Lessons of Fukushima must not be forgotten
By Tsai Ya-ying 蔡雅瀅
On Feb. 14, a magnitude 7.3 earthquake occurred off the coast of Japan’s Fukushima Prefecture. The fact that the Fukushima Dai-ichi and Fukushima Dai-ni nuclear power plants have been decommissioned, and the Onagawa, Tokai Dai-ni, Higashidori and Kashiwazaki-Kariwa nuclear power plants are not operational might have prevented a nuclear accident.
Following the March 11, 2011, Tohoku earthquake, tsunami and resulting Fukushima nuclear disaster, Japan’s nuclear reactors were shut down in stages for safety checks. In June 2012, Japan for a while ran on zero nuclear power, which it did again for 11 months from September 2013.
As of Feb. 8, 24 of Japan’s reactors have been decommissioned, while nine have not applied to be reactivated. Permission has been granted for the configurations of seven reactors to be modified, while 11 others are under review, based on new regulatory requirements. Only nine reactors have been reactivated, of which just four are operating.
Nuclear power’s contribution to Japan’s power generation fell from 25 percent in 2010 to 6 percent in 2018, while renewable energy grew from 9 to 17 percent. Denuclearization seems to encourage the development of green energy.
The epicenter and depth of the Feb. 14 earthquake were close to those of the 2011 earthquake. Both quakes were caused by the subduction of the Pacific Plate under the North American Plate.
The Feb. 14 earthquake is considered to be an aftershock of the 2011 quake. That there can still be aftershocks 10 years later in a region where a powerful earthquake triggered a nuclear disaster demonstrates the importance of carefully locating nuclear power plants.
A statement that accompanied the referendum on the Longmen (龍門) Nuclear Power Plant, also known as the Fourth Nuclear Power Plant, in New Taipei City’s Gongliao District (貢寮) said that no active faults had been discovered in the geological zone of the plant and that the nearest active fault is 35km away.
However, geological records for the seabed near the Fourth Nuclear Power Plant — provided by the Central Geological Survey at a seminar on Sept. 2, 2019 — showed that faults F4, F5, F6, F7 and F8 were probably active, and that fault F2 might become active. The records also showed that faults F4, F7 and F8 could join into a single fault and that fault F2 could be joined with them.
A Control Yuan investigative report concluded that before the Fourth Nuclear Power Plant was built, two low-velocity zones had been found between its two reactors, and that multiple discontinuous shear results or disturbance zones had been found within the plant.
Denser shear zones where discovered as the plant was being built. When the foundations were being dug, these features were filled with concrete, strongly suggesting that attempts were being made to cover up the problem and prevent it from being examined.
Following the Fukushima disaster, the Legislative Yuan demanded that the area around the plant be given a thorough “health check.” The results of this investigation showed that there is an active normal fault about 90km long in the sea off the plant’s site, which has serious implications for its safety. Oddly, this was not followed by any in-depth investigation and discussion.
The passage of time might dilute people’s memory of a nuclear disaster, but geological structures do not forget where an earthquake took place. Given that the Fourth Nuclear Power Plant lies on a fault zone, Taiwanese must not forget the lessons of the Fukushima nuclear disaster.
Tsai Ya-ying is a lawyer affiliated with the Wild at Heart Legal Defense Association.
Translated by Julian Clegg