ML20209G013
| ML20209G013 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 04/27/1987 |
| From: | Gallagher J PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| To: | Muller D NRC, NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| NUDOCS 8704300449 | |
| Download: ML20209G013 (2) | |
Text
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PHILADELPHIA ELECTRIC COMPANY 2301 M ARKET STREET P.O. BOX 8699 PHILADELPHIA, PA.19101 (215) 841 5001 April 27, 1987 JOSEPH W. G ALLAGHER Docket Nos. 50-277 50-278 Mr. Daniel R. Muller BWR Project Directorate #2 Division of BWR Licensing ATTN:
Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C.
20555
SUBJECT:
Peach Bottom Atomic Power Station Units 2 and 3 License Amendment Application dated June 30, 1986
Dear Mr. Muller:
On June 30, 1986, Philadelphia Electric Company (PECo) submitted a License Amendment Application regarding the addition of a surveillance test on the time delay undervoltage relay cn the Reactor Protection System (RPS) for Peach Bottom Units 2 and 3.
In a letter dated September 9, 1986, the NRC requested additional information related to this Amendment Application.
The request is restated below along with PECO's response.
Request:
b Based on the information presented in your June 30, 1986 amendr.ent request we have not been able to conclude that the solenoid valves are capable of performing their function when subject to voltage below 95 volts for fcur (4) seconds nor have we been able to conclude that other equipment connected to the Reactor Protection System (RPS) power supply is capable of performing their function when subject to voltages below the Technical Specification limit of 113 volts for four (4) seconds.
Please provide additional substantiating information to support the argument that using a four-second time delay for undervoltage tripping will not have any adverse effect on components of the RPS including the scram pilot solenoid valves.
i 8704300449 B70427 DR ADOCK 05000277 D
PDR g
O Mt. D2nial R. Mullor April 27, 1987 PIga 2
Response
The effects of voltages below 95 volts on the scram solenoid valves has been established by tests performed by General Electric in 1986.
These tests were conducted on a pressurized solenoid valve to determine their performance on low voltage transients.
When voltage was reduced, the valves were found to chatter between 58 and 75 volts.
The solenoid valves were allowed to chatter for several one-minute intervals and then checked for leakage after being closed.
The results were the same as the original baseline test, indicating that the low voltage test conditions had not affected valve performance.
Voltages below the 58-volt dropout value cf the solenoid valves caused the solenoids plunger to drop out thus opening the valves.
This satisfies the fail safe design operating condition for control rod insertion.
Philadelphia Electric Company has determined that normal plant low voltage transient would not go below 95 volts at the solenoid terminals.
Because the General Electric Testing determined the solenoid valves can be subjected to voltage below 95 volts with no degradation on their ability to perform their safety function it can be concluded that an abnormal voltage below 95 volts for four (4) records will not adversely affect the solenoid valves or the Reactor Protection System.
The only other equipment supplied through the RPS power supply that could be potentially affected by voltages below 113 volts are the RPS logic relays and scram contactors.
These relays and contactors operate in a normally energized condition.
Voltages between 113 volts and 95 volts, which are within the limits of normal plant conditions, are not expected to affect the operation of this equipment.
Voltages below 95 volts, which could affect this equipment however, will cause the relays or contactors to dropout thereby satisfying the fail safe design operating function.
Any operation of RPS logic relays and scram contactors that is required during 4 seconds of voltage below 113 volts would function correctly, since this equipment is de-energized to perform its intended function.
If you have any additional questions, please do not hesitate to contact us.
Very truly yours, d:> 0 0.
cca T. P. Johnson, PBAPS Resident Site Inspector
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