The first wall section of Saltstone Disposal Unit 8 (SDU 8) at the Department of Energy's Savannah River Site in South Carolina was installed earlier this month.

SDU 8 will stand 43 feet tall and 375 feet in diameter, and have a 33-million-gallon capacity, just like two SDUs built recently at the site. The 25 wall sections of SDU 8 are being constructed using high-strength, reinforced concrete and will be wrapped with seven layers of more than 300 miles of steel cable for added strength.

The flooring of SDU 8 is more than halfway complete. The concrete floor sits on top of a multilayer foundation: a geosynthetic clay liner and high-density plastic liner sandwiched between two concrete layers called “mud mats.” The floor is being completed in 14 sections.

The disposal units are built to safely and permanently contain decontaminated salt solution processed at Savannah River, the DOE reported on March 9.