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If you’re reading this, and you oppose nuclear energy, there’s a good chance that you do so as you’re concerned about nuclear waste. In fact, if you’re reading this and support nuclear energy, there’s a good chance you’re still somewhat concerned about nuclear waste. This concern is very reasonable – there’s a lot of fear in the public mind about nuclear waste, and not a lot of easy to access information about what it is, and what can be done with it. In fact, I myself was once opposed to nuclear energy, and when I did, a main reason was nuclear waste.
What is nuclear waste?
In the production of power from nuclear reactor, there are several different kinds of waste produced – Low Level Wastes (LLW), Intermediate Level Wastes (ILW) and High Level Wastes (HLW). The LLW and ILW include everything from lightly contaminated equipment and fluids used within a power station, up to the dismantled reactor cores and other components. However, what people usually think of when they hear the term nuclear waste is the spent fuel – the uranium rods that have been ‘burned’ in a nuclear reactor, and the plant operator no longer wants to use.
I watched ‘Into Eternity‘ last night on More4 (It was titled ‘Nuclear Eternity’ on the channel here), and I must say the film was a wonderful work of art. The imagery was fantastic, the music was entertaining, the narrative compelling. However, being an engineer I was somewhat frustrated by the lack of technical discussion, and instead a heavy reliance on philosophical questions. If you’ve seen the film, and I suggest you do before reading this entry, you’ll notice that the interviewees (mostly technical staff working on the Onkalo repository) were somewhat taken-a-back by this kind of question.
So, in this entry, I’d like to discuss some of the technical issues which I believe were somewhat missed in the film. The first is the issue of how long the waste has to be stored for. The 100,000 years needed to store spent fuel is based on the radiological toxicity (how dangerous it is to humans).
As can be seen from the diagram, the danger from the fission products (what you get when you split the uranium atom) is more or less gone after between 500-1000 years. These are the worst bit of the waste, and they are what you want to guard against. After this, you have the actinides remaining. In a nutshell, these are what you get when uranium captures a neutron, but doesn’t split. These are still dangerous if you ate or came into contact with a large amount of them, but they will be largely diluted by the rest of the material in the repository. They also happen to be some of the heaviest elements known to man, and so are unlikely to ever migrate to the surface, even if they come into contact with water. As can be seen from the diagram, they are the reason why the spent fuel is still more radiotoxic than the original ore for a period greater than 1000 years.
The first step in building this organisation is perhaps to decide what its goals are. In doing this, the development of a charter seems a wise idea. This will of course be subject to revision and further additions etc.
These are some preliminary ideas that I have had. Perhaps they should later be divided into goals/objectives etc:
- Promote, through an evidence based approach, the use of Nuclear Energy for Electricity Generation and other applications.