Experience is required in lieu of a degree. But, to your point, no degree is required.
We should be finding every opportunity to get people into jobs that don't require a degree but require specialized skills, as it sidesteps an inflated credential gate (Sidenote: I don't think college is entirely useless, but its value has been drastically disconnected from its cost for some time).
"A reactor operator license requires 3 years of experience as an operator for a nuclear reactor. This can be as a field operator, or can include military/naval time. No college degree required. A certain amount (Typically 1 year) must be at a similar plant design and 6 months must be on site before starting license class.
A senior reactor operator can be "instant" or "upgrade". The upgrade process is a reactor operator becoming a senior reactor operator and requires an RO to have at least 1 year of licensed experience. For instant candidates, you need an engineering degree, or certain types of naval experience as a watch officer, plus on site time, plus 3 years experience in the industry (or naval experience).
These time requirements are time required PRIOR to starting license class. The class itself is around 18-20 months."
Source: https://www.reddit.com/r/energy/comments/3nm9ox/whats_it_lik...