(Fusion not fission) Fission is what we already have and generates dangerous waste. To save on asset generation (making a building), just reuse an already existing reactor. This is an advanced research for well up in the research list.
Recipe. Power in to get it started only if easy to set it up that way. Takes a lot of power to get the tokomak going.
Fuel made from hydrogen and glass (pellets) or just hydrogen as a gas no pellets.
Water, same input as a regular reactor, water to cool the reactor it self and water for steam just like the already existing reactors.
Output, Helium (non radioactive and just exhaust through a chimney or maybe add some way to use it somewhere) and LOTS OF STEAM to run turbines for power.