10 MW reactor doesn't mean 10 MWh output. A modern nuclear reactor with 10 MW gross capacity has approximately 9 MW net capacity, that means it yearly output is about 78840 MWh (9*24*365), but you have reduce some days for revision, so the yearly output is about ~72000 MWh..
This this article is wrong it should be able to power 5000 household and not 50000 assuming average household consumption of 2000 watts.
The yearly average electricity consumption of a chinese household is about 1349 kWh or 1.349 MWh for the year 2010. 2016 it might be higher, but I don't have the current number.
1.349 MWh * 50000 = 67450 MWh
I think 50000 household should be correct.