Just because a university has a nuclear reactor on campus doesn't necessarily mean that one will build "technical knowledge" with respect to nuclear energy. Building one's technical knowledge means reading the scientific and technical journals in order to understand the relevant issues of the day, and even then one has to dig deep. Also, read the trade press like Nuclear News and Nuclear Plant Journal to get an idea of who is doing what and who is hiring.
Berkeley has a decent program. Digby MacDonald (formerly at PSU) is there, and Don Olander is still there, but probably only taking a few grad students. I'm not familiar with the other faculty.
NCSU has a good program and do the schools that QuantumPion mentioned.
At the moment, many of the new builds are on hold because of cheap natural gas and subsidized wind power.
If one wants to go into nuclear, then one should diversify into thermal process or energy generation in general in order to be able to move into non-nuclear areas if nuclear doesn't pick up.
These days, having skills in programming and computational physics, particularly FEA and CFD, with knowledge of materials, especially with mechanics of materials, fluid transport and fluid-structure interaction, and corrosion would be helpful.