Oregon senator to ask for GAO probe of Hanford nuclear site Published February 23, 2013 YAKIMA, Wash. - A spokesman for Oregon Sen. Ron Wyden says the senator will ask the Government Accountability Office to investigate a monitoring and maintenance program for underground waste tanks at the nation's most contaminated nuclear site. The request follows news Friday that six tanks at the Hanford Nuclear Reservation are leaking. Wyden toured the site Tuesday after it was announced last week that one tank was leaking. His spokesman, Tom Towslee, said Friday that the senator would seek the investigation following the announcement of more leaking tanks. Wyden is the new chairman of the Senate Energy and Natural Resources Committee. He has said he'll seek a commitment during confirmation hearings for the next energy secretary that all radioactive waste at Hanford will be cleaned up.