Nuclear is zero-emission clean energy. Nuclear energy is the ‘third safest technology’, after hydroelectricity and wind. Nuclear reactors emit virtually no air pollutants during their operation. In contrast, fossil fuel power plants, particularly coal power plants, are the main emitters of greenhouse gases, sulfur, and nitrogen compounds.
The air pollutants that nuclear power plants keep out of the air we breathe include,
- Nitrogen oxide (NOx), a gas that reacts with sunlight and forms fog. Its presence in air modifies other pollutants like ozone.
- Sulfur dioxide (SO2), a toxic gas when combined with water vapor and sunlight to cause acidic rain.
- Particulate matter, a mix of solid and liquid droplets suspended in air; contributes to acid rain and climate change.
- Mercury, a neurotoxin that causes poisoning to death.
- Carbon dioxide (CO2), a key contributor to climate change.
Energy experts are conducting more studies to access nuclear energy’s potential as an ecological energy form. One such study concluded that the use of nuclear power has prevented about 1.84 million air pollution-related deaths. The same study also estimated that by replacing fossil fuel with nuclear power an additional 420,000 – 7.04 million future air pollution deaths could be prevented.
So, the answer to the question is: nuclear energy is safer for the atmosphere (unless there’s leaks or accidents).
How Does Nuclear Power Affect the Environment?
Since nuclear energy currently provides 10% of the total electricity generation in the world, it’s important to take into account the impact it has on the environment.
Nuclear waste disposal is an environmental issue
Nuclear waste is categorized into two: low-level waste and high-level waste. Some can remain radioactive for a few hundred years and gradually undergo decay while some others retain radioactivity for eternity.
Currently, there’s no long-term solution for nuclear waste. There’s no way to dispose of the waste in an environmentally safe or responsible way; most are sealed in temporary, above-ground facilities. With an increase in nuclear power demand, such facilities are running out of space and, the nuclear industry is facing waste management issues.
When leaked, radioactive wastes can drastically affect animal and plant life, causing genetic aberrations, chronic diseases, or developmental issues.
In addition to the mining wastes, there are also materials and equipment used in nuclear plants. Radioactive laundry facilities where gear and uniforms of nuclear workers are laundered also release radiation into the environment. These are difficult to safely dispose of when the reactor shuts down, thus posing the threat of radiation contamination.
Read more: Nuclear Power and Problems Associated With Nuclear Power
On water quality and aquatic ecosystems
Water is the sacred thread that connects all steps during nuclear fission. When released, the coolant water with radioactive discharges poses a severe threat to the aquatic ecosystem. It starts with a decrease in dissolved oxygen levels and a rise in pH.
Coolant water cannot hold dissolved oxygen and organic materials decompose faster in high temperatures. This results in algal bloom, which in turn creates hypoxic zones (areas with less or no oxygen), ultimately killing aquatic fauna and flora.
Coolant water from reactors makes the lakes and other water bodies inhospitable for fishes by accelerating metabolism. The result – loss of aquatic biodiversity.
What do Nuclear Power Plants Release Into the Air?
Although nuclear reactors do not emit fly-ash or noxious greenhouse gases into the air as fossil-fuel-power plants do, there are a few fission products that pollute the air. They are,
1. Volatile fission products
They include the isotopes of halogens bromine and iodine, and the noble gases xenon and krypton. At ultra-high temperature rubidium, cesium, antimony, and tellurium are also released.
Among these, iodine-131 is produced in large amounts and when inhaled can cause thyroid abnormalities.
The amount of xenon and krypton produced in commercial plants are many times higher for immediate discharge to the atmosphere, even if the most efficient dispersal method is used. Radioactive xenon and krypton in the atmosphere cause mainly an external, rather than an internal hazard.
2. Non-volatile fission products
This category includes all noble gases and is present in the affluent as particulates. Some halogens are also included in this category. These non-volatile fission products become airborne due to the processes which allow the escape of mists, sprays, or droplets. Another significant contaminant is strontium-90.
3. Paniculate dispersions of fuel materials
They are mainly the fission isotopes of uranium and plutonium. Upon disintegration, these heavy metals disintegrate and emit energy. However, owing to the low MPCa (maximum permissible concentration) values (2 X 10″13 /ic/cc. for plutonium-239), monitoring their presence in air is difficult.
4. Induced activity particulate components
When air is used to cool the thermic reactors, dust and impurities will arise. Various gaseous components like nitrogen-16, argon-41, oxygen-19, and neon-23 may also become activated by high neutron flux during fission reactions.
of gaseous and/or particulate components of exposed air. These vary in importance as hazards, depending upon the reactor type and the probability of accidental release. They are discussed in the following
Do Nuclear Power Plants Give off Radiation?
Yes. Four kinds of nuclear radiation exist within a nuclear plant: alpha, beta, gamma, and neutron.
- Alpha rays or alpha radiation consists of two protons and two neutrons. Alpha rays do not travel far in the atmosphere and can be stopped by a thin sheet of paper. It does not permeate the skin and cause side effects only when inhaled or ingested.
- Beta rays consist of high-energy electrons. They have better penetrability than alpha rays and can be stopped by aluminum foil or wood shielding. Exposure to beta rays can burn the skin.
- Gamma rays are high-energy photons that can permeate body tissues and damage cells and DNA. Attenuation is by lead or concrete shields.
- Neutrons are the subatomic particles and don’t pose threat unless there’s fissionable material to elicit a nuclear chain reaction in the reactor.
All radioactive isotopes – Uranium 235, Plutonium 239, Iodine 131, Cesium 137 – in the reactor emits any of the four radiations upon decay.
To understand the amount of radiation produced and emitted from a plant, it’s important to know the radiation dose of isotopes and reactor types. Sievert (Sv) is the international unit to measure radiation. Roentgen is used to detect x-rays and gamma rays emitted under normal temperature, pressure, and humidity.
Typically, in a contained environment, radiation that comes off from a reactor could be minimal. According to the U.N. report, the annual average effective dose from natural background radiation 2.4 mSv worldwide.
Upon leaking, a reactor can emit radiation as high as 1000 sieverts or more. The radiation levels were about 300Sv/hr, (300,000mSv/hr) during the Chernobyl disaster. According to the Japanese Government, the radiation dose rate during the Fukushima Daiichi nuclear disaster was 400 mSv/h. According to unverified sources, the dose rates were as high as 1,000 mSv/h.
How Much Pollution is Caused by the Nuclear Power Plant?
There is no way to assimilate radioactive materials from nuclear plants in the soil, water, or the air. They remain there for thousands of years and affect the environment.
When radioactive substances land in soil, they react with various soil nutrients. This alters the chemical and biological profile of soil, thus rendering the soil infertile and hazardous.
Genetic modification in crops is evident in crops growing in such polluted soil; when herbivores consume plants, chances are that they retain radiation levels; the radiation effects ultimately reach higher levels of the food chain, when the herbivores are hunted for food. Thus nuclear pollution orchestrates Biomagnification.
The smallest particles of the radioactive material called fallout to settle on the leaves of plants and trees. When grazed by animals, these chemicals enter the ecosystem.
Is it Safe to Live Near a Nuclear Power Plant?
The horrifying scale of leaks at Japan’s Fukushima Dai-ichi nuclear facility in 2011 and the Chernobyl disaster in 1986, has made everyone think about the cost of living near nuclear plants. According to some nuclear scientists, living near a nuclear plant is nothing different than living in a big, metro city. In fact, they say that cancer rates and risks are much lower around reactors.
A study by Jaeyoung Kim et al found that there’s no association between the risk of thyroid cancer and living near nuclear power plants.
The Lifespan Study of Hiroshima & Nagasaki survivors summarized that the primary detectible long-term effect of radiation exposure was cancer, not gene mutations.
A study by Jablon et al. in 1991 proved ‘no excess deaths’ due to leukemia and lymphoma among young adults living near nuclear plants in the United States.
In continuation with several similar studies, the Nuclear Regulatory Commission (NRC) has funded the National Academy of Sciences (NAS) to design a detailed study on cancer incidence near NRC-licensed facilities. The scientists concluded that “any data collected during the pilot study will have limited use for estimating cancer risks in populations near each of the nuclear facilities or for the seven nuclear facilities combined because of the imprecision inherent in estimates from small samples.“
Accidental release of radioactive materials may occur due to human or mechanical error. Nuclear Regulatory Commission suggests that people living within 10-50 miles of a nuclear plant should check for radiation in local water bodies, crops, and soil.
References:
https://pubs.acs.org/doi/abs/10.1021/es3051197?source=cen
https://ec.europa.eu/energy/sites/ener/files/documents/164.pdf
https://pubmed.ncbi.nlm.nih.gov/26638017/
http://www.nap.edu/catalog/11340/health-risks-from-exposure-to-low-levels-of-ionizing-radiation
http://www.ncbi.nlm.nih.gov/pubmed/1999880
http://www.nrc.gov/reading-rm/doc-collections/fact-sheets/bg-analys-cancer-risk-study.html
