You mean a closed pod, with some sort of liquid and a feral ghoul or a deathclaw inside ? Then I don't know.
Otherwise if it is an open pod you can just place the guy inside and add him a travel package to the editor location with infinite duration (or a xmarker heading if you use only 1 NPC). Be sure you disable all fallout behaviour in this package
and add a script to the character with :
Begin onload
if getstage frozenguyQuest <10
setrestrained 1
endif
end
Begin onactivate
if getstage frozenguyQuest <10
return
endif
end
I've made it for a cloning lab and it works like a charm. There is only a slight visual "bump" when the camera angle changes but they stay in place in their pod, like frozen.
With the script you can't interact with the character, so you should add an activator nearby to release him.
activating the device will advance to queststage 20 or whatever, and will unrestrain him so he is no longer restrained each time you meet him.
For the package, use the same getstage condition.