KMAC:
There is definitely a market for Radiation Protection Specialists. As I've been telling my students (I'm a Radiation Protection Instructor for the US Department of Energy at the Savannah River Site), the average age of a nuclear worker today is ~50 years of age, and we're looking at retiring within the next 10 years. It takes roughly 6-7 years to become a fully-qualified Radiation Protection Specialist (sooner if you're a go-getter), thus about the time you get qualified, my peers and I will be heading for the door! There are 103 operating nuclear reactors with more being built, and each needs a cadre of Radiation Protection Specialists, not to mention the Deaprtment of Energy sites across the country. Your background as a firefighter/paramedic/HAZMAT responder is a big plus. Have you considered becoming a reactor operator? The career path for an operator is far better than that of an RP Specialist. Once you obtain a Senior Reactor Operator license, the sky is the limit. You have all the background that they're looking for in operators, for you'll be part of the site fire brigade, and each site has a HAZMAT Response Team, and needs paramedics too.
As for the degree, I'd go for the B.S. degree in Nuclear Engineering Technology at Thomas Edison; you can even do it on-line. The bachelors' degree will open more doors for you.
If you are amenable to re-locating, there are opportunities throughout the country. Good luck on your career!