Waste Transfer Brings Idaho’s Underground Tanks a Step Closer to Closure

Idaho Cleanup Project crews recently transferred liquid sodium-bearing waste from Tank 188 to Tank 189, leaving only two waste tanks — 187 and 189 — to be treated at the Integrated Waste Treatment Unit. The three tanks and a spare vessel will then be washed and grouted.

It was the first transfer of sodium-bearing waste from tank to tank at the Idaho National Laboratory Site since the early 2000s

IDAHO FALLS, Idaho — Cleanup crews recently transferred more than 20,000 gallons of radioactive liquid waste from one 300,000-gallon storage tank to another to reduce the environmental footprint of three underground waste tanks at the Idaho National Laboratory Site and expedite their closure.

Benefits of the waste transfer are many. It reduces the risk of the single-walled, stainless steel tank leaking, makes progress on a regulatory commitment, mixes waste forms in the receiving tank to benefit further waste treatment, and ensures uninterrupted tank waste processing at the Integrated Waste Treatment Unit (IWTU) when it is set to resume operations in late spring or early summer this year.

“This was the first transfer of sodium-bearing waste from tank to tank since the early 2000s,” said Operations Manager Ryan DeMott. “Because the transfer lasted about 10 hours and was accomplished across multiple shifts, it took collaboration from multiple teams to keep the transfer going and ensure constant monitoring was in place.”

Idaho Cleanup Project crews at the Idaho Nuclear Technology and Engineering Center used existing infrastructure to empty Tank 188 to its heel, with the liquid waste being transferred to Tank 189. IWTU will process liquid waste from tanks 187 and 189. A fourth tank, 190, has always been on hand as a spare vessel, but it hasn’t been used.

The Idaho Department of Environmental Quality (DEQ), which has Resource Conservation and Recovery Act authority over the tank farm, approved the waste transfer. The U.S. Department of Energy Office of Environmental Management had been paying penalties of $6,000 each day to DEQ for the three remaining tanks in the tank farm that contain liquid waste. With the transfer consolidating sodium-bearing waste to two tanks, the state has reduced the daily penalty to $4,000.

“I want to personally thank the state for working with us to affect this transfer,” said Dan Coyne, president of Idaho Environmental Coalition, the site’s cleanup contractor. “Our regulators are crucial to our cleanup success. Both the state and Environmental Protection Agency have supported a bias for action, which benefits our mission and gets cleanup accomplished sooner.”

Liquid waste in the tank farm was generated during the decontamination of spent nuclear fuel reprocessing lines. The IWTU was constructed to convert about 900,000 gallons of waste from the three tanks to a more stable granular solid using steam-reforming technology. To date, IWTU has treated 279,000 gallons of waste. Once converted to a solid, the waste is transferred to stainless steel canisters, loaded into concrete vaults and stored in a product storage building onsite until a permanent repository becomes available.

Following the conclusion of liquid waste treatment, all four tanks will be washed, grouted with concrete, and closed under state and federal regulations. Ultimately, a cap will be constructed over the entire tank farm to protect the underlying Snake River Plain Aquifer.

This work is being conducted under the Resource Conservation and Recovery Act in support of the 1995 Idaho Settlement Agreement.

-Contributor: Erik Simpson