Because the products of nuclear fission emit hazardous levels of radiation, generate heat, and could be used in weapons called "dirty bombs," they must be reprocessed and/or stored in secure locations and cooled. Laws passed in the 1980s directed the federal government to evaluate storing the nation's nuclear waste in the Yucca Mountain, which is located on federal land in a remote area of southern Nevada. After the government spent $15 billion to evaluate and develop the Yucca facility and after nuclear power plant operators paid about $30 billion to the federal government to store the waste, the Obama/Biden administration shut down the project in 2009. Inquiries to the administration by the Nuclear Regulatory Commission and the Government Accountability Office showed that the decision "was made for policy reasons, not technical or safety reasons." Trump tried to reopen this project, but Congress would not fund it, and Biden has now taken it off the table.