CWI completes sodium-treatment project at DOE site

CH2M-WG Idaho, LLC, a cleanup contractor at the Department of Energy’s Idaho Site, recently completed a sodium-treatment project seven weeks ahead of schedule and nearly $1 million under budget.

The work was “technically challenging,” according to a CH2M-WG Idaho news release. CH2M-WG also is known as CWI.

The sodium — a reactive liquid metal — was used as a reactor coolant 20 years ago, the release said.

Crews with the Decontamination and Demolition Program used a large storage tank as a vessel to treat 480 pounds of bulk sodium that was stored in drums at the Materials and Fuels Complex. During the treatment process, sodium was introduced into the tank and an aqueous solution was added to cause the metal to react in a controlled environment.

The sodium at MFC was used as coolant for the Experimental Breeder Reactor-II, which first began operations in 1961.

Sodium is a challenge to handle, the release said, because it reacts with water and sometimes air.

For the most recent project, crews were able to increase the sodium-treatment volume through the use of temperature monitoring techniques and tank heating capacity improvements that sped up sodium-treatment times. Also, a redesign of the injection nozzles eliminated cool-down time between treatment runs, the release said.

“The system, process and procedures were much improved over previous treatments,” crew member Eric Garcia said in the release. “We were able to shave seven weeks off our schedule using this re-engineered, streamlined approach. Most importantly we did it safely.”

The tank used in this treatment process is being dried and will be disposed of at an on-site landfill this month.