Winston, Some of movie footage in this latest footage is terrific! Project Orion is probably the only real hope of reaching the nearest star in a reasonable amount of time, say 40 years with appreciable payload. The specific impulse on the nuclear-powered thermal NERVA is way to low for interstellar travel, although, it may be practical for interplanetary flight. The nuclear test ban treaties and the public's abhorrence of putting thousands of nuclear bombs in a rocket have effectively killed this project.
There is the laser project out there to aim a field of lasers at tiny space probes, but this technology is essentially unproven. There is a simple formula for rocket propulsion that gives the effective exhaust velocity as a function of the mass that is converted to energy. Nuclear energy gives exhaust velocities that are on the order of a few psol (percent of the speed of light).