Iranian state television is reporting that the Islamic Republic has begun redesigning its Arak heavy water reactor to limit the amount of plutonium it can make as part of the country's temporary deal over its nuclear program with world powers.

A video posted Wednesday on state television's website showed Iranian nuclear chief Ali Akbar Salehi saying colleagues were now working on the reactor. He said the work came as part of regular inspections at the reactor.

The reactor at Arak is a heavy-water facility that could produce substantial amounts of plutonium that can be used as the fissile core of a nuclear weapon. Iran has offered to redesign it to produce only a fifth of the plutonium it could make. The West has asked Iran to completely replace it.