Drones to map Idaho high-level waste store

Friday, 9 September 2022

The US Department of Energy's (DOE's) Office of Environmental Management (EM) Calcine Retrieval Project (CRP) manages calcined high-level waste (HLW) stored at the Idaho Nuclear Technology and Engineering Center (INTEC). Calcine is a dry, granular waste form from the processing of liquid wastes. The project supports the DOE's legal obligations to remove calcined HLW from Idaho and the long-term strategic goal to protect human health and the environment.

In 2015, DOE initiated an independent analysis of alternatives for the treatment and disposal of calcined waste. The analysis determined that treatment and disposal of calcined HLW are uncertain at this time because treatment technologies are immature and there is no designated long-term storage site. DOE concluded that, regardless of treatment and disposal uncertainties, all treatment and disposal options require retrieval of calcine from cylindrical storage bins, known as bin sets.

Three CRP engineers have recently completed initial training on piloting a lightweight, carbon fibre-caged drone with automated flight stability features inside a test facility at INTEC and then inside a more confined space within the facility as part of their training provided by the drone manufacturer.

"Learning to fly an expensive, high-performance drone can be very stressful," said CRP engineer Kevin Young, who arranged the training. "There were no crashes, and at the end of the day, all three were competently manoeuvring the drone around obstacles and through very tight spaces within the test facility."

The training served as initial practice for a complicated mission planned for later this year. Engineers will fly the drone inside a waste storage vault at INTEC that houses a set of four cylindrical bins, known as Bin Set 1, that contain 220 cubic metres of calcine.

The waste will ultimately be transferred using pressurised air from Bin Set 1 to Bin Set 6, allowing Bin Set 1 to be closed. Once the mission is complete, data collected by the drone will create a detailed map of the piping and other obstructions within the concrete vault to prepare for positioning waste removal equipment.

"Mapping the inside of this vault is a challenging problem," Young said. "The vault is not designed for human access, and even if it were, the radiation levels are way too high for a person to go inside. Using the drone is the safest and most cost-effective solution for getting the data we need."

In addition to developing a retrieval system for calcine removal from Bin Set 1, the CRP team is responsible for developing a strategy to retrieve, treat and repackage an additional 4200 cubic metres of calcine from five other bin sets. All calcine must be ready to leave the state of Idaho by 2035 in compliance with a 1995 Idaho Settlement Agreement milestone.