It is almost a year since the massive earthquake and tsunami off the east coast of Japan on March 11, 2011 which triggered the Fukushima nuclear disaster. This article gives an overview of why the nuclear disaster happened, why it is still occurring, the main preliminary lessons, its implications to date and its effects in Europe. (It should be noted that information and new insights about Fukushima are appearing almost on a daily basis.)
Article by Dr Ian Fairlie for SGR website, 7 March 2012
The nuclear accident 
Following the earthquake, the three operating reactors at the Fukushima Dai-ichi nuclear plant automatically shut down because of huge lateral vibrations caused by the quake. But the quake also disconnected the reactors from the national grid, therefore their cooling pumps could not operate. Emergency diesel-powered pumps kicked in but these were unwisely located in reactor basements which were flooded by the tsunami arriving 20 minutes later. The result was inexorable rises in nuclear fuel temperatures until the fuels melted then started to boil.
Because of the paramount need to remove the large amounts of decay heat from nuclear fuels both in the reactors and in the spent fuel ponds, cooling failures resulted in a compound, cascading series of explosions and other events which are still being unravelled. The major events were as follows:
- core meltdowns occurred in the reactors of Units 1, 2, and 3;
- explosions destroyed the reactor buildings of Units 1, 3, and 4;
- an 'explosive event' damaged the containment structure inside reactor 2;
- several fires broke out at Unit 4 (luckily, reactor 4 was offline at the time of the earthquake);
- spent fuel stored in the pools of Units 1–4 overheated as their water levels dropped;
- many workers suffered high radiation exposures and often had to be evacuated;
- machinery for reactors 1–4 damaged by floods, fires and explosions remained inoperable.
A probable hydrogen explosion at Unit 1 on March 12 exposed its spent-fuel pool to the open air, released radioactive matter into the environment and caused delays in cooling Unit 3. The ensuing huge explosion at Unit 3 a day later damaged seawater injection lines and vent lines for Unit 2, producing delays in its cooling. It is likely this caused the 'explosive event' on March 15 inside the reactor at Unit 2. Seconds later, a fourth explosion wrecked the spent fuel pond at Unit 4. In other words, explosions at one unit hampered responses to the damage at others, leading to a chain-reaction of explosions and radiation releases. No wonder staff members at the plant were often terrified and TEPCO (the electricity utility) wanted to withdraw all personnel from the plant at one stage.
Within about six hours of the Japanese earthquake and tsunami, it appears that full or partial nuclear fuel meltdowns had occurred within Units 1, 2 and 3 at Fukushima due to the inexorable heat from radioactive decay inside the fuel. This was quickly followed by the molten fuel (at ~2,000 °C) melting its way through the steel pressure vessels into secondary concrete containment vessels. It is now thought these containment vessels have cracked and much fuel is now in the basement areas of the reactors. At the same time, the water in the spent fuel ponds above the reactors also began to boil causing their water levels to drop thus exposing spent fuel to the atmosphere.
So within a few days of the earthquake/tsunami, four major explosions had occurred: one at each of the relevant Fukushima Dai-ichi Units. These explosions wreaked massive damage with the result that the reactor buildings at Units 1 and 4 in particular may collapse. It is important to note that the reactor malfunctions, resulting fuel meltdowns and explosions were due to the earthquake as well as the tsunami, contrary to the explanations given by TEPCO and the Japanese regulators which only mentioned the tsunami . The point is that the many Japanese nuclear reactors near fault lines are considerably more vulnerable to earthquakes than to tsunami.
Ever since the accident occurred, the main preoccupation has been to keep the nuclear fuels cool. This applies not only to the melted nuclear fuels in the reactor cores but also the large volumes in the storage ponds at Units 1, 2, 3 and 4. Some of this latter fuel has been exposed to air and has melted, and it is feared that at least one of the four explosions occurred in the fuel ponds.
The continuing disaster
A year after the accident, it is still continuing in slow motion and will do so for years. Major efforts are still being made to keep the reactor fuel cool to stop it from melting through the bottoms of the reactor buildings into the soil below, although the concrete bases are about 10 m thick. If this were to occur, Japan would be deep in uncharted areas: further explosions would likely occur. Water is also still being pumped into the storage pools to keep their spent fuels covered.
In addition, it is hypothesised that criticality excursions are recurring in nuclear fuels . It is also becoming known that many nuclear fuel fragments are spread throughout the plant and even as far as the large town of Iitate over 30 km away. A major headache is the structural instability of the wrecked reactor buildings which may collapse at any time due to the massive weight of the storage ponds situated, again unwisely, on top of the reactors. This would spill thousands of tonnes of dangerous spent fuel and radioactively-contaminated water over the site.
When we look further afield the situation is no better, as very large amounts of radioactivity were dumped into the sea and emitted to atmosphere. The latter resulted in about a thousand square kilometres of land being contaminated with fallout and large amounts of crops and produce being contaminated. Over 100,000 people have had to be evacuated from their homes, possibly for decades. These effects are on top of the estimated 20,000 people killed by the earthquake and tsunami themselves. The situation is truly numbing and our hearts go out to the Japanese people struggling with the horrible consequences of the earthquake/tsunami and of the Fukushima disaster.
How long will this dire situation continue? It is hard to say, but officials from the International Atomic Energy Agency privately talk of years: other scientists say decades. Up until recently, contaminated water from the cooling operations was being dumped on land and into the sea. Nowadays this water is mainly being pumped into huge temporary holding tanks.
Health Effects 
Few deaths have been recorded at Fukushima so far, certainly in comparison to the thousands caused by the earthquake/tsunami. About 7 deaths to military personnel and plant operators were apparently caused by the site explosions. According to a survey by the NHK TV station, 68 patients from evacuated hospitals died during the long hours of evacuation. None of these deaths were due to radiation exposures. But fears remain about longer-term effects, as radiation has decades-long latency periods before most solid cancers appear. Increased incidences of thyroid cancers – a prominent effect after Chernobyl – are unlikely to appear for another three years.
It is too early to make firm predictions, but judging from the exposures and effects seen at Chernobyl, it is likely that at least a few thousand fatal cancers will occur among those exposed to Fukushima’s radioactive fallout. In addition, it is likely that Fukushima plant workers will suffer as the Japanese Health and Labor Ministry reported that nearly 100 workers had exceeded legal radiation limits by June 2011.
Fukushima is clearly a serious disaster but it is not as serious as Chernobyl. Radioactive air emissions are much more important than radioactive sea discharges in terms of their resulting radiation doses to people, andthe dispersed radioactivity to air from Fukushima has been estimated to be about 10% to 40% of the amount dispersed from Chernobyl. About a thousand square kilometres near the Fukushima were contaminated, but at Chernobyl the area affected was much larger. Over 200,000 square kilometres throughout Europe were seriously contaminated, according to the European Commission.
Although the Japanese Government has announced it had “achieved phase 1 of its plan” to bring the Fukushima nuclear crisis under control, this statement – like many official announcements – is misleading as the reactors are clearly not in a stable condition and the nuclear crisis is not under control.
A very recent report  by the chair of the independent Rebuild Japan Initiative Foundationis worth noting. It reveals many institutional failures at Fukushima and shows that TEPCO and the Japanese Government and its nuclear agencies were completely unprepared for the disaster at almost every level. This lack of preparation was caused by the myth that the risk of major nuclear accidents is vanishingly small, which nuclear power proponents had nurtured over decades. It was aggravated by poor communications and lack of trust within and between government agencies and TEPCO. Interestingly, the report also shows that the disaster, bad as it was, could have been worse. Apparently, luck was on the side of the Japanese at several junctures during the disaster.
Perhaps the simplest of the lessons to be learned from Fukushima is that nuclear power is a supremely unforgiving technology. When things go wrong, they can go very, very wrong with consequences which are extremely difficult to remedy, even in advanced industrial nations. But nuclear power is merely a complicated way of boiling water and, after Fukushima, many countries are beginning to examine safer energy policies.
The Political Fallout in Europe
Interestingly, different countries have responded in diametrically opposite ways to the Fukushima disaster. In the UK, the coalition government, most political parties and many parts of the media appear to be ignorant of, or perhaps in denial about, the continuing events at Fukushima. Certainly most of the UK press and the BBC are heavily pro-nuclear in their outlooks. The result is that the UK remains strongly pro-nuclear. This was starkly illustrated on July 18, 2011 when only 14 out of 650 UK MPs voted against the government’s Nuclear Policy Statements. In contrast, two weeks earlier, on June 30, the German Parliament voted by 513 to 79 to phase out all nuclear power by 2022.
The government’s nuclear bias was also shown when freedom of information requests in July 2011 revealed deep collusion between the government and the nuclear industry . Apparently, civil servants in energy and business departments attempted tominimise the impact of the Fukushima disaster on public support for nuclear power by leading and co-ordinating a public relations response to the Fukushima disaster with the nuclear industry. In 2011, the UK government did request the Chief Inspector of Nuclear Installations to report on the implications for British reactors from Fukushima. But with a few caveats, his final report was a whitewash for nuclear power: the Government’s plans for up to eight new nuclear power stations were little affected.
In France, which obtains about 75% of its electricity from nuclear reactors , the nuclear worm appears to be turning. An opinion poll in June 2011 showed 77% opposing the building of new nuclear plant . The French Presidential and Legislative elections in May and June 2012 respectively are currently expected to result in a Socialist President and a PS-Green coalition government formally opposed to new nuclear power. The Socialist Party has called for a moratorium on new reactors and pledged a national debate on energy transition if elected.
In Germany, several 250,000-strong demonstrations took place after Fukushima with the result that major reversals occurred in regional (Lände) elections and opinion polls showed large increases in opposition to nuclear power. The Merkel government has now adopted a very strong anti-nuclear policy with seven (out of 16) reactors already closed and with the remainder to be phased out by 2022. Stiff anti-nuclear windfall taxes have also been imposed on nuclear power companies.
In Italy, an astonishing 94% of the electorate in a national referendum in 2011 opposed new nuclear in which forced the (then Berlusconi) government to abandon its nuclear plans. In Switzerland, 25,000 attended an anti-nuclear demonstration, and the Swiss cabinet decided against new build: in effect supporting a phase-out programme as its old plants retire.
With Austria, Denmark, Portugal, Norway, Ireland and Greece all non-nuclear and phase-out programmes also in Spain and Belgium, European support for nuclear power is on a clear downward path. Add to this the major problems in the construction of new reactors in France and Finland , and it is little surprise that French and Germany nuclear companies are looking to the UK as a safe haven for new nuclear projects - with the coalition government offering enthusiastic, not to say slavish, support.
It is a sobering thought that on the nuclear power issue after Fukushima, the UK appears to be increasingly out-of-step with the majority of its European Union neighbours.
Dr Ian Fairlie is an independent consultant on radioactivity in the environment. He holds an MSc in radiobiology and a PhD in radioactive waste studies. Website: http://www.ianfairlie.org/
Notes and references
1. Among the better websites on Fukushima, Wikipedia has a number of pages including http://en.wikipedia.org/wiki/Fukushima_Daiichi_nuclear_disaster which is a large entry whose table of contents runs to 50 lines and whose references number over 350. Its webpage on health effects http://en.wikipedia.org/wiki/Radiation_effects_from_Fukushima_Daiichi_nuclear_disaster is almost as large. These two sites are kept up-to-date, are well-informed, and with good sources. Most important, they are pretty even-handed. Even counting the overlap, these two sites represent a vast amount of work: it seems they are maintained by a team or teams of Japanese academics.
2. Adelstein J, McNeill D (2011). Meltdown: What Really Happened at Fukushima? http://www.theatlanticwire.com/global/2011/07/meltdown-what-really-happened-fukushima/39541/
3. The evidence for this is the continuing production of iodine-131which can only come from recent nuclear fissions. In addition, bursts of high levels of gamma radiation are occurring without official explanation. See: http://www.zerohedge.com/article/are-nuclear-chain-reactions-still-occurring-fukushima?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+zerohedge%2Ffeed+%28zero+hedge++on+a+long+enough+timeline%2C+the+survival+rate+for+everyone+drops+to+zero%29
4. Funabashi Y, Kitazawa K (2012). Fukushima in review: A complex disaster, a disastrous response. Bulletin of the Atomic Scientists. March/April. http://bos.sagepub.com/content/68/2/9.full.pdf+html
5. Edwards R (2011). UK government shared intelligence with nuclear industry, documents show. The Guardian, 5 December. http://www.guardian.co.uk/environment/2011/dec/05/uk-government-intelligence-nuclear-industry
6. IAEA (2012). PRIS Power reactor information system. France. http://pris.iaea.org/Public/CountryStatistics/CountryDetails.aspx?current=FR
7. Ipsos (2011). Global Citizen Reaction to the Fukushima Nuclear Plant Disaster. June. http://www.ipsosglobaladvisor.com/
8. Montonen C (2011). Nuclear adventures in Finland and elsewhere. SGR Newsletter no.39. /resources/nuclear-adventures-finland-and-elsewhere