This site noted that Russia was adding hundreds of megawatts of nuclear power for only $200 per KW using uprates of existing reactors. $200 per kilowatt is the lowest cost of new energy generation from any energy source.
Idaho Samizdat points out that in the 1970s and 1980s around 25 units were being built a year, so raising that number to around 55 is within reach. Achieving that goal would enable 1400 nuclear reactors by 2050. This is analysis for the larger gen 3.5 nuclear reactors and gen 4 reactors. Most of the reactors would be built in China and Asia. China is planning on 1.5-2 GW reactors and then many smaller pebble bed reactors and a few breeder reactors. The 55 nuclear reactors per year is just a prediction based on large reactors, which would mean 1400 reactors generating up to 2500 gigwatts. Factory mass produced chinese pebble bed reactors or Hyperion Power Generation system reactors or Russian or Indian small breeder reactors could be produced in the hundreds each year.