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!