The efficiency of pressurized water reactor (PWRs) and boiling water reactor (BWRs) is limited to around 33 percent, because water can be heated to only a certain temperature and only a certain amount of heat can be taken out of water. If that limit were pushed higher, more heat could be extracted, and the plant would generate more energy at a lower cost.
Nanofluids -- base fluids such as water interspersed with tiny particles of oxides and metals only billionths of a meter in diameter. Buongiorno's nano-spiked water, transparent but somewhat murky, can remove up to two times more heat than ordinary water.
Here is a pdf list of global nuclear reactors. It breaks down the type of reactors. 214 reactors are PWR and generate 206 GW. 53 are PWR-WWER (russian Water-Water Energetic Reactor) and generate 35 GW. 90 are BWR and generate 79 GW. In total they make up about 80% of the global nuclear power. A 50% improvement in power generation would add 160GW of power
The maximum output capacity of installed wind power in 2005 was about 59 GW.
160GW would be more than double all of the current global renewable (not including hydroelectric) energy sources.
Here is the global electricity usage forecast. Currently the world is using about 4000GW.