At the end of April this year, Prime Minister John Howard announced plans to increase uranium mining and prepare Australia for nuclear power. He, and many others, have argued that nuclear power is part of the solution to the looming ‘climate crisis’. With its ‘clean and green’ credentials being widely promoted, nuclear power could be the way forward. But is it really as clean as we are told?
First things first, what is nuclear energy?
Nuclear energy can be produced by bombarding Uranium fuel rods (like the green rod that Homer finds in his shirt in the opening credits of The Simpsons) with neutrons. This splits the U atoms into other smaller elements and produces heat.
It is this heat that is used to boil water which in turn drives turbines to produce electricity. Yes, nuclear reactors are kind of like giant kettles.
Seems great, doesn’t it?
On the surface nuclear power seems like a great solution to our ‘climate crisis’ but that’s only because I haven’t mentioned greenhouse gasses (CO2).
A common claim of the nuclear power industry is that nuclear power produces no greenhouse gasses. This is false when you look at the big picture.
Clean and green claims fall down fairly easily simply by asking ‘how does the uranium get to the plant?’ Now CO2 comes into the equation. If Uranium appeared by magic, then you could say that a nuclear power plant is clean and green, that’s if you also forget the toxic waste that can remain radioactive for hundreds of human lifetimes.
But let’s put that issue aside for a moment and look at the energy production process from a little further back.
CO2 in the mining process
From the ground
So for starters, Uranium ore needs to be mined from the ground using heavy machinery. These machines will no doubt produce greenhouse gasses.
As with most metals, Uranium is not found like nuggets of gold, it is found in ores which need to be refined. Some ores have a higher percentage of Uranium in them than others. This is important as larger quantities of low quality ores (with a lower percentage of Uranium) need to be mined to obtain the same amount of Uranium than from higher quality ores.
In her book Nuclear Power is Not the Answer, Helen Caldicott highlights that some low grade ore may require so much processing that more energy may be used to obtain the Uranium than can be obtained from using it in nuclear power plants.
The ore must then be transported, obviously producing more pollution.
At the mill
Once the Uranium ore gets to the mill to be refined it is crushed and mixed with water (aren’t we in a drought?) where the Uranium is leeched out with acid. This leaves a Uranium-rich mixture which is dried at 700oC (using electricity), forming what is known as yellowcake. From this point I pose the question:
Are greenhouse gases produced by nuclear power?
It is quite obvious that there are several steps in the process of nuclear power generation that produce CO2. But there’s more.
Converted again, then again
Uranium goes through two more processes before it is converted into pellets, which are built into fuel rods to be used in power plants. Like every process before it, energy is used in the process and the Uranium must be transported.
Other sources of CO2 in the nuclear process
Ok, that was the process of mining and refining the Uramium, what about building the facility? Nuclear power stations are huge and use large amounts of building materials. Won’t some CO2 be produced in this process?
What about the waste produced? This will obviously not be stored on site. It will need to be transported by trucks (producing CO2) to a waste disposal site (which would need to be developed) to store the waste.
Closing thoughts
All of this and cost or safety issues haven’t even been considered. I hope you can see that the bottom line is, if you want a nuclear power plant to be clean and green, sweep the floors and reach for a tin of paint and a brush, that’s as close as it’s going to get.
How do I know this?
Caldicott, H 2006,
Nuclear Power is Not the Answer: to Global Warming or Anything Else, Melbourne University Press: Australia
Conservation Council of SA 2002,
Nuclear SA http://www.ccsa.asn.au/nuclearsa/index.html
Hamblin, W & Christiansen, E 2004,
Earth’s Dynamic Systems, 10th edn. Pearson Prentice Hall, United States of America, pp.713-714.
Mines and Processing Centres 2007, Australian Atlas of Mineral Resources,
http://www.australianminesatlas.gov.au/info/factsheets/uranium.jsp
South Australian Chamber of Mines and Energy,
Uranium SA,
http://www.uraniumsa.org/
