Nuclear power
The complex issues surrounding the basic building blocks of life
Regan Meloche
Contributor
“We live in a society absolutely dependent on science and technology and yet have cleverly arranged things so that almost no one understands science and technology. That's a clear prescription for disaster. – Carl Sagan, American Astronomer
The advocates of nuclear power claim that it is a safe, clean, and an abundant source of energy. Opponents claim that there are too many short-term and long-term risks associated with using nuclear power, citing the recent nuclear crisis in Japan as concrete evidence of its disastrous consequences. Dr. Edward Mathie, Professor of Nuclear Physics at the University of Regina, believes that the lack of support for nuclear power comes from a general misunderstanding of the science behind it. This article will be and in-depth look intoon some of the main issues surrounding nuclear power, as well some important background information, and finally a look into the future of nuclear power this controversial energy source.
The constant, looming threat of nuclear arms proliferation as well as the tragic events in Japan have made the nuclear debate as important as ever. With energy demands always on the rise, this pivotal technology may eventually become more and more necessary, as will our basic understanding of it.
Today there are over 440 nuclear reactors operating in 32 countries, accounting for nearly 15 per cent of the world’s total energy supply. The United States alone accounts for nearly a quarter of these reactors, which supply the country with 20 per cent% of its energy needs.
France and Lithuania lead the field way in percentages with over 75 per cent of their energy coming from nuclear power. Along with Australia and Kazakhstan, Canada is one of the largest uranium producers in the world, and about 15 per cent of its energy is from nuclear power. Canada is also one of the leaders in nuclear research and technology, with Ontario’s Chalk River laboratory being one of the world’s main suppliers of cancer-treating medical isotopes.
How it works
Nuclear power plants work in a very similar way to fossil fuels plants. Both use some type of fuel to heat water into steam, which drives turbines. An electrical generator then turns this motion into electricity. Where the two processes differ is on the fuel source and how it generates heat. Fossil fuel plants burn coal or natural gas to heat up the water. Nuclear plants use a process called nuclear fission to break the nucleus of a special kind of uranium atom, releasing huge amounts of energy in the form of heat.
Imagine a very tall, old building on its last legs. All it needs is a slight push to come crashing down. Now say that a fast moving car provides this push. The building collapses, releasing huge amounts of stored energy. This is how nuclear fission works. The uranium atom is like that unstable building. It has lots of hidden energy inside, but it just needs a little push.
In the 1930’s it was discovered that bombarding a uranium atom with a neutron ( a neutral subatomic particle) caused the uranium atom to split up. The amount of energy released corresponds to the difference in the energy "banked" in the uranium nucleus and the energy "banked" in the fission products. This energy is equal to the mass of the atom times the speed of light squared (Einstein’s famous ‘E=mc2’). While the mass of a single uranium atom may not be very small, the speed of light squared is quite large, and if you get enough uranium atoms, you can create a lot of energy with a very small amount of fuel.
Now imagine that the unstable building is closely surrounded by tons of other equally unstable buildings. If the first one falls, then a chunk of it hits another building, causing it to collapse, and so on. Similarly, when that first uranium atom is split up, it emits more neutrons that go on to split the next uranium atom. This chain reaction process is the basis for all nuclear power today.
Another process known as nuclear fusion involves putting atoms together rather than splitting them apart, but according to Dr. Mathie, who’s worked in the field for many years, practical nuclear fusion always seems to be 20 years away.
The difference between using nuclear fission to produce energy and using it to make nuclear weapons depends on the amount of control you have over the reaction, as well as the grade of fuel. Nuclear bombs, such as the one that hit Hiroshima, are detonated by setting off a completely uncontrolled chain reaction with a high-grade fuel. Huge amounts of energy are released, devastating the surroundings.
In a nuclear power plant, however, the chain reaction, which takes place with a low-grade fuel in a water bath, is regulated by control rods made of boron or cadmium. If the nuclear reactor starts getting too hot, these control rods are lowered into the water to absorb excess neutrons, effectively reducing the amount of fission taking place, and slowing the reaction.
If the control systems in a nuclear power plant fail, the reactor can overheat, causing damage to the core. This is known as a meltdown. Although nuclear power plants use a different grade of uranium than nuclear weapons, an uncontrolled reaction can still lead to a deadly, but non-nuclear, explosion. However, the resulting explosion could release harmful radiation into the nearby environment.
This is why nuclear power plants, like the ones in Japan, are equipped with several levels of containment in case of such an emergency. These steel and concrete containment structures are supposedly able to withstand extreme force; including hurricanes, collisions with jumbo jets, terrorist attacks, and earthquakes.
The strength of these containments and the safety of using nuclear power were put to the ultimate test with the recent tragedy in Japan. The vulnerable nuclear reactors were automatically shut down immediately following the earthquake.
Despite being shut down, the nuclear reactor continued to produce heat. Cooling pumps are supposed to automatically cool the reactor, but the problem with the reactor in Japan was that there was no power being supplied to these cooling pumps. The power grid had also shut down after the earthquake, the backup generator was taken out by the following tsunami, and the final backup batteries only lasted for a short period of time.
Without power, the pumps failed and the reactor began to overheat once again. The last-ditch effort was to pump boron-laced seawater through the structure to help cool the core. The effectiveness of this is still unclear, as many news reports seem to contradict each other on issues of how much radiation escaped through the containment, or how dangerous the radiation in the area is, and whether or not the plants will be operation again. Which should be impossible if seawater is being pumped through the core.
While the nuclear crisis in Japan is the consequence of both nature and human short-sightedness, the nuclear disaster at Chernobyl, Ukraine in 1986 had nothing to do with a natural disaster, and everything to do with management and poor engineering practice.
Dr. Mathie dismisses the Soviet containment design as a jokevery substandard. They had poor management, poor training, and poor design, none of which would have been accepted by Western standards.
Hundreds of thousands had to be evacuated from their homes and permanently relocated. The death toll at Chernobyl varies widely depending on the source. The World Health Organization and the UN put the immediate death toll at 31 with about 4,000 cancer-related deaths afterwards, while Greenpeace puts the long-term death toll above 90,000. This huge discrepancy possibly stems from the fact that one quarter of us will die of cancer regardless of radiation poisoning, which wasn’t taken into account by the UN.
Seven years before Chernobyl, there was a meltdown at one of the reactors at Three-Mile Island, Pennsylvania. Due to a strong, well-designed containment structure, there was not a single death or injury caused by the accident. Chernobyl and Three-Mile Island were caused by poor training practices and low operational standards.
Mathie emphasizes that we cannot understate the impact of training when it comes to nuclear power, and we learned from Three-Mile Island by raising operators to a much higher standard.
Key Issues
Just as with fossil fuels, the nuclear process begins with mining the fuel, uranium. Uranium by itself is as harmless as granite in terms of radiation, but trapped beneath the ground with the uranium is radon gas, and this carcinogenic gas is part of what causes opponents to protest nuclear power so rigorously.
They argue that it poses a danger to the workers as well as contaminates nearby water sources. It is true that miners have died in the past from radiation poisoning. The advocates of nuclear power maintain that, as with every aspect of the modern nuclear industry, the mining process has become strictly regulated since then.
Ventilation systems are in place to ensure the workers are safe. As for the surrounding environment – Radon gas is very heavy and has a short lifespan. In the event of a leak, the gas does not travel very far from the mining site, where it is taken care of by ventilation systems.
Any gas that does travel far gets diluted in the atmosphere, rendering it harmless. Mathie reminds us that radon gas is also a naturally occurring element that is and has always been present in the earth’s atmosphere, and we’ve survived just fine.
The unit of measurement of radiation dose is the milliSievert. Radiation only starts to become dangerous at about 100 mSv per year. Depending on where you live, you receive an annual dosage of about 2 mSv per year, which is all purely natural radiation. A uranium miner in a properly regulated mine will receive a maximum dose of between 4 to 10 mSv per year. Regulations require that miners must stay under the annual limit of 20 mSV per year for a period of 5 years.
The uranium is extracted from the ore and, depending on the application, enriched into a useable form called U-235. These pellets are inserted into tubes, and these tubes are used in the nuclear reactor.
Once the fuel is used up, there is leftover fuel and fission products that must be handled very cautiously as they are also radioactive. While many storage sites are close to the reactors themselves, transporting the material is another issue surrounding the nuclear debate.
The transportation of radioactive material over land and water happens at every stage of the nuclear cycle. The containers have undergone rigorous testing to prove how durable they are.
Look up “‘Nuclear Flask Endurance Testing in USA”’ on YouTube to see for yourself. Before any used fuel is transported from the reactor site, it is immersed in water for a period of time while the heat and radiation levels go down.
There is a concern over whether or not nuclear waste should be temporarily stored, or permanently disposed of. Some are wary of disposing of it because it may become a valuable resource at some point in the future. But no matter where the waste ends up, geological surveys must be done on the proposed site before any waste is deposited there.
The waste must then be subject to very strict security measures to make sure that it doesn’t get into the wrong hands.
The USA originally had plans of storing its nuclear waste at a geological deposit at Yucca Mountain, Nevada. After being carefully studied and surveyed for over 20 years, Yucca Mountain was finally declared to be a safe deposit in 2002. This decision was overturned by President Barack Obama in 2009. Obama says he is not opposed to exploring nuclear power, but he claims he was looking out for the interests of Nevadans, the majority of which are opposed to being responsible for storing the rest of the country’s nuclear waste.
An alternative to storing all the waste from a nuclear plant is to reprocess a portion of it into fuel that can be reused.
This procedure involves extracting the valuable plutonium and uranium from the rest of the waste. This is slightly controversial because the products from reprocessing can accumulate into what is called “weapons grade material."
The fuel used for nuclear reactors is under 5 per cent U-235, while nuclear weapons grade material is at least 90 per cent. Because of this risk as well as the high cost involved, many countries, US included, do not reprocess fuel.
Other countries such as France, UK, Russia, and Japan have achieved economic success from reprocessing. Canada is the only country that uses a system that does not even require fuel enrichment in the first place. Dr. Mathie says that it comes down to a question of what is economical for each country, although reprocessing may eventually become a necessary procedure.
Proliferation
This brings us to the final issue, nuclear proliferation. Most pro-nuclear arguments consist of strict policy, organization, and regulation of the entire nuclear process. It is the case with mining, operation, transportation, and storage. Opponents of nuclear power believe that regulations aren’t enough, and that since there is no 100 per cent% safeguard against nuclear arms proliferation, nuclear power is too dangerous.
The NPT, Nuclear Non-Proliferation Treaty, was enacted in 1970 and calls for non-proliferation of nuclear material, disarmament of nuclear weapons, and peaceful use of nuclear technology.
Up to 9 countries may currently possess nuclear arms, and only 5 of these are part of the 187 countries that form the NPT. India, Israel, Pakistan, and North Korea are the countries that are not part of the NPT and either have nuclear weapons or are suspected of having them.
India is strongly in favor of nuclear cooperation. However, they have been denied membership unless they agree to disarm their nukes. India sees this as unfair because neighboring China is allowed to be part of the NPT as a nuclear weapons country and their other neighbor, Pakistan, is also suspected of having them.
India believes this would leave them too vulnerable, their government believes that they should be allowed to use nuclear weapons as a deterrent. Not being part of the NPT means that India does not get to trade nuclear technology.
In recent years, countries like France and the United States have agreed to trade nuclear technologies with India based on their clean record of non-proliferation. The International Atomic Energy Agency, IAEA, is another proliferation deterrent created by the UN that keeps records of all nuclear activities. They also, conduct routine inspections of civil nuclear facilities. While claiming numerous successes, they continue to have trouble dealing with several non-cooperating countries.
In the event of a nuclear war, millions would be killed instantly; millions more would die soon after due to radiation and the lack of medical attention. The world could then go through a period known as nuclear winter.
If one nuke goes off, many more nukes will follow. Dust and smoke would rise into the air, blocking the sun’s rays, and creating a period of cold and darkness.
This would lead to the extinction of many plants and animals, effectively disrupting the natural order of the planet. Any civilization that doesn’t get wiped out would revert to a prehistoric state. As Einstiein famously stated, if World War III is fought with nuclear weapons, then World War IV will be fought with sticks and stones. It is clear that the peaceful use of nuclear technology is one of the most important issues today.
A Final Word
Upon hearing the word "nuclear", many people might imagine a similar situation to the one is just described before. But, we must realize that the word "nuclear" can exist without being followed by the word "weapon."
Nuclear technology is present in important aspects of everyday life, whether we recognize it or not. There is a whole field of nuclear medicine that uses radiation to diagnose patients by injecting radioactive isotopes in the body. These isotopes are used every day throughout the world, and a large portion of the world’s radioactive isotopes is manufactured at Canada’s Chalk River Laboratories.
So what does the future hold for nuclear power?Nuclear reactors typically have a lifespan of about 40 years, often with an additional 20-year extension. Since most of today's reactors were made in the 80s, many of the new
reactors that are being constructed today will merely be replacing those due for retirement, and they will be much safer and more efficient.
China currently has the biggest investment in future use of nuclear power with nearly 30 reactors currently under construction and many more planned.
The nuclear crisis in Japan has caused some nuclear power nations to reassess their strategies for using nuclear technologies. However, the world population is expected to be as high as 9 billion in less than 40 years. In order to meet the energy demands in the cleanest way possible, there must be a balance of energy sources.
Wind and solar are very clean, but they can only account for a small portion of the energy supply. Hydroelectric and geothermal are other good contributors, but both are limited
by geological factors. Fossil fuels will continue to be the dominant energy source for many more years, and developments are being made with clean coal and carbon capture technologies.
If we want any chance of meeting tomorrow’s energy requirements, nuclear power may be the only option, whether you like it or not.
Just as early humans used rocks as both deadly weapons and as tools, so too can nuclear power be used for the detriment, or benefit of mankind.
Strict regulations can only sway public opinion so far, but it’s ultimately up to governments, nuclear energy companies, and scientists to work together to prevent any further nuclear crises – preventing disaster, and sustaining society.
This is a really strong, compelling article. Good show!