Since the nuclear accident in the Japanese Fukushima Dai-Ichi plant in March 2011, nuclear power popularity has dropped around the world. In Germany, the public reaction lead to an hastened nuclear phase out.  China and India slowed down their nuclear roll-out, Switzerland suspended the licensing for three new plants. Japan itself deferred all its plants until the structure of regulations for nuclear power plants was reviewed by a government’s commission. Is nuclear power dead? And should we regret that? Read on to find out.

Nuclear power: how it works

Despite the fact that nuclear energy is a main source of electricity in both Europe and the US for over 4 decades, the public seems to be terribly mis- or uninformed. The mainstream media and some non-educated activists didn’t help of course. So let’s make sure we all know what we are talking about.

In fact, the process of electricity generation with nuclear power is just a “helluva way of boiling water”, to say it with Einstein’s words. Just like any other thermal power plant, steam is generated to drive a turbine, which in its turn is connected to an alternator that generates electricity. Instead of burning coal, gas or biomass, this time it is the fission of a heavy element such as uranium-235 that releases the energy to heat up the water.

Fairly simple, isn’t it? Well… it’s more complicated than that. When a heavy element splits in two lighter fragments, it also releases neutrons. Those can initiate the fissioning of another uranium-235 atom, leading to a chain reaction. It is crucial that the number of generated neutrons and the number that is absorbed in the Uranium-235, the structural materials of the reactor vessel and the control rods are nicely balanced. If more neutrons are absorbed than released, the reactor falls silent. Too much neutrons on the other hand lead to a run-away reaction, which scientists call a supercritical reactor. The reactor heats up very quickly which can lead to a meltdown, forming of hydrogen gas that can eventually explode and spread radioactive material into the atmosphere.

Fukushima Dai-Ichi: tragedy or miracle?

When the disastrous Earthquake of 9.0 on the Richter Scale hit Japan on the 11th of March 2011, the Fukushima Dai-Ichi’s 3 operational reactors shut down automatically along with multiple other nuclear reactors in that part of the country. The nuclear power plants are built and foreseen to shut down in case of large seismologic activity and all the safety measures clearly did their job.

One of the origins of the problems that escalated into what was quickly labeled a nuclear disaster, is the fact that Japan’s electricity grid is in the hands of a limited number of private companies. Historically the transmission grid evolved in two different synchronous zones, one at a frequency of 50Hz (like we have in Europe) and one at 60Hz (like in the US). There is only a limited number of connections between the two parts. When the nuclear plants in the north of Japan shut down due to the earthquake, the demand was suddenly too high for the power plants that were still operational. The limited interconnection with the South of Japan didn’t allow to import enough energy from that side. Result: the grid chucked it up and the northern part of Japan was out of electricity.

On the 11th of March, a tsunami that reached 14-meters height smashed onto Japanese Sendai region coast (photo:

Now you are probably wondering what that has to do with the Fukushima Dai-Ichi reactors. The problem is that even after an emergency stop of a nuclear reactor, the fission products in the reactor keep decaying and emitting heat for quite some time. This heat still has to be removed. And for that you need cooling water, pumped around by pumps that need electricity. But the grid was down, remember? Luckily there are safety measures for (nearly) everything. The nuclear plants are equipped with emergency diesel generators to keep the pumps alive in case of loss of electricity supply.

What the designers of the nuclear power plant did not foresee, is the devestating 14-meters high tsunami that hit 55 minutes later and that drowned that same diesel generators. Luckily the designers of the plant had built in yet another safety measure: an emergency battery supply. But just like your powerbank cannot get your phone to the end of the week, so couldn’t the batteries of the Fukushima Dai-Ichi plant. It didn’t take long before they went out. At that point, only some passive passive pumps kept circulating cooling water in the reactor units. But that was far from sufficient to keep the reactors from overheating and partially melting.

During the following days (the electricity still was not back), a series of events followed one another and escalated in the Fukushima disaster. Due to the lack of cooling, the reactor core cooked out all its remaining cooling water. The cladding of the fuel rods started to react with the oxygen in the reactor building, leading to the formation of hydrogen gas. This eventually led to hydrogen explosions in reactor building 1, 2 and 3. The plant workers helplessly stood by, watched and ran away (well, if they were smart). A few days later another explosion followed in the reactor 4 building. The reactor itself was not operational during the earthquake and the fuel was taken out of the reactor vessel to cool down in a storage pool. In all the bustle with the reactors 1, 2 and 3 it seems they forgot to keep an eye on the fourth one, where the fuel rods also came in contact with air with another explosion as a result.

An areal view of two of the reactor buildings pf the Fukushima Dai-Ichi plants after a build-up of hydrogen lead to an explosion that blew of the roof (source: pinktentacle)

Later, large pumping trucks were brought in to pump in water to cool down the reactor vessels. By that time, a region of 20 km radius around Fukushima had been evacuated and a large screening campaign was set up to monitor nuclear contamination of food. In the end, the quick and efficacious work of the Japanese authorities avoided a humanitarian disaster. Not a single person died due to radioactive contamination. What many seem to forget is that in the meantime the death toll of the tsunami was still on the rise towards a stunning 19000 deaths. More than 2000 people have never been found back. While the Western media showed pictures of “another Tjersnobyl”, Japan counted its dead the sea had left in its wake.

Nuclear power is not dead (yet)

It will not surprise you though that the Japanese people had enough of nuclear power after the evacuation of a zone of 630 km² around the Dai-Ichi plant. There might not be any deadly victims of the nuclear accident, but the psychological damage to all of those who were forced to leave behind everything they had is substantial. Some might never see the places back were they grew up, played as kids, had their first kiss. Although the largest part of the evacuation zone is safe now, the government is reluctant to let people return. The International Atomic Energy Association (IAEA) already concluded in 2013 that most of the region had radiation levels well below the allowed levels. The ongoing displacement of the evacuees is creating unneccessary damage. For many, the whole story could well be a traumatic page of their life. My point is, we shouldn’t over exaggerate the damage of the accident, nor should we downplay the psychological impact on the direct victims.

Before the 11th of March 2011, Japan heavily relied on nuclear energy to feed its energy hungry industry and population for many years. With 50 nuclear reactors, atomic energy provided 28% of its electricity needs. Everything changed after the Fukushima Dai-Ichi accident. Japan’s government decided to take out all its other nuclear plants out of operation under huge public pressure. The country is struggling with its energy supply now, and became the largest importer of LNG (Liquid Natural Gas) and the second biggest importer of coal after China.

The impact in the rest of the world is all with all quite limited, except for Europe. Fueled by often somewhat disproportional and misleading media coverage, many European countries started questioning the need for nuclear in their electricity mix. At that moment, Finland, France and the UK were building new plants. After some hesitations, they have continued the projects. Switzerland revisited its plans to build new plants. Germany seems to be the one country (over-) reacted the strongest. After large public pressure, politicians decided to phase out their old plants more quickly than originally planned. And also more quickly than makes sense from an investment point of view. A nuclear power plant requires enourmous investments to build. Normally they rely on government subsidies to get a break-even. In times where the Germans were also questioning the amount of money they were flushing through the toilet by lending it Greece, it is strange that closing power plants before their due time — which is basically also throwing away money from tax payers before you — was not an issue.

China is investing hugely in nuclear energy to feed their growing electricity demand (photo: Westingtonhouse)

China and India continue their construction of nuclear plants. We in Europe often tend to forget the challenge they are facing. A growing population, a growing economy and a growing welfare comes at a price. The energy demand in China is growing so rapidly they cannot afford not using all means possible to accommodate the needs. In addition the Chinese government is faced with huge public pressure due to the devastating air pollution in the large cities like Beijing. Nuclear power is a welcome alternative to the polluting coal power plants. At the moment China has already 30 nuclear reactors in operation and another 24 are being build at the moment. 24. We in Europe are getting mad about one more plant more or less, in China they build them en masse. Oh, and they also succeed in doing that cost effectively and on schedule, which cannot be said from the projects in France, Finland and the UK at the moment. Seems like the Chinese have learned and surpassed the French in their nuclear expertise.

Anyway, it is clear that nuclear energy is not dead at all. Although the enthousiasm in the public opinion is low, the escalating energy demand in non-OECD countries asks for large measures. Nuclear power just offers too much advantages to leave out the energy portfolio of countries like China. It is safe (whatever people may think), reliable and relatively clean.

Nuclear and the climate

I’m quite sure that some of my readers are a bit confused by now. Was Elias not a bit a climate activist and stuff? Yes, I am. But an educated one.

I don’t have anything against public debates about nuclear, in fact I encourage people to discuss the way how we want to power our societies in a reliable and clean way. That’s why I want to present you two arguments that make me believe that nuclear power is an option to keep within reach, at least for the near future.

The footprint of different types of electricity generation technologies. Nuclear is still one of the cleanest options (graph: Food for Thought blog)

The first one is the following: if you let me choose between a few thousands tonnes of CO2 diffused in the atmosphere bound to stay their for at least 100 years or a concise package of nuclear waste safely stored in dedicated waste disposal caverns deep under the ground, the decision is rapidly made. We are spending our so-called carbon budget at an alarming rate. If we keep putting greenhouse gases in the atmosphere at the current rate, we are through the total amount of carbon we can safely emit to limit global warming by 2°C in around 20 years. We are running short of time to change the way we are fueling our societies, whether you like it or not. And nuclear could well be a solution to do that in a cleaner way.

Let’s get us some numbers to look what are the best options to generate electricity from an environmental perspective. In the graph above the greenhouse gas emissions are given for different energy generation technologies. We then quickly see that nuclear, considered over the whole lifetime of the plant and taking into account fuel production and disposal is still the best option we have. Yes, it takes a lot of concrete and steel to built the plant, but the fact that they are built to last at least 40 years and run nearly non-stop makes that the amount of emissions per unit energy generated is very low. Renewables like solar and wind also don’t combust fossil fuels, yet the production of steel for a wind turbine and the heating of Silicium during the production of solar panels is quite energy intensive. Nothing unusual, but since wind and solar only have a limited number of operating hours a year –that is: only when the sun is shining and the wind is blowing– the carbon footprint is higher than nuclear.

A second important point to make is the safety aspect of nuclear. After Fukushima many countries imposed stress tests to their nuclear plants to reassess the ability of the reactors against natural disasters or terrorist attacks. The industry keeps improving and learned from the few accidents that happened in the past. In fact, the only nuclear accident with deadly results we have had so far was the 1986 Tsjernobyl accident. Estimates vary, but it is expected that in total four to nine thousand will eventually have died from the radiation spread by the fires after an explosion in the Tsjernobyl reactor. But truth is we will never now how many lives are lost. A few hundred, mainly emergency workers, died in the first weeks after the accidents to due to the very high doses of radiation they were exposed to. On the longer term evacuees that saw high levels of radiation might eventually died from cancer. Problem is that you cannot distinguish a radiation induced cancer from other cancers and thus will never know the true death toll of the accident in Tsjernobyl. One thing that we do know for sure is that if the Soviet government at that time would have acted more efficacious, many people’s lives could have been saved.

After the Fukushima accident, a major screening campaign was set up in the region (photo: cbsnews)

The point is, even if there were nine thousand people that died in the wake of Tsjernobyl, that is fairly low in comparison with other sources of energy generation. Yearly thousands of coal miners still loose their lives deep under the ground to feed the hungry mouths of coal plants. The World Health Organisation estimated that around 7 million, yes you read that right, people died prematurely in 2014 due to air pollution. That is more than the population of Brussels, Paris and Berlin combined.

The point is this. The chances of you dying in a car accident is way higher than you dying due to a nuclear disaster, yet many people don’t perceive the risk in such a way. The chances of a nuclear disaster are so small, yet when it happens the impact might be substantial. But even then. With appropriate and efficacious action such as hapenned in Japan, the damage can be limited.

And by the way, for all of you still feeling a bit uneasy about the dangers of radiation, I like to quote journalist Will Boisvert. Radioactive contamination works like other mild toxins — alcohol, car exhaust, trans fat — that we live with every day: a huge dose can kill us; a modest dose poses modest risks; a tiny dose is innocuous.


First of all I encourage the fact that people debate the energy provision of the world. But as an engineer I get often frustrated about the fact that some people start debating about something not knowing what they are talking about, at all. It’s like me trying to give a girl fashion advice. It doesn’t bring any added value.

Secondly the nuclear accident showed how misinformed the general public is about nuclear energy. Five years later and in the midst of nuclear debates in my home country Belgium, not much seemed to have changed. So: share this article with your friends so we all get a bit better educated on the topic. I included the main sources for this article at the bottom, feel free to read a bit further. I only scratched the surface here.

Third thing we learned is that nuclear power plants are, despite all the safety measures, far from perfect still. Stress tests and new standards followed the events in Fukushima and that is a good thing. Safety first and we should keep improving it. Yet if we look back at the event we have to be fair and admit that the sometimes apocalyptic messages back in 2011 were completely off base.

And last but not least: nuclear is a plausible energy production option we should not put aside because of irrational misunderstandings. Don’t get me wrong, I’m a huge fan of renewables. I’m currently developing a new renewable technology myself and I know how difficult it is to make it cost competitive. In the energy portfolio of the near future, I think there is a place for nuclear. At least, it will buy us time until we come up with better solutions.

Main sources and further reading

The Fukushima accident, World Nuclear Association

The future of Nuclear Power After Fukushima

Nuclear power in China, World Nuclear Association

Global Carbon Budget 2015, Global Carbon Project