Dismantling the Intake Structures

Crews have begun dismantlement work on the intake structures located between the Unit 2 and Unit 3 turbine buildings. The structures played a key role in San Onofre’s circulating water system.

The main steam condensers at SONGS utilized ocean water for cooling. The steam from the low-pressure turbines would pass through the condensers where cool ocean water in the condenser’s titanium pipes absorbed the heat from the steam and discharged that heat to the ocean through large pipes that extend underwater more than a mile off-shore.

Because the water was pulled from the ocean, great efforts were made to protect sea life and keep debris from reaching the condenser. This was accomplished through a series of “traveling” bar rakes and screens. They were called “traveling” because a large portion of the device rotates into and out of the sea water in deep wells in the intake forebay. The bar rakes removed larger debris (greater than 1-inch) and the screens removed debris down to 3/8-inch.

Debris collected on the bar rakes and screens would be removed by a wash spray system and the material would be collected into trash baskets for disposal. Fish elevators and a return sluice would direct fish caught in the system back to the ocean.

The intake structure components, some more than 50-feet long, are in the process of being removed, cut-up, and hauled away as part of the decommissioning of SONGS.