High-level radioactive waste is very dangerous, and can remain so for tens of thousands of years before decaying to safe levels. It is highly radioactive and is a major barrier to the expansion of nuclear power. If there is to be a “nuclear renaissance”, a sophisticated method of dealing with this waste must be refined. This point itself has sparked a surprising number of debates. For example, how do you write “danger” on a concrete box, when in 5,000 years the word “danger” may no longer exist? What symbols could we use to let people know to leave it well alone?
As you can see from the graph below, the radioactivity of nuclear waste takes about 10 000 years to return to that of the original ore. The black line, indicating the total waste products, is the important one. Accidents Consider the words Chernobyl, Three Mile Island or, more recently, Fukushima. What do you think when think of them? Some people were (are) so terrified of the threat of radiation and various other scary things from previous accidents that even the idea of such things happening again makes them completely averse to nuclear power as a whole.
In terms of disadvantages of nuclear power, this is a big one. Whatever improvements in safety the nuclear industry has developed, public opinion may very well rest in these events. There’s no right or wrong answer here. Technically speaking, nuclear power remains one of the safer energy sources, but Fukushima has reminded the world what can happen when something goes wrong. Proliferation Some forms of nuclear reactor, known as “breeder” reactors produce plutonium, which can, conceivably, be used to make nuclear weapons, most likely in the orm of a “dirty bomb”.
This is a conventional explosive mixed with radioactive material with the intention of spreading the material across a wide area to do even more damage. There are other reactors which do not have this problem, but it is another issue that must be addressed before the possibility of a nuclear future can be taken seriously. In fact, there are reactor designs, and fuels for them, which would also significantly reduce the amount of waste produced.
Fuel Nuclear fuels are, physically, even rarer than fossil fuels. Fossil fuels at least are made on Earth, albeit over millions of years. Heavy elements like Uranium are only made as stars die, in supernovas. Our solar system actually formed from the remains of another star, at which point heavier elements were made. Essentially, once they’re gone, they’re gone. Only in particle accelerators can heavier elements be made.