[RightWhale]

Russia has been supporting Iran's nuke program

Nuke is short for nuclear. That is, all things that use nuclear processes such as splitting or merging nuclei. It could be weapons, but it also includes municipal power production and medical instruments. It might even include illuminated watchdials and commercial food preparation.

[RusIvan]

Nuke is short for nuclear.++

Ok I got it. But here on FR I frequantly saw the use of "nuke" in sense of warhead. WMD.

"Nuclier" on other hand is more for civilian atomic.
So Russia sold that reactor but as I red in press the russian experts believe that iranians can't extract nothing weapon class from it.