On May 14, sources at Tokyo Electric Power Co. released information that would change the course of future energy policy in Japan. They said that on the night of March 11, high-level radiation of 300 millisieverts per hour was detected inside a containment building in the Fukushima No. 1 nuclear power plant, suggesting that the earthquake itself caused major damage to the No. 1 reactor's pressure vessel or piping — not the unusually devastating tsunami, as the company had previously maintained.
This belated revelation shows that in an earthquake-prone country like Japan the safety of nuclear plants can never really be assured. No matter how high new tsunami walls are built, earthquakes will happen again.
That revelation casts light on the cost of upgrading the plants. Already, many of Japan's nuclear plants are offline because of routine maintenance, safety checks and general repairs. The total cost of new anti-earthquake and tsunami prevention measures, and of future repairs after another quake, is incalculable.