Below is an article I wrote for the South Australian Mines and Energy Journal on carbon emissions of uranium mines. (This, and others in the SACOME series, have also been published by my co-author, Ben Heard, on DecarboniseSA.com). This is a new version of a blog post I published on BNC a few years ago — but streamlined, simplified and updated. I hope you find it useful.
South Australia is host to the single largest known deposit of uranium in the world, at Roxby Downs. The recent plans to massively expand production at its Olympic Dam mine will take uranium production from 4,000 tonnes of uranium oxide (tUO2) in 2010-2011 to 19,000 tUO2 by the early 2020s. This enlarged open-cut polymetallic mine, run by BHP Billiton, will also produce 730,000 tonnes of copper (the principal product) and 25 tonnes of gold.
Some environmentalists have objected stridently to this plan for an expanded mine, including Greens MLC Mark Parnell who said: “Our state risks being left with a huge carbon black hole as we become the greenhouse dump for one of the world’s richest companies“. Such hyperbolic claims are easily made and can sound persuasive. But are they be supported by evidence? Let’s consider the accuracy and context of such an argument from a climate science perspective.
The greenhouse gas emissions from the mine expansion will come predominantly from heavy use of diesel and other liquid fuels for vehicles and mining equipment, and a 650 MW increase in electricity demand (likely gas powered), including the supply of 200 ML/day of desalinated water to the site. The result is that carbon dioxide equivalent emissions could peak at 4.7 million tonnes per year (tCO2-e). The Environmental Impact Statement acknowledged this would add almost 10 per cent to South Australia’s forecast emissions in 2020 under a business-as-usual scenario.
Now, let us consider the net effect of this on global greenhouse gas emissions.
The uranium from the expanded mine will fuel nuclear power plants in countries like the U.S., France, U.K., South Korea, China and Japan, to be used for electricity generation. A modern 1,000 MWe thermal nuclear reactor requires about 170 tUO2concentrate each year, in order to fabricate 16 tonnes of slightly enriched fuel rods. This plant will then produce 8,000 gigawatt hours (GWh) of reliable, on-demand electricity, used to directly displace baseload coal or gas.