Iran Questions Need to Ship Unsold Heavy Water

Says Excess Water Is Already on the International Market Either Way

Iranian officials have sent a letter to the International Atomic Energy Agency (IAEA) arguing that the P5+1 nuclear deal’s provision on selling excess heavy water should not oblige them to export the water abroad before an actual buyer is found for it.

This is a fair argument for a few reasons, as the P5+1 deal only caps Iran’s stockpile at 130-tonnes and says the rest “will be made available for export on the international market.” The US actually bought the first of Iran’s exports of heavy water, but it led to political controversy, so they didn’t buy anymore.

Which is the big problem. Iran doesn’t need all this heavy water because the Arak reactor which was meant to use it is being redesigned with international help, and the language in the deal was meant to give Iran access to an export market for the costly heavy water refinery they’d already built.

Heavy water itself isn’t dangerous in any way, and has important scientific applications, which is why it sells for a pretty decent price on the international market. The problem is, the same US sanctions making other commerce with Iran difficult are also making it hard for Iran to find buyers for the water.

Which isn’t Iran’s fault, and also isn’t a security issue. Pressure over Iran being “in violation” of the heavy water stockpile limit, simply because they couldn’t find a buyer in a timely fashion, has led Iran in the past to send some of the water to Oman, but it’s a needless expense, and Iran argues that the water is “on the market” as required whether it’s sitting unbought in a warehouse in Oman or in a warehouse in Iran.

Author: Jason Ditz

Jason Ditz is news editor of