I reviewed the video, and the claim is false. It’s too small. Although from the sound of a launch in the video, it *might* be driven with solid fuel, it’s not nuclear powered. The one in the shop is certainly not.
It’s silly propaganda, too, like the Iranian hoaxes.
I’d love to see the physics of a nuclear reactor providing thrust. If it converts heat to steam, the amount of water necessary to convert to steam and power a missile would require so much water and so large a reactor, it wouldn’t get off the ground.