Removal of radioactive waste from a major single-shell tank, AX-102, is getting underway at the U.S. Energy Department’s Hanford Site in Washington state.

AECOM-led tank farm contractor Washington River Protection Solutions announced via social media Thursday its workers would start waste retrieval over the weekend. It is the latest effort to relocate waste from leak-prone single-shell tanks to double-shell tanks in order to prevent contamination of the nearby Columbia River.

The Tri-City Herald reported Friday work is getting underway at the first of 10 tanks at the A and AX tank farms. A similar waste retrieval project was completed in November 2017 on 16 tanks at the C Tank Farm at Hanford, after about 19 years of work.

The contractor is using pressurized water and robotic equipment to dislodge about 30,000 gallons of highly radioactive and chemical waste from AX-102, WRPS noted in a one-minute video on Twitter. Waste from the A and AX tank farms will be transferred to a double-shell tank over the next few years, WRPS said.

The contractor said it took several years to design and build the infrastructure to retrieve waste from the single-shell tanks. Crews dug trenches in the AX farm to install electrical infrastructure to power the retrieval system.

Fifty-six million gallons of radioactive and chemical waste are stored in underground tanks at Hanford, left over from decades of plutonium production.

The Washington state Department of Ecology is pressing DOE to put a plan in place by fall 2023 for moving all waste from 149 single-shell tanks to double-shell tanks at the Hanford Site.

Eventually, the Energy Department plans to vitrify much of the 56 million gallons of tank waste into a glass-like substance for disposal. Vitrification of low-activity waste at the Waste Treatment Plant being built by Bechtel National is supposed to begin by 2023. Low-activity waste is believed to represent about 90% of the total waste stockpile.