It can be hard to tell which announcements from Iran are true, which ones are wish-fulfillment, and which ones are simply Iran trying to keep up with the Joneses. Consider that when you hear the news that Iran is planning to build nuclear submarines.
According to Iran’s semi-official Fars news agency, Rear Adm. Abbas Zamini said that Iran is “at the initial phases” of this sub-making venture. The news agency also noted the admiral’s recognition of Iran’s “astonishing progress in developing and acquiring civilian nuclear technology for various power-generation, agricultural and medical purposes,” which allows Iran to “think of manufacturing nuclear-fueled submarines.” Read: this is still in the conceptual stage. Zamini also said that all countries have the right to manufacture nuclear-powered submarines for peaceful purposes. And Iran wouldn’t violate any international treaties by doing so — unlike, say, if it built the bomb.
In other words, it’s a military program involving nuclear energy, but with enough distance from a nuclear weapons program to give Tehran freedom to build it.
If Iran can pull it off. It’s possible, though it’ll be difficult and take a long time. First, Iran will have to miniaturize the country’s nuclear technology into a safe and working power plant capable of powering a sub. Second, one does not just install a nuclear plant onto a submarine. Iran will have to build a new sub from scratch around the future sub’s nuclear plant.