The U.S. Department of Energy announced the purchase of 32 metric tons of heavy water from Iran for $8.6 million and expects delivery within weeks.  Under the terms of the nuclear agreement, Iran is currently permitted to keep 130 tons of heavy water and only 90 tons once the redesigned Arak reactor is commissioned. Iran's lead nuclear negotiator, Abbas Araqchi, said Iran has about 70 tons of excess heavy water and is in talks with another, non-American company to sell the remaining stock.