Nukes on the moon?

Not bombs, but reactors.  There are small, safe reactors that might fit on a rocket, and perhaps even a moon lander.  This is a speculation, but it may be possible.  According to this, the reactors are the size of hot tubs.  Doesn't say what it weighs.   Now, the Altair lander for the Constellation program can carry tons of cargo.  If the hot tub size reactor doesn't weigh too much, it might just fit.  With as much power as one of these generates, it would be possible to do a lot of interesting stuff.