March 11, 2016
At this fifth anniversary of the Tohuku earthquake and tsunami that triggered the meltdowns at the Fukushima Daiichi nuclear reactors, it is important to critically look at what went wrong and what went right. The reactors at the Daiichi plant did a very good job of protecting lives; Stanford University researchers John E. Ten Hoeve and Mark Z. Jacobson have estimated the number of cancer-related mortalities (130) and morbidities (180) due to radiation exposure. Additionally, the bravery of the Fukushima workers (the Fukushima 50) who fought to protect the public must also be noted. The reactors certainly failed to protect property, as a significant portion of the area around the plants remains evacuated. There was also a failure in the safety culture in the nuclear industry in Japan. It is important to recognize all of these contributions to both the cause and mitigation of the accident at Fukushima Daiichi.
The official report of the Fukushima Nuclear Accident Independent Investigation Commission stated that there was a mindset that allowed Japan’s nuclear industry “to avoid absorbing the critical lessons learned from Three Mile Island and Chernobyl; and how it became accepted practice to resist regulatory pressure and cover up small-scale accidents.” This is a critical failure of the industry and one that was not unknown. Reports on the 1999 criticality accident at the Tokai-mura fuel cycle facility clearly call out that the “root causes of the accident were: (1) inadequate regulatory oversight; (2) lack of an appropriate safety culture; and (3) inadequate worker training and qualification.” In the intervening 11 years, not enough was done to learn in the regulatory environment in Japan. Fukushima led to a revamping of the regulatory environment in Japan, including the formation of the Nuclear Regulation Authority (NRA) in September 2012. Early reports indicate that the NRA is successfully revamping the safety culture in Japan.
The reactors at Fukushima Daiichi, designed in the 1960s, failed under extreme circumstances, and those failures led to the evacuation of a large area of land, much of which will remain off-limits for the foreseeable future. Can the protection of property be improved? New reactor designs such as Westinghouse’s AP1000 would have fared much better, even in the regulatory environment of Japan. Going forward, the nuclear industry would be wise to start building more reactors that rely on passive safety. Few can argue that this isn’t the direction being taken by most reactor vendors. While the loss of property is certainly a consequence one wants to avoid, these early reactors were still very successful in saving the lives of the populace.
The Fukushima reactors protected the public so well from the radiation that, as the data provided by Ten Hove and Jacobson show, evacuation procedures need to be reevaluated. If we assume that 130 fatalities from radiation exposure are to be expected over a period of decades, and given the 600 deaths that occurred in the immediate evacuation, sheltering in place must be given more consideration in future incidents. Fear by the authorities cannot drive mass evacuation of the public. Both Fukushima and Hurricane Katrina showed that the elderly are impacted to a greater degree by such large incidents. The science of evacuation must be the subject of greater study to help determine best practices on where and when to evacuate. Blanket exclusion zones based on distance are almost certainly the worst way to determine who should be evacuated during a nuclear incident.
In spite of the danger to themselves, the workers at Fukushima did an incredible job under trying circumstances in mitigating the effects of the meltdowns. There were failures at Fukushima Daiichi that the industry must rectify, one of the best-known being the failure of the safety culture in Japan. The NRA is demonstrating improvement in this safety culture. Regulators are going to have to revisit the evacuation process in the event of a nuclear event because the accidents develop slowly, and the reactors do a very good job of protecting lives. New reactors must retain this demonstrated ability to protect lives and significantly improve the ability to protect property.
As we reach the five-year mark, the events at Fukushima Daiichi continue to affect humanity’s ability to combat climate change. The nuclear industry has to continue to demonstrate that it is learning from the past in order to improve our future. This learning must be implemented even when it is counter to what has always been done. Analysis of accidents has always been used to improve engineering in aerospace, civil works, medicine, etc.; the same is to be expected in the nuclear field. This only occurs if science wins out over fear. Unfortunately, it is still unclear if fear or science will be the lasting outcome of the meltdowns at Fukushima Daiichi.
Illinois Institute of Technology