I'm so glad that you brought up TRIGA. For those who don't know, the story of TRIGA is quite fascinating from our perspective. The pitch was rather simple, "Build a reactor that a teenager could play with" (without supervision). And they succeeded.
The reactor was designed in the span of a few months. They started in the summer of 01956. The first one was commissioned and built in May of 01958. And it ran until 1997, steadily producing 250 MW with occasional "pulses" up to 1,000 MW, the entire time.
Let's take a minute to appreciate that. They went from design to implementation in less than 2 years, that's lightning fast even in startup terms. And their design has never malfunctioned, ever. AFAICT, there are 66 of these reactors out there in the world that have operated for nearly 7 decades with 0 incidents. Some of them are even true to form and are operated by teenagers!
And I suspect that's the real reason why nuclear power is so expensive. While regulatory burdens, subsidies, and general corruption do indeed explain the exponential cost increases for nuclear power, the truth is that these are proximate causes. The distal cause is simple; the reactors suck. We've been designing them wrong for decades now, and we need to make rethink them from the ground up.
Luckily, I'm not the only person who thinks that. Far more smarter people have been bringing the fun back to nuclear engineering, and we are finally getting a series look at concepts like pebble bed reactors.
I hope that someday we'll have forever batteries and power sources that are small, self-contained, and can be carted for use anywhere, including space.
Achieving this goal requires everything from the kinds of modular designs NuScale https://www.nuscalepower.com/ and Terrapower https://www.terrapower.com/ are working on to Zeno Power's radioisotope systems, https://www.zenopower.com/
I am excited for the future again.