March 10, 2021

expert comment in advance of the 10th anniversary of Fukushima

Tomorrow will mark the 10th anniversary of the Tōhoku earthquake and tsunami, and the resulting nuclear accident at the Fukushima Daiichi Nuclear Power Plant in Japan in 2011.

Prof Jim Smith, Professor of Environmental Science at Portsmouth University, said: 

“Ten years after the Fukushima accident, the science so far has confirmed both the initial expectations of low health risks from radiation and the often devastating psychological and social impacts of the accident. The initial rapid evacuation and ban on contaminated foodstuffs have kept radiation doses to the population well within the range people get from natural background radiation in many countries, including the UK. But the evacuation – in many cases permanent – of more than 150,000 people damaged lives and destroyed livelihoods. 

“Surprisingly, though, the most devastating consequence of Fukushima may be its climate change impact. Germany’s response to Fukushima was to begin phase-out of its nuclear plants, whilst continuing generation of electricity from highly polluting brown coal. It has been argued¹ that this has led to more than 1000 lives shortened annually due to increased air pollution as well as hundreds of megatonnes of extra CO2 emitted.

“Proponents of nuclear power will point to the low expected direct health effects of the Fukushima accident, and to reports of now abundant wildlife² in the abandoned areas. But the understandable fear of nuclear remains and it has hugely complicated decisions on nuclear’s role in combating the threat of climate change.”

¹ https://www.nber.org/system/files/working_papers/w26598/w26598.pdf

² https://esajournals.onlinelibrary.wiley.com/doi/pdfdirect/10.1002/fee.2149

Prof Richard Wakeford, Centre for Occupational and Environmental Health at the University of Manchester, said:

“A large (magnitude 9) earthquake just off the east coast of Japan in March 2011 and consequent tsunamis led to a major accident at the Fukushima Dai-ichi nuclear power station and significant releases of radionuclides from the three reactors operating at the station at the time.  The accident shook the world and much of the shock was because a major nuclear accident occurred in a technologically advanced nation. 

“Basically, the accident occurred because the station was inundated by a tsunami that damaged emergency equipment and flooded the back-up electricity generators, so the three hot reactor cores were left without adequate cooling leading to damage to, and melting of, nuclear fuel.  This was a failure of “defence in depth”: if the first defensive line fails (in this case, the tsunami seawall) there must be reliable defences in reserve.

“Fortunately, the radiation doses received by workers and the public were nowhere near the high doses received after the Chornobyl accident in 1986.  The first concern after an accident at an operating nuclear reactor is to ensure that doses received by thyroid glands, especially those of children, from intakes of radioactive iodine are limited by appropriate protective measures, such banning local milk supplies.  It would appear that restricting intakes of radioiodine was largely successful, although a handful of workers received high thyroid doses.  It is unlikely that excess thyroid cancer cases (or excess cases of other cancers) will be detected, and the large number of thyroid cancers among those exposed as children around Chornobyl will not be repeated after the Fukushima accident.

“Of some interest is the approximately 100 cases of thyroid cancer found by sensitive ultrasound screening of around 300,000 young people in Fukushima Prefecture in the first few years after the accident.  There are a number of reasons why these cases are very unlikely to be attributable to radiation exposure, including that they did not occur in those who were youngest in March 2011, as would be expected from the Chornobyl experience.  This is more likely to be a screening effect where small tumours are found by sensitive screening, which has been observed before, e.g., in South Korea in the early-2000s.

“The significant challenge to the radiation safety community is to ensure that major nuclear accidents can be avoided, or the consequences limited.  Robust independent regulation is essential, and regulatory systems have been strengthened around the world (especially in Japan) as a result of the Fukushima accident.  It would be reassuring to think that in-depth international inspections of safety systems of nuclear plants could be agreed and that if failings were found remediation work would have to be undertaken or there would be repercussions, but this may be a bridge too far for some countries.”

Comments sent out 09/03/2021:

Prof Geraldine Thomas, Chair in Molecular Pathology at Imperial College London and Director of the Chernobyl Tissue Bank, said:

“On March 11^th 2011, the northeast coast of Japan was shaken by a large earthquake, followed by a tsunami that devastated a large area of the coast.  Nearly 20,000 people died as a result of earthquake and tsunami, but sadly the date has become synonymous with an event that, had we handled it better, would have killed no-one, neither then nor in the future – the nuclear accident at Fukushima Dai-ichi power station.  

“The earthquake caused a failure of the electricity supply to the power station, and the tsunami disrupted the second method for reducing the reactors’ temperature – a diesel pump located at sea level.  The result was that 3 of the 4 active reactors at the time were subject to a partial meltdown and volatile radioactive isotopes, principally of iodine and caesium, were released into the atmosphere, exposing the population that lived to the north and west of the power station site. This prompted a hurried evacuation of the local areas, involving around 100,000 people.  

“That evacuation is now known to have resulted in a further loss of life, through insufficient medical support being available to move the sick and frail, and through lifestyle changes and psychological consequences as a result of the breakdown in community and family life. This was a complex situation, involving infrastructure issues due to the earthquake and tsunami, and uncertainties around the doses of radiation to which the public may be exposed.  With hindsight, it is now known that the doses of radioiodine to the thyroid of young children were very low, and that no discernible increase in thyroid cancer would be expected¹. In contrast to the Chernobyl accident, that happened 25 years before the Fukushima accident, the situation played out in the full glare of the media. This led to a series of alarming headlines, which were further supported by ill-informed social media comment from those with an axe to grind over the use of nuclear power.

“There are two factors that affect the health of the population after a nuclear accident – the physical effect of radiation on those exposed and the psychological effect of the fear of radiation exposure, which affects both those exposed and those not exposed.  Both Chernobyl and now Fukushima have shown that the psychological effects are much greater that the physical effect of exposure on the health of the population. We can take simple actions to limit the physical effect of radiation, but mitigating the psychological effects depends on dispelling myths around nuclear power plant accidents.  Scientific studies take many years of work to gather the evidence on which we base our conclusions, opinions can be spread by social media in seconds.   

“The appropriate response to any emergency situation is a balanced approach to risk mitigation. With accidents at nuclear power plants, we have enabled one risk, that of exposure to low doses of radiation, to be blown out of all proportion, opening the door to other risks that have been shown to be more harmful to public health. A more rounded approach to the actual, rather than the perceived, health risks of nuclear power might stand us in better stead for our considerations of how we best mitigate the risks of global climate change.”

¹ http://www.unscear.org/docs/publications/2020/UNSCEAR_2020_AnnexB_AdvanceCopy.pdf

Prof Laurence Williams FREng, Centre for Nuclear Engineering, Imperial College London, said:

“The accident at the Fukushima Daiichi  nuclear power plant was an accident made in Japan. The fact that the nuclear safety regulator at the time (NISA) was not independent was a major contributor to the accident. Had there been a strong, effective and independent nuclear safety regulator, the nuclear reactors at the site would have survived the earthquake and the subsequent tsunami.

“Ten years on it is important to remember that independence is the cornerstone of effective nuclear safety regulation and we forget this at our peril.” 

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Declared interests

None received.