ML20234F095
| ML20234F095 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 09/17/1987 |
| From: | Hukill H GENERAL PUBLIC UTILITIES CORP. |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| 5211-87-2174, NUDOCS 8709230024 | |
| Download: ML20234F095 (2) | |
Text
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GPU Nuclear Corporation GOU l uclear
= rs" 'So Middletown, Pennsylvania 17057 0191 717 944 7621 TELEX 84 2386 Writer's Direct Dial Number:
September 17, 1987 5211-87-2174 U.S. Nuclear Regulatory Commission Attn:
Document Control Desk Washington, DC 20555
Dear Sir:
Three Mile Island Nuclear Station, Unit 1 (TMI-1)
Operating License No. DPR-50 Docket No. 50-289 Inservice Testing (IST) - EG-V17A/B This is in response to the NRC's Safety Evaluation Report (SER) concerning IST of Pumps and Yalves, dated March 19, 1987.
In accordance with the SER, GPUN is required to send a letter providing justification if it is determined that the failure of EG-V17A/B would not cause degradation of diesel generator performance and the valves need not be included in the IST Program.
EG-V17A/B are three-way,1/4" solenoid operated vent valves with a 3/16" orifice.
This valve closes when starting air is admitted to the emergency diesel generator.
Failure of the valve to close would not prevent the diesel from starting because the supplied air capacity available during the starting sequence exceeds the sum of that which would be lost through the small orifice plus the minimum necessary to start the diesel. The result would be more frequent air compressor cycles after diesel starts in order to replenish the air start receivers.
As the diesel starts, at approximately 250 rpm (increasing) EG-Vl7 opens.
The purpose is to vent the pressure remaining between the diesel air start solenoid valves (EG-Vl6s) and the engine.
The failure of EG-Vl7 to open and vent does not impair the starting ability of the diesel or lead to any failure because venting would occur through the 12 diesel cylinder head check valves.
The diesel cylinder head check valves open to allow starting air to enter each of the 12 cylinders.
Therefore, GPUN concludes that EG-V17A/B are not essential for the starting or operation of the diesels but are provided only to assure a more positive and somewhat more rapid venting of the piping between the air start solenoid valves and the engine in order to prevent long term diesel head cylinder check valve seat burning and long term wear to the air start distributor. The annual diesel inspection conducted in accordance with GPUN procedure SP 1301-8.2 would result in the identification and correction of any problems that might occur.
8709230024 870917 ADOCK0500g9 PDR P
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GPU Nuclear Corporation is a subsidiary of the General Public Utilities Corporation
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5211-87-2174 September 17, 1987 The vendor, Fairbanks-Morse Engine Division of Colt Industries, by letter dated August 24, 1987 also concurs that failure of EG-V17A/B would have no effect on the starting or operation of the emergency diesel generators and that the annual inspection and overhaul is adequate to identify and resolve potential seat burning problems of the diesel cylinder head check valves or abnormal / excessive wear of the air start distributor.
In conclusion, EG-V17A/3 are not needed to mitigate an accident and are not needed to shutdown the plant.
Because EG-V17A/B have no safety function, they will not be added to the IST program.
Sincerely,
. D.
il Vice President & Director HDH/MRK/spb:0987A cc:
G. Edison R. Conte W. Russell
)
J. Stolz l
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