You pipe it somewhere and burn it, in a heater, or an engine, or a smaller generator, the way natural gas is used today. Or fill a tank with it and power a vehicle.
However, I appreciate the point made about hydrogen escaping and causing embrittlement of materials.
You want to use thermal energy to make hydrogen, then burn that hydrogen to make thermal energy, possibly even to harvest that thermal energy to produce electricity...
The idea is that nuclear fission produces thermal energy, the production of hydrogen provides a means of storing and transporting that energy to its point of use. It might be useful to draw a diagram.
Electricity is really just another means to the same end. You can't use all of the energy generated by a power plant, at the plant site, so you transport the energy to places where it's needed.
However, I appreciate the point made about hydrogen escaping and causing embrittlement of materials.