Nuclear Reactors 37 - Active Faults Under Japanese Tsuruga Nuclear Power Plant
I have written extensively about the problems in Japan that followed the Fukushima disaster. One major problem was the fact that the nuclear industry was being monitored by the same Japanese government agency that promotes industrial development and trade. After Fukushima, a new agency, the Nuclear Regulation Agency (NRA), was created to deal with nuclear regulation independently. A new set of much more strict nuclear safety regulation was drawn up. There is great pressure to restart the Japanese fleet of around fifty reactors which were all shut down following Fukushima. While the owners of the reactors are supposed to implement the new strict regulations before restarting their reactors, there has been criticism of the new regulations on the grounds that there are loop holes that give reactor owners years in which to implement the new regulation fully. Presumably, the reactors would operate as they did before Fukushima while the required changes were being made. Considering the safety record of some reactors owners such as TEPCO, the owners of Fukushima power plant where the reactors melted down, it might be better if none of the reactors were permitted to restart until all the mandated changes had been accomplished.
Since the Fukushima disaster started with a massive earthquake, there is obvious concern in Japan about danger from future earthquakes. Considering that about twenty percent of the seismic activity on Earth occurs in the area of Japan where three tectonic plates meet, it seems like a valid concern. There is a vast network of inactive and active faults under Japan. One important aspect of the Japanese nuclear regulations is that no reactor will be allowed to operate if it is above an active fault. For years, the NRA and its predecessor agencies have been analyzing the complex set of fault lines beneath the Tsuruga nuclear power plant on the east coast of Japan. There is evidence of a quake a few thousand years ago which qualifies that particular fault as being “active”. There are other faults nearby and the NRA is afraid that if they moved together they could generate a quake more powerful than previously thought.
Recently, the NRA told the Japanese Atomic Power Company (JAPCO), the owners of the Tsuruga nuclear power plant, that they would not be allowed to operate the plant because the fault beneath the plant was active. JAPCO has insisted that the fault under the plant should not be classified as active. It turns out that JAPCO did not make seismic readings about the fault available to the Japanese government from studies done in 2005.The NRA has said that if convincing scientific evidence is provided that proves that the fault is not active, then they would consider reversing their decision.
In addition to denying that the fault under their reactor is active, JAPCO has refused to submit a requested report on what would happen to the spent nuclear fuel stored at Tsuruga in the event of an earthquake caused by the fault under the plant. If the reactor at Tsuruga is a GE Mark I or Mark II design like the reactors at Fukushima, then the spent fuel is stored in a pool on the fourth floor of the reactor building. If the water covering the spent fuel rods drains away because of damage caused by a quake, the rods will burst into flames and inject huge amount of radioactive gases and particulates into the atmosphere. Given the results of the Fukushima disaster, any such radiation plume would circle the whole Northern Hemisphere and endanger a majority of the human race.
While the Japanese government has made changes to the way they regulate nuclear power plants, it appears that the operators of the nuclear power plant are refusing to respect the authority of the NRA. If this continues, it almost guarantees another major accident. The public backlash against another accident could end the use of nuclear power in Japan permanently.
Tsuruga Nuclear Power Plant:
