Nuclear Power - Is our Fear Jeopardising our Future?

This is just a small post to share a video of a talk by Michael Shellengerger; an environmental policy expert who has dabbled in a large area of climate change topics from the planetary boundary hypothesis, to carbon pricing and beyond. This talk discusses how the impact of declining nuclear energy production is having a negative effect on our overall 'clean' energy productions, while also looking at the public's perception of nuclear, and the barriers this presents for the future of nuclear energy and climate change.

Michael's talk brings forward a number of thought provoking points, so if you would like to discuss any of them, please leave a comment down below.

Nuclear Fusion - The Future of Nuclear Energy?

A month or so ago I talked about ‘the science behind a nuclear power plant’ with a brief description of nuclear fission, which is the process of splitting an atom into two smaller atoms and is the way we harness nuclear energy for electricity at the moment. Today I’ll be talking about nuclear fusion, which is seen by some scientists as the way forward for nuclear power and part of the key to a greener future with near unlimited energy supply.

Nuclear fusion, in the way most people will know about it, is the process that powers the sun and ultimately is responsible for all life as we know it on this planet (ITER 2016). In the sun, hydrogen atoms are fused together a number of times to produce a helium atom, and it is this fusing of atoms that produces the energy.

Nuclear Fusion Process in the Sun (Wikipedia 2016)

However on Earth, things have to be done slightly differently; the nuclear fusion that occurs in the Sun begins at roughly 15 million °C, which is pretty hot as you’d imagine (FusionForEnergy 2015). Sadly on Earth, we don’t have it as easy. Due to the sheer size of the sun, it emits immense gravitational forces which produce intense pressure as well as a high heat which allow it to carry out its nuclear fusion (WNA 2016). On earth, we are not able to produce pressures on such a magnitude so we have to compensate for this by increasing the temperature input to around 50 million °C (WNA 2016). The most efficient and feasible reaction scientists are able to perform at the moment is a fusion of deuterium and tritium, which is essentially two different heavy forms (isotopes) of hydrogen (HyperPhysics 2016).  The tritium and deuterium are fused together and a helium atom is created, with a neutron as a by-product; it is this reaction that produces the energy. The aim is to get enough of these fusion reactions to occur continuously that the process will be self-sufficient, and more energy will be produced than is inputted. When this is achieved, nuclear fusion will produce 4 times the energy yield of fission, and for every time pressure within the reaction is doubled, the energy produced is increased four-fold (WNA 2016) (MIT News 2016).

D-T Nuclear Fusion Process on Earth (AtomicArchive 2015)

Now this is all sounds amazing, but there must be some reasons why we aren’t doing this right now; and there are quite a few as you’d imagine. First up is that extremely high temperature that is required to even begin the reaction. This is needed to overcome the electrostatic forces that act as a gateway to the fusion of the hydrogen atoms (WNA 2016). The issue isn’t creating the temperatures, but creating a device that could contain such a reaction for long periods of time. Without a long enough time period, the fusion reaction wouldn’t be able to be self-sufficient and have a net-energy output (WNA 2016). Secondly there is a slight issue of fuel; while the deuterium occurs naturally in seawater (the deuterium in a gallon of seawater has the energy equivalent of 300 gallons of gasoline), the tritium is a bit harder to come by (HyperPhysics 2016). The tritium has no sizeable natural source and due to its radioactivity, has a half-life of around 12 years, which means it has to be bred from lithium; this could possibly be a bottleneck in fuel supply (HyperPhysics 2016). Finally a big problem is the cost and scale it is going to take to research and finally produce a workable reactor. Initial costs of a fusion power plant are estimated to be around £10 billion, but the research for it is even higher, with ITER (International Thermonuclear Experimental Reactor) the centre of nuclear fusion experiments expecting to cost over €20 billion to even construct let alone run the experiments (EUROfusion 2016) (Bloomberg 2016). As fusion reactions are in a gas form compared to fission which occurs in a solid form, the energy released is less concentrated, so fusion reactors will be bigger and more costly to build and maintain (WNA 2016).

ITER Construction Site (Science 2015)

Other than the near unlimited energy that seems oh so far away, are there any other positives? Well, like nuclear fission they would only have a negligible contribution to greenhouse gas emissions if any and are seen as a way to help reduce our CO₂ emissions (WNA 2016). Unlike fission, fusion reactors are easily shutdown and it would be near impossible for a Chernobyl or Fukushima situation to occur (CCFE 2016). The issue of containing the reaction is also seeing positive results, with magnetic fields which hold the plasma where the reaction takes place being the preferred method (MIT News 2016). In terms of waste, no long-lived radioactive products are produced and any unburnt gas is dealt with on sight. There is the slight issue about the reactor structure itself becoming radioactive due to long-term bombardment of high-energy neutrons, but the radioactivity itself would be easily dealt with (WNA 2016). A big concern is a tritium release into the surrounding environment, however this is hoped to be dealt with by forgoing tritium altogether, and just fusing deuterium with deuterium instead (WNA 2016).

Nuclear Fusion Reactor with Magnetic Field (FusionForEnergy 2015)

Nuclear fusion is often seen as the finish line for nuclear energy, and part of the end game in reaching our planet's energy needs. With nuclear fusion experiments breaking previous records and devices containing the reaction for longer periods of time and at higher pressures being built, it seems we are edging closer to the goal (MIT News 2016). However, a long-running joke since the 70’s is that commercial nuclear fusion is always 40 years away, and as you can probably guess, is the latest estimate for now as well (CCFE 2016). Perhaps nuclear fusion is just one nut we’ll never be able to crack?

If you have any questions or are just curious about nuclear fusion, don’t hesitate to leave a comment down below and I’ll get back to you as quick as I can. 

Uranium Reserves – How much is there?

Uranium, as touched upon in a previous blog post, is the fuel used for nuclear fission and is primarily obtained through mining. As an element in the Earth’s crust, uranium is a relatively common metal on the scale of tin or zinc (Kidd 2011). Throughout the crust, uranium is found in different concentrations known as ppm (parts per million), which is how much of a certain rock is uranium. Rocks which have higher ppms will be given a higher grade and will therefore be more economically viable to exploit. The viability of the ore-body will also be dependent on the cost of energy produced from other sources, as a higher energy cost would in turn make more ore-bodies with lower ppms viable (WNA 2016).

Uranium can be found in various regions around the world, although are highly concentrated in certain places, with the top 5 countries having roughly 66% (OECD 2016) of known recoverable resources and just over 75% of Uranium output (Mining-Tech. 2014). The top dog in terms of uranium resources by far is Australia, with 29% of total known recoverable reserves, with Kazakhstan, Canada and Russia each having a respectable 13-9% each (WNA 2016). This spread of uranium reserves across the global and political landscape would mean it would be hard to truly blockade a country from accessing uranium to feed its nuclear intent.

Global distribution of Uranium in the top 15 countries  (OECD 2016)

Uranium per Country with Cost (WNA 2016)

The big questions are how much uranium is there? And how long will the uranium last? This is mainly measured from the price of extracting said uranium, as some ore-bodies will cost more to extract. At a price of USD 130/kg and less, there is predicted to be 5.7 million tons of identified uranium that can be mined (OECD 2016), which if matched up with the 2006 uranium requirements of 66,500 tons, which would last roughly 85 years (Chmielewski 2008). Different sources using slightly different values calculate 80 years and 90 years of Uranium supply left at this price (Kidd 2011) (WNA 2016). These calculations are based on a scenario that nuclear energy doesn't really change going into the future, and a whole range of different scenarios could increase or decrease viable reserves. A decrease would only likely come about if the overall cost of producing energy decreased to a point, that nuclear energy was being priced out by other energy sources. If prices dropped to a point where only uranium mined at a price of USD 80/kg or less was viable, then only 37% of the 5.7 million tons mentioned earlier, would be able to be mined (OECD 2016). Increases of viable reserves could be caused by a number of things; simply an increase in the price of energy would allow more orebodies to be mined that were once too expensive. Discovery of further uranium resources from geological predictions will of course increase supply, with (Chmielewski 2008) estimating that we would have enough Uranium to last 300 years. Recycling plutonium from spent fuel cells could increase the life of today’s known uranium supply by 70 times, which would mean the reserves could last up 3000 years! Technological advances also have the capability to reduce mining costs and extend the life of fuel cells, with the new Generation-IV fast neutron reactors with their closed fuel cycle producing 100 times the energy with the same quantity of uranium (Chmielewski 2008). All these factors have the potential to come together, to give us the uranium we need for thousands of years.

Worldwide uranium resources and potential years of generation (Chmielewski 2008)

Uranium resources have been increasing significantly since 1975 in correspondence to increased expenditure on exploration. This would suggest that as exploration increases, viable reserves of uranium would also increase, with previously uneconomic uranium from Florida once again being examined for possible extraction, and lower-grade ore bodies such as those in Morocco also being investigated (Kidd 2011). This is because, the uranium fuel only makes up a fraction of the cost of nuclear energy; only 2% of the cost is attributed to the uranium, with the vast majority attributed to building the plant, operating and maintenance. This means that a theoretical doubling of uranium prices would only add a 2% increase on to final electricity bills (Chmielewski 2008).

Known Uranium Resources, their prices and Exploration Expenditure (WNA 2016)

As technology advances and additional orebodies become viable and are discovered, it appears that reserves of uranium will be around for thousands of years to come if managed correctly. This could pave the way to an era of cleaner energy if managed correctly. This is dependent on the research and exploration being done however, which may be at risk from investment as recent discoveries of cheap shale have the potential to side-track nations away from uranium exploration. Or there is the potential that uranium may not be needed at all by 2050, with hopeful estimates that we could have nuclear fusion power plants in operation by then!

Public Opinion on Nuclear Energy

Nuclear energy has always been one of the most divisive sources of energy; with support depending on the country, how well informed the public are, and the events occurring around the world at the time. There are a number of factors that influence the public such as nuclear waste, security, cost of energy, reliance, safety, the media, climate change and many more.

Chernobyl

There isn’t much data on public opinion prior to the Chernobyl disaster; but in a poll conducted by Harris in the US in 1975, 63% supported building more nuclear power plants (Rosa et al., 1994). This dropped however, to 44% in 1979 after the Three Mile Island accident, and further still to 34% after Chernobyl in 1986 (Rosa et al., 1994). However, the American public recognised nuclear energy as a potential large scale energy source, as in a poll by Cambridge during the late 1980’s; 67%-78% said that nuclear energy was a good or realistic choice for the future (Rosa et al., 1994). In West Germany, one of the closest Western nations to the Chernobyl disaster, polls suggested around 15% supported a withdrawal from nuclear power prior to the disaster; after the disaster, this rose to 37% the following year, and 65% the year after that (Peters et al., 1990). It is noted however, that even after the Chernobyl disaster, parties who supported withdrawing from nuclear power (along with public opinion) didn’t have much, if any, increase in support in Germany’s parliamentary elections the following year, suggesting that although there was a concern, nuclear energy is not something at the forefront of the public minds.

(Rosa et al., 1994)

Fukushima

After the Fukushima disaster in 2011, the German parliament chose to phase out nuclear power (Dorothee et al., 2016). This was in direct contrast to a decision made 6 months earlier to extend the nuclear power plant run-time. This would mean that Fukushima had a direct effect on the decision of the German parliament; but perhaps this was also influenced by the medias reporting? Prior to the Fukushima disaster, Nuclear power was a dividing issue in Germany, with 43% in support and 37% opposed. A few days after the accident, global support fell from 57% to 49% which is to be suspected (Dorothee et al., 2016). News in Germany in the following year also changed dramatically; with the economical (-21%) and energy aspects (-11%) of nuclear energy seeing much less coverage, and on the other side, a large increase in the coverage of the risks of nuclear (+23%) and the demonstrations (+12%) against (Dorothee et al., 2016).

Level of  different themes represented in the news (Dorothee et al., 2016)

Present

Global public opinion on Nuclear Issues (Mycle Schneider 2009)

In today’s time, opinion is very much split depending on the country in question, with a Globescan poll of 18 countries in 2005 suggesting 34% of respondents are not in favour of building new nuclear plants, but prefer to just keep the old plants, 28% want to build new nuclear plants, and 25% want to close down all plants as soon as possible (OECD 2010). Support for closing all nuclear power plants is highest in countries which don’t have any, such as Jordan and Saudi Arabia (OECD 2010). Support in the EU is also slightly lower than the global average, with issues such as safety, security and reliance being a concern on the continent.
Support is also dependent on the level of knowledge around the subject. When respondents were informed about the positive impacts of climate change, support for nuclear expansion increased on average by 10% (OECD 2010). This is mirrored in the US, with 60% either slightly opposing or slightly in favour of nuclear energy; when they feel very well informed, 54% are strongly in favour with another 22% somewhat in favour (Bisconti Research 2016). Even a moderate amount of knowledge on the subject, leads to a 77% in favour for nuclear energy.

(Bisconti Research 2016)

There is even a split in views between the genders, with woman in a range of countries such as the US, UK, Switzerland, Sweden, Turkey, Japan and more, being less supportive than men towards nuclear energy since the 1990’s, roughly 39% support for men, compared to 27% for woman (Sundström et al., 2016). This is seen throughout the range of issues with nuclear, with woman being less accepting of nuclear power in general, more opposed to constructing new plants and more concerned about the produced waste (Sundström et al., 2016). The 'health and safety concerns' argument is most commonly used to explain this difference,  with woman believed to have heightened concern for the health and safety of others, and greater sensitivity to the associated risks of technologies such as nuclear, which has potential for a catastrophic accident. (Sundström et al., 2016)

In conclusion, support for nuclear energy has fluctuated greatly over the years, in response to the disasters and development in the world. Prices of fuel, level of education and even gender can have an effect on support towards nuclear energy. What can be seen though is that when the advantages are explained to people, especially involving climate change, the public are much more willing to get behind the idea of nuclear energy; it just depends if they think those benefits outweigh the risks.

Nuclear power in France: A Success Story?

In my last couple of blog posts, I’ve been talking about when Nuclear energy goes wrong. But it is important to remember that Nuclear energy does have its successes. In one place this is evident is France, which produces the largest amount of nuclear energy as a percentage of its total electricity production compared to any of country in the world; around 70-80% depending on France’s electricity demand for the day (Philip Ball 2011). In 2007, France had the second largest EU population of 63 million, the world’s 7^th largest GDP, and 8^th largest energy consumption, while still providing 47% of all nuclear energy in the EU (Mycle Schneider 2009). Hopefully this gives you a picture of the scale of France’s nuclear power programme.

Nuclear share of total energy generation (Adamantiades et al. 2009) 

Why and How

In 1973, an oil crisis occurred caused by an embargo by the members of OAPEC (Organisation of Arab Petroleum Exporting Countries) due to American involvement in the Middle East (no surprise there). This led to France’s president at the time, Pierre Messmer, to release a plan in 1974 to gain energy independence for France through Nuclear power (WNA 2016). This led to a large scale nuclear power project which was envisioned to produce 170 nuclear power stations by 2000 (Sezin Topçu 2007); while the number of stations was only 58 in 2011 (Philip Ball 2011), the efficiency of their energy production makes up for the lower amount. The rise in nuclear power was backed with at least 75% of all public research and development expenditures for energy being used for nuclear fission between 1985 and 2001 (Mycle Schneider 2009).

As France is relatively low in energy resources apart from coal that is out-priced by cheap imports (Philip Ball 2011), Nuclear energy was one of the only viable options that could give France the energy independence it desires. Other advantages of nuclear over coal is the fuel used; Uranium doesn’t degrade over time while coal does, It has 1/10 the cost of coal in terms of equivalent energy produced, and is 4 magnitudes (10⁴) smaller than coal in terms of equivalent energy (Adamantiades et al. 2009) .

From the outset, the French Government chose to reprocess used fuel to re-cover uranium and plutonium, to help reduce the amount of high-level waste that needs disposal. This has led to 20% of all the electricity produced by EDF (Electricte de France) to come from recycled fuel (Philip Ball 2011). For the disposal of final waste, France is planning on opening a deep geological repository for a permanent solution. Research at its facility in Bure, has confirmed the rocks suitability to the task and should this go ahead, it could store all of France’s current nuclear waste, and that created in the coming 20 years from its completion (Declan Butler 2010).

Is it a true success?

Final energy supply in France in 2007 (Mycle Schneider 2009)

From what I’ve talked about already, it seems this is a total success. France produces a large amount of nuclear energy, should soon have the capacity to store its waste and you would think also has a decreased CO₂ emission. However this isn’t the whole case. In terms of final energy, only 16% of this comes from nuclear energy, a large difference from the ~75% of electricity that nuclear produces (Mycle Schneider 2009). This is due to the fact that only 21% of final energy supply is electricity, with a large chunk of the final energy supply, 73%, being fossil fuels (Mycle Schneider 2009). Of this 73%, 48% is oil, which begs the question; Has France gained energy independence through nuclear? To me it seems like a no. It is true that they have covered large strides since 1973 in terms of nuclear production, but this doesn’t really include sectors that aren’t electricity production. Transport, residential and industrial use is not really affected by the increase in nuclear power, and won’t be until electrification of vehicles and processes reaches a wider audience. CO₂ emissions haven’t really fallen either, and since the 1990s, have either remained stagnant or increased slightly over the years .The fact that in 2007, per capita oil consumption in France was higher than the EU average, than in a non-nuclear Italy, and in Germany who is phasing out nuclear (Mycle Schneider 2009); Too me it is the final nail in the coffin for France’s energy independence.

CO2 Emissions from France in 1970-2006 (Mycle Schneider 2009)

France’s story makes me wonder, that for how far France has come in terms of nuclear energy, it has a long way to go if it wants to be energy independent and for nuclear energy to be a big part of that. But is it possible for a country to be powered solely by nuclear? Can all the processes be powered by nuclear that are now driven by fossil fuels? Electric powered cars are available now, but larger costs and reduced range stops them from becoming the main source of transport. Perhaps the technology is not where it needs to be, for nuclear power to become the large force in energy production it could be.

Fukushima - A Nuclear Disaster II

Today will just be a quick blog on the second disaster to score a 7 on the International nuclear and Radiological Event Scale, the Fukushima Disaster (WNA 2016). The result of the damage caused by a 15-metre tsunami following a major earthquake of magnitude 9.0 on Japans East Coast; this disaster has forced around 154,000 people to be evacuated from their home with no real knowledge of when, or if, they will be able to return (Reconstruction Agency).

Location of the Fukushima power plant and evacuation zones (CNN 2011)

The first video is slightly technical, but it is a very good explanation of the events that unfolded from an objective point of view. It explains how this particular nuclear reactor works, which in turn will allow a better understanding of why the reactors went into meltdown and the path it followed.

The second video is produced by Greenpeace and looks at the impacts that the radiation has had on the environment and the local population. As Greenpeace is a noted activist against nuclear power, it is good to keep in mind that this video will most likely contain some bias against nuclear power which may or may not be true (Greenpeace).

If you have a bit more time to spare and want to watch a documentary style video of the disaster such as those on TV, here is another option.

If you are really interested in the details of the Fukushima Disaster, I'd recommend taking a look at this web page by the World Nuclear Association; it contains a good summary with lots of detailed subsections for you to investigate depending on your interest.

Chernobyl - A Nuclear Disaster

When nuclear power is mentioned in a conversation, the Chernobyl disaster is often one of the topics quickly brought up, and for good reason; it is one of only two disasters, alongside Fukushima, to score a 7 (the highest) on the International nuclear and Radiological Event Scale (PIF). I shall quickly summarise the causes of the disaster and then look into its impacts.

International Nuclear and Radiological Event Scale (IAEA)

Causes

On the 25^th April 1986, the crew at Chernobyl reactor 4 began arrangements for a test that would run the plant at a very low power, to determine how long the turbines would carry on spinning and supplying energy to the water circulating pumps after a loss of power (WNA 2016). The design of these reactors was such that they were highly unstable at the low power that this test would operate at, mainly due to accelerated nuclear chain reaction and power output if the cooling water for the reactors was lost. For the test to be carried out, the automatic shutdown mechanisms also had to be disabled, which did not comply with operational procedures; however, the operators had not even been informed of the possible explosive consequences of the test they were about to perform (WNA). These factors all combined to put the reactor in a very unstable condition before the test had even started.

Location of Chernobyl in Ukraine (Wordpress)

The test began in the early morning of the 26^th, with the inserting of control rods into the reactor creating a large power surge that created a large increase in heat (NEI 2015). The hot fuel interacted with the cooling water to rapidly create steam which in turn increased the pressure. This increase of pressure partially removed the 1000 ton cover off the top of the reactor, jamming the half-inserted control rods, and rupturing the fuel channels (WNA 2016). The steam generation spread throughout the rest of the core and created a steam explosion, which released the radioactive fission products into the atmosphere. The Chernobyl power plant lacked the containment structure that is seen in most nuclear power plants around the world. Without this, the radioactive fission products were free to escape into the atmosphere (NEI 2015).

Impacts

Soviet scientists reported that between 13% and 30% of the 192 tonnes of fuel was released into the atmosphere for a period of roughly 10 days (NEI 2015). The main problematic radioactive materials released were the short-lived Iodine-131 with a half-life of 8 days; and the longer lived Caesium-137 with a half-life of roughly 30 years (WNA 2016) (A half-life being the amount of time it takes for the amount of material to decrease(decay) by half). Substantial amounts of radioactive material were deposited in North-West Ukraine, Belarus and parts of Russia, with Belarus receiving 60% of contamination that fell on the Soviet Union (NEI 2015). This resulted in the resettlement of civilians over the years, with 116,000 resettled by the summer of 1986, and a further 230,000 in the coming years (UNSCEAR 2008).

Map of Caesium-137 deposition levels as of December 1989 (UNSCEAR 2008)

Around 350,000 clean-up workers, or liquidators, were brought in to help contain and clean up the radioactive debris during the following two years after the disaster. 240,000 of these liquidators received the highest radiation doses while working within the 30km zone around the reactor (WHO 2006). 134 liquidators received doses even higher and were diagnosed with acute radiation sickness (ARS), with 28 workers dying in 1986 due to this (UNSCEAR 2008). In the table below, you can see that the level of radiation that populations received following the disaster is actually quite low and comparable to natural background levels. It is estimated that in the top three exposed populations, Liquidators, Evacuees and Residents of the SCZs, cancer deaths from radiation exposure has only increased 3-4% above the norm; while in the residents with low contamination, it has potentially only risen 0.6% (WHO 2006).

Average radioactive dose accumulated over 20 years (WHO 2006)

There was a large increase in thyroid cancer following the disaster in those exposed as children or adolescents (>14 years old) (UNSCEAR 2008). This was due to the release of radioactive iodine which was then taken up into the thyroid. This was not the result of direct exposure however, poor management in the following weeks meant milk was consumed from cows that had pastured in iodine contaminated fields. Radioactive iodine became concentrated in their milk, which when drank by children with preexisting iodine deficiencies, caused the iodine to accumulate in the thyroid at greater concentrations (WHO 2006). If milk had been brought in from elsewhere, a lot of the radiation-induced thyroid cancer could have been avoided. The prognosis for thyroid cancer is very good however, with treatment being highly effective even in advanced stages (WHO 2006).The graph below shows that as Iodine has a low half-life, thyroid cancer was only prevalent in children under the age of 10 at the time of the incident and has not affected those born after the disaster.

Thyroid cancer incidence rate in Belarus for children under 10 years old at diagnosis (UNSCEAR 2008) 

Estimated average thyroid doses to children and adolescents living at the time of the accident (UNSCEAR 2008) 

Overall the Chernobyl disaster has had a massive effect on the local human population and the local environment, clearly showing the extreme negative effects that a nuclear disaster could have with a 4300km² exclusion zone now in place around the old reactor (WNA 2016). Also needing to be factored in is the continued maintenance of the structure that houses the old reactor to prevent further radioactive leaks. However studies done at the time seem to have overestimated the effects that radiation would have on its immediate surroundings. Recent studies have shown that deaths from the resulting radiation are much lower than they had anticipated, and that the environment inside the exclusion zone is in fact thriving, with a much greater biodiversity and abundance of species than before (WNA 2016). Perhaps this disaster was not as bad as we once thought?

The Science Behind a Nuclear Power Plant

The process that powers a nuclear power plant is nuclear fission. While nuclear fusion is the process of fusing two or more lighter elements into a larger one, such as that which happens in stars; nuclear fission is the splitting of a large atom into two or more smaller atoms (Diffen).  Although nuclear fusion produces a larger amount of energy than fission, we do not currently have the technology to overcome the barriers needed to attain it.

Nuclear Fission vs Nuclear Fusion  (Duke Energy)

While this topic may be quite new for some readers, I sadly don’t have enough space to explain properly some of the elements I’ll be discussing. If you want to know the basics about atoms and isotopes, or would just like a small refresher click this link and check out the different pages.

In a nuclear reactor, an element called Uranium is used as the fuel. This element has a number of isotopes, with an isotope being the same element, but with a different number of neutrons.  Nuclear fuel consists of the isotopes U-238 and U-235, with the U-235 being the fissionable isotope. In the nuclear reactor, neutrons are fired at the U-235 which make it become U-236 as the number of neutrons have changed (NEI 2016). This makes the uranium unstable and causes it to split apart into two new atoms and three neutrons, while also releasing the energy that we collect. The three released neutrons can then split more uranium, which in turn release more neutrons and so on. This creates a chain reaction which is now self-sufficient and will carry on until the fuel is spent (WNA 2016). If you find any of this confusing, check out the first page of this link which will hopefully clarify any issues, or post a comment down below.  

Nuclear Fission involving U-235  (BBC Bitesize)

Now that all the nuclear science is out of the way, the rest of a nuclear power plant is practically the same as a conventional plant that burns coal, oil and natural gas. Energy from the reaction, which in our case is the splitting of U-235, is used to heat up water to its boiling point which is where it would normally be converted into steam (Darvill 2016). However, the pipes that contain the water are pressurised, so the water stays in its liquid form. This water is transported through another tank called a steam generator which contains water under lower pressure. The heat is then transferred from the heated water in the pipes to the water in the steam generator which boils into steam as it is under lower pressure (Darvill 2016). This steam then turns a turbine which turns a generator which then produces the electricity that we all know and love.  The steam is then condensed back into water and returns to the steam generator to repeat the process.  This can all be a bit much too follow, so below is a gif showing the overall process and also a small video with an explanation.

Nuclear Reactor Diagram  (What is Nuclear)

In the following weeks I shall be discussing success stories and disaster incidents of nuclear energy, starting with the Chernobyl disaster. If you have any questions about today’s post, please do not hesitate to ask in the comments below, and I shall answer to the best of my ability. I’ll also leave a video down below; it gives a brief history of nuclear energy, its processes and has follow on videos of its pros and cons that can be found at its end as well. 

Nuclear Power as an Energy Source in the Modern World

The world as we know it is going through an energy and climate crisis and no one seems to have a convincing argument of what to do. How long will conventional fossil fuels last? Will renewable energy be able to plug the energy gap? How much of an impact will fossil fuels have on the planet? When people talk about energy production for the future, you always hear about wind, solar, and often a new exploitation of fossil fuels, which for now is the fracking of shale gas. But often not nuclear energy, which gets me thinking; why is nuclear energy ignored?

Over the course of the coming months through this blog, I shall be exploring the potential of nuclear energy as an answer to our energy and climate crisis. Nuclear energy often goes unmentioned in the news, unless something goes wrong. This has the potential to create a negative stigma towards a theoretically lucrative energy source. However, when nuclear power stations go wrong, they go badly wrong, with disasters such as Chernobyl and Fukushima coming to mind. Perhaps the negative reputation is well deserved? Or perhaps it is just a lack of proper public awareness of nuclear power?

I will be writing this blog from a neutral standpoint; as someone who doesn’t really know the complete story about nuclear energy and is curious of its potential benefits, along with the associated risks that come with it. In secondary school, energy sources was a hotly contested issue in Geography lessons with renewables vs fossil fuels being the majority of the discussion. This has always made me think, what is wrong with nuclear power? Fossil fuels use has increased linearly over the last few decades, with China’s and India’s recently increased development of power grid infrastructure and vehicular usage adding a recent surge since the year 2000. An increase of a particularly dirty fossil fuel, coal, is seen; with it contributing a larger percentage of primary energy supply in 2014 (28.6%) compared to 1973 (24.5%). In the same time period, renewable energy has increased only 1.3% (IEA - Key World Energy Statistics 2016). If renewable energy is supposed to be the saviour of humanity and the environment, as it is so often portrayed in the media and in education, we may be playing a waiting game that we can’t afford to play.

Graph of World Energy Consumption  (IEA - Key World Energy Statistics 2016)

It seems to me, that we are reaching a point where not exploring nuclear power as a bigger source of energy will cause detrimental effects to our environment and climate. Greenhouse gases have been rising steadily since fossil fuel burning began in earnest and on May 9^th 2013, CO₂ levels passed 400 ppm for the first time in recorded history (NASA 2013). As a proclaimed low-carbon source of energy (niauk), maybe nuclear power is the answer we’ve been looking for?

To see whether it is the answer that we, as a world are looking for; I shall be researching and discussing a number of topics, weighing up both sides of the arguments and hopefully, by the end, reaching a conclusion that will have convinced you, as well as myself, either for or against nuclear power.

A brief overview of topics, case studies and questions (not a definitive list by any means) I aim to look at are below:

•          What is Nuclear Fission?
•          Nuclear energy use and its contribution to Climate Change
•          The safety of nuclear energy
•          Nuclear Disasters – Chernobyl and Fukushima
•          Nuclear Success Stories – France
•          Nuclear Fusion and the future of nuclear energy

My next post will be about the processes that occur within a nuclear power plant. I’ll be briefly discussing the fuel used and then the overall process of Nuclear Fission, which is the driving force behind a nuclear power plant. Do not fear about it being overly complicated! As someone who hasn’t touched Physics since GCSE, my aim is to make the explanation as simple as possible, leaving the complicated nuclear physics to the experts.

 If you have any comments, questions or suggestions on topics, don’t hesitate to ask down below!