What people fail to remember is that the Fukushima reactor shut down properly. The tsunami knocked out power lines that would have supplied power to keep cooling pumps and other necessary systems operating. No problem. The plant had emergency generators to provide power should outside power is lost. But the tsunami swamped the emergency generators. The sea wall protecting them was too low. The generators should have been mounted higher. But still the reactor itself functioned as designed and shut down. It was the loss of power, outside and emergency that caused the problem.