I think you have made a fundamental error concerning the generation of excess heat by nuclear power plants, and how steam plants work.

Conversion of energy from one form to another always involves inefficiencies. It has to do with thermodynamic losses in the conversion process. When you create steam in a power plant to drive a turbine for electrical generation, most of the energy carried in the steam is lost as waste heat. It makes no difference whether this steam was created by nuclear fission, or burning fossil fuels. The steam turns the turbines, and then condenses into water, which is still very hot. This hot water is then dumped into a stream or the ocean, or lost by evaporation in a cooling tower. It has nothing to do with radioactivity, its just how steam engines work.

In fact, all heat engines have similar waste heat losses, even internal combustion engines. When gasoline is burned in an automobile engine, only a relatively small amount of the energy in the fuel goes into moving the car. The vast majority (about 70% I believe) goes out the tailpipe in hot exhaust gases, or is radiated out through the cooling system--fan and radiator. These are not losses due to friction, even in a hypothetical perfectly lubricated mechanical drive train you still lose about three quarters of the energy in the fuel to the atmosphere.

Engineers try to minimize these losses by using the waste heat to pre-heat feed water to the nuclear reactor (or the boiler of a fossil steam plant), or cascading the steam through multi-stage turbines, (each optimized for a different pressure/temperature regime), but at each step the efficiency drops, and the total efficiency of the system never exceeds the so-called Carnot efficiency (after the physicist who figured this out). This efficiency is always around 30% for heat engines using a working fluid. You can improve the efficiency somewhat at higher temperatures and pressures, but there are still theoretical limits. No matter what you do, the bulk of the energy in the fuel is lost as waste heat. The locomotives and steamships of the late 19th century had already achieved the maximum efficiency allowed by thermodynamics. We haven't been able to improve much on their work because this is not a question of engineering refinement, we are up against a fundamental physical law.

Your statement "70.5% of the power was wasted and converted into heat through various reactions with the energetic particles created by nuclear fission." is incorrect. That 70.5% is lost as waste heat because of the laws of thermodynamics, not because of anything having to do with nuclear power. No matter how you generate the steam, after you spin the turbine (or push the pistons), the steam condenses into hot water which still contains a lot of unusable energy--waste heat. Radioactivity has nothing to do with it.