The Pros And Cons Of Fossil Fuels

Fossil fuels are the predominant energy source in the modern world, mainly consisting of coal, natural gas and oil. Its extensive use can be attributed to the affordability and reliability of fossil fuels, with these factors preventing renewable energy sources like wind and solar power from surpassing its usage, and in the example of Australia, “around 86% of … electricity is generated from [fossil fuels], with renewable energy sources [making] up the remaining 14%” (Origin Energy, 2015). However, fossil fuels are not without disadvantages, which include its detrimental impact to the environment through the emission of greenhouse gases, as well as its eventual exhaustion in the near future. With the world’s population growing and the supply

3, the thorium itself must become uranium-233 by absorbing neutrons, as the thorium is not fissile itself. The equation for this fuel cycle is given as: 23290Th + 10n --> 23390Th + β- --> 23391Pa + β- --> 23392U

This uranium-233 undergoes the process of nuclear fission, where a large nucleus splits into two or more smaller nuclei and releases an amount of energy. This release of energy is known as the mass defect or the binding energy, which is the energy required to keep the nucleus intact. The products of nuclear fission vary depending on the isotope of the element, and in the case of uranium-233, the most common products are strontium and xenon. The equation for nuclear fission for uranium-233 is given as:

Fig. 4 Uranium-233 nuclear fission equation

As seen in Fig.4, there is a 94% chance of fission occurring, yielding xenon-137, strontium-94 and three neutrons. The mass defect of this equation, or ∆m, is given as:

∆m = mp – mr
∆m = (23392U + 10n) – (13754Xe + 9438Sr + 3 10n)
∆m = (233.039635207u + 1.008701u) – (136.911562125u + 93.915361312u + 3 x 1.008701u)
∆m = 0.19530977u
∆m = mass defect (u) mp = mass of the products (u) mr = mass of the reactants

Compared to the energy released by uranium-233 in fission (0.0753231185857987 PJ/kg), the uranium-233 is much more efficient and effective.

“Australian energy consumption rose … in 2014-15 to around 5920 petajoules” (Australian Government, 2016). Therefore, if TMSRs were in use in Australia in 2014-15, the amount of uranium-233 needed to power it would be:

5920PJ ÷ 0.0753231185857987 PJ/kg = 78594.72776949184kg

“At the end of December 2012, Geoscience Australia estimated that Australia’s … thorium amounted to about 595 000 tonnes … assuming an arbitrary figure of 10% for mining and processing losses in the extraction of thorium, the recoverable resources of Australia’s thorium could amount to about 535 500 tonnes”("Thorium", 2013). Assuming that the energy consumption in Australia in future years is the same as Australia’s energy consumption in 2014-2015, thorium would be able to power Australia for:

535 500 000 kg ÷ 78594.72776949184kg / year = 6813.43 years

Being able to power Australia for about 6813.43 years at the current rate of energy consumption, switching to TMSR is a clear option to ensure a stable future in terms of