ML19290E460
| ML19290E460 | |
| Person / Time | |
|---|---|
| Site: | Trojan File:Portland General Electric icon.png |
| Issue date: | 02/08/1980 |
| From: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | Goodwin C PORTLAND GENERAL ELECTRIC CO. |
| References | |
| NUDOCS 8003110298 | |
| Download: ML19290E460 (1) | |
Text
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o UNITED STATES
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1990 N. CALIFORNIA BOULEVARD REGION V 0,
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WALNUT CREEK, CALIFORNIA 94596 February 8,1980 Docket tio. 50-344 P ortland General Electric Company 121 S. W. Salmon Street Portland, Oregon 97204 Attention: ttr. Charles Goodwin Assistant Vice President G entlemen:
The enclosed IE Bulletin flo. 80-04, is forwarded for action.
A written response is required.
If you desire additional infonnation regarding this matter, please contact this office.
Sincerely, fWwfC R. H. Engelken Director
Enclosure:
IE Bulletin tio. 80-04 cc w/ enclosure:
J. W. Lentsch, PGE F. C. Gaidos, PGE 80 03110 2 T
UNITED STATES SSINS tio.:
6820 NUCLEAR REGULATORY COMMISSION Accessions No.:
0FFICE OF INSPECTION AND ENFORCEMENT 7910250504 WASHIf;GTON, D.C.
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February 8, 1980 IE Bulletin No. 80-04 ANALYSIS OF A PNR MAIfl STEAM LINE BREAK 1.'ITH CONTINUED FEED'JATER ADDITION Description of Circumstances:
Virginia Electric and Power Co. subnitted a report to the fluclear 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 feeduater systen had not been considered in the earlier analysis.
On October 1,1979, the foregoing information was provided to all holders of onerating licenses and construction permits in IE Information flotice ?!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, fluine Yankee Atonic Power Conpany inforred the flRC of an error in the main stean 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 resulting from the low steam generator pressure reactor trip signal.
R2 analysis nf 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 DUPLICATE DOCUMENT 1.
Review the containment p.
potential for containmen Entira document previously entered into system under:
-O ??/0250EdY h
No. of pages: