Nuclear justification for manned spaceflight

Given the desire to use nuclear propulsion for deep space exploration
(i.e. VASIMR, Mars 1986, Mars 1994, etc.), but the danger of
uncontrolled re-entry of radioactive materials ( see Cosmos 954),
maybe all nuclear reactors in LEO should be put there by manned
vehicles, reside on manned platforms, and be manually controllable.
Always having a "man-in-the-loop" provides the same type of additional
safety margin that pilots give to commercial planes.