Radiation, meltdown & nuclear waste, all these are associated with nuclear energy, its understandable, but there is too much of a bad rep about nuclear energy. So how can we flip those associations so people say, low-carbon, safe & reliable. Lets go through its history, how it works, the iffy stuff, but most importantly, why you shouldn’t be afraid.
Shaky Past
Unfortunately, you can say that nuclear energy started with a bang. The first use, towards the end of the Second World War, was for nuclear weapons, a threat that is still present today. After it, scientists managed to harness the energy within an atom and the first nuclear power plant1 became active in 1954 near Moscow, in Obninsk, in the USSR. At that time, nuclear was seen as the way out of a fossil fueled world, but that wasn’t how it went.
After the disasters of Three Mile Island in the US, Chernobyl in Ukraine and Fukushima in Japan, many countries continued their use of fossil fuels instead of making the switch. A decision that has cost the planet. So lets break down each event and discuss how they happened.
Three Mile Island, 1979
Located in Pennsylvania, the reactor had overheat due to coolants not reaching it by some shut valves. Despite emergency precautions working, the heat had melted the fuel rod cladding and radioactive isotopes were released in the coolant. By the time someone had noticed that radiation levels were exceeding norm and had breached the 4ft thick walls, releasing radiation to the surrounding area. Luckily this incident didn’t escalate further and no direct deaths have been related to this incident. Due to this, the American public have grown very weary of nuclear energy, partly because of media at the time exaggerating the consequences. A more detailed overview can be found by clicking on this link.
Chernobyl, 1986
The more internationally known disaster was the Chernobyl accident, one that claimed the lives of around 45 people and caused a 30km exclusion zone around it for the foreseeable future. After doing a routine safety check on the newest of the four reactors, most of the control rods (more on that later) were removed creating a chain reaction that led to an explosion. There have been estimates that the radiation levels released from that explosion was equivalent to 400x the amount of the bomb that was dropped on Hiroshima. This radiation was released in the atmosphere and spread all over Europe raising concerns about cancer risks.
With a concrete sarcophagus having been built, at the expense of the workers, the radiation levels deteriorated the structure that a new structure had to be placed over it. In 2017, the international community covered the initial concrete structure by steel dome, one that will last at least 100 years. Due to the high radiation levels in the area, as well as the long half life of the uranium fuel used, Chernobyl will only be habitable in about 20,000 years. There are disputes on why this happened, with the design of the reactor and personnel on sight at the time being the main reasons. But whatever caused the meltdown, this incident taught important lessons on the safe operation and testing of nuclear powerplants.
The scary fact is that despite reactor 4 having blown up, the other 3 reactors were still operational until 2000. If you want to know more, click on this link
Fukushima, 2011
The last incident stumped the resurgence of nuclear power that had significantly risen since Chernobyl, even in the US, and came from a nuclear energy powerhouse, Japan. On March 11th 2011, Japan was struck by three catastrophic events right after each other. The first two events were out of their hands, a magnitude 9.0 earthquake struck off the coast of Japan, causing a 15m Tsunami to strike the coast. This subsequently disabled the power supply and the cooling of three reactors at the Daiichi powerplant. The reactor survived the earthquake, but once the tsunami hit, the generators and backup generators were wiped out making them loose power to cool themselves. Despite the death toll remaining zero (other than 1 suspected worker who died from lung cancer a few years on), the incident has left a mark on the region.
Despite the radiation released from the incident, it quickly dispersed and other than the 2.4% of the Fukushima prefecture that remains uninhabitable, most residents still live there. The total radiation released ended up being 15x less than Chernobyl (still a very large number), which resulted in a ban of goods from Fukushima including: fish and rice. However the direct response was much better. Up to 14 million cubic meters of radioactively contaminated soil has been collected and piled up in a secure location to revitalise agricultural interests, which is now at safe levels. Again, if interested to find out more, visit this link.
We have looked into the disaster, but we haven’t really discussed what it really is and how it works, so lets look at that.
Unclear on Nuclear?
Nuclear energy, for now at least, is powered by a process called fission. This is process where you have a heavy element like Uranium, which becomes unstable due to an additional neutron causing it to decay into two smaller daughter elements. This process releases energy for each each atom. Scale that up to the large amount of atoms per fuel rod you can get large amounts of energy. The fission process is seen below.
As you can see, this process releases another set of neutrons, which is where the danger comes in. These neutrons can go on and hit other uranium atoms and make them unstable too. If you don’t control the release of these neutrons, you’ll get a chain reaction and you’ll get an overwhelming amount of energy. This is an atomic bomb. Now what happens in a nuclear reactor is a bit different.
Above you can see the different parts of a nuclear reactor, where we’ll start on the left hand side, the reactor core. The reactor core is where the fuel elements (also known as fuel rods) undergo fission and release the energy and neutrons. To control the neutron release there are control rods (seen above the fuel elements), which absorb the neutrons so there is no chain reaction. The amount of control rods can be changed depending on energy demand/ stability of the nuclear reactor. This process of fission heats up the water that gets pumped through it, creating steam. This steam runs through a turbine which generates the electricity.
Without this water running past the reactor core the nuclear reactor will overheat and the core itself will start to melt. This is called a meltdown, and has been the causes of problems for the Three Mile Island and Fukushima incidents. Now what happened at Chernobyl was slightly different. The sudden increase in heat production ruptured the fuel rods. The hot particles then reacted with the water creating immense amounts of steam to build up the pressure within the core which eventually created an explosion. To set minds at ease now, this was a design fault of the type of reactor used then and is not used in the rest of the world.
What’s the Big Deal
Now despite the incidents in the past, its use has continually grown up till 2010 and has slightly recovered since the Fukushima accident as seen in the graph below.
There are a lot of positives that come with nuclear energy too. First of all, other than the extraction and processing of the rare earth materials that are used for the fuel, the whole production of electricity is green. The only emission that comes out of it is water vapour. Even though uranium and other materials aren’t renewable, the amount that is available to us can power the entire population for a long time. Unlike other renewables like solar and wind, the energy output can easily be changed depending on the demand. So why haven’t we turned to nuclear as the main source of our energy, and why has it only supplied 10% of the total energy production if its so useful to us.
The Bad Stuff - other than the accidents
Radiation
This is the biggest fear that many people have, especially if there are talks of a nuclear power plant being built nearby to settlements. Now considering the events of Chernobyl and Fukushima, its not entirely just because of being close to it during a normal lifecycle, but the added ‘what if’ factor. We’ll get to the accidents later, so right now we just solely focus on the radiation.
Now radiation is a general term and can have different types where not all of them are as bad as you think. To start off, you have two types of radiation, ionizing and non-ionizing. Ionizing radiation is where the ionization process occurs, which is when radiation has so much energy it can knock electrons out of atoms2. This is harmful for living things as this would cause damage to cells and the DNA and can cause mutations that can lead to cancer. The sources of ionizing radiation can come from the sun, x-rays and CT scans and obviously radioactive materials used in powerplants.
Within ionizing radiation you have three types and their threat is judged by two criteria, penetrability and ionization ability.
The first type is alpha, which has the highest ionization ability, meaning it can really cause some big damage. However, it does not get far and can be blocked by a piece of paper. This means if it lands on your skin, its not that harmful, it will kill the cells around it but that’s pretty much it. If it gets in you, if swallowed or inhaled it can have more damaging effects.
The next is beta, which is in the middle of the playing field for both criteria. It can pack a punch but not as powerful as alpha, but it would require a few millimeters of aluminium to stop it. It can therefore penetrate the upper skin layers and can cause a radiation burn.
The last is gamma radiation, the most common which you are exposed to everyday of your life. Gamma has the least ionizing ability but can penetrate pretty much anything. Because of this ability, it is used in a lot of applications, especially in medicine, for example x-rays, CT scans and medical tracers. Now gamma is still dangerous, but only in high quantities and depending on the exposure time.
Non-ionizing radiation is the rest of the bunch, the harmless ones. This includes microwaves, which heat up your food, radio waves that are used for communication signals and even the visible light that you see.
Security
Since the first atomic bomb, nuclear energy and technology has been a big issue between countries. Starting with the arms race between the US and USSR, it currently causes issues with countries wanting to use nuclear energy whilst other countries being concerned that they would use the technology for the production of atomic weapons. The main example here is between the US and Iran, an issue that still has to be properly resolved, click here to find out more. If the knowledge of nuclear technology goes to more countries, it would heighten tensions between countries further escalating current issues. That being said around 32 countries have nuclear power plants, whereas 9 only have nuclear weapons.
Disposal
Once the nuclear fuel has been spent it has to be disposed of securely and safely. The problem here is that uranium and many other radioactive isotopes have long half life’s, many that can span millions of years. Half life is the time it takes for the radioactivity, or the number of radioactive atoms to half. This is the reason why Chernobyl will be uninhabitable for the next 20,000 years. With the radiation levels being high for a long time, it is very important to store these away from the general public. With the amount we use, we run out of secured space quite quickly which.
Cost
Another issue that makes nuclear a bit hard to develop is that it requires a high initial capital investment. Due to the more complex technology and extra safeguarding measures, it only makes sense to make a nuclear power plant when near a large population center.
This is where the problems end.
Why we shouldn’t be afraid
Now with all the issues and accidents with nuclear energy, you may be surprised that it didn’t die out earlier, but there is more to it than you think. The main reason nuclear energy gets such a bad rep is because of the media. So lets debunk the problems just stated.
Accidents Debunked
The accidents that were mentioned before were big, and were dangerous, especially Chernobyl. But one thing that needs to be considered is the frequency of these accidents. Three Mile Island and Chernobyl happened in the relatively early days of nuclear energy and have taught us a lot about the design and operation of these powerplants. Since then, the only accident to happen was caused by one of the most powerful earthquakes followed by a tsunami. The total death toll due to nuclear energy incidents is 46, which all come from Chernobyl. Now if we compare that with coal and gas powerplants, nuclear energy doesn’t seem so bad. A study conducted by NASA in 2013 shows that the deaths due to nuclear energy is around 40 times lower than gas and coal. This is mainly coming from the fact that gas and coal emit CO2 whereas nuclear doesn’t. The following graphic below paints another picture even more in favour of nuclear.
This graph just shows how safe nuclear energy is and more alarmingly, how bad fossil fuels are for human health and the environment.
Radiation Debunked
Now you will be surprised how much radiation you are exposed to in your daily life and how much you would be exposed to if you lived near a nuclear power plant for a year. Have a look at the infographic below.
Yes you read that right, the radiation you are exposed to by living near a nuclear power plant is 29x lower than the amount that your body produces in a year. As a reference to nuclear accidents mentioned before, the first responders of Chernobyl (none of whom were in any sort of radiation suit) were exposed to up to 16,000mSv, a guaranteed death sentence. Luckily since then, and due to the nature of the accident, the highest dosage at Fukushima was 680mSv.
Cost Debunked
Now despite the initial costs being high, the operating costs which equate to cost per kWh (kilo-Watt-hour) of electricity is significantly lower than most energy sources. According to this report by the World Nuclear Association in 2005, the average cost per kWh was $1.72 cents, which is significantly lower than gas and oil.
Another thing you can see is that the price is stable and declining, something that gas and oil are particularly bad with. Now obviously this was nearly 20 years ago but it shows that it can turn out cheaper over the lifetime of the plant. Due to improving technology, nuclear reactors can now be smaller and be more modular. Small Modular Reactors (SMRs) are cheaper, require less space and can be added depending on demand. Companies like Rolls Royce are on their way to building the first one in the UK which could power 1 million homes per reactor. SMRs also drastically reduce the time it takes to build a nuclear reactor as they use off-the-shelf components, which are already standardised with other components.
Nuclear Waste Recycling
It gets better!
That nuclear waste that emits radiation for thousands if not millions of years is really just a reality in the US. Many countries recycle their nuclear waste. In the process of fission, only a small percentage (4%) is wasted. This small amount makes the rest of the fuel rod not as efficient in making energy, but it doesn’t mean it is fully spent. The waste gets separated from the useful fissile material and only this ends up in storage facilities. By reducing the amount of waste, in turn, we reduce the half life of it, as most of it will be spent. This results in 97% of waste only having a half life of a few decades3 rather than tens of thousands.
In the US the amount of nuclear waste that can be recycled could power the US for a further 100 years, but the technology was never commercialised4.
So what do you think of nuclear energy? Do you think we should move forward with nuclear energy or transition to other renewable energy sources?
Till next week,
Maxime
References:
Links in the text (highlighted in blue) offer wider reading and light referencing where necessary. Texts/ sources of information used more widely are linked below.
This weeks thanks to:
World Nuclear Association
International Atomic Energy Agency
The United States Environmental Protection Agency
International Atomic Energy Agency - Special Report - A pioneer of Nuclear Power, A.M. Petros'yants, 1984, volume 26, no.4, https://www.iaea.org/publications/magazines/bulletin/26-4
United States Environmental Protection Agency - Radiation Basics 2023
https://www.epa.gov/radiation/radiation-basics#ioniandnonioni
World Nuclear Associattion - Radioactive Waste – Myths and Realities 2022
https://world-nuclear.org/information-library/nuclear-fuel-cycle/nuclear-wastes/radioactive-wastes-myths-and-realities.aspx
CNBC - The energy in nuclear waste could power the U.S. for 100 years, but the technology was never commercialized - 2022
https://www.cnbc.com/2022/06/02/nuclear-waste-us-could-power-the-us-for-100-years.html