Stock in the producers of steam plants. The typical method of converting heat to electrical power is to boil water, run the steam through a turbine to get rotary mechanical energy, and use that to turn a generator shaft.

Coal uses the same basic idea, but uses coal to make heat; diesel and natural gas generators burn the fuel to create rotational mechanical energy directly.

Conversion of diesel and natural gas power generation to nuclear process of any kind is likely to result in a lot of steam plant construction.

Alternately, you could buy training as a steamfitter, since a breakthrough that results in a large number of steam plants being built will spike demand for people who can do the work, and the training takes several years.