On the contrary, I contend it is a valid pronouciation common amoung some 75 million Southerners and apparent other English speakers. Who am I to diagree with Merriam-Webster?

"Though disapproved of by many, pronunciations ending in \-ky&-l&r\ have been found in widespread use among educated speakers including scientists, lawyers, professors, congressmen, U.S. cabinet members, and at least one U.S. president and one vice president. While most common in the U.S., these pronunciations have also been heard from British and Canadian speakers."

Merriam-Webster link for "nuclear" -- check the right most pronounciation