ML20054L046
| ML20054L046 | |
| Person / Time | |
|---|---|
| Site: | Maine Yankee |
| Issue date: | 06/30/1982 |
| From: | Garrity J Maine Yankee |
| To: | Clark R Office of Nuclear Reactor Regulation |
| References | |
| RTR-NUREG-0737, RTR-NUREG-737, TASK-2.K.3.25, TASK-TM IHG-82-119, MN-82-123, NUDOCS 8207070108 | |
| Download: ML20054L046 (2) | |
Text
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Fi MAIREAd*' UARHEE A10ml0P0l'KRCOMPARU*
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June 30, 1982 JHG-82-119 MN-82-123 United States Nuclear Regulatory Commission Washington, D.C.
20555 Attention: Office of Nuclear Reactor Regulation Division of Licensing Operating Reactors Branch #3 Mr. Robert A. Clark, Chief
References:
(a) License No. OPR-36 (Docket No. 50-309)
(b) USMIC letter to MYAPCo. dated October 31, 1980 (c) MYAPCo. letter to USNRC dated January 15, 1982 (MN-82-04)
Subject:
NUREG-0737-II.K.3.25, Effect of Loss of A.C. Power on Pump Seals
Dear Sir:
In Reference (c) we committed to submitting the subject report.
This report is enclosed.
We trust this information is satisfactory, however, should you have any questions, please contact us.
Sincerely yours, MAINE YAtKEE ATOMIC POWER COMPANY l
John H. Garrity, Senid r Director Nuclear Engineering and Licen.*ing JHG:pjp
Enclosure:
II.K.3.25 Report (1 page)
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MAINE YANKEE ATOMIC POWER COMPANY F
II.K. 3.25 Effect of Loss of Alternatirg Current Power on Pump Seals During either normal operation, or hot standby operation (Reactor Coolant Pump not running), the Maine Yankee pump seals are s@ ported by three subsystems as follows: the Reactor Coolant Pump (RCP) seal water supply system, the RCP seal return or leakage system, and cooling water to the seal cooler. The following paragraphs describe the effects of a loss of offsite power on these subsystems and, therfore, the effect of this event on the pump seals.
The Maine Yankee RCP seals are designed to operate on pump shaft leakage.
However, to promote seal life and to limit seal contamination, the Maine Yankee RCP seals are provided with a source of sealing water which is slipstreamed from the plant's charging (makeup) system. This seal water supply is not necessary for continued seal operation but nonetheless would be maintained following a loss of offsite power event.
The chargirg pumps at Maine Yankee double as High Pressure Safety Injection Pumps. Because of this, they are powered from the diesel backed Engineered Safeguards Busses and would, therefore, continue to operate following a loss of offsite power.
All of the active valves necessary to maintain a source of supply to the charging pumps and, to maintain seal water delivery to the RCP seals, receive their operating and control power from either the diesel backed Engineered Safeguards Busses, or the battery backed AC Vital Busses and, therefore, remain operable following a loss of offsite power.
Thus, the RCP seal water supply system continues to function following a loss of offsite power.
The RCP seal water return system is simply a pipirg system which receives the controlled bleed flow and leakage flow from the seals and returns it via a filter and cooler to the charging pump suction. All of the active valves in this system receive their operating and control power from either the diesel backed Ergineered Safeguards Busses or the battery backed AC Vital Busses.
The Seal Water Return Cooler is cooled by chargirg pump recirculation water and thus, the seal water return system would be unaffected by the loss of offsite power event.
Finally, the RCP seals are provided with an integral seal cooler.
These coolers are provided with coolirg water from the plant's Primary Component Cooling (PCC) system.
The PCC system is also a safeguards system.
Therefore, the power necessary to operate and control the system's pumps and valves is provided from either the diesel backed Engineered Safeguards Busses or the battery backed AC Vital Busses. Seal coolirg will, therefore, remain operable following a loss of offsite power.
From the above discussion, it can be seen that all of the subsystems which support RCP seal operation remain operable following a loss of offsite power.
It can, therefore, be concluded that these seals would not be effected by this event.