Analysis & Opinions - Bulletin of the Atomic Scientists

Comparing Nuclear Accident Responses at Three Mile Island, Chernobyl, and Fukushima

  • Daine L. Danielson
  • Vladimir Kobezskii
  • Anna Kudriavtseva
| Aug. 31, 2020

The viability of nuclear energy has long focused on concerns about nuclear safety. The government and industry responses to the three major nuclear reactor accidents—Three Mile Island (TMI), Chernobyl, and Fukushima—offer insights about how to prevent and respond to nuclear accidents. While there is no perfect strategy for prevention or response, past experience can and should inform decisions on regulating nuclear power in the future. The following comparison of three accidents reveals that independent oversight and a strong safety culture are paramount to rapid response, organized evacuation and repopulation, and clear communication to local publics during and after an accident at a nuclear power plant.

Physical aspects of the response to a nuclear accident. Immediately following a nuclear power plant accident, the first goal of the physical response strategy is to manage radiation exposure and minimize public safety risks. However, these rapid responses are often carried out in conditions of poor information; the extent of damage to a nuclear reactor and resulting risk zones are still unknown. Each of the three major nuclear reactor accidents has spurred at minimum a rapid response to events unfolding at the reactor site, but the wider physical responses reveal contrasting approaches.

At Fukushima, a prompt and organized evacuation prevented any radiation-related casualties despite dangerous radioactive dispersal. Nonetheless, it is estimated that over 2,200 disaster-related deaths stemmed from maintaining the evacuation, demonstrating that the very measures taken to prevent radiation exposure can incur secondary public safety risks “in contrast to the little risk from radiation if early return had been allowed.” In comparison the response at Three Mile Island was similarly prompt, but the evacuation procedure was less organized. Contradictory messages from the government and public media spurred an estimated 144,000 of the local population to self-evacuate despite limited radiation levels, resulting in 12 casualties. Last, immediate safety measures at  Chernobyl were hampered by government attempts to keep the extent of the damage secret and a widespread, politically motivated belief that the RBMK reactor of the type at Chernobyl was inherently failsafe. This delayed response increased the public health risks from prolonged radiation exposure, resulting in heightened rates of pediatric thyroid cancer and radiation poisoning in the surrounding area.

Debate continues on the correct balance between radiation exposure risks on one hand and evacuation, displacement, and repopulation risks on the other. At TMI, where no significant radiation was released, radiation risk was not a primary concern after initial evacuations. At Chernobyl, due to the severity of the release, a 30-kilometer radius was evacuated and remains largely unpopulated. At Fukushima, however, a radiation threshold of 20 millisieverts per year was used to determine evacuation need. This level is widely accepted as safe, but has raised controversy, as some consider it to be far too conservative for use in a disaster scenario, given the known public health costs of evacuation and displacement. Finding the best path forward for public health, therefore, requires a holistic view of radiation risks in combination with evacuation, displacement, and repopulation risks.

The three accidents demonstrated different long-term prevention and repopulation strategies. While the limited radiation release at TMI allowed for rapid repopulation, lingering radiation at both Chernobyl and Fukushima have prevented a complete resettlement. In Chernobyl, nearly all of the 350,000 evacuees were permanently relocated as the radiation leaks and persisting health risks continue. However, some locals refused to leave the area, and some even returned to the borders of the exclusion zone despite the risks. Finally, in the case of Fukushima, large radiation releases and the related health risks—due in part to the earthquake and tsunami that precipitated the nuclear accident—necessitated widespread evacuation of over 160,000 people. Resettlement, however, has been slow, with over 80,000 of those evacuees still affected and ongoing efforts to resettle these displaced groups. The fact that only one radiation-related death has occurred at Fukushima may be partly credited to the successful initial evacuation. However, as the displacement continues, evacuation-related deaths also mount, illustrating the aforementioned delicate balance between evacuation risks and the need for radiation safety....

For more information on this publication: Belfer Communications Office
For Academic Citation: Danielson, Daine L., Vladimir Kobezskii, Anna Kudriavtseva and Ariel Petrovics.“Comparing Nuclear Accident Responses at Three Mile Island, Chernobyl, and Fukushima.” Bulletin of the Atomic Scientists, August 31, 2020.

The Authors