involving nuclear physics, you should be able to pronounce "nuclear" and "nucleus." (Hint: "Nucular" and "Nuculus" are wrong.)
(Documentary was "Faster than the speed of light" on BBC4 last night, now on iplayer.)
To me that particular mispronunciation makes the speaker sound like a toddler struggling to get their tongue around a new word.
Oh dear, have just found a Wikipedia article that says this pronunciation is so established some dictionaries mention it, though none say it's correct. I suppose it's only a matter of time before this idiocy is legitimised.
en.wikipedia.org/wiki/Nucular