ML19331C966
| ML19331C966 | |
| Person / Time | |
|---|---|
| Site: | Zion File:ZionSolutions icon.png |
| Issue date: | 07/24/1980 |
| From: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Reed C COMMONWEALTH EDISON CO. |
| References | |
| NUDOCS 8008200540 | |
| Download: ML19331C966 (1) | |
Text
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o UNITED STATES g
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NUCLEAR REGULATORY COMMISSION REGION lil e
799 ROOSEVELT ROAD GLEN ELLYN. ILLINOIS 60137 JUL 2 4 S80 Docket No. 50-295 Docket No. 50-304 Commonwealth Edison Company ATTN:
Mr. Cordell Reed Vice President Post Office Box 767 Chicago, IL 60690 Gentlemen:
The enclosed IE Bulletin No. 80-18 is forwarded for action. A written response is required.
In order to assist the NRC in evaluating the value/ impact of each bulletin on licensees, it would be helpful if you would provide an estimate of the manpower expended in conduct of the review and prepara;;on of the reports required by the bulletin.
Please estimate separately the manpower associ-ated with corrective actions necessary following identification of problems through the bulletin.
If you desire additional information regarding this matter, please contact this office.
Sincerely,
. [>
b 4 / ames G. Keppler F
Director
Enclosure:
IE Bulletin No. 80-18 cc w/ encl:
Mr. D. L. Peoples, Director PDR of Nuclear Licensing Local PDR Mr. N. Wandke, Plant NSIC Superintendent TIC Central Files Mr. Dean Hansell, Office of Director, NRR/DPM Assistant Attorney General Director, NRR/ DOR 8008200 f yO
I SSINS No.: 6820
'i Accession No.:
UNITED STATES 8005050062 NUCLEAR REGULATORY COMISSION 0FFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C. 20555 July 24, 1980 IE Bulletin No. 80-18 i
MAINTENANCE OF ADEQUATE MINIMUM FLOW THRU CENTRIFUGAL CHARGING PUMPS FOLLOWING SECONDARY SIDE HIGH ENERGY LINE RUPTURE l
Description of Circumstances:
Letters sis.ilar to the May 8,1980 notification made pursuant to Title 10 CFR Part 21 (enclosure) were sent from Westinghouse to a number of operating
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plants and plants under construction (list, within enclosure) in early May, 1980.
The letters and the enclosed "Part 21" letter conuin a complete description of the ootentit,1 problem sumarized below. The letters indicated that under certain conditions the centrifugal charging pumps (CCPs) could be damaged due to lack of minimum flow before presently applicable safety injection (SI) termination criteria are met. The particular circumstances that could result in damage vary somewhat from plant to plant, but involve unavail-ability of the pressurizer power operated relief valves (PORVs), with operation of one or more CCPs repressurizing the reactor during SI following a secondary system high energy line break. Since the SI signal automatically isolates the CCP mini-flow return line, the flow through the CCPs is determined by the individual pump characteristic head vs. flow curve, the pressurizer safety valve setpoint, and the flow resistances and pressure losses in the piping and in the reactor core. That minimum flow may not be adequate to insure pump cooling, and resulting pump damage could v o a e design criteria ilt before current SI termination criteria are met.
Westinghouse recommends that plant specific calculations outlined in the letter (2nclosure) be performed to determine if adequate minimum flow is assured under all conditions. If adequate minimum flow is not assured, Westinghouse recommends specific equipment and procedure modifications which will result in adequate minimum flow. The recomended modifications assure availability of the necessary minimum flow by assuring that the mini-flow bypass line will be open when needed, but will be closed at lower pressures when the extra flow resulting from bypass line closure might be necessary for core cooling.
DUPLICATE DOCUMENT I
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