ML19344D064
| ML19344D064 | |
| Person / Time | |
|---|---|
| Site: | Zimmer |
| Issue date: | 02/14/1980 |
| From: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Borgmann E CINCINNATI GAS & ELECTRIC CO. |
| References | |
| NUDOCS 8003110169 | |
| Download: ML19344D064 (1) | |
Text
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UNITED STATES tlc; NUCLEAR REGULATORY COMMISSION y
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FEB 14 B3f-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 Gentlemen:
Our letter dated February 8, 1980, regarding IE Bulletin No. 80-04 was in error.
It should have stated for information only.
No written response is required.
Sincerely, I
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James G. Kepple Director
Enclosure:
IE Bulletin No. 80-04 cc w/ enc 1:
Mr. J. R. Schott, Plant Superintendent Central Files
-Director, NRR/DPM Director, NRR/ DOR PDR Local PDR NSIC TIC l
Harold W. Kohn, Power Siting Commission Citizens Against a Radioactive Environment Helen W. Evans, State of Ohio 8008110/df
UNITED STATES SSINS Mo.:
6820 NUCLEAR REGULATORY COMf11SSION Accessions No.:
0FFICE OF INSPECTION AND ENFORCEMENT 7910250504 WASHINGTON, D.C.
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February 8, 1980 4
IE Bulletin No. 80-04 ANALYSIS OF A PWR fiAIN STEAli LINE BREAK UITH CONTINUED FEEDUATER ADDITION Description of Circumstances:
Virginia Electric and Power Co. submitted a recort to the Nuclear Regulatory Comission dated September 7,1979 that identified a deficiency in the original analysis of containment pressurization as a result of reanalysis of stean line break for North Anna Power Station, Units 3 and 4.
Stone and Webster Engineering Cornoration performed a reanalysis of centainment 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, containnent design pressure would be exceeded in approximately 10 minutes. The long tern 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 infornation was provided to all holders of operating licenses and construction permits in IE Information Notice !!o. 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, flaine Yankee Atonic Power Company inforned 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 zern or low power at the end of core life, the licensee identified an incorrect oostulation that the startup feedwater control valves would remain positioned "as is" during the transient.
In reality, the startup feedwater control valves will rano to 80% full open due to an override signal resultina 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 pow reactors listed in Enclosure 1.
Review the containment p potential for containmen Entire document previously entered into system under:
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No. of es:
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