So what is nuclear power?
And what makes its radiation so dangerous?
Written by Sammi Queenan
Nuclear energy occurs when atoms split apart (fission) or when atoms combine (fusion). Fusion occurs naturally in stars like the Sun. Inside the Sun, fusion reactions continue for billions of years and give off enough energy to make the Earth a warm and bright place. Fission, on the other hand, is a form of radioactive decay, and humans have learned how to control fission reactions to produce enough energy to power everything from navy submarines to entire cities.
Active cooling towers of the Byron Generating Station in Illinois. . Photo courtesy of Michael Kappel
Fission is much easier for people to control than fusion, which is why we use fission to generate energy in nuclear power plants. To do so, we need to use unstable atoms like Uranium 238, which basically have too much energy for their own good. We often call unstable atoms radioactive atoms.
When we add extra energy to radioactive atoms (usually by shooting neutrons at them), they split into two new atoms. The leftover energy gets released in the form of tiny, subatomic particles called radiation.
Inside a nuclear reactor, we use this radiation to split apart more atoms and keep the cycle going long enough to produce large amounts of energy. Nuclear power plants use this energy to boil water that then spins a turbine and creates electricity that we can use.
However, this form of high-energy radiation can cause problems for people if it comes in contact with our body because it has enough energy to destroy cells in our tissues and damage DNA.
At the Fukushima Daiichi power plant in Japan, the main safety concern is not the radiation inside the reactors, but rather the radioactive particles that were released by explosions following the nuclear meltdown of three reactors in March 2011.
Those particles still have enough energy to make other atoms radioactive. If people accidentally touch, breath or drink anything contaminated with radioactive particles, then the radiation has an easy path into our bodies. Thankfully, the Japanese government has done a good job of protecting citizens and workers inside the plant from this kind of contamination, and no one has gotten sick from radiation yet.
'If people accidentally touch, breath or drink anything contaminated with radioactive particles, then the radiation has an easy path into our bodies.'
That being said, the human body can easily deal with small doses of radiation. Every day we’re hit with radiation from space and from inside the earth. Potassium-rich foods (like bananas) emit radiation too. In the United States, the legal limit for radiation exposure is 5 rem per year, which is actually only one-fifth of the exposure you’d need to see any changes in your body.
We decided to calculate our own radiation exposure for the year, and here’s how the numbers added up:
Terrestrial (from the ground) – Montana 46 mrem
Cosmic (from space) -- Missoula elevation 3000 feet 41 mrem
Internal from food (mostly potassium) 40 mrem
Airplane travel to Japan (5000 miles) 5 mrem
Living in a stone, brick, or concrete building 7 mrem
So, ignoring possible radon exposure in the hostels, those we will be exposed to about 0.140 rem this year (excluding the frequent-fliers in the group). That’s only about 3% of the legal limit.
You can calculate your own annual radiation exposure on the EPA’s website.