A lot of people react strongly to the pronunciation of the word nuclear as \ˈnü-kyə-lər\. It gets on their nerves. And it’s true that \ˈnü-kyə-lər\ is considered stigmatized, meaning that while some educated speakers say it this way, others think that it’s questionable or unacceptable. But let’s think for a minute about why this particular pronunciation, \ˈnü-kyə-lər\, is used by so many people. There are lots of words, some of them very common words, that have the pattern we hear in \ˈnü-kyə-lər\. Words like muscular, popular, circular, regular, molecular, and cellular. But the phonetic pattern for nuclear only shows up in pretty rarely heard words, the medical terms cochlear and trochlear. We simply hear one pattern much more frequently than we hear the other. And by analogy, many people’s ears gravitate toward the more common sound. Even if you dislike the \ˈnü-kyə-lər\ option, it’s good to know that there’s probably a linguistic reason behind it.
(via @MerriamWebster, @PeterSokolowski)