I'm an old school kind of guy. When I want to use nukes in space I want to use NUKES. I prefer Orion ;^>
Actually, Prometheus is excellent, from what I've seen. It does harken back to some of the earliest proposals in Von Braun's visionary stuff from the 50's and 60s, but there's nothing wrong with that, and the techniques and technologies have come a really long way. Do you know if they're going to incorporate some of the Russian powerplant stuff we got after the wall fell? I understand that was really good technology, reliable, robust, simple.
My only real problem is with the name. You do know what happened to Prometheus after he gave man fire, don't you? How's your liver? Who came up with that name?
The reactor design is being handled by Argonne and I think KAPL, and it is supposed to be a fast reactor. I am involved in radiation testing of components in the power conditioning and distribution bus. We're trying to get the folks at JPL and Glenn to think about silicon carbide, since it has that nice wide bandgap and thus is inherently rad-hard as well as being able to operate at high temperatures.
The JIMO concept is quite extraordinary. The idea of being able to go into orbit around one of the moons, hang around for awhile and make your observations, then blast out of orbit and go over to another one, is almost Star Trek kind of stuff when you think that until recently the best we've done is either flyby or one-time orbital insertion, either by aerobraking or beefed-up retrorockets.