ML18051A497
| ML18051A497 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 07/26/1983 |
| From: | Vandewalle D CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | Crutchfield D Office of Nuclear Reactor Regulation |
| References | |
| REF-SSINS-6820, REF-SSINS-SSINS-6 IEB-80-04, IEB-80-4, NUDOCS 8308010326 | |
| Download: ML18051A497 (2) | |
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- consumers Power company General Offices: 1945 West Parnall Road, Jackson, Ml 49201 * (517) 788-0550 July 26, 1983 Dennis M Crutchfield, Chief Operating Reactor Branch No 5 Nuclear Reactor Regulation US Nuclear Regulatory Commission Washington, DC 20555 DOCKET 50-255 - LICENSE DPR
- PALISADES PLANT - MAIN STE.AM LINE BREAK WITH CONTINUED FEEDWATER ADDITION (Reference TE Bulletin 80-04)
NRC letter dated September 7, 1982 requested additional information to the Consumers Power Company submittal of April 26, 1982 regarding the effects of a single active failure either in the actuating circuitry, including the actu-ating devices (relays and solenoid valves) or of the actuated devices (the feedwater regulating valves or feedwater bypass valves) for a Main Steam Line Break Accident.
NRC review of the Main Feedwater and condensate systems determined that a single active failure to one of the feedwater regulating valves or feedwater bypass valves could cause it to remain open after re-ceiving the low steam generator pressure trip signal thus allowing the conden-sate pumps to continue pumping water through the tripped main f eedwater pumps into the ruptured steam generator.
Consumers Power Company responded to this request October 26, 1982 with a commitment to perform more analysis and resolve the identified problems resulting from the new system design require-ments.
Consumers Power Company has completed the analysis and determined that meeting the new NRG-imposed system requirement will require a modification to the main feedwater system.
This modification which is presently scheduled to be completed during 1985 Refueling Outage involves modifying the control circuitry of the main feedwater stop valves, CV-0742 and -0744 and feedwater bypass valves CV-0734 and -0735 to close on low steam generator pressure.
Also included in this modification will be the addition of a control valve in series with CV-0734 and one in series with CV-0735 to meet single failure 8308010326 830726 PDR ADOCK 05000255 G
PDR OC0783-0012A-NL02
DMCrutchf ield, Chief Palisades Plant MAIN STEAM LINE BREAK
- WITH CONTINUED FEEDWATER ADDITION July 26, 1983 2
criteria which will also close on steam generator low pressure.
This modifi-cation, along with the existing system means that on a steam generator low pressure signal following a main steam line break, the following valves will trip closed:
the feedwater reg valves, the existing bypass valves, the main feedwater stop valves and the new bypass valves.
Nuclear Licensing Administrator CC Administrator, Region III, USNRC NRC Resident Inspector - Palisades OC0783-0012A-NL02