The Department of Energy, under agreement with EPA and Washington State, is cleaning up radioactive waste at its Hanford site. It finished retrieving waste from one group of underground tanks-a 'tank farm'-and it has begun retrieving waste from 2 of the remaining 17.

If DOE classifies the residual waste in tanks as something other than high-level waste, and the state approves it, DOE can fill the tanks with grout and leave them in place. This could avoid some risks and save $18 billion. But DOE's legal authority to do this is unclear.

We recommended that Congress consider clarifying DOE's authority to manage the residual waste.

Example of a Single-Shell Tank at Hanford, WA

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