ML19210C412
| ML19210C412 | |
| Person / Time | |
|---|---|
| Site: | Maine Yankee |
| Issue date: | 11/06/1979 |
| From: | Groce R Maine Yankee |
| To: | Reid R Office of Nuclear Reactor Regulation |
| References | |
| WMY-79-127, NUDOCS 7911140202 | |
| Download: ML19210C412 (2) | |
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ENGINEERING OFFICE WESTBORO, MASSACHUSETTS 01531 617-366-9011
,-2 A B.3.2.1 WMY 79-127 November 6, 1979 United States Nuclear Regulatory Commission Washington, D.C.
20555 Attention: Office of Nuclear Reactor Regulation Mr. Robert W. Reid, Chief Operating Reactors Branch No. 4 Division of Operating Reactors
References:
(a) License No. DPR-36 (Docket No. $u-309)
(b) MYAPC letter to USNRC dated February 14, 1979 (WMY 79-10)
(c) Telephone conversation between R.T. Turcotte, YAEC, and H.K. Shaw, USNRC on November 7, 1979
Dear Sir:
Subject:
Maine Yankee Auxiliary Charging Pump Operation Our letter, Reference (b), provided information relative to the operating history of the positive displacement auxiliary charging pump at Maine Yankee.
In a recent telephone conversation, Reference (c), additional detail was given regarding the purposes for which the pump has been used.
This letter is to briefly document that discussion.
Maine Yankee utilizes the auxiliary charging pump to recirculste liquid in the safety injection lines. This function is normally performed at very low power levels af ter completion of refueling and is not anticipated to be needed during normal power operation.
A pressure control valve is utilized to maintain recirculation line pressure between 300 and 700 psig which is necessary to maintain adequate liquid levels in the safety injection tanks and to assure proper mixing in the lines. The piping system is designed to withstand pressures of approximately four times the recirculation pressure.
This operation takes approximately 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> per year.
Based on this information, Mainc Yankee believes there is sufficient design and operating margin when performing recirculation, to eliminate the potential for pipe cracks due to charging pump vibratory loads.
Maine Yankee has also used the auxiliary charging pump for primary plant hydrostatic testing, strong boric acid injection, and chemical injection into the RCS for cleaning purposes. Currently, we conduct these operations by use of alternative equipment which has proven to be more efficient and less time i;n9
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United States Nuclear Regulatory Commission November 6, 1979 Attention:
Mr. Robert W. Reid, Chief Page 2 consuming. Maine Yankee concludes that the very low service duration of 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> per year at pressures far below system design does not constitute a threat to the system integrity.
We trust that this communication will conclude all needed information for your staff to close this issue.
Should you have any questions relative to this matter, please contact Mr. Richard T. Turcotte at 617-366-9011.
Very truly yours, MAINE YANKEE ATOMIC POWER COMPANY-1 Robert H. Groce Senior Engineer - Licensing RTT/kaf
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