The letter is signed by the chair and ranking minority member of the Senate Energy and Natural Resources Committee (Ron Wyden, D-Oregon, and Lisa Murkowski, R-Alaska) and the chair and ranking minority member of the Senate Appropriations Subcommittee on Energy and Water Development (Diane Feinstein, D-California and Lamar Alexander, R-Tennessee).

The US Department of Energy (DOE) last revealed the cost and schedule for the US contribution to ITER in its FY2007 budget submission, providing a year-by-year funding profile, saying that it would total $1.122 billion and that funding would be completed in FY2014. In 2008, DOE revised this estimate to a "range" between $1.4B to $2.2B but provided no year-by-year funding profile. In its latest (FY2014) budget submission to Congress April 10, DOE states that since 2008 several factors "have placed upward pressure on the cost range" but they do not give a new range. The budget submission also does not give a year-by-year spending profile, stating that "DOE and its oversight organizations have agreed to support an annual funding level of no more than $225 million per year beginning in FY2014. The current ITER schedule calls for completion of construction in late 2020.

The Senate press release states "DOE recently pledged to cap U.S. funding for ITER at $2.4B" though when and how DOE made that pledge is unclear. The DOE had spent only $0.54B on ITER through FY 2012 and had planned on spending $150M in FY2013 prior to any cut required by "sequestration". For FY2014, the Presidents budget proposed increasing this to $225M, largely by reducing the U.S domestic fusion budget, including termination of funding for the Alcator C-Mod experiment at MIT and reductions in the High Energy Density Laboratory Physics and theory programs.

Copies of the Senate press release and the letter to the GAO are available from Fusion Power Associates on request: fusionpwrassoc@aol.com