Sputnik News- There is almost no risk of Iran exceeding the cap on heavy water set in its nuclear deal with world powers.
Tehran committed to keeping its stock of heavy water, used to cool the Arak nuclear reactor, at no more than 130 metric tons under the Joint Comprehensive Plan of Action (JCPOA) deal in July 2015 in return for sanctions easing.

"We talked about excess heavy water. Iranians claim they’ve found a buyer. As of now, its stock is within the limits set in the JCPOA. There is currently no risk of their exceeding those limits," Voronkov said.
He was speaking in the wake of a Joint Commission meeting, made up of envoys from signatory countries, namely Iran, Russia, China, France, Germany, the United States, and the United Kingdom. The envoy added Russia had bought the previous batch of excess heavy water and was not considering additional purchases.