ML13333A322

Submits Proposed Mods to Air Supply Sys of Subj Facil.Mods Will Ensure Availability of Air Supply to Req Equip After Loss of Main Air Header Due to Fire in Lube Oil Reservoir & Conditioner Area

ML13333A322
Person / Time
Site:	San Onofre
Issue date:	11/22/1978
From:	Baskin K Southern California Edison Co
To:	Ziemann D Office of Nuclear Reactor Regulation
References
TAC-48143 NUDOCS 7811280259
Download: ML13333A322 (2)

Text

Southern California Edison Company P. 0. BOX 800 2244 WALNUT GROVE AVENUE ROSEMEAD, CALIFORNIA 91770 K. P. BASKIN Nbr2 98TELEPHONE MANAGER, GENERATION ENGINEERING November 22, 1978 213-572-1401 Director, Office of Nuclear Reactor Regulation Attn: Mr. D. L. Ziemann,'Chief Operating Reactors Branch #2 Division of Operating Reactors U. S. Nuclear Regulatory Commission Washington, D. C. 20555 Gentlemen:

Subject:

Docket No. 50-206, Provisional Operating License No. DPR-13 Fire Protection Program Review San Onofre Nuclear Generating Station Unit 1 In accordance with the agreements reached with members of the NRC staff as a result of our telephone conversation of November 9, 1978, we formally submit the proposed modifications to the air supply system of San Onofre Nuclear Generating Station, Unit 1. These modifications will ensure the availability of air supply to required equipment following a loss of the main air header due to fire in the lube oil reservoir and conditioner area.

The following description of the air supply modifications includes the time for completion of each change within the proposed seven week schedule which ends on December 31, 1978.

1. Salt Water Cooling Pump Discharge Valve - POV6 Install a local air supply (accumulator) with appropriate fittings.

The operator will not have to attach connections, only operate the solenoid valves in order to open POV6. To be completed by the end of third week of schedule.

2. Steam Supply Valve for Auxiliary Feed Water Pump -

CV113 Tubing to be routed from air pallet line using valves 3/4" -

200-60 as takeoff to CV113. Final connection to be made by operator when required by disconnecting normal line to air regulator of CV113 and connecting new line. To be completed by the end of fourth week of schedule.

REG:

7 8112 80,2-5

-KMr.. D. L. Ziemann -

NRC November 22, 1978

3. Air Supply to Auxiliary Control Panel Tubing to be routed from air pallet line using valves 3/4" -

200-60 as takeoff to Auxiliary Control Panel. Final connection to be made by operator when required by disconnecting the normal air line to the regulator in the panel and connecting new line.

To be completed by the end of fourth week of schedule.

4. Control Air From Auxiliary Panel to Steam Dump Valves Reroute existing air tubing from Auxiliary Control Panel to SV175 out of Fire Zone 9A. The valve SV175 is in area 9A but at the north wall about 30 feet from dyked area. The tubing will penetrate into 9A at north wall to connect with SV175. To be completed by the end of fifth week of schedule.

5. Motive Air For Steam Dump Valves A manifold will be installed at the north end of turbine deck. Tubing will be routed from this manifold to two of the Steam Dump Valves.

When required, the operator will disconnect the existing air line to the regulator and connect the new line.

In order to supply air to the manifold, the operator will run the air pallet air hose to the manifold, make connection, and open the supply valve. To be completed by the end of seventh week of schedule.

Confirmation of material availability will be completed by the end of the third week. We will notify you if any material problems result that affect the above completion dates.

In addition, as indicated in our letter of October 18, 1978, on this subject, we have completed the evaluation to determine the fire rating to be assigned to the penetration seals of the 4160V switchgear room and the north wall of the turbine building adjacent to the lube oil reservoir and conditioner area. The results of our evaluation indicate that a three hour seal fire rating will not result in cable derating problems. We will therefore utilize pene tration seals with a three hour fire rating as part of the final modifications for the 4160V switchgear room. However, since we will provide "water curtain" protection for the north wall of the turbine building, we will utilize pene tration seals with a one hour fire rating or better as part of the final modi fications for this area.

If you have any questions, or desire further information, please contact me.

Very truly yours,