I came across this piece and this one on NASA's efforts to use Nuclear reactors in space probes and ships.
People have a natural anti-nuclear reaction when they start to hear suggestions like this one. Fears, founded or unfounded, of accidents occuring and potential disastrous consequences are to be expected.
This technology has been sold as a necessary requirement for missions to Mars or beyond. I'm not so sure that is true.
I really think that this effort has more to do with NASA getting the public comfortable with the concept of using Nuclear power in space. If successful they may become less jittery about ideas that NASA has proven could work in the past and deliver huge increases in rocket efficiencies... like say nuclear rockets...