ML19351C954

Forwards Response to Questions Raised at 800918 Meeting Re Fuse Protection Associated W/Hot Shutdown Panel

ML19351C954
Person / Time
Site:	Farley
Issue date:	09/30/1980
From:	Clayton F ALABAMA POWER CO.
To:	Schwencer A Office of Nuclear Reactor Regulation
References
NUDOCS 8010080423
Download: ML19351C954 (4)

Text

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( Alabama Power Company 600 North 18th Street Post Office Box 2641 Birmingham, Alabama 35291 Telephone 205 250-1000 L

leo *r'scWiff.'ni Alabama Power-the Sou*nern electrc svStem September 30, 1980 Docket No. 50-364 Director of Nuclear Reactor Regulation U. S. Nuclear Regulatory Comission Washington, D. C. 20555 Attention: Mr. A. Schwencer Gentlemen:

JOSEPH M. FARLEY NUCLEAR PLANT - UNIT 2 HOT SHUTDOWN PANEL DESIGN Uuring a working meeting held in Bethesda, Maryland, on September 18, 1980, the staff raised questions concerning fuse protection associated with the hot shutdown panel. Alabama Power Company has reviewed this design and proposes te provide alternate power supply and/or a separate fuse for ,

the circuit going to the Hot Shutdown Panel as described in the Attachment l to this letter.

If there are any questions, please advise.

Very truly yours,

_ h . / :: s y ?

F. L.~C1ayton Jr. ,

l RLG:de Attachment cc: Mr. R. A. Thomas Mr. G. F. Trowbridge Mr. L. L. Kintner (w/ attachment)

Mr. W. H. Bradford (w/ attachment)

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8010080423 h

ATTACHMENT

'During the September 18, 1980, meeting at the NRC office in Bethesda, the Staff expressed concern with regard to the control power supplies associated witn the hot shutdown equipment provided with control switching capability from the Main Control Board (" REMOTE") to the Hot Shutdown Panel (LOCAL").

Since the same control power supply is used for both " REMOTE" and

" LOCAL", the concern is that a fire in the cable spreading room might disable the power supply (before the control is switched from " REMOTE" to " LOCAL"), so that before taking control from the Hot Shutdown Panel, the operator will be required to take some additional actions, like replacing blown fuses or resetting breakers in the switchgears, load centers and MCC's. In order to climinate this concern we recommend to modify the controls of the subject Train B equipment, so that different control power supplies will be provided for " REMOTE" and " LOCAL" control. (*)

The following equipment is provided with control capability from the Train B Hot Shutdown Panel:

1. Charging Pump IC

2. Charging Pump IB - Train B

3. Component Cooling. Water Pump 1A r e 4. Component Cooling Water Pump 18 - Train B

5. "tiotor Driven Aux. Feed Pump 1B

6. Emergency Pressurizer Heater Back-up Group 1B  ;

7. Boric Acid Transfer Pump 1B

8. Aux. Feed Water - Flow Control Valves - Train B solenoids The selector switches for the above items are located in the Selector Switch Box (SSB) - 2605C-B.

- The first 6 components in the above list are powered from a 4KV Switchgear or 600V Load Center. In this case the control power supply is taken from the Switchgear or Load Center and in turn comes from a 125V DC - Train B Distribution Panel. Presently this power supply is used for both " REMOTE" and " LOCAL" control. The proposed modification provides a separate power supply, when the control is switched to ,

" LOCAL". This power supply is taken from the Selector Switch Box and  !

in turn comes from a 125V DC - Train B Distribution Panel, different from the one which provides control power to the 4 KV Switchgears and 600V Load Centers. The attached Sketch #1 shows the selection of the control power supply for " REMOTE" and " LOCAL" control.

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- The Boric Acid Transfer Pump IB (item 7 on the above list) is powered from an MCC and the 120V AC control power is provided by the 600/120V -

, Control Power Transformer located in the MCC. In this case an additional fuse will be added to the Control Power Transformer, to provide a separate path for the can'.rol power, when the pump is controlled from the Hot Shutdown Panel.

The design for Train B solenoids of the Aux. Feed Water - Flow Control Valves (item 8) provides separate control power for " REMOTE" and

" LOCAL" control (see 2BE-880).

These modifications will be completed by the end of the first refueling.

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