Cleaner than coal burning power plants, nuclear power plants were thought to be the wave of the future for some time. Releasing nothing but water vapor boiled off during the energy production process, these power plants are costly to build, but offer energy at a lower overall cost than other traditional power plants do. They offer much, but come with risks attached, despite engineers’ attempts to prevent disasters. How do they affect the world’s oceans, and what are the realities we face?
Nuclear Power: The Basics
A clean energy alternative that has reduced dependence on fossil fuels, nuclear power begins inside massive nuclear reactors. It all starts with a radioactive uranium bundle which has been enriched to contain about 2 to 3 percent more U-235 than natural uranium – nowhere near what weapons grade uranium has been enriched to, which tends to be within the 40 to 90 percent range.
Inside the bundle, fission takes place, creating heat capable of generating energy. To illustrate just how powerful even a small amount of highly enriched uranium is, picture one pound of a grey metallic substance sitting next to a tank that contains one million gallons of gasoline. The metallic substance is the enriched uranium that keeps a nuclear powered ship or submarine running; it contains the same capability to produce energy as that million gallon tank of gasoline does.
Back to the U-235, where nuclear fission is happening and heat is being generated; this substance is housed inside big fuel rods that sit in huge tanks of water, which is superheated by the ongoing fission reaction. As the water is heated, it keeps the fuel rods from overheating and melting down, plus it creates a massive amount of steam, which is concentrated to turn massive turbines that lead to electric generators. Once electricity has been generated, it enters the energy grid and is available for use by end consumers.
The only byproducts are steam, which enters the atmosphere and evaporates, and spent fuel rods, which continue to produce radioactive isotopes and which must be managed. Spent fuel rods from nuclear power plants are normally kept in secure underwater storage facilities; sometimes, spent radioactive fuel is used for medical and industrial applications. Even though these fuel rods have been effectively shut down, they continue to release heat and must be cooled with flowing water.
Risks Associated With Nuclear Power Production
Today, 47 countries rely on nuclear power plants for at least some of their electricity, and there are almost 450 of these plants in operation. Some countries, like Lithuania and France, get more than 75% of their power from nuclear reactors, others, like the US, which gets about 20 percent of its power from nuclear sources, use several different power production methods. When plants are in good repair and functioning properly, risks are extremely low – the danger exists mainly in the “what if” factor; what if an accident occurs?
The risks associated with production of nuclear power are real, as was powerfully demonstrated by the March, 2011, Fukushima-Daiichi disaster that followed one of the worst earthquakes and tsunamis ever recorded. Tens of thousands of Japanese citizens had to flee their homes and leave their businesses behind as a partial nuclear meltdown occurred inside the damaged facility. The odds of an identical mishap occurring are small; yet, accidents large and small happen and with those accidents come a number of related problems for people, animals, and the environment:
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Cancer – Low doses of ionizing radiation over a long period of time can lead to cancer in humans and animals. Children and adolescents are at greater risk, as their bodies are still growing, and marine organisms living near power plants where water used for cooling is released back into the environment are at elevated risk as well.
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Nuclear Waste remains radioactive for thousands of years. It must be stored, in essence, forever, to prevent people and animals from being exposed to harmful radiation. Nuclear waste is often stored in temporary sites. Sometimes it is moved from one site to another, creating the potential for disaster, and at times, it is dumped in the oceans.
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Environmental Impact – When nuclear plants are built along rivers, the water released back into the rivers is warmer, and it causes environmental change over time, affecting not only the fish and other animals that live there, but the plants as well.
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Terrorism – A real concern, even though nuclear power plants are designed to withstand bombardment and even to survive impact by a jumbo jet flown in at high speed. Plant security is at an all-time high, reducing this risk; however, the potential for terror attacks does exist.
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Acute Radiation Syndrome – If the worst case scenario does occur, and radiation escapes, radiation sickness can occur on a grand scale. While small doses lead to symptoms such as nausea, infection, and hair loss, massive doses result in neurological problems and usually lead to death.
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Mutation – Mutations can be caused by exposure to radiation, as we are now able to see in the area surrounding Chernobyl, where humans and animals alike have been affected. Miscarriage, stillbirth, congenital defects, neonate mortality, chromosomal abnormalities, and deformities are just some of the problems caused by radiation-induced germline mutations.
Ocean Ecosystems and Nuclear Power Plants
Even though the oceans and seas are massive, with water covering two thirds of the earth’s surface, these bodies of water, along with the plants and animals living in them, are incredibly susceptible to human influence, both positive and negative. One of the biggest problems currently faced with relation to nuclear power production is the dumping of nuclear waste into the ocean, where isotopes are eventually diffused.
The majority of nuclear waste found in the oceans comes from submarine and ship reactors, as well as from damaged reactors which have been jettisoned. The rest of the known nuclear material in the oceans is solid spent waste that has been legally dumped in the oceans; it is left over from the nuclear power process, medical, research, and industrial uses and is sealed in concrete drums to help mitigate nuclear risk. The danger to marine life and humans varies along with the concentration of radioactive waste contained in the drums.
The greatest risk comes from the potential for accident – again, from that “what if” factor. Scientists are still waiting to see what the long-term effects will be for marine life around Fukushima; in the short term, fish and shellfish are unsafe to eat due to radiation exposure, birds and animals died in the aftermath, and brown seaweed, which is a staple and is harvested off the coast of Japan, has been contaminated with radioactive isotopes.
While nuclear power plants were once seen as an alternative to plants that produce harmful byproducts including greenhouse gases that are released day in and day out, better solutions include wind power, wave power, and solar power; with these renewable and completely non-toxic solutions, risks are completely eliminated. Due to accidents and the growing cost of constructing new plants to replace old, outdated reactors, their numbers are expected to decline. By promoting education, and by lobbying for renewable energy where you live, you can help to make it happen faster, ensuring that we and our planet stay healthy and safe.