Updated May 13, 2025

The Waste Encapsulation Storage Facility (WESF) stores 1,936 highly radioactive cesium and strontium capsules underwater. The main risk at WESF is water draining from the pools that store the radioactive capsules. Once exposed, the extreme radioactivity of the capsules makes human entry impossible and results in a widespread release of contamination.

The Tri-Party Agencies just pushed the deadline for transferring these capsules to a safer kind of storage from August 31, 2025 to September 30, 2029. Hanford Challenge is incredibly concerned about how a four year delay will increase the risks this facility poses to human and environmental health.

On April 25, 2025 the agencies notified the public that they had revised the Tri-Party Agreement milestone for completing this transfer from Aug. 31, 2025 to Sept. 30, 2029. Ecology was first notified in November 2021 that the August 2025 milestone was at risk of being missed due to the COVID-19 pandemic and supply chain issues. The changed milestone gives DOE and its contractor four years to complete the capsule transfers.

There are a total of 18 dry storage casks and the contractor and DOE estimate it will take two months to load each cask with the capsules. That means if everything goes according to plan, it would be 36 months (or 3 years) to transfer the capsules from start to finish. DOE told the Hanford Advisory Board that the capsule transfer operations would start in FY26 (late calendar year 2025) and their goal was to finish transfers by the end of calendar year 2028. Ecology agreed to add an additional year to the milestone to account for any unexpected downtime during the transfers. While they gear up to do this work safely we will continue to monitor the progress of this high-risk cleanup project. Join us in keeping the pressure on for DOE to get this work done safely and require testing of the concrete in the storage pools following the removal of the capsules to dry storage.

Learn more about the Waste Encapsulation Storage Facility below.

Additional Hanford Challenge materials & Videos on WESF:

  • Read Hanford Challenge’s 2022 comments on Permit Modification for increasing storage capacity of WESF G Cell, here.

  • See our 2020 Say What? Guide, here.

  • See our 2020 sample comments, here.

  • Read Hanford Challenge’s 2020 comments on Permit Mod to add WESF to RCRA Permit, Section III as Operating Unit Group 14, here.

  • Columbia Riverkeeper & Hanford Challenge 2020 webinar “Why Scientists Fear a Chernobyl-Like Catastrophe at Hanford,” here.

  • Dunning, Dirk - WESF Presentation, click here.