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799 ROOSEVELT ROAD GLEN ELLYN, ILLINOIS 60137 FEB 81880 Docket Nos. 50-10, 50-237, 50-249, 50-254, 50-265, 50-295, 50-304, 50-373, 50-374, 50-454, 50-455, 50-456 and 50-457 Commonwealth Edison Company ATTN:
Mr. Cordell Reed Vice President Post Office Box 767 Chicago, IL 60690 Gentlemen:
The enclosed IE Bulletin No. 80-04, is forwarded for action. A written response is required.
If you desire additional information regarding this matter, please contact this office.
Sincerely, o M }b
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., James G. Keppler Director
Enclosure:
IE Bulletin No. 80-04 cc w/ enc 1:
Mr. D. L. ".ples, Director Mr. Gunner Sorensen, Site of Nuclear Licensing Project Superintendent Mr. B. B. Stephenson, Mr. R. Cosaro, Project Station Superintendent Superintendent Mr. N. Kalivianakis, Central Files Station Superintendent Director, hPR/DPM Mr. N. Wandke, Station Director, NRR/ DOR Superintendent PDR Mr. L. J. Burke, Site Local PDR Project Superintendent NSIC Mr. T. E. Quaka, Quality TIC Assurance Supervisor Mr. Dean Hansell, Office Mr. R. H. Holyoak, Station of Assistant Attorney Superinterdent General 80 03110 ocl 2
UNITED STATES SSINS No.-
6820 a,
NUCLEAR REGULATORY COMMISSION Accessions No.
OFFICE OF INSPECTION AND ENFORCEMENT 7910250504 WASHINGTON, D.C.
20555 February 8, 1980 IE Bulletin No. 80-04 ANALYSIS OF A PWR MAIN STEAM LINE BREAK WITH CONTINUED FEEDWATER ADDITION Descri,,. n of Circumstances:
Virginia Electric and Power Co. submitted a report to the Nuclear Regulatory Commission dated September 7, 1979 that identified a deficiency in the original Enalysis of containment pressurization as a result of reanalysis of steam line break for North Anna Power Station, Units 3 and 4.
Stone and Webster Engineering Corporation performed a reanalysis of containment pressure following a main steam line break and determined that, if the auxiliary feedwater system continued to supply feedwater at runout. conditions to the steam generator that had experienced the steam line break, containment design pressure would be exceeded in approximately 10 minutes.
The long term blowdown of the water supplied under runout conditions by the auxiliary feedwater system had not been considered in the earlier analysis.
On October 1, 1979, the foregoing information was provided to all holders of operating licenses and construction permits in IE Information Notice No. 79-24.
The Palisades facility did an accident analysis review pursuant to the information in the notice and discovered that with offsite power available, the condensate pumps would feed the affected generator at an excessive rate.
This excessive feed was not considered in the analysis for the steam line break accident.
On January 30, 1980, Maine Yankee Atomic Power Company informed the NRC of an error in the main steam line break analysis for the Maine Yankee plant.
During a review of the main steam line break analysis, for zero or low power at the end of core life, the licensee identified an incorrect postulation that the startup feedwater control valves would remain positioned "as is" during the transient.
In reality, the startup feedwater control valves will ramp to 80% full open due to an override signal resulting from the low steam generator pressure reactor trip signal.
Reanalysis of the event shows the opening of the startup valve and associated high feedwater addition to the affected steam generator would cause a rapid reactor cooldown and resultant return-to power, a condition outside the plant design basis.
Actions to be Taken by the Licensee:
For all pressurized water power react with an operating license and those reactors listed in Enclosure 1:
1.
Review the containment pressure potential for containment overp DUPLICATE DOCUMENT Entire document previously entered into system under:
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