IR-40

[4] Iran's leadership decided to construct a natural uranium (i.e. not requiring enrichment to produce fuel) nuclear power plant, using heavy water as moderator and coolant, in the mid-1980s.

[13][14] Aspects of IR-40's design will also serve as a prototype and testbed for the larger 336 megawatt Darkhovin Nuclear Power Plant under construction near Ahvaz.

[citation needed] There are some proliferation concerns about the reactor's ability to produce enough plutonium for several nuclear weapons each year.

However the IAEA has reported that it found no indication of ongoing reprocessing activities, required to extract plutonium from the spent fuel.

Natural-uranium fueled heavy-water reactors were originally designed for producing weapons-grade plutonium usable for construction of nuclear weapons.

[19] Use of enriched uranium fuel combined with extended operations would reduce the reactor's ability to produce weapons-grade plutonium.