The United States signed an agreement on Friday in Vienna to buy 32 tons of Iran’s heavy water for $8.6 million in order to prevent Tehran from violating the nuclear deal.

For the first few years after signing the deal, which was reached in July, Iran is not allowed to stockpile over 130 tons of heavy water, which can be used to produce weaponizable nuclear material. But Iran overproduced its heavy water and risked exceeding the allowed amount. The U.S. decision to buy Iran’s heavy water appears to be motivated by the desire to protect the nuclear accord, as well as to legitimize Iran’s nuclear program and encourage other countries to rely on Iran for nuclear material. Energy Secretary Ernest Moniz told the Wall Street Journal that the new U.S. purchase “will be a statement to the world: ‘You want to buy heavy water from Iran, you can buy heavy water from Iran. It’s been done. Even the United States did it.’”

Some nuclear experts believe that “the U.S. move comes close to subsidizing Iran’s nuclear program in a bid to keep the agreement alive,” the Journal wrote. “We shouldn’t be paying them [Iranians] for something they shouldn’t be producing in the first place,” argued David Albright, president of the Institute for Science and International Security, a nonpartisan anti-proliferation think tank. Several nuclear experts said that because heavy water can be used to produce weapons-grade plutonium, Iran’s production of the material is still a proliferation concern, particularly since restrictions imposed on Iran’s nuclear program will be lifted after 10-15 years.

Congressional leaders, already outraged by the administration’s reported plans to grant Iran access to the U.S. dollar, have criticized the purchase, arguing that it goes well beyond what is required by the nuclear deal. “U.S. taxpayers should not have to subsidize Iran’s nuclear program by buying heavy water that Iran produces in excess of what’s allowed under the flawed nuclear agreement,” Sen. Mark Kirk (R – Ill.) stated. House Foreign Affairs Committee Chairman Ed Royce (R-Calif.), asserted that “Far from curbing its nuclear program, this encourages Iran to produce more heavy water to sell – with a stamp of U.S. approval – on the international market.” In a letter (.pdf) to Moniz last week, Royce asked how the U.S. will pay for the heavy water and what guarantees the administration has that the funds would not be used by Tehran to support terrorism. U.S. officials have not yet specified whether U.S. dollars would be involved in the transaction for heavy water.

[Photo: Nanking2014 / WikiCommons ]