The music score is primarily based on Niccolò Paganini's "Moto Perpetuo (Op. 11)".
The arduous, amorous ginger tabby pursuing Tom sounds uncannily like Pepe Le Pew, right down to the catchphrase, "C'est la Guerre!" Of course, Mel Blanc voiced both characters.
The film was released in January 1965, but its copyright notice states the year as "1964". Suggesting a delay in its release.
The title is a play on the term 'Atomic energy' - referring to energy derived from the atom (or rather, the splitting of it). The term was more in vogue at the time than 'Nuclear energy'.