I think this would be an interesting idea, if handled properly. Snobbish, vain, immortals obsesessed with maintaing their appearance.
Then you have vampires. Probably the twilight kind.
That was really rude and sick if that's how your humor is. Stilborns are a very serious thing and if you get a laugh out that you need help
Do you know how radiation works? A decaying particly flings off pick des off itself splitting dna . A massive amount of energy and radiation is required for transformation but it is possible to duplicate this into a process that anyone who understands basic science could sit comfortably with the math and science. I don't know that it has to be targeted to become one, since all have been random.
There's no way that could be safe if your still relying on radioactivity to trigger the mutations. The chance for damaging mutations, and cell death would be high. It'd be much safer to try other routes besides ghouldom.
On the last bit to explain in fallout 3 during the quest rileys rangers you go to the chop shop in the underworld located in a museum in the ruins that ghouls have hauled up in. The doctor is successful y research img a means to return a ghouls skin to its previous state. To break it down fir you ghouls skin no longer divide so the telemeres or ankled s in the ends of there cells never get shorter. It is possible to reverse this on the skin so that it regenerates and retains its new found immortality. Im sorry if that's a bit over anyones head.
I don't see how his research can be described as successful when he has not found a working solution to the ghoul problem. Also, considering that their skin is literally rotting away, we don't have much reason to believe that the skin cells enjoy the biological immortality of other organs.