Saturday, 26 January 2019

Could Nuclear Power Solve the Climate Crisis?

It is the last refuge of capitalist (and traditional socialist) supporters, as the scientific evidence of man-made, carbon induced, climate change mounts. It certainly has the advantage over such ideas as carbon capture and storage, which gets plenty of attention, but does not currently exist anywhere on a large scale. Nuclear power, of course does exist and has for many years now. Is it the silver bullet answer to climate change, whilst keeping the capitalist system of endless accumulation going?

The International Energy Agency (IEA) estimates that, in 2013, total world primary energy supply was about 18 Terawatts (TWh). One TWh is equivalent to 5 billion barrels of oil per year or 1 billion tons of coal per year, it also used to be the globe’s entire energy consumption in 1890. Of this amount of energy, nuclear supplied less than 10%, with most being provided by coal, natural gas and oil. Advocates of nuclear power emphasise the relative reliability of it over wind, solar and wave power.

Renewable energy accounts for less than a quarter of this energy, but is on the increase. Is it possible for a combination of renewable and nuclear power to provide for all of our energy needs, thus reducing carbon emissions, and put a check on climate change?

In 2011, Derek Abbott, Professor of Electrical and Electronic Engineering at the University of Adelaide in Australia, working on a figure of 15 TWh concluded that nuclear could not feasibly provide all of this power, but it also highlights the difficulty providing even half of this energy from nuclear.

Abbott estimates that to supply 15 TW with nuclear only, we would need about 15,000 nuclear reactors. His findings, some of which are based on the results of previous studies, are summarised below. 

Land and location: One nuclear reactor plant requires about 20.5 km2 (7.9 mi2) of land to accommodate the nuclear power station itself, its exclusion zone, its enrichment plant, ore processing, and supporting infrastructure. Secondly, nuclear reactors need to be located near a massive body of coolant water, but away from dense population zones and natural disaster zones. Simply finding 15,000 locations on Earth that fulfill these requirements is extremely challenging.

Lifetime: Every nuclear power station needs to be decommissioned after 40-60 years of operation due to neutron embrittlement - cracks that develop on the metal surfaces due to radiation. If nuclear stations need to be replaced every 50 years on average, then with 15,000 nuclear power stations, one station would need to be built and another decommissioned somewhere in the world every day. Currently, it takes 6-12 years to build a nuclear station, and up to 20 years to decommission one, making this rate of replacement unrealistic.

Nuclear waste: Although nuclear technology has been around for 60 years, there is still no universally agreed mode of disposal. It’s uncertain whether burying the spent fuel and the spent reactor vessels (which are also highly radioactive) may cause radioactive leakage into groundwater or the environment via geological movement.

Accident rate: To date, there have been 11 nuclear accidents at the level of a full or partial core-melt. These accidents are not the minor accidents that can be avoided with improved safety technology; they are rare events that are not even possible to model in a system as complex as a nuclear station, and arise from unforeseen pathways and unpredictable circumstances (such as the Fukushima accident). Considering that these 11 accidents occurred during a cumulated total of 14,000 reactor-years of nuclear operations, scaling up to 15,000 reactors would mean we would have a major accident somewhere in the world every month.

Proliferation: The more nuclear power stations, the greater the likelihood that materials and expertise for making nuclear weapons may proliferate. Although reactors have proliferation resistance measures, maintaining accountability for 15,000 reactor sites worldwide would be nearly impossible.

Uranium abundance: At the current rate of uranium consumption with conventional reactors, the world supply of viable uranium, which is the most common nuclear fuel, will last for 80 years. Scaling consumption up to 15 TW, the viable uranium supply will last for less than 5 years. (Viable uranium is the uranium that exists in a high enough ore concentration so that extracting the ore is economically justified.)

Uranium extraction from seawater: Uranium is most often mined from the Earth’s crust, but it can also be extracted from seawater, which contains large quantities of uranium (3.3 ppb, or 4.6 trillion kg). Theoretically, that amount would last for 5,700 years using conventional reactors to supply 15 TW of power. (In fast breeder reactors, which extend the use of uranium by a factor of 60, the uranium could last for 300,000 years. However, Abbott argues that these reactors’ complexity and cost makes them uncompetitive.) Moreover, as uranium is extracted, the uranium concentration of seawater decreases, so that greater and greater quantities of water are needed to be processed in order to extract the same amount of uranium. Abbott calculates that the volume of seawater that would need to be processed would become economically impractical in much less than 30 years.

Exotic metals: The nuclear containment vessel is made of a variety of exotic rare metals that control and contain the nuclear reaction: hafnium as a neutron absorber, beryllium as a neutron reflector, zirconium for cladding, and niobium to alloy steel and make it last 40-60 years against neutron embrittlement. Extracting these metals raises issues involving cost, sustainability, and environmental impact. In addition, these metals have many competing industrial uses; for example, hafnium is used in microchips and beryllium by the semiconductor industry. If a nuclear reactor is built every day, the global supply of these exotic metals needed to build nuclear containment vessels would quickly run down and create a mineral resource crisis. This is a new argument that Abbott puts on the table, which places resource limits on all future-generation nuclear reactors, whether they are fueled by thorium or uranium.

As Abbott notes, many of these same problems would plague fusion reactors in addition to fission reactors, even though commercial fusion is still likely a long way off.

The 15TWh figure that Abbott uses, is less than 18TWh figure that the IEA uses for 2013, so Abbott’s estimate is either from a different source or else is from 2011 or before, and the energy consumed had risen by 3TWh 2013. It is likely that the amount of energy consumed did rise, as it constantly does, see the diagram below.

If I think back maybe 10 years or so, I now have many gadgets; smart phone, iPad and laptop, which I didn’t have then, all of which require power. Likewise, HD televisions, which most people have switched to, take about five times as much as the old televisions. The capitalist system just keeps creating demand for energy, and this will continue to be case. The system would die otherwise.

So, certainly if we do not replace capitalism, nuclear power is not going to keep pace with demand for energy, and it is unlikely that even in combination with renewable energy, future energy demand will be met. As Abbott’s finding show, it is just not feasible.

1 comment:

  1. Building new nuclear energy plants take also way to long, compared to renewables like wind and geotermal energy!