Chernobyl was disastrous because design flaws were not relayed to the plant engineers. It took years of roadblocked research to find out what had happened. Even the man that had helped to design the RBMK reactor did not consider a meltdown was possible because the xenon that ended up poisoning the reactor would burn off under normal circumstances.

The meltdown could have been prevented if not for the soviet government inexplicably withholding critical information about the reactor from it’s own engineers.