nuclear power is a blessing
there has yet to be a nuclear rocket, but i'm hoping for one
"*Icarus Interstellar* is an international organization dedicated to
technical achievements enabling interstellar
spaceflight<http://en.wikipedia.org/wiki/Interstellar_spaceflight>.
Research is performed by volunteer citizen scientists with a wide swath of
backgrounds, ranging from NASA <http://en.wikipedia.org/wiki/NASA>,
ESA<http://en.wikipedia.org/wiki/European_Space_Agency>,
professional scientists, university professors, students, science fiction
writers, artists, thinkers and enthusiasts.

Design teams are coordinated around research projects with a central theme,
such as the design of a mainly fusion
propulsion<http://en.wikipedia.org/w/index.php?title=Fusion_propulsion&action=edit&redlink=1>
based
engine, such as Project Icarus (Interstellar Probe Design
Study)<http://en.wikipedia.org/wiki/Project_Icarus_(Interstellar_Probe_Design_Study)>
and Project Hyperion <http://en.wikipedia.org/wiki/Project_Hyperion>, a
human occupied worldship (interstellar migration ship) study."
it may not yet be a perfect practise, but it can be better
http://en.wikipedia.org/wiki/Pebble-bed_reactor

what you are talking about is just like a statistical likelihood that
anything will fail, this can be improved with better and better failsafe
mechanisms.