Just answering myself after some reading today. No, not really Because fission caused by free neutrons (which are rare) is something different from more common

Just answering myself after some reading today. No, not really Because fission caused by free neutrons (which are rare) is something different from more common "spontaneous" radio-decay. That does beg the question; what is the cause that we don't yet understand, what lies behind little bits of the universe falling apart?