The incident at the Fukushima Daiichi nuclear plant in Japan shows how vulnerable we are to scenario’s that ar not predictable. A nuclear power plant is the most controlled and checked environment to ensure the safety of a whole nation. But then a simple earthquake can take out all the safety and back-up safety plans and create a disaster.
What happened (according to what the press writes) was, due to the earthquake there was a buildup of hydrogen gas that exploded and blew the roof of the first reactor. Nothing wrong with the nuclear reactor, no significant radiation leakage. Then the tsunami came and caused a major power outage with the result that the cooling systems to the reactor failed. Overheating of the reactor core will lead to a build-up of heat causing a meltdown like in Chernobyl in the Sovjet Union.
Of course there are several back-up plans, like a diesel powered generator and in last resort batteries. These back-up cooling systems all failed due to the tsunami so there is was no cooling of the reactors possible. Now they are trying to cool them down with seawater adding boron to slow down the reactions in the reactor. These are the last ditch attempts to stop a meltdown from happening.
Even if they are able to stop the worst from happening this plant will never be used again due to the use of seawater they used to flood the facility. This just shows that a nuclear power plant can never be safe enough. The plants in China are earthquake proof, but just not an 8.9 earthquake. There will always be a ‘but’ when it comes to safety, and all you need is one disaster…
The use of one big power plant for a nation made me think of the TED video that Tristan posted. There they mentioned small reactors that can be used to power town or cities, they are burried in the ground and work for long periods of time without being serviced. Maybe these are some viable options if we want to continue with nuclear energy. Smaller plants mean more control and smaller problems.
references: http://edition.cnn.com/2011/WORLD/asiapcf/03/14/japan.nuclear.reactors/index.html?hpt=T1
Nuclear energy is the future 
Niels,
These are indeed troubling times for Japan. But I think that the media is exxagerating. The explosion that happened only damaged the outer structure. The inner Structure, which contains the nuclear reactor, is protected by a pressure vessel. This vessel is placed in a concrete containment room that can only be damaged if a 9.9 magnitude earthquake occured right under the reactor and if the pressure vessel melts it will still contain the reactive material. These facts we need to keep in mind.
People also think that this will be a repeat of the Chernobyl incident. The Following arguments will show otherwise. The Chernobyl reactor had no concrete containment room and they used grafite in the reactor which caught fire and caused the explosion that generated a huge cloud of radioactive material.
Japan is not to blame for this disaster. I think that they resisted this incident very well with 55 reactor on there island! These things will happen again, we can do nothing about the plate tectonics of our planet and we still need to produce sustainable energy at an affordable price.
I’d like to add that the outer container was designed to blow apart when dramatic situations occurs like an earthquake. It’s more safe than letting the inner pressure build up and allow the reactor vessel to be damaged.
We should also take in mind that however this was an unfortunate event, a lot of the damage that has been done could possibly be prevented.
The diesel generators were swamped by the tsunami ( that easily overcame the sea walls surrounding the Fukushima plant) because they were placed in a low-lying area because of misplaced confidence that the sea walls would protect them. If they had been placed on a higher setting they wouldn’t have flouded. This would have prevented the output of nuclear waste into the air.
The existence of nuclear plants will always contain certain risks but the disaster in Japan shouldn’t mean the end of nuclear energy. Japan is a pretty easy target for earthquakes when you consider it’s proximity to geological faults and the presence of several vulcanos.
Europe or even Russia are not directly targets for these kinds of natural disasters, so maybe when we are discussing that ‘nuclear energy is the future’ we should first consider it’s geographical location.
source: New York times
Tristan,
I agree with your statement that this will not escalate to the same magnitude as the Chernobyl incident and that the plants are much safer nowadays. The problem however is the rise of the temperature in the reactor core, what if this amounts to an explosion, will the concrete walls contain this explosion? If so will it also contain the radioactivity, or will the walls have been damaged slightly? These are all important questions, especially when you see the reaction of the world to this ‘not so dangerous’ explosion in a nuclear power plant…
I agree that Japan is not to blame. What this does show is that no matter how you prepare for a disaster, it can still go wrong. There were several back-up plans but none of them worked. you can compare it with BP oil leak, the safety measures weren’t enough and a disaster happened.
Maybe these disasters can have a positive note, a faster adaptation to new energy sources that are less dangerous.
Niels,
The reactors are “light-water reactors”. In worst case scenario they would not explode even if they overheated. Whats so special about this reactors is when they lose coolant, the reaction will also be interrupted. in this scenario there will be leakage but only a very small amount if the ventilation system is controlled well. An explosion is out of the question.
I understand your point for faster adaptation, but how long will that take ? Many people could have no electricity and you think they gone solve it by placing the whole area with windfarms or solarpanels? of course I think this disaster will be imprinted in the minds of the people once again like Chernobyl and Three mile island. Its sad those people know nothing about the safety and operations of nuclear plants but they are the first to protest against it.
I trust on the nuclear engineers and the people who know something about it instead on the media and frightened people.
Tristan,
I think you misunderstood the point I was trying to make with the faster adaptation. People are always against change, thus also against new technologies that require some adaptation. I am not implying that they should not build another nuclear power plant, just that they might be more open to new ways of producing energy in the future due to these disasters.
Thank you for the clarification on the type of reactor. However you say leakage is small if it is controlled, but it is clear that they have no control over the power plant at this moment. So there still is the chance of a disaster in the making.
You say you trust the nuclear engineers, but if we read the remarks that Ina made in the comment above. We read that the generators were flooded because they were placed in low lying land. Does this sound like good judgement of the plant builders and all the safety supervisors?
Maybe nuclear power is a safe and green way of producing energy, once we remove the human factor from the equation.
I think we can rule out a disaster even if the cooling can’t be controlled they will vent certain amounts of gasses , which are obviously dangerous but they won’t lead to a catastrophe..
To get a better view on what is happening in the reactors of the Fukushima power plant, you should take a look at this. It is a scheme of how the nuclear power plant works and what will happen before a meltdown.
Furthermore I partly agree with Niels. I think nuclear energy production is safe, probably the safest and most efficient way of harvesting energy around the world. However a disaster can never be excluded.
This incident rises a lot of questions. For example: the Belgian political party Groen! is reconsidering the decision to close the biggest nuclear plants in Belgium in 2025. They mention the disaster in Fukushima as one of their arguments to close the plants in 2015, which was the original plan. Also Germany closes 7 of their nuclear plants, build before 1980, because of the Fukushima incident.
First of all, I believe these reactions are overly excessive. What happened in Japan is horrible, I will not deny that, but it is caused by a nature catastrophe, and not by an incident in the nuclear power plant itself. I don’t believe such a disaster can strike Belgium or Germany.
Of course this closing of nuclear plants has to be compensated. As Ina said before in her post “Should nuclear power plant stay open?”, Belgium is very depending on his nuclear power. If we shut down the plants, we will have to import even more energy of our neighbours.
So, as long as we have a high need of energy, I don’t think nuclear plants should be closed immediately, without any good alternative.
On the following link there is a clear explanation of what exactly happened inside the reactors at the Fukushima Daiichi nuclear plant. For the interested.
link: http://www.economist.com/node/18398734?story_id=18398734&CFID=159621825&CFTOKEN=83294459