This is one of the reasons why, as an undergrad, I switched from nuclear engineering to physics: at the end of the day, we're still using heat and turbines, just with extra, more dangerous steps; although the materials engineering aspect is recognizably challenging, I found it not particularly thrilling.

At other, far end of the scale, if Hawking radiation does exist, black holes could be considered converters of mass to energy, skipping all of the conservation of baryon and lepton numbers ... although at very large timescales until you have a fizzy, spicy nano black hole on hand.

Controlled capture of the various types of radiation (sometimes I find that word to be sloppy) to extract the kinetic energies does not seem to be physically impossible, but I have oft wondered how as I think about various nuclear batteries which have existed. Indeed, the article doesn't even break it down enough: beta ought to be split into beta-plus (positrons) and beta-minus (electrons), and they skipped some 2p emissions. My guess is that not only will each need its own approach, but that each of those would be subdivided into different energy bands, not unlike having different compounds for chlorophyll-A and chlorophyll-B, only for, say, fast neutrons versus thermal neutrons.

And I think that's gonna be materials engineering again. Whoops!