A little miracle of technology - the atomic power stations are going up.

We're bombarded with radiation all the time...

...from everyday objects like a watch.

Most people think that radioactive waste is some kind of...

...but in actual fact, it looks a little bit like this - black glass.

It will be radioactive for hundreds of thousands of years,

and this is why we really need to think about its long-term future.

The danger of radioactive waste is here today,

and goes on and on tomorrow.

In full operation,

it will supply electricity for a million people.

Climate change, the gases blamed for global warming,

are pumped out in ever bigger quantities.

The window of time to mitigate the climate crisis

is shrinking by the day, really.

The problem is how to reduce greenhouse gases.

Nuclear power has a long proven record

as a non-fossil energy source.

Nuclear energy is not a solution to climate change.

Nuclear energy has a fraught history.

Greeted with optimism in the 1950s,

its reputation was clouded by atomic bomb tests

and disasters like Chernobyl,

but as global leaders work to tackle climate change,

nuclear power's allure has come full circle.

Once up and running, nuclear power stations

emit no carbon dioxide or other greenhouse gases,

and nuclear's constant energy generation sets it apart

from renewable sources of energy, whose output can vary.

For the past 60 years or so, it has provided

a very important type of electricity, which we call...

That's the type of electricity that guarantees that 24/7,

no matter when you want to flip on or off your light switch,

the lights will be there.

The inherent dangers of nuclear energy

make it a controversial energy source,

and not everyone agrees it's worth the risks it brings.

Nearly all of our nuclear waste

is at coastal sites in one way or the other.

These are locations that are liable to coastal processes,

storm surges, sea-level rise.

Those are highly vulnerable

to the worst impacts of climate change that we can foresee.

I'm concerned about the dangers it poses.

In 2011, a devastating earthquake and tsunami in Japan led to meltdown

at the Fukushima Daiichi nuclear reactor.

As a result of the Fukushima accident,

both Japan and Germany, for different reasons,

have decided to shut down rapidly

their national nuclear energy output.

They ramped up coal and gas output

for a few years after the accident.

Dr Kharecha's research found that there were health consequences

linked to this reduction in the use of nuclear energy,

as both countries increased their use of fossil fuels

in subsequent years.

As a direct yet unintended consequence

of their decision to drastically reduce their nuclear power output,

after the Fukushima accident, both Japan and Germany together

lost the opportunity to prevent

over 28,000 air-pollution-induced premature deaths

that were as a result of fossil fuel power use.

Japan is slowly restoring its nuclear capacity,

while Germany has increased its renewable energy output

over the past decade, although that was accompanied by a steep rise

in energy prices for the public.

For countries with nuclear in their energy mix,

such as the UK, Finland, and China, constructing efficient new reactors

is both expensive and time-consuming.

Hinkley Point C, Britain's first nuclear reactor since 1995,

will cost...

...at least twice as much as the London 2012 Olympic Games,

and this figure continues to rise.

Modern nuclear reactors are designed meticulously,

and built to withstand earthquakes and other threats,

including plane crashes, but even the best designed nuclear reactors

create radioactive waste, and that needs careful disposal.

In the UK, we have about four and a half million cubic metres

of radioactive waste.

The largest portion of this, about 96%, is low-level waste.

High-level waste is very high radioactivity material,

but we have the smallest volume of this, just less than 1%.

The radiation from high-level waste is so intense that,

if you were to touch it,

you'd receive a radiation dose about a million times more than you would

receive throughout an entire year just from natural radiation sources.

It's extremely high for several thousands,

even hundreds of thousands of years, so, ideally,

where we want to be is in a place where we can isolate those wastes

from future populations in a safe way -

for example, digging a very deep hole underground

and disposing of the waste there forever.

This solution is known as a...

...where waste is disposed of

between 200m and 1,000m

below the Earth's surface.

Because most people don't like the idea

of living next to radioactive waste, it's been very difficult

for governments to find a suitable site, let alone start building one.

Finland is currently the only country in the world building

a permanent underground storage facility for their nuclear waste.

Every nation with nuclear power has so far stored its waste

in temporary facilities, and those facilities are ageing.

I'm not against deep disposal, because I think ultimately,

we'll have to deal with our present waste that way,

but that is so far ahead

that the problem here and now is safe storage.

And all the time we're waiting for the holy grail

of a deep disposal facility. The job of that facility is to deal with

the massive amounts of nuclear waste that we already have.

The idea that we should be piling more and unknown quantities

for further ahead is absolutely ludicrous, in my view.

If we don't get our hands on clean energy and rapidly scale them up

by as much as possible within the next few decades,

then we're leaving a massive, massive burden

on future generations.

We need to completely decarbonise the electricity sector,

and ideally also the overall energy sector,

if we're to avert the worst impacts

of the human-caused climate crisis.

As our understanding of the climate crisis deepens,

and energy demands continue to grow, the necessity that our energy

comes from non-fossil fuel sources makes nuclear power hard to ignore.

It is expensive and it can be dangerous

if safety protocols are not followed.

The highly radioactive waste it generates is hugely challenging

to store safely, but it also provides a reliable power baseline,

keeping the lights from turning off on a cloudy, windless winter evening

and meeting countries' energy needs

as they transition away from fossil fuels.

And...