ML19344D070
| ML19344D070 | |
| Person / Time | |
|---|---|
| Site: | La Crosse File:Dairyland Power Cooperative icon.png |
| Issue date: | 02/14/1980 |
| From: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Linder F DAIRYLAND POWER COOPERATIVE |
| References | |
| NUDOCS 8003110177 | |
| Download: ML19344D070 (1) | |
Text
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uq[o, UNITED STATES
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7, NUCLEAR REGULATORY COMMISSION lh, E
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GLEN ELLYN. ILLINOIS 60137 fEB 14 NU Docket No. 50-409 Dairyland Power Cooperative ATTN:
Mr. F. W. Linder General Manager 2615 East Avenue - South La Crosse, WI 54601 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, c4
,s f James G. Keppler Director
Enclosure:
IE Bulletin No. 80-04 cc w/ enc 1:
Mr. R. E. Shimshak, Plant Superintendent Central Files Director, NRR/DPM Director, NRR/ DOR PDR Local PDR NSIC TIC Mr. John Duf;fy, Chief Boiler Inspector, Department of Industry, Labor and Human Relations soo.11o i77
UNITED STATES SSINS No.:
6820 NUCLEAR REGULATORY COMfilSSION Accessions No.:
OFFICE OF INSPECTION AND Ef! FORCE!1ENT 7910250504 WASHIt'GTON, D.C.
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, M Qb February 8, 1980 IE Bulletin No. 80-04 ANALYSIS OF A PWR liAIN STEA!1 LINE BREAK UITH CONTINUED FEEDtlATER ADDITION Cescription of Circumstances:
Virginia Electric and Power Co. subnitted a report 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 Corporation 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 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 flotice flo. 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 Atomic Power Company inforned the NRC cf an error in the main steam line break analysis for the fiaine 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 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 resultino 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:
wo 71/0250EoY h
No. of es:
.