70 years ago nuclear power was heralded as the solution to all of our energy woes. A clean, virtually inexhaustible source of energy that would move us away from our reliance on fossil fuels and pave the way for the atomic future.
That was the plan at least, as countries worldwide bought
into the nuclear dream today there are nearly 450 nuclear reactors
around the world in the UK 15 nuclear reactors provide around 20 percent
of the country's energy needs and in the USA 99 reactors account for 30%
of the world nuclear energy generation.
So keen were governments to jump on the uranium-drawn bandwagon. That billion of pounds were invested, power plants were commissioned, and
electricity was pumped out with apparently little in the way of a long-term
plan. Because it turns out using radioactive materials to
generate clean energy, isn't actually so clean after all.
While uranium might not pump out any nasty gases like fossil
fuels do. It leaves behind a lasting legacy in the form of high-level
radioactive nuclear waste. That same radioactivity that hits the water in a
nuclear reactor, has a tendency to linger once that fuel is discarded,
and linger I mean really linger, for at least 250,000 (a quarter of a million)
years. That means that the spent fuel can't just be washed down the sink or
put out with the weekly bin collection.
If we were to be
exposed to it without protection, then the intense radioactivity would scramble
our DNA, it would kill off cells, and ultimately result in a pretty
quick and unpleasant death.
So, it needs to be dealt with very, very carefully, which
makes it all the more remarkable, but there's still not a consensus on exactly
how to deal with it.
At the moment spent fuel is stored in pools and the reactor
sites for 10 to 20 years, where water does an excellent job of shielding
the radiation and dispersing the heat that's produced. But it can't be left
there forever, so a long-term disposal solution must be found.
Currently, there are over 20,000 square meters of
spent nuclear fuel, lurking at the bottom of pools all over the world which
will need a final resting sooner or later.
it's simple, in theory, all that we need is for the nuclear waste
to be sealed in a shielded container and then that content is put somewhere
well out of the way for a few hundreds of thousands of years. The problem is
finding somewhere that will remain sufficiently out of the way, as our
civilization continues to expand. Our oldest archaeological sites are
just ten thousand years old, and their significance has long been lost
to the mists of time. So, how can we be sure that any nuclear waste
won't be disturbed in millennia to come? There's no shortage of Harebrained
Schemes that have been considered and I should probably say were rejected.
You could blast it off
into space well away from earth and its inhabitants, but launches can fail and the
possibility of radioactive waste raining down from the sky makes this a non-starter.
You could bury it. Deep beneath the seabed where miles of
water and thick mud will shield the radiation. Or even better, at a
subduction zone where the movements of plates of the Earth's crust push it down
deeper into the mantle.
However, international conventions don't allow the disposal
of any waste in our global oceans and the thing about subduction zones is that what
goes down tends to come back up and radioactive volcanoes are really something
you want to be starting.
In fact, one of the most promising solutions is actually one
of the most boring literally, I couldn't resist it, burying our spent nuclear
fuel in boreholes deep beneath the earth's surface is probably our best bet
for securely disposing of it for vast periods of time. These so-called geological
disposal facilities would rely on the unbreakable immovable nature of the rock,
to completely entombed the potentially harmful waste for, well if not forever,
then at least for a very, very, very long time.
But sorry we can't just dig a really big hole and throw in a
load of fuel rods even disposing of fuel inside the rock can be a deceptively
complicated process. First, the site needs to be selected the ideal location is
somewhere that is geologically stable far away from faults That rupture
and cause earthquakes if drilled. The packaging of the waste is also important
to make sure it stays where it's put, spent fuel is first encased in insoluble
resin and then placed into thick steel containers. Several of these containers
are put inside steel or a copper sarcophagus which is then surrounded by buffer
materials, specifically designed to absorb the radiation. The fuels' final
resting places in deep underground bunkers could then be backfilled with
concrete to prevent any later disturbance. And the best way to avoid
disturbance, well some developers think it's to intentionally forget about, it
no signs or warnings could mean that future generations would simply lose track
of where we left the radioactive waste and that's a surefire way of
making sure that it's not looted or intentionally interfered with but there's
that minor problem of accidentally stumbling across it. With facilities planned
for nearly a kilometer down though hopefully, that's fairly unlikely, what's
also unlikely but not impossible is that over the hundreds of thousands of
years it will take for the radioactivity in the wastes to decay away. The
waste containers may also decay away leaving spent nuclear fuel sitting unprotected
ready for any passing water to wash it away and that is most definitely not
something you want.
To protect against
that engineers have come up with an ingenious solution with a pretty cool
sounding name a hydraulic cage, yeah it works by surrounding the waste
containing chambers with a layer of gravel, any water that finds its way
through the rock will find it easier to flow through the gravel around
the chamber, rather than flow through it, and that keeps the nuclear waste nice
and dry inside
So, yeah bit by bit scientists and engineers are overcoming
the challenges facing the nuclear disposal problem, but that the final
and possibly biggest challenge is not one of science but one of politics, despite
some really quite promising solutions for long-term storage and disposal the public in many countries is still incredibly suspicious of all things nuclear.
Yeah,, and political, environmental resistance has already put the brakes on the disposal
plans in the UK and in Germany.
Quite simply people don't want to be anywhere near a nuclear
waste dump no matter how safe it's designed to be as of 2018 only
one country Finland has made any real progress in implementing a geological
disposal facility and that's mostly thanks to a major ongoing public outreach
and finance program.
Back in the 1950s, nuclear power was the energy solution
of the future, one that promised to fuel our graduation into a cleaner, more
efficient, and optimistic time. How ironic then there are attitudes to the not-so-shiny reality of nuclear waste is so archaic.
Let's hope that Finland can pave the way and set an
example for the rest of the world before we find ourselves knee-deep in radioactive
waste. Because nuclear is after all a major source of power for
many countries, who have already committed huge amounts of money and
infrastructure to getting that energy out, but who are then unwilling to invest
the same in dealing with the waste that it creates.
I would love to hear what you think we should be doing with
our nuclear waste so where do let me know in the comments below:
I'm also really looking forward to hearing all of your
opinions on nuclear energy as a whole. Just remember to play nice please,
the kids:
0 Comments
Be helpful in the comments below: