Cesium-Strontium Capsule Dry Storage
Reducing Risk Through Safer Long-Term Storage
At Hanford’s Waste Encapsulation and Storage Facility (WESF), 1,936 highly radioactive capsules containing cesium and strontium are currently stored underwater.
These capsules were originally retrieved from Hanford’s underground tanks in the 1970s to reduce the temperature inside the tanks and improve their stability.
Why Move the Capsules?
While the capsules are currently stored safely, a significant earthquake or other extreme event could cause water loss from the storage pool. Without water for cooling, the capsules could overheat, potentially leading to a breach.
To further reduce risk, the U.S. Department of Energy (DOE) and its contractor, the Central Plateau Cleanup Company, are working to relocate the capsules into dry cask storage.
Why Move the Capsules?
While the capsules are currently stored safely, a significant earthquake or other extreme event could cause water loss from the storage pool. Without water for cooling, the capsules could overheat, potentially leading to a breach.
To further reduce risk, the U.S. Department of Energy (DOE) and its contractor, the Central Plateau Cleanup Company, are working to relocate the capsules into dry cask storage.
The Dry Storage Solution
Dry cask storage uses robust, sealed containers that:
Do not require water for cooling
Provide long-term, passive safety features
Offer increased resilience against seismic and environmental events
Project Timeline
2025: Capsule transfers from the pool to dry casks are scheduled to begin
Within 2–3 years: All capsule transfers will be complete
Once in dry storage, the capsules will be monitored to ensure safe, long-term containment.