ML19290E419
| ML19290E419 | |
| Person / Time | |
|---|---|
| Site: | Midland |
| Issue date: | 02/08/1980 |
| From: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Howell S CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| References | |
| NUDOCS 8003110113 | |
| Download: ML19290E419 (1) | |
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8 UNITED STATES 7,
NUCLEAR REGULATORY COMMISSION 5
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.. c REGION 111 o
799 ROOSEVELT ROAD o
GLEN ELLYN. ILLINOIS 60137 FEB 8198a Docket No. 50-329 Docket No. 50-330 Consumers Power Company ATTN:
Mr. Stephen H. Howell Vice President 1945 West Parnall Road Jackson, MI 49201 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, hfego0w JamesG.Keppbr Director
Enclosure:
IE Bulletin No. 80-04 cc w/ enc 1:
Central Files Director, NRR/DPM Director, NRR/DCR PM 1 :al PDR h IC TIC Ronald Callen, Michigan Public Service Commission Myron M. Cherry, Chicago 8003110l(b
UtilTED STATES SSINS fio.:
6820 NUCLEAR REGULATORY COMfilSSION Accessions No.:
OFFICE OF INSPECTION Atl3 Et! FORCE' TENT 7910250504 WASHIt'GTON, D.C.
20555 February 8, 1980 IE Bulletin No. 80-04 A!1ALYSIS OF A PWR ftAIN STEA!i LINE BREAK L'ITH CONTINUED FEEDUATER ADDITION Description of Circunstances:
Virginia Electric and Power Co. submitted a recort to the fluclear Regulatory Connission 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, containment design oressure would be exceeded in approximately 10 minutes.
The long tern b wwdown 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 ocerating licenses and construction permits in IE Information ?!otice ?!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 Atomic Power Conpany inforned the f!RC of an error in the main steam line break analysis for the !1aine 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 resulting from the low steam generator presswe reactor trip signal.
Reanalysis of the event shows the opening of ti.e 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:
= 9 9/033 0 E0Y h
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