Team Finishes First Inspection of Hanford’s Seventh Cocooned Reactor

RICHLAND, Wash. — Risk reduction is a key component of the U.S. Department of Energy Office of Environmental Management (EM) cleanup mission at the Hanford Site. Placing the K East Reactor into interim safe storage, also known as “cocooning,” in October 2022 marked a significant accomplishment in that mission.

This summer, a team with EM contractor Hanford Mission Integration Solutions’ (HMIS) Long-Term Stewardship Program finished its inspection inside and outside the interim safe storage structure.

“These protective enclosures reduce risks to the Hanford workforce and the environment,” said Tashina Jasso with EM’s Site Stewardship Division at Hanford.

The steel cocoon built around the deactivated reactor protects the building while the radioactivity in the core decays over the next several decades, making it safer for workers to complete facility disposal in the future.

The annual inspection is part of EM’s Post-Cleanup Surveillance and Maintenance Program. It gave radiation technicians an opportunity to confirm no contamination has left the sealed reactor core.

An HMIS team flew a drone inside the space between the structure and the reactor building to inspect the reactor’s roof and outside walls. They also used the drone to inspect the roof of the overall enclosure.

“That’s been a game changer from a safety perspective,” said Joy McCrea, Environmental Field Support director with HMIS. “With the drone, we can now get a bird’s-eye view of the roof while keeping everyone safely on the ground.”