IDAHO FALLS, Idaho – EM and cleanup contractor Fluor Idaho at DOE’s Idaho National Laboratory (INL) Site created inventive new fuel buckets that allow them to store more Advanced Test Reactor (ATR) spent fuel elements in the remaining space of a spent nuclear fuel dry storage facility.

   “It was exciting to watch the team as they shared ideas on how to accomplish the goal of increasing storage capacity,” said Russ Cottam, manager of Fluor Idaho’s spent nuclear fuel projects. “When they realized they had come upon a viable option, the energy of the team was palpable.”

   Using creative geometry, Fluor Idaho engineers, criticality safety and thermal analysis experts, operations personnel, and fabricators developed a four-compartment stainless-steel bucket that fits inside each fuel canister to provide for the storage of 24 ATR spent fuel elements per canister at the Irradiated Fuel Storage Facility of the Idaho Nuclear Technology and Engineering Center. Previously, only 16 ATR spent fuel elements fit in a fuel canister, which measures 18 inches in diameter and 10 feet, 9 inches in length.

   The fuel storage facility is currently at 93-percent capacity. The Fluor Idaho Spent Nuclear Fuel Program needed to maximize the facility’s unused space so it can transfer the remaining spent nuclear fuel from a pool storage basin to dry storage by 2023 to comply with an Idaho Settlement Agreement milestone.

EM and Fluor Idaho previously used buckets that each held eight Advanced Test Reactor fuel elements. Crews stacked two of these buckets inside each fuel canister for a total of 16 spent fuel elements per canister in storage.
EM and Fluor Idaho previously used buckets that each held eight Advanced Test Reactor fuel elements. Crews stacked two of these buckets inside each fuel canister for a total of 16 spent fuel elements per canister in storage.
The new four-compartment bucket holds a total of 24 spent fuel elements in the same amount of space as the previously used buckets that held 16 of the elements.
The new four-compartment bucket holds a total of 24 spent fuel elements in the same amount of space as the previously used buckets that held 16 of the elements.

   It took several months to complete designs, conduct engineering analysis, and refine the fabrication process for the new fuel bucket, Cottam said.

   “When the first production buckets were fabricated and passed the stringent inspections, we knew we had succeeded,” he said.

   The new bucket is segmented differently than the previous version, allowing fuel handlers to stack spent fuel elements in different configurations, resulting in more of the elements being loaded in the same amount of space.

   “After verifying that four new fuel storage buckets could be adjacently configured inside a fuel canister, the spent nuclear fuel program knew the goal to extend the mission of the dry storage facility was achievable,” Fluor Idaho ATR Wet-to-Dry Project Manager Roger Friesz said. “It was certainly a reason to celebrate the hard work of the many who were involved along the way.”

   This innovative approach to spent nuclear fuel storage, combined with analyses that permit a shorter cooling period for the fuel in an existing dry storage facility, will extend the storage capacity of the INL Site dry storage facility. It will also contribute to the ATR mission by simplifying the process for storage and reducing costs of ATR spent fuel movements and storage