By Arveent Kathirtchelvan
Nuclear power plants are large, consistent generators of electricity. Throughout the world, their usage has proven to be vital in ensuring energy security whilst lowering carbon emissions significantly. However, the usefulness of these power plants goes further than just electricity generation. These plants can be made the focal points of various applications, some of which are highly relevant to Malaysia’s current conditions.
Malaysians are often faced with a shortage of fresh water, with dry seasons sapping dam levels from Pulau Pinang to Selangor and elsewhere. Yet, a cursory glance at the map of Malaysia shows us practically surrounded by water, though, mostly being seawater, it cannot be readily used for drinking or agriculture. However, if we can somehow turn this to potable fresh water, it would go a long way in supplementing our natural freshwater supplies which rely on natural catchment areas and dammed rivers, resources which may prove to be dwindling with the current onset of climate change.
Enter seawater desalination plants. In these, seawater is used as feedstock to produce pure, fresh water by removing most, if not all, of the salt dissolved within it. Amongst the ways this can be done is heat application for evaporation or distillation. Nuclear power produces a lot of heat that can be utilised for this type of desalination, either as excess heat after electricity generation or direct heat without any such generation. This is especially true with newer reactors that run with high exit temperatures of coolant such as the Very-High-Temperature Gas-Cooled Reactor currently being developed in China, which proves that this application is fast becoming more and more practical.
However, another more contemporary application of nuclear power plants to desalinate seawater is through reverse-osmosis. This utilises the electricity produced by nuclear power plants to run large pistons pushing saltwater through porous membranes which only allow through water molecules and filter out the salt. Usually, a lot of electricity would be needed for this process to produce significantly large amounts of fresh water, which poses a problem for conventional power producing technologies as a lot of fuel (particularly fossil fuels) would be used up whereas renewable energy systems simply do not produce enough electricity consistently for this to be feasible.
Nuclear power plants, on the other hand, can generate the large amounts of electricity needed from relatively miniscule resources, and in a continuous manner. This allows for these plants to be dispatched to run reverse-osmosis systems in such a manner as to keep up water resources in our dams. What is more important is that, in today’s reality of rapid climate change, creeping sea levels gradually are deteriorating our fresh water sources and uncertain rain events further exacerbate the situation. An unseen effect of the lack of fresh water is the deterioration of arable land for agriculture, another problem that may be solved through the utilisation of desalination plants.
The Hydrogen Economy
What has been quite exciting recently is the usage of hydrogen buses in Sarawak. They are said to be the beginning of the future of transportation for Malaysia, however, depend on a steady supply of hydrogen gas as fuel. Since hydrogen does not exist in its gaseous state in nature, the generation of hydrogen gas is paramount for not only this application, but many others. Projections for the supply of hydrogen, unfortunately, show that the demand for the gas, to be used in various applications from industrial reactants to power storage, are skyrocketing far beyond the ability to make it.
Hydrogen is actually a very useful product. It is a raw material used in many chemical processes including the Haber Process to make ammonia, manufacturing acids and can be used as a coolant in power stations. A more enticing prospect for the usage of hydrogen gas now is as energy storage. Generated hydrogen can be dispatched whenever energy is needed for certain processes, whilst being stored whenever it is not. This is evident in the example of the hydrogen bus. Vehicles running on hydrogen fuel cells run more efficiently than those that run on fossil fuels. In addition to this, hydrogen can also be used to make biomethane by reacting with carbon dioxide which then can be used as fuel in internal combustion engines. This has the added benefit of capturing carbon dioxide from the atmosphere into useful fuels, continuously recycling it in a circular manner.
However, how does one generate enough hydrogen in a clean manner to achieve these goals? Once again, nuclear power comes into play. Currently, most hydrogen is made from the steam reforming of natural gas, a fossil fuel. Hence, what is essentially to be a carbonless energy source is dependent on carbon-based resources to be formed. However, an alternative source of hydrogen is in the electrolysis of water, that is the utilisation of electricity to separate the hydrogen and oxygen atoms of water into hydrogen gas and oxygen gas. For this, a large amount of electricity is needed, which can be supplied by nuclear power plants, following the same logic of using nuclear-generated electricity to produce reverse-osmosis water. With nuclear reactors diligently producing hydrogen, we can realise the potential of the hydrogen economy whilst stockpiling a vital resource that can generate significant economic benefits as well.
Both examples we have discussed so far show that nuclear power remains ever-relevant in today’s world and even projecting to the future. Whilst conventional wisdom may indicate the electricity produced by nuclear power could be substituted for renewable sources, in reality the inconsistency and small amount of electricity produced by them make this highly impractical. Of course, these are currently secondary uses for nuclear power, with electricity generation coming out as its most significant contribution. It is notable that all of these uses are superior in terms of emissions compared to conventional means are nuclear power releases the lowest amount of pollutants overall. It is therefore necessary, if we are to behave responsibly, that we accept nuclear power as a crucial piece in the puzzle that is a brighter, cleaner, more secure future.
Featured image from IAEA.org