We made the mistake of lumping nuclear energy in with nuclear weapons, as if all things nuclear were evil. I think that’s as big a mistake as if you lumped nuclear medicine in with nuclear weapons.Patrick Moore,
former Director of Greenpeace International
Nuclear power comes in two flavours. Nuclear fission is the flavour that we
know how to use in power stations; fission uses uranium, an exceptionally
heavy element, as fuel. Nuclear fusion is the flavour that we don’t yet know
how to implement in power stations; fusion would use light elements,
especially hydrogen, as its fuel. Fission reactions split up heavy nuclei
into medium-sized nuclei, releasing energy. Fusion reactions fuse light
nuclei into medium-sized nuclei, releasing energy.
Both forms of nuclear power, fission and fusion, have an important
property: the nuclear energy available per atom is roughly one million
times bigger than the chemical energy per atom of typical fuels. This
means that the amounts of fuel and waste that must be dealt with at a
nuclear reactor can be up to one million times smaller than the amounts of
fuel and waste at an equivalent fossil-fuel power station.
Let’s try to personalize these ideas. The mass of the fossil fuels con-
sumed by “the average British person” is about 16 kg per day (4 kg of coal,
4 kg of oil, and 8 kg of gas). That means that every single day, an amount
of fossil fuels with the same weight as 28 pints of milk is extracted from
a hole in the ground, transported, processed, and burned somewhere on
your behalf. The average Brit’s fossil fuel habit creates 11 tons per year
of waste carbon dioxide; that’s 30 kg per day. In the previous chapter
we raised the idea of capturing waste carbon dioxide, compressing it into
solid or liquid form, and transporting it somewhere for disposal. Imagine
that one person was responsible for capturing and dealing with all their
own carbon dioxide waste. 30 kg per day of carbon dioxide is a substantial
rucksack-full every day – the same weight as 53 pints of milk!
In contrast, the amount of natural uranium required to provide the
same amount of energy as 16 kg of fossil fuels, in a standard fission reactor,
is 2 grams; and the resulting waste weighs one quarter of a gram. (This 2 g
of uranium is not as small as one millionth of 16 kg per day, by the way,
because today’s reactors burn up less than 1% of the uranium.) To deliver
2 grams of uranium per day, the miners at the uranium mine would have
to deal with perhaps 200 g of ore per day.
So the material streams flowing into and out of nuclear reactors are
small, relative to fossil-fuel streams. “Small is beautiful,” but the fact that
the nuclear waste stream is small doesn’t mean that it’s not a problem; it’s
just a “beautifully small” problem.