- there was no one really in charge of such matters during most of the pertinent decades (first leg of Mao's regime): politics were the sole concern, leading to well-known disasters such as the Great Leap Forward ( https://en.wikipedia.org/wiki/Great_Leap_Forward ) and disdain (or worse) towards whistle-blowers https://en.wikipedia.org/wiki/Banqiao_Dam#Whistle-blower )

- the (Soviet) designers had no skin in the game

A nuclear reactor built and used in such a context may trigger some bad events in way less than 23 years, as a mere few seconds are sufficient for it to do so.