Whoops! It has been awhile. Sorry!
I was partway through this blog post when I got a new job that required
me move to a different state. A new job
writing scripts for online science tutorials.
In other words, I got hired to basically do what I started this blog to
practice doing: communicating science.
As such, I let the blog fall by the wayside for the past few
months. After having a couple people
tell me they liked reading the blog and I should get back to writing it (which
is a couple more people than what I thought read the blog), I’ve decided to get
back to writing (I hope).
Anyway,
for this post, Christian S. asks, “Is nuclear energy dangerous?”
Courtesy
Archive.org
Yes.
But
then again, lots of things can be dangerous.
Driving cars can be dangerous.
Peanut butter can be dangerous.
Even stairs can be dangerous (especially after leg day).
Or
if you are Charles Xavier.
But
being dangerous doesn’t mean that something is bad or worthless. It comes down to, do the benefits outweigh
the possible harms? So with today’s blog
entry, I’m going to start off describing what nuclear energy is followed by how
nuclear energy is dangerous (actually answering the question asked). Finally I will talk about the benefits of
nuclear energy.
As
I’m sure we all remember from science class, atoms are the smallest unit of
matter that still has properties of an element.
All atoms, no matter which element, are made up of smaller particles
called protons, neutrons, and electrons (which are made up of even smaller
particles that I’m not going to go into because that’s a confusing rabbit hole
I’ll most likely get lost in). The dense
core of the atom, the nucleus, is made up of protons and neutrons and electrons
orbit around it. Each atom of an element
has a specific number of protons in its nucleus, so an atom that has 8 protons
in the nucleus has completely different properties from an atom that has 9
protons in its nucleus (8 protons is oxygen while 9 protons is fluorine). It is possible for a nucleus of a specific
atom to have a different number of neutrons as another nucleus of the same type
of atom. Atoms that have the same number
of protons but different numbers of neutrons are called isotopes. As the number of protons and neutrons in a
nucleus increases (most number of protons in an element discovered so far is
118 in the element Ununoctium), some elements
become unstable and can break down. When
this happens, they release protons and neutrons from their nucleus in an effort
to become more stable while also releasing energy. This is known as radioactive decay.
Nuclear
power plants use the process of nuclear fission to produce electricity. In simplistic terms, nuclear power reactors would
shoot a neutron into the nucleus of an atom of some fissionable material (such
as uranium) which is unable to stably absorb the neutron. The nucleus then splits into smaller
fragments, which also releases energy, radiation, and more neutrons. These neutrons can hit other uranium atoms
causing them to split as well, releasing more energy, radiation, and neutrons
which can hit other atoms. This chain
reaction can continue with no further outside involvement until all the
fissionable material has been used up.
However, nuclear power reactors control the chain reaction through a
variety of processes such as the use of materials that can stably absorb
neutrons (the fewer neutrons flying around, the more controlled and slower the
reaction progresses).
The
energy released during fission heats water to create steam. The steam is used to spin a turbine that
produces electricity.
Dangers:
Before
I begin talking about the dangers associated with nuclear energy, I will
mention a danger NOT associated with
nuclear energy, an explosion like a nuclear bomb. It is impossible for
a nuclear power plant to explode like a nuclear bomb (Truth #2). Nuclear plants do not
use uranium that is enriched enough.
That
said, there is always a chance that an accident could occur at a nuclear power
plant. The worst type of
accident is a meltdown, where the core of the reactor gets too hot and the fuel
cracks, releasing radioactive gas; or the hot, radioactive material melts and
damages the protective structures so it can reach the environment.
In
the event of a nuclear power plant accident, danger exists from
the plume of radioactive material that may be released and contaminate people
and things that are outdoors, from radioactive material that is ingested or
breathed in, or from radiation exposure to those living nearby the power plant. Radiation can damage the DNA in the cells of
the body, either causing mutations or the death of the cells. If a high enough dose of radiation is
received all at once, death occurs due to cellular death and organ damage. Lower levels of radiation exposure can cause
genetic mutations that could lead to cancer, even years later. Even a relatively minor incident in which
radioactive material leaks into the environment could cause health problems or
environmental damage.*
The
chances of an accident occurring are very small, however. Reactors are designed
with multiple layers of protection and redundancies to make the chance of an
incident occurring very small. In fact, a type of
incident like the one that occurred in Chernobyl could not occur here in the
United States because that type of reactor was never built here (Truth #7).
And
just as a nice visual aid to illustrate the difficulty of the public being
exposed to high levels of radiation (plus I love the source), here’s how safe you would be swimming in the pool used to
store spent nuclear fuel rods until they were safe for transport. Really makes you think, though that whole
lead poisoning thing at the end means you shouldn’t try it.
*It
all depends on the dose of radiation you receive and how often you receive
it. Humans are exposed to numerous
sources of radiation in their everyday lives (1, 2). In fact, you absorb slightly more radiation
from eating a single banana than you do from
living within 50 miles of a nuclear power plant for one year. Our body is usually able to repair the damage
caused by this low level of radiation.
Benefits:
One
of the major benefits of nuclear energy is a lack of air pollution
production or carbon dioxide release. You
could easily make the argument that the type of pollution that would occur if a
nuclear incident occurred is more damaging to the environment and human health than
the air pollution and carbon dioxide release of traditional power plants, but
it comes down to the difference between a potential harm vs a guaranteed and
currently occurring harm.
Also,
the “energy density” of uranium (and other
nuclear energy material) is greater than that of coal, oil or natural gas. In other words, if you have a pound of
uranium vs a pound of coal, the energy that you could harvest from the uranium
is many times greater than what you could harvest from the coal. Nuclear power could thus reduce our
dependence on fossil fuels, and specifically reduce our dependence on foreign
oil. Additionally, the cost of producing
energy via nuclear power is lower than the cost of producing energy with fossil
fuels.
And
just as an aside, it is interesting to note that in the 50+ years of
commercial nuclear power, there has been no radiation-related health events in
the public linked to the operation of nuclear power plants.
So
Christian, to answer your question, there are dangers involved with nuclear
energy, but those dangers are taken into account in the design of reactors and
the risk of something bad happening is very small.
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