Considering BAe didn't come in to being until 1977 it's unlikely they're anything to do with "early" nuclear developments, unless they're just well-used rebranded hand-me-downs.....but the British aviation industry would never do anything like that......
As it clearly said British Aerospace Stevenage, then I suspect it was for Missile testing, at least thats what they were working on back in the 90's when I used to visit the ABB Automation factory next door.
