The Chinese have always been great builders by tradition & history (e.g. Great Wall of China etc.). However, let's hope the building/assembling of China's floating nuclear plant on Spratlys will be real safe according to international standards. If in future there are leakages or damages, it could cause Disaster to close-by/neighbouring countries/territories. We hope nothing like the Japanese disaster on Fukishuma (sic) would happen.
Nuclear reactors are very safe in general.
Two of the four reactors that had major accidents (LP-1 and Three Miles Island) were built before there was a man on the moon.
The Chernobyl accident was caused by lack of communication and wrong procedures which both are human error.
The Fukushima reactor was destoryed by a tsunami, one of the greatest forces of nature, the reactor was built with a bad choice of location. (Actually almost the entirety of Japan is unsuitable for reactors as the chances of earthquake and tsunami are too high) Also 15891+ was killed by the Tsunami, none by the reactor or radiation.
IMO there's nothing to worry about.