This is correct. The objective is to verify that the weapon you're seen being dismantled is indeed a real warhead and not a fake one. It should be noted that a

This is correct. The objective is to verify that the weapon you're seen being dismantled is indeed a real warhead and not a fake one. It should be noted that a fake one could include some random nuclear material and still would be a fake so you can't just measure radioactivity.