OK, so we now know briefly how nuclear energy is produced alongside a little background history, but what are the real benefits of such an energy source?
If we look at the largest sources of energy in today’s society we find that they are not evenly distributed over the planet. Over 68% of oil is concentrated in the volatile region of the Middle East and around 67% of gas reserves are concentrated in Russia. This introduces a risk in terms of reliability on the supply of energy for other countries, it also allows these regions to monopolise  these resources of energy. Furthermore with the introduction of the Kyoto agreement which demanded that signatories decreased their CO2 emissions in order to reduce global warming, nuclear power plants seemed like an extremely attractive option. Some countries utilised nuclear energy more than others. As we can see from the graph below showing the percentage of electricity produced from nuclear sources from 1980-2004, there is a huge increase in France from 22% to 80%. This is due to the fact that France is very poor in natural fossil fuel sources and therefore a large emphasis is placed on nuclear energy.

Japan is researching methods in which energy in the transportation sector can also be generated by nuclear energy. This involves replacing the hydrocarbons such as gasoline and diesel oil with hydrogen, electricity or synthetic liquid fuels. Using nuclear energy we can produce these energy carriers, or if not we can combine nuclear energy and fossil fuels by a synergistic process. Again this eradicates or at least minimises the emission of carbon dioxide. In order to produce hydrogen, nuclear electricity can be used to electrolyse water, or with the addition of heat can be used in high-temperature electrolysis of steam. Hydrogen energy can be used in various sectors such as fuel cell vehicles and fuel cells to supply electricity to rail trains and marine vessels, also hydrogen can be used in jet engines to propel aircrafts. With regards to electricity, the Japanese government are introducing electric automobiles into the market which allow supply of nuclear energy in the transportation sector through the battery-powered car. However the batteries in these cars are very expensive and therefore production is low. The introduction of a hybrid plug-in car (illustrated below) combined the benefits of nuclear energy and the low costs of using fossil fuels. It was illustrated that on average a hybrid plug-in car could cover 70% of the distance that a Japanese car travels per day running on electricity generated by nuclear energy, and then travels the remaining 30% of the distance using petroleum. This means that around 70% of CO2 emissions resulting from fossil fuel burning can be cut down if these plug-in hybrid cars were mass-produced and introduced into society.

As well as being used in the generation of electricity, nuclear energy was also used in propulsion. The nuclear energy is compacted into vehicles that must travel long distances without refuelling. This is used in naval vessels such as submarines and aircraft carriers. For example in the Cold War there were 100 nuclear powered submarines and a significant number of aircraft carriers in the US fleet. The first aircraft carrier to be deployed was the enterprise used in 1961 and illustrated below. You can see as a tribute the  men on board the ship are standing in a formation on the flight deck spelling out Einstein’s formula.

It’s obvious from this that nuclear energy does pose very beneficial for the economy, yet it is still one of the smaller contributors to energy in today’s society. Why is this? Possibly because alongside the benefits it also brings problems and dangers to the table….

Today’s society consumes more energy than ever, and energy demand will continue growing as bigger, better and faster technologies are introduced. Energy consumption rate has risen by over 50% in the past 20 years.  The pressing issue here is that renewable energy sources (solar, wind, hydro etc.) are not providing sufficient energy to meet demand and non-renewable sources (Coal, Crude Oil etc.) are inevitably coming to an end. Furthermore the production of greenhouses gases impacts the climate thus further complicating matters and adding to the problem. Therefore, there has never been a more crucial time for the utilisation of nuclear energy. This type energy is generated as a result of controlled nuclear reactions i.e. nuclear fission, and can be used in various ways, be it in reactors or even in bomb making!!

In order to understand the impacts of nuclear energy, it is useful to first explore its history and how it was received by the general public. This will build a good foundation to allow analysis of recent issues and problems presented by nuclear energy, exactly what caused these problems and how harmful or disastrous they could be. Once the problems are recognised, it is vital that they be addressed, after detailed investigation, with solutions such as suitable waste immobilisation. It will also allow for discovery and evaluation of the great benefits nuclear energy introduces and the great impact this has on the economy and the environment. In this Nuclear blog I aim to discuss and investigate nuclear energy as a replacement energy source as well as how it can be coupled with renewable energy to meet the economic constraints of today’s society and most importantly how the waste it produces can be immobilised efficiently. It will also explore how, over history, nuclear energy was manipulated in the production of nuclear weaponry i.e. the atomic bomb.

To get things rolling I want to start this blog with a report on the brief history of nuclear energy. Nuclear energy dates back to late 1800’s. To be exact ionising radiation was discovered by Wilhelm Rontgen in 1895 producing continuous x-rays by passing an electric current through an evacuated glass. Progressive steps were taken in the research of radiation until 1902 when Ernest Rutherford illustrated that radioactivity creates a different element by emitting an alpha (2 protons & 2 neutrons) or beta particle (an electron) from the nucleus. To understand how this works let’s look at an atom of nitrogen.

The yellow spheres are the protons, and the orange spheres are the neutrons, combined they form the nucleaus and give the atom its mass number (mass number = protons + neutrons). Nitrogen contains 7 protons (carrying a positive charge) and 7 neutrons with a mass number of 14. The 7 small white spheres orbiting the nucleas in shells are the electrons (carrying a negative charge). These numbers characterise the nitrogen atom, therefore if they are altered there would be changes in the element.  Using this research Rutherford illustrated, in 1919, that all the particles fired from a radium source into nitrogen could form oxygen as a result of the nuclear rearrangement. He fired alpha particles (2 proton & 2 neutrons) at the nitrogen atom, this in turn increased the amount of protons and neutrons in nitrogen from 14 to same amount as in an isotope (an atom of an element with the same number of protons but different number of neutrons) of oxygen, and thus the element was converted from nitrogen to oxygen.

In the 1930s research accelerated and scientists were experimenting with bombarding atoms with protons and neutrons in order to create artificial radionuclides. It was also illustrated that upon bombardment of the nucleus with the neutron, the neutron is captured causing severe vibration and leading the nucleus to split into two not quite equal parts thus releasing significant amounts of energy. This is called nuclear fission and it was discovered this fission reaction could release further more neutrons which in turn would lead to more fission resulting in a vast amount of energy being released. Since its discovery nuclear energy, used with bombs and reactors, has been received with great controversy. It is associated with mutation, atomic weapons and universal doom. It is a prime example of irrational public fear of a misunderstood technology. This is illustrated by a recent survey undertaken in America and Japan showing that reactor accidents evoked more feelings of dread amongst the public than any other modern risk, including problems that harm millions of people annually. Also in the early days nuclear scientists were seen as alchemists due to the misunderstanding of the transmutation capabilities of nuclear science. This misunderstanding led to the labeling of nuclear energy as the ‘elixir of life’ in the early 20th century. Such an ideology was reinforced by the discovery that radium was useful in treating certain types of cancer, however the press reported that radium was capable of fully conquering all types of cancer (media hype). By the 1930s radium was included in pastes, powdered pills, tonics and even mineral waters to cure baldness, restore youth etc. However the public eventually came to learn that radium has as much chance of causing mutations and cancer as treating it. Up until this point nuclear energy was only seen to be useful for medicinal purposes, however over the late 20th century nuclear fission energy was harnessed and used in several ways, with the main use being in the nuclear fuel cycle delivering the nuclear energy we know today. Nuclear fission occurs when a heavy atomic nucleus breaks into smaller pieces (decay) releasing energy. This process can also be accelerated by bombardment of the nucleus with neutrons. Let’s take for example uranium, the most stable isotope has a mass number of 238 (146 protons + 92 neutrons) and is the slowest decaying. Uranium 235 decays slightly faster, however is still relatively stable. If we were to bombard U-235 with neutrons, the neutron would attach to the nucleus and form U-236, a very unstable isotope. This decays rapidly into an atom of barium and krypton. This is called induced fission. This is illustrated in the diagram below.

Bombarding a Nucleus with a Neutron to create Induced Fission

Nuclear scientists manipulated this energy and began using it in nuclear reactors. In 1951 the Experimental Breeder Reactor illustrated electric power can be generated from a nuclear source demonstrating the possibility of breeding plutonium. It was also illustrated that the water in reactor can be left to boil thus generating steam directly. However there was scepticism regarding the dangers of the instability associated with the boiling. As a result BORAX tests were undertaken to show that boiling reactors can operate safely and as a result further work was implemented illustrating electrical generation in 1955. This resulted in the commercial manufacture of boiling water reactors with the first being put into operation in Illinois, USA in 1960. Research in the USA led to the discovery of the pressurised water reactor with the first being used to produce commercial electric power at Pennsylvania USA in 1957. These reactors have been enhanced and improved through the year up until today, to produce the nuclear energy we know and hate/love (?).