If you want a "zero moving part reactor," what you are really looking for is: https://en.m.wikipedia.org/wiki/Fission_fragment_reactor https://en.m.wikipedia.or

If you want a "zero moving part reactor," what you are really looking for is: https://en.m.wikipedia.org/wiki/Fission_fragment_reactor https://en.m.wikipedia.org/wiki/Fission_fragment_reactor And its spaceflight cousin: https://www.projectrho.com/public_html/rocket/enginelist2.php#id--Nuclear_Thermal--Fission_Fragment_Type https://www.projectrho.com/public_html/rocket/enginelist2.ph... Though they are not peltier devices either.