Fears of radioactive contamination of groundwater and the Savannah River were voiced on March 11 by elected Georgia officials, residents living downriver from the Department of Energy's Savannah River Site, and scientists with the Institute for Energy & Environmental Research. The institute also released a report warning that DOE's current cleanup plan will leave at least 1 million curies of radioactivity in 51 underground tanks at the site, which, although in South Carolina, borders Georgia. DOE intends to leave most of the radioactive waste volume at the site, mixed with grout inside the tanks. The elected officials and institute charge that the cleanup will create a "de facto high-level radioactive waste dump" as the steel tanks break down. DOE however, maintains that most of the radioactivity—if not most of the volume—will be vitrified and moved to underground storage at the high-level waste repository being planned for Yucca Mountain, in Nevada. The elected officials and the institute say that radioactivity left in the grouted waste, although technically legal, will be 14 times above the highest level of radioactivity allowed for shallow land burial, which the tank waste will become over time. The site holds two-thirds of the total radioactivity in the U.S. nuclear weapons complex, the result of decades of plutonium and tritium production there.