Wednesday 4 November 2015

Is nuclear a waste of time? Part 2

The costs of waste disposal are vast, often accounting for 10% of the overall pricing (WNA 2015). Costs are contextually variable yet persistently high, with the waste disposal including the costs in exploration of suitable geologically stable sites, the engineering needs for the storage and also administrative costs to name a few (IAEA 2014). For example the lowest expenditure was $1.1 billion by India and the greatest was a staggering $19.5 billion spent by South Korea (IAEA 2014).

Costs of nuclear waste disposal for South Korea (IAEA 2014).

One of the answers is reprocessing, with it claimed in 2000 by the British Nuclear Fuel that 97% of nuclear waste can be recycled and reused (BBC 2000). Whether this potential is capable of being fulfilled however is another question. The reprocessing is predominantly focused on the conversion of “fertile uranium to fissile plutonium” (WNA 2015) – with it believed that an extra 25-30% of energy can be derived from the uranium that has already been processed initially. This would tie in with the previous blog on the costs of nuclear energy, as more energy would be generated for every $ spent of excavation for uranium for example.

Three general methods of reprocessing are available from the use of heat; electric currents or fluids in order to seperate the metals and allow access to the plutonium which can be engaged with as fuel (WNA 2015). The per $ excavation improvements however are seen to be made redundant by the fact that reprocessing is currently not economically viable within the French EDF company (WNA2015). That due to the impurities in uranium then the conversion costs are often 3x greater than the use of new uranium – this may therefore limit reprocessing and reduced global waste from being achieved on a vast scale. However, it may be seen that once the uranium stores are depleted this may force reprocessing as an essential practice; the necessity may provide the stimulus for innovation and reduced costs which may allow for greater reprocessing opportunities.

The lack of economic viability may explain for the limited level of global reprocessing – with the current global capacity at 4,500 tonnes of waste a year – compared to the 300 million tonnes that are produced each year ONLY from OECD countries (WNA 2015). Arguably, this shows the near negligible ability reprocessing currently has, but it must also be acknowledged as a step in the correct direction. The policies of waste are internationally variable with the UK and France promoting reprocessing, compared to Canada and Sweden for example that have policies in place for disposal (WNA 2015). The USA is seen to have a prevention of reprocessing that was put in place in 1974 under the presidency of Jimmy Carter (Forbes 2014). It was prevented due to the lack of cost-effectiveness and the danger of it being utilised as a threat to national security – however it seems ridiculous that a valuable resource is being wasted when it could aid the emission reductions of a country run by oil. The waste production would drop by 50% if the ban was lifted (Forbes 2014) – the USA more than anyone, with the vast emission production, is in drastic need of utilising every carbon-free resource available rather than simply “throwing it away”.

This leads to the difficult trade-off between safety and renewable energy – is the waste permanently sealed off in storage for safety purposes or is it left open, as it may become an increasingly valuable resource for future generations (WNA 2015).

Japan, as mentioned, has had a complicated relationship with nuclear energy for years – however despite large negativity from much of the public, two plants were agreed to be reopened in the Spring of this year (Normile 2015). The issue being that this will add further waste to the 17,000 tonnes that are currently within cooling pools. There is a strong desire for reprocessing yet the reprocessing plant constructions have been substantially delayed and therefore excess fuel will continue to be created – the planned opening is March 2016 (Normile 2015). The Redox extraction method looks to separate the useful uranium and plutonium from the used fuel, this would consequently vastly reduce the level of waste – however disposal of the highly radioactive residue byproduct will remain an issue. One method tested is vitrification where the by-product is inserted within glass – it is deemed more durable than the metal storage in commercial use. However, the complex chemistry and high costs are likely to limit its expanded use (Normile 2015)

Such alternative storages are needed in particular within Japan due to the fact that the underground storage is prevented as geological stability is unlikely to persist for long periods due to the sensitivity of the global location – along with the negative stigma that has arisen from a history of nuclear disasters. This means many will oppose the storage of nuclear waste anywhere in their proximity (Normile 2015). NIMBYism therefore arises again. Furthermore, an ever increasing concern will be the room for storage if it is continually produced and in need of safe storage for 1000s of years. There is only limited areas of suitable geological stability where deep storage is permissible. This had led to some suggestions of disposing of waste in outer space (Burns 1978)!

Despite this there is hope! Research from the University of Sheffield claims the volume of waste could be reduced by up to 90% by using burn furnace slag from metal refineries in the vitrification process (UOS 2013). This would reduce previous vitrification costs and overcome the concern of limited storage space. Waste would be reduced using other waste, a win-win scenario!

Vitrification - the answer to nuclear waste storage concerns?

It is clear there is much room for potential growth within reprocessing which could ultimately end this particular critical attack of nuclear energy. Often the radioactivity longevity may be over exaggerated in the media and society - therefore the risks are unlikely to persist for as long as many fear. Despite this it remains a great issue, the trade off between permanent sealing for safety or providing access for future use is one of the largest challenges - predominantly due to future technological advances being unknown. My opinion here is that waste in inevitable within energy production whether it is nuclear, fossil fuels or even solar energy which is seen to produce toxic waste water and carbon emissions during the panel construction (Nunez 2011). If nuclear is going to be a stopgap before more acceptable renewable resources are capable of fulfilling demand then these challenges will only be temporary issues. Therefore, dealing with and accepting these problems - whether it is through increasing reprocessing efforts or continuing to safely store - is essential to receive the high levels of carbon free energy that are urgently required today.

Solar panel construction also contributes to high levels of waste (Nunez 2011).

An issue that will be expanded upon within the next few posts will be the link to warfare and terrorism, with nuclear waste production "tightly and ambiguously linked with weaponry technology" (Armaroli 2006). Costs and fears of waste disposal sites and nuclear plants are therefore further increased by the security measures required to limit such potential energy falling into the wrong hands?!

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