<i>What about the SP100 or old Soviet designs? They had both reactors (the infamous radioactive-sodium ones) and a nuclear drive. The designs exist for space-nuclear reactors, there just aren't any being built right now. </i><br /><br />As far as I can determine, the SP-100 was never built. if it had, if would have delibered enough power but would have to deployed several km away from the station<br /><br />No Russian reactor has flown in space since 1987 (Kosmos 1867). the reacors were too small small to be useful for a station the size of the ISS (a few kW only). I don't know what the safe distance would be for such a small design, but i would hazard a guess of several 100 m.<br /><br /><i>Doesn't bother me as long as it's run by responsible parties who don't flush their coolant into space.</i><br /><br />No way presently exists for the safe disposal of reactors in LEO.<br /><br />I this this whole discussion is silly. Just because of problem with a bearing people want to go nuclear in space, swapping a technology that is simple, reliable, safe, and high proven for a technology which is none of these.<br /><br />On that notee, let'ssnot highjack this thread further. If people want to discuss how reactors might (or might not) be used o power stations in LEO, start a new thread.<br /><br />Jon<br /><br /><br /><br /> <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em> Arthur Clarke</p> </div>