Always a nice option to have for offense or defense but depends how the game is panning out. You may not need them.
I think its at least good to get some of the nuclear reactor research out of the way. Then they are there for the rocket route or the navy route later. Don't have to build the reactors until the path is chosen.
I'm in a game right now where oil is hard to get and I have allot of rare minerals. Nuclear navy is more affordable.
