Once again in keeping with the P5+1 nuclear deal, the IAEA has confirmed today that Iran has exported 11 metric tonnes of heavy water abroad, confirming that the water arrived at its “destination outside Iran,” but not saying specifically where it would be.

Under the deal, Iran is allowed to keep its heavy water facility operational, and to keep 130 metric tonnes in the country, with excess being exported into international markets. The deal primarily aimed to guarantee international market access for Iran with a plant redesign reducing their need for such water, though it’s also meant another “cap” that people can accuse Iran of violating.

This has been a recurring problem, because Iran’s first major export to the United States fueled a major Congressional backlash and since then Iran has struggled to get countries to buy the heavy water in a timely fashion, meaning at times they’ve gone slightly above 130, as last month they reportedly had 130.1 metric tonnes on hand, before sending some to Oman.

It may ultimately be that this additional water was sent to Oman as well, since the IAEA didn’t provide details. Since the cap only applies to heavy water held directly in Iran, they have been able to avoid violations by storing excess heavy water in Oman while they wait for buyers to emerge.

At any rate, heavy water is not dangerous in any way, not radioactive nor of any value in any form of weaponry. It has applications in scientific research, and also in certain types of civilian nuclear reactors, like Iran’s initial Arak reactor design.