ML19344D058
| ML19344D058 | |
| Person / Time | |
|---|---|
| Site: | Midland |
| Issue date: | 02/14/1980 |
| From: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Howell S CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| References | |
| NUDOCS 8003110157 | |
| Download: ML19344D058 (1) | |
Text
,
ga uog I
<?
'o UNITED STATES g,
[',, f NUCLEAR REGULATORY COMMISSION q-
-- e REGION lli D,,
8 799 ROOSEVELT ROAD 8
,c GLEN ELLYN. ILLINOIS 60137 Docket No. 50-329 Docket No. 50-330 Consumers Power Company ATTN:
Mr. Stephen II. Howell Vice President 194~ West Parnall Road Jaceton, MI 49201 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, w bN.
Etl James G. Keppler Director
Enclosure:
IE Bulletin No. 80-04 cc w/ enc 1:
Central Files Director, NRR/DPM Lirector, NRR/ DOR PDR Local PDR NSIC TIC Ronald Callen, Michigan Public Service Commission Myron M. Cherry, Chicago 800311o 153
UNITED STATES SSINS No.:
6820 NUCLEAR REGULATORY COM!!ISSION Accession's No.:
0FFICE OF INSPECTION AND ENFORCEMENT 7910250504 WASHINGTON, D.C.
20555 February 8, 1980 J
ANALYSIS OF A PWR fiAIN STEA!i LINE BREAV, L'ITH CONTINUED FEEDWATER ADDITION Description of Circunstances:
Virginia Electric and Power Co. submitted a recort to the Nuclear Regulatory Connission dated September 7,1979 that identified a deficiency in the original analysis 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 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 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 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 punps 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, !!aine Yankee Atomic Dower Conpany 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 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 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 l
entered into system under:
- 7'1/0250EdY h
No. of es:
'