The Tennessee Valley Authority has also begun a process of holding public meetings and gathering input in preparation for potentially signing on as a MOX customer, he said.
Tom Clements, an anti-nuclear activist with the Alliance for Nuclear Accountability, said he was glad that the GAO had revealed the cost increase, something he said NNSA has long refused to do.
"Confirmation of a stunning $2-billion cost increase of the MOX plant construction spells big trouble for the project," Clements said. "There has been nothing short of a cover-up by NNSA of the huge cost increase, so GAO has done a public good by doing what NNSA adamantly has refused to do."
NNSA officials did not immediately comment on the report or the MOX budget.
Kinnard can be reached at http://twitter.com/MegKinnardAP