It has been almost 12 months since the Fukushima nuclear disaster began. Although the Great East Japan earthquake and the following tsunami triggered it, the key causes of the nuclear accident lie in the institutional failures of political influence and industry-led regulation. It was a failure of human institutions to acknowledge real reactor risks, a failure to establish and enforce appropriate nuclear safety standards and a failure to ultimately protect the public and the environment.
Greenpeace International commissioned the "Lessons from Fukushima" report that addresses what lessons can be taken away from this catastrophe. The one-year memorial of the Fukushima accident offers a unique opportunity to ask ourselves what the tragedy – which is far from being over for hundreds of thousands of Japanese people – has taught us. And it also raises the question, are we prepared to learn?
There are broader issues and essential questions that still deserve our attention:
- How it is possible that – despite all assurances – a major nuclear accident on the scale of the Chernobyl disaster of 1986 happened again, in one of the world’s most industrially advanced countries?
- Why did emergency and evacuation plans not work to protect people from excessive exposure to the radioactive fallout and resulting contamination? Why is the government still failing to better protect its citizens from radiation one year later?
- Why are the over 100,000 people who suffer the most from the impacts of the nuclear accident still not receiving adequate financial and social support to help them rebuild their homes, lives and communities?
These are the fundamental questions that we need to ask to be able to learn from the Fukushima nuclear disaster. The just released Greenpeace report looks into them and draws some important conclusions:
- The Fukushima nuclear accident marks the end of the ‘nuclear safety’ paradigm.
- The Fukushima nuclear accident exposes the deep and systemic failure of the very institutions that are supposed to control nuclear power and protect people from its accidents.
End of nuclear safety paradigm
Why do we talk about the end of a paradigm? After what we have seen of the failures in Fukushima, we can conclude that ‘nuclear safety’ does not exist in reality. There are only nuclear risks, inherent to every reactor, and these risks are unpredictable. At any time, an unforeseen combination of technological failures, human errors or natural disasters at any one of the world’s reactors could lead to a reactor quickly getting out of control.
In Fukushima, the multiple barriers that were engineered to keep radiation away from the environment and people failed rapidly. In less than 24 hours following the loss of cooling at the first Fukushima reactor, a major hydrogen explosion blew apart the last remaining barrier between massive amounts of radiation and the open air.
Probabilistic Safety Assessments
At the heart of claims of nuclear safety is an assumption that accidents, which lead to significant releases of radiation, have a very low probability of occurring. International safety regulators have adopted a nuclear safety paradigm under which, for accidents that are categorised as ‘design basis’ events, the design of a plant must guarantee no significant radioactive releases will occur. These events are also often referred to as ‘credible’ accidents. Accidents involving significant radiation releases, like those at Fukushima Daiichi are called ‘incredible’ or ‘beyond design basis’ events. These are claimed to be of an extraordinary low probability. These numbers are the results of PSA (probabilistic safety assessment) studies. However, PSAs cannot provide meaningful estimates for accident frequencies (probabilities), since they cannot take into account all relevant factors (e.g. they cannot cover inadequate regulatory oversight) and the factors that are included are beset with huge uncertainties (e.g. regarding earthquakes).
The designs for all reactors in operation, including the Fukushima Daiichi units, were established in the 1960s. The ‘design basis’ of reactors was based upon ‘reasonably foreseeable’ accidents, i.e. accidents that, according to industry experts, could be expected. Also the designs applied the antiquated engineering modelling and methodology available during that time period more than 40 years ago.
In the following decades, accidents involving significant radiation releases that were initially deemed as ‘incredible’ began to occur, such as Three Mile Island (1979) and Chernobyl (1986). Despite some development in nuclear assessments, e.g. in terms of the kind of accidents taken into account, the nuclear sector did not question the safety paradigm but carried on using the model, i.e. the probabilistic risk assessments, to justify the allowance of certain reactor weaknesses and vulnerabilities.
Regulators and the industry call nuclear power ‘safe’, because their calculational methodology depicts events that could cause a significant accident, like the one that occurred at Fukushima Daiichi, as extremely unlikely. Reactors were allowed to be constructed in ways that do not allow them to withstand such events. According to probabilistic risk assessments, the chance of a ‘beyond design basis’ accident, which causes a core melt and a significant radioactive release, is less than once in a million years of reactor operation. The Fukushima Daiichi disaster, however, has shown this theory of nuclear safety to be false.
By 2011, the world had accumulated just over 14,000 years of reactor operating experience. The International Atomic Energy Agency (IAEA) safety guidelines state that the frequency of actual core damage should be less than once in 100,000 years. Hence, with more than 400 reactors operating worldwide, a significant reactor accident would be expected to occur approximately once every 250 years.
Culminating with the Fukushima Daiichi accidents in 2011 there have been five major accidents involving significant fuel melt during the past 33 years: Three Mile Island (a Pressurised Water Reactor) in 1979, Chernobyl (a RBMK design) in 1986, and the three Fukushima Daiichi units (Mark 1 Boiling Water Reactors) in 2011. Based upon these five meltdowns, the probability of significant accidents is in fact one core-melt for every 2,900 years of reactor operation. Put another way, based upon observed experience with more than 400 reactors operating worldwide, a significant nuclear accident has occurred approximately every seven years.
The theory of nuclear safety espoused by the nuclear power sector has given regulators, reactor operators, and the public a false sense of security. For industries that require a high level of reliability, such as aviation and nuclear generation, institutional failures are the major contributor to real-world accidents. Surveys of nuclear and other high-reliability industries show that 70% of real accident rates are caused by institutional failures. Despite this, the probabilistic risk studies produced by reactor operators to predict the frequency of component failures leading to radioactivity releases do not take into account failures of operators and regulators overseeing the plant. The empirical evidence shows that reactor accidents are more than one order of magnitude more likely than predicted by the nuclear industry’s modelling. This historical record clearly contradicts the industry’s claim of nuclear safety. Instead of being low-probability events as asserted by the nuclear industry, reactor meltdowns are regular events with significant consequences.
Failure of human institutions
In Japan, the failure of the human institutions inevitably led to the Fukushima disaster. The risks of earthquakes and tsunamis were well known years before the disaster. The industry and its regulators reassured the public about the safety of the reactors in the case of a natural disaster for so long that they started to believe it themselves. This is sometimes called the Echo Chamber effect: the tendency for beliefs to be amplified in an environment where a limited number of similarly interested actors fail to challenge each other’s ideas. The tight links between the promotion and regulation of the nuclear sector created a ‘self-regulatory’ environment that is a key cause of the Fukushima Daiichi disaster.
It is symptomatic of this complacent attitude that the first concerns voiced by many of the decision makers and regulators after the accident were about how to restore public confidence in nuclear power – instead of how to protect people from the radiation risks. This has also been the case with the UN’s IAEA, which failed to prioritise protection of people over the political interests of the Japanese government, or over its own mission to promote nuclear power. The IAEA has systematically praised Japan for its robust regulatory regime and for best practices in its preparedness for major accidents in its findings from missions to Japan as recently as 2007 and 2008.
Lessons to be learned
The institutional failures in Japan are a warning to the rest of the world. These failures are the main cause of all past nuclear accidents, including the accident at Three Mile Island in the US and the disaster at Chernobyl in Ukraine. There are a number of similarities between the Chernobyl and Fukushima nuclear disasters: the amounts of released radiation, the number of relocated people, and the long-term contamination of vast areas of land. Also the root causes of the accident are similar: concerned institutions systematically underestimated risks, other interests (political and economic) were prioritised over safety, and both industry and decision makers were not only fatally unprepared, but were allowed to establish an environment in which they existed and operated without any accountability.
Governments, regulators and the nuclear industry have stated they have learnt big lessons from the past. Yet, once again they failed to deliver. How confident can we be that the same will not happen again?
The report "Lessons from Fukushima" is available at: http://www.greenpeace.org/international/en/publications/Campaign-reports/Nuclear-reports/Lessons-from-Fukushima/
Sixty centimeters of cement on seabed off Fukushima. Tepco is to cover a large swathe of seabed near the battered reactors with cement in a bid to halt the spread of radiation, the company announced on 22 February 2012. A clay-cement compound will be laid over 73,000 square meters (equivalent to around 10 soccer pitches) of the floor of the Pacific Ocean in front of the Fukushima Daiichi plant on the nation’s northeast coast. The cover will be 60 centimeters thick, with 10 centimeters expected to be eaten away by seawater every 50 years, the Tepco official said. “This is meant to prevent further contamination of the ocean… as sample tests have shown a relatively high concentration of radioactive substances in the sea soil in the bay,” a company spokeswoman said. 'Relatively high'? sounds not worth 60 cm of cement… So, relatively high compared to what?
Japan Today, 22 February 2012
11,000,000,000,000 yen for Tepco bailout. Tepco (Tokyo Electric Power) is set to receive a government bailout that may cost as much as 11 trillion yen (US $137 billion or 102 bn euro) after the Fukushima nuclear disaster, the largest in Japan since the rescue of the banking industry in the 1990s. Japan’s government included 2 trillion yen in this year’s budget for the Nuclear Damage Liability Facilitation Fund, the bailout vehicle for Tepco. The government plans to budget 4 trillion yen in the next fiscal year and has issued 5 trillion yen of so called delivery bonds, which the state fund can cash in for financial aid to Tepco. The funds redeemed can only be used to compensate those affected by the disaster.
Bloomberg, 24 February 2012
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