When you pass a nuclear power plant in the distance as you drive down the road, it’s
impossible not to think about the power these towering buildings hold.
Scientist Enrico Fermi supervised the opening of the first nuclear power plant in 1942,
and now our landscapes are dotted by mighty nuclear reactors.
These powerful energy plants provide over a fifth of the United States’ electricity,
and don’t have the carbon footprint of other energy sources like coal and fossil fuels.
So why not build more?
One reason - nuclear waste and radioactivity.
When managed correctly, nuclear plants are processing powerful radioactive energy that
needs to be disposed of correctly to keep the environment and the people handling it
safe.
And if someone wasn’t handling the plant’s safety correctly, like a certain bald bumbler
from Springfield, things could go very badly.
D’oh.
The risks of nuclear energy became crystal clear in 1979 in Londonderry Township, Pennsylvania
at the Three Mile Island nuclear plant.
While the reactors were stable, a failure in the mechanical systems regulating the safe
venting of gases broke down, and allowed a large amount of nuclear reactor coolant to
escape.
That led to a partial meltdown of Reactor 2, creating a major radiation leak near the
city of Harrisburg.
A voluntary evacuation of a twenty-mile radius around the plant followed.
Thankfully, no one in the plant was injured and later tests showed no increased risk of
cancer, but it took fifteen years to clean up the surrounding area.
It remains the worst nuclear accident in United States history - but is dwarfed by the massive
nuclear meltdown in Chernobyl, which caused major casualties and rendered areas surrounding
the Ukrainian plant uninhabitable to this day.
Given the risks, it’s no surprise that nuclear waste and by-products are strictly regulated
by the government.
Modern nuclear plants keep waste to a minimum by recycling used fuel back into uranium-based
and mixed-oxide fuel, but four percent of nuclear waste can’t be processed and remains
highly radioactive.
Radioactivity is a waiting game, as the toxic quality of the waste decreases over time.
Measured in half-life, or the time it takes for a radioactive substance to reduce to half
of its nuclear value, the time it takes for nuclear waste to neutralize varies wildly.
Some common isotopes like Strontium-90 have a half-life of around thirty years, but other
powerful artificial nuclear isotopes like Plutonium-239 have a half-life of over twenty
thousand years.
Not only is it radioactive enough to kill anyone exposed to it, but it could be an unpleasant
surprise for whoever digs it up in the far future.
Nuclear power plants operate in thirty-one countries, including all of the world’s
largest economies, and much of Asia and Africa are planning new builds.
The regulation of nuclear waste is overseen by the International Atomic Energy Agency’s
joint convention on spent fuel management, and they work to keep the world safe.
The risks of exposure to nuclear waste include higher risk of cancer, higher risk of birth
defects in pregnant women, and in high concentrations organ failure and death.
Most nuclear waste comes from nuclear power plants and nuclear arms, but medical and industrial
waste and natural radioactive materials also pose a risk.
Nuclear waste comes from two main sources - front-end and back-end.
Front-end nuclear waste comes from the extraction of uranium, and contains radium.
The depleted uranium that comes from it is extremely dense and is often recycled into
anti-tank shells and other metals where extreme durability is needed.
Back-end nuclear waste comes from spent fuel rods and is packed with beta and gamma radiation.
These powerful energies come with extremely long half-lives and are formed in nuclear
reactors.
Some of the most challenging waste to dispose of comes from nuclear weapons materials, and
the plutonium used to create these powerful bombs is extremely difficult to separate and
isolate.
That makes nuclear weapon disposal a growing concern, especially in the aftermath of the
cold war when the US and Russia drastically slashed their nuclear arsenals.
The world is less likely to end now, but what are we going to do with all those things that
can end the world?
The classification of nuclear waste determines the priority level of the processing and disposal.
The lowest-priority nuclear waste is uranium mill tailings, which are created by the rough
processing of uranium ore.
While they don’t contain a high level of radioactivity, they have long half-lives and
are full of metals with other health risks like arsenic and lead.
Low-level waste is the most common waste type, because it’s anything that came into contact
with radioactivity.
Common in hospitals and processing plants, it can include paper, clothing, tools, and
filters that are used by people working with nuclear energy.
These objects pick up trace levels of radioactivity and should be disposed of safely instead of
being processed with standard trash.
Intermediate waste is usually the by-product of nuclear processing, and is harder to dispose
of than low-level waste.
Resins, chemical sludge, and metal coverings that have been exposed to nuclear energy long-term
pick up the harmful radioactivity and the hazardous nature builds over time.
When breaking down a nuclear reactor for decommissioning, even the building materials surrounding the
core can build up radioactivity.
Before disposing of this waste, it should be safely shielded to prevent exposure.
Then there’s high-level waste, and this is what everyone thinks about when they hear
about nuclear power plants.
The alarms start blaring.
The hazmat suits go on.
High-level nuclear waste is as radioactive as you think, but the good news is there are
effective waste to contain it.
When a nuclear fuel rod serves its purpose and is taken out of the core, it becomes high-level
waste.
While the number of high-level waste objects is small compared to the other classes, the
level of radioactivity is so high that it accounts for over ninety-five percent of total
radioactivity caused by nuclear energy.
While most radioactive isotopes produced by high-level waste are high-powered but have
a short half-life, the presence of isotopes like plutonium makes it critical to ensure
it’s contained safely.
So what’s the best way to dispose of nuclear waste?
That’s what nuclear-energy using countries have been arguing over for decades.
Most experts say the best solution for long-term disposal is by constructing a deep underground
facility, similar to a mine, that can contain large amounts of high-level waste away from
humans and be sealed up in between disposals.
But that’s easier said than done, and no country has finished one - although Finland
is close to completing their Onkalo spent nuclear fuel repository on their west coast.
Currently, countries use a number of alternative systems that are considered safe, but imperfect.
The first step to minimize the impact of nuclear waste on the environment is to neutralize
it as much as possible.
This is done by processing it and stabilizing it into a form that loses its explosive properties.
Some countries mix the waste with sugar and then calcinate it into a solid object by processing
it through a rotating tube.
Turned into glass, the waste products are bonded to the other molecules and then poured
into stainless steel and sealed.
They’re then stories underground, where the waste products are trapped for thousands
of years without leaking radioactivity into the environment.
Other technologies include ion exchange, where medium-level wastes are neutralized by concentrating
the radioactivity into a much smaller volume.
This makes them easier to contain, but isn’t recommended with the volatile high-level wastes.
But when the time range for nuclear waste to become deactivated can reach into the millennia
or longer - with some rare isotopes having a half-life of over a million years - scientists
are concerned that these storage methods could come back to haunt us.
That’s why we’ve eliminated many of the more short-sighted methods of nuclear waste
disposal, like ocean disposal.
Up until the 1990s, many countries including the United States and the Soviet Union would
dump drums of contained nuclear waste into the ocean, especially in the coastal regions
of Somalia.
Somalia hasn’t had a functioning government since the 1990s, and the pirates weren’t
going to mess with a large ship bearing a country’s flag when they could go after
smaller merchant ship, so countries thought anything goes out there.
The Arctic ocean was also a popular choice for the Soviets, as they controlled a huge
coast in the north.
Overall, 137,000 tons were dumped in the water by European countries in thirty-four years,
and it took its toll on the oceans.
Tests of areas where dumping was common found elevated levels of radioactivity, and in 1993
a treaty was passed banning ocean disposal of nuclear waste.
The most common current method for nuclear waste disposal is above-ground disposal, where
waste is sealed up in a steel cylinder with an inert gas that won’t react with it, and
then sealed in radiation-shielding concrete.
The radiation-proof drums are then sealed in a storage facility near the nuclear power
plant.
This is how big plants handle their waste in-house, and it’s popular for a few reasons.
First, it’s handled internally and the plant doesn’t have to get approval and fight their
way through government red tape to find a dumping facility.
Second, it’s inexpensive and doesn’t require construction or expensive materials.
Finally, the waste remains on site for reprocessing - which remains the best solution for solving
the nuclear waste question.
The secret weapon for eliminating nuclear weapons is chemists and physicists, as these
scientists have developed ways to chemically separate fission products and unused uranium
from used nuclear fuel.
This started by extracting Plutonium, with its long half-life, from nuclear fuel to be
used in the construction of nuclear weapons.
But as the focus shifted from bombs to energy plants, scientists developed ways to create
a new type of nuclear fuel from the remnants of the old.
MOX nuclear fuel, or mixed oxide fuel, is created in high-level facilities from nuclear
waste coming from plants around the country, and has become a top way of disposing of nuclear
waste in Europe.
In America, the government is focusing on research and commercial nuclear fuel reprocessing
isn’t widespread yet.
So what will nuclear waste disposal look like in the future?
One of the biggest possibilities is space disposal, as this will get the radioactivity
as far away from people as possible.
The problem (besides the possibility of poisoning some aliens that will come looking for revenge)
is that technology isn’t there yet.
While technology like mass drivers and space elevators is in development, the carrying
capacity of our current space shuttles is limited and would only be able to carry a
small amount of nuclear waste.
The money that goes into every space shuttle launch is high, and the program is far from
fool-proof.
The loss of the Challenger and the Columbia shuttles proves that a catastrophic accident
is possible - and a space shuttle disaster carrying a nuclear payload could contaminate
a large area.
Could we transform nuclear waste into less-harmful waste with a shorter half-life?
That was the dream of the scientists behind the Integral Fast Reactor, an experimental
reactor that would use a nuclear fuel cycle that reprocessed fuel through electrorefining.
It would extract almost all the energy contained in uranium, cutting fuel requirements by two
orders of magnitude.
Unfortunately, the design had problems with leaking cooling fluid and the project was
cancelled by the US Government in 1986, but research is ongoing and new fission reactors
that have much more processing power than the traditional light water reactors are under
development now.
The earth itself might be our best ally for disposing of nuclear waste, as man-made structures
underground are the top proposal for future storage facilities.
By digging out large, stable bunkers in sparsely populated areas of a country, nations could
keep their nuclear waste in a centralized location and reduce the risk of leaks happening
in multiple locations.
Deep borehole disposal is an alternative that creates narrower but much deeper holes capable
of storing the waste up to three miles under the Earth, where any leaks would be far away
from humans.
The big holdup?
Besides developing the technology for safe deep-earth drilling, getting approval from
governments is a holdup.
Many countries have rejected proposals out of fears that the disposal won’t be safe
or that it could destabilize the ground.
The consequences of a nuclear accident are massive and long-term, as the residents of
Pripyat, Ukraine know all too well.
In the heart of the Chernobyl nuclear plant is the Elephant’s Foot, a mass of solid
nuclear waste caused by the 1986 meltdown.
Dense and hard to damage, it was so radioactive when released that it would kill anyone who
was in the same room as it.
Today, over thirty years later, it’s still highly radioactive and poses major health
risks to anyone who is exposed.
So however we neutralize our nuclear waste, let’s make sure it stays there.
Want to learn more about the worst nuclear disaster in history?
Watch “How I Survived Chernobyl” or check out this video instead.
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