0:00:08 > 0:00:12Lying on the remote northwest coast of England
0:00:12 > 0:00:15is one of the most secret places in the country.
0:00:19 > 0:00:2365 years ago, it helped make Britain a world superpower.
0:00:27 > 0:00:31And within its walls is material that could devastate life on
0:00:31 > 0:00:33this island and beyond.
0:00:35 > 0:00:36This is Sellafield.
0:00:38 > 0:00:42Costing around £2 billion a year, it's the most controversial
0:00:42 > 0:00:44nuclear facility in Britain.
0:00:45 > 0:00:47I'm a nuclear physicist
0:00:47 > 0:00:50and I've been fascinated by this place for much of my career.
0:00:50 > 0:00:53I've heard the stories about the extraordinary experiments,
0:00:53 > 0:00:58the jaw-dropping machinery and the incredibly costly science.
0:00:58 > 0:01:00And I've also heard about the problems,
0:01:00 > 0:01:04the risks and controversies, the terrifying accidents.
0:01:04 > 0:01:08I got a phone call, "Pile one's on fire."
0:01:08 > 0:01:10I said, "Good God, you don't mean the core?"
0:01:10 > 0:01:11He said, "Yes."
0:01:12 > 0:01:15Now, they're giving me and the television cameras
0:01:15 > 0:01:17access to discover the real story.
0:01:17 > 0:01:20We're going inside Sellafield.
0:01:26 > 0:01:28We've been given access
0:01:28 > 0:01:30to some of Britain's most secret buildings.
0:01:32 > 0:01:35It's eerie being so close to something so deadly.
0:01:38 > 0:01:41That's the first time it's been touched in, probably, 51 years.
0:01:41 > 0:01:45I'll be encountering some of the most dangerous substances on Earth.
0:01:47 > 0:01:48It's your dose for the year.
0:01:48 > 0:01:50- That's your dose for the year in one...- Yeah.
0:01:50 > 0:01:52OK, so we should go out of the way now.
0:01:52 > 0:01:55I'll reveal the nature of radioactivity.
0:01:56 > 0:01:59And I'll even attempt to split the atom.
0:02:01 > 0:02:06I believe that Sellafield tells a unique and important story...
0:02:09 > 0:02:12..because it reveals Britain's attempts past, present
0:02:12 > 0:02:15and future, to harness the almost limitless power of the atom.
0:02:15 > 0:02:19It's why I think the tale of this place is one of the most
0:02:19 > 0:02:22important scientific stories of our age.
0:02:38 > 0:02:41I'm just about to go through the main gate and into Sellafield.
0:02:41 > 0:02:46I have to say, I'm pretty excited, but also a bit nervous, because
0:02:46 > 0:02:50I've had to go through some very tight security procedures to get in.
0:02:51 > 0:02:55Over the last few months, all my personal details have been
0:02:55 > 0:02:57heavily vetted by the security services.
0:02:59 > 0:03:02And, of course, every piece of filming equipment has had to be
0:03:02 > 0:03:05very, very carefully checked and re-checked.
0:03:05 > 0:03:07Now, finally, we're ready to be let in.
0:03:13 > 0:03:18This intense security is a reminder of how potentially dangerous
0:03:18 > 0:03:20what's stored here actually is.
0:03:20 > 0:03:24In the wrong hands, much of this material would be deadly.
0:03:26 > 0:03:29From hereon in, we're operating under strict national
0:03:29 > 0:03:33security procedures, and some of the images on this film
0:03:33 > 0:03:35are going to have to be blurred out.
0:03:35 > 0:03:39We can't show building numbers or routes or security cameras.
0:03:45 > 0:03:50I can already see experimental nuclear reactors, power stations
0:03:50 > 0:03:53and nuclear storage facilities.
0:03:54 > 0:03:57There are over 1,000 separate buildings.
0:03:58 > 0:04:02In fact, this site covers over six square kilometres.
0:04:03 > 0:04:06It's the most complex nuclear facility in Europe.
0:04:15 > 0:04:19One of the first impressions I get is that this place is buzzing
0:04:19 > 0:04:21with activity.
0:04:21 > 0:04:26Radioactive waste and spent nuclear fuel arrives here nearly every day.
0:04:28 > 0:04:32In case of an incident, there are regular drills by the security
0:04:32 > 0:04:34and emergency services.
0:04:36 > 0:04:39And all with good reason, because some of the most dangerous
0:04:39 > 0:04:42buildings in the world are here at Sellafield.
0:04:46 > 0:04:51I'm going to start by visiting one, because in here are clues
0:04:51 > 0:04:55that reveal the story of Britain's entry into the nuclear age.
0:04:58 > 0:05:01This is one of the infamous Sellafield storage ponds.
0:05:01 > 0:05:05The size of eight Olympic swimming pools, it's the largest open
0:05:05 > 0:05:07nuclear pond in the world.
0:05:07 > 0:05:13For about a decade, between the mid 1950s and 1960s, this five metre
0:05:13 > 0:05:17deep water was used to store a huge range of nuclear waste,
0:05:17 > 0:05:21all sorts of experimental nuclear fuels, highly radioactive
0:05:21 > 0:05:26isotopes, hazardous irradiated debris and contaminated leftovers.
0:05:31 > 0:05:37And, now, Sellafield is starting to clear these so-called legacy ponds.
0:05:37 > 0:05:38I think go for this one.
0:05:42 > 0:05:46The hundreds of tonnes of waste down here are a physical record of
0:05:46 > 0:05:48the history of Sellafield.
0:05:54 > 0:05:59And hidden deep within this debris is evidence of the top secret
0:05:59 > 0:06:01project that started it all.
0:06:08 > 0:06:10Britain's race to build an atom bomb.
0:06:12 > 0:06:17In 1945, the world looked on in awe as these terrifying new
0:06:17 > 0:06:20nuclear weapons were unleashed on Japan.
0:06:22 > 0:06:26Their extraordinary power came from inside the atom.
0:06:27 > 0:06:32And it was a German chemist, called Otto Hahn, who first stumbled
0:06:32 > 0:06:36across the power inside an atom almost by accident.
0:06:37 > 0:06:42In 1938, in his Berlin laboratory, Hahn was investigating
0:06:42 > 0:06:44a metal called uranium.
0:06:48 > 0:06:52This tiny disc is a sliver of uranium.
0:06:52 > 0:06:54This is what the fuss is all about.
0:06:54 > 0:06:59Now, uranium is the heaviest naturally occurring element.
0:06:59 > 0:07:05Its nucleus is made up of over 200 particles, protons and neutrons.
0:07:05 > 0:07:08Otto Hahn was fascinated by uranium and wondered what happens
0:07:08 > 0:07:13when a single neutron hits the nucleus.
0:07:13 > 0:07:16But what he found when he did his experiments...
0:07:16 > 0:07:17made no sense at all.
0:07:22 > 0:07:25Now, I know this is a cliche and I've said it many times before,
0:07:25 > 0:07:29but this single experiment really did change the world for ever.
0:07:31 > 0:07:35Without realising it, Otto Hahn had taken the first step
0:07:35 > 0:07:37into the nuclear age.
0:07:39 > 0:07:42For what we think is the very first time on television,
0:07:42 > 0:07:46we're going to re-create a version of the actual experiment carried
0:07:46 > 0:07:49out by Otto Hahn three-quarters of a century ago.
0:07:50 > 0:07:55This accelerator will produce a beam of particles containing neutrons.
0:07:57 > 0:08:02And I can drop this piece of uranium right in its path, just down here.
0:08:03 > 0:08:05Now, turn on the beam.
0:08:06 > 0:08:10Just like in Hahn's experiment, my uranium is being bombarded
0:08:10 > 0:08:11with neutrons.
0:08:31 > 0:08:35One hour later and it's fizzing with radioactivity.
0:08:39 > 0:08:43Now, with uranium, gamma ray spectroscopy always shows
0:08:43 > 0:08:46these three energy peaks.
0:08:46 > 0:08:49This is the unique signature of uranium.
0:08:49 > 0:08:52But after bathing our sample in neutrons for an hour,
0:08:52 > 0:08:54we get a different picture.
0:08:54 > 0:08:55Have a look at this.
0:08:56 > 0:09:00Now, in yellow, we get the same three uranium peaks
0:09:00 > 0:09:02but we also get a new one.
0:09:04 > 0:09:07Because this peak is the characteristic signature,
0:09:07 > 0:09:09not of uranium, but of barium.
0:09:15 > 0:09:20But the nucleus of a barium atom is about half the weight of uranium.
0:09:23 > 0:09:28So, how can a single neutron turn heavy uranium into light barium?
0:09:32 > 0:09:36The only possible explanation is if the nucleus of uranium
0:09:36 > 0:09:40is splitting into two roughly equal fragments.
0:09:40 > 0:09:43What we've done in this lab today is exactly what Otto Hahn
0:09:43 > 0:09:44did in his experiment.
0:09:44 > 0:09:46We've split the atom.
0:09:51 > 0:09:56I believe Otto Hahn's accidental discovery in 1938
0:09:56 > 0:09:58marks the beginning of the nuclear age.
0:10:01 > 0:10:04Because his experiment showed that something even more
0:10:04 > 0:10:06extraordinary had happened.
0:10:06 > 0:10:10The two fragments produced by the uranium nucleus weren't just
0:10:10 > 0:10:14falling apart, they were exploding apart with enough
0:10:14 > 0:10:19energy from a single nucleus to move a grain of sand.
0:10:20 > 0:10:22Now, that may not sound like much,
0:10:22 > 0:10:25but imagine how much energy could be produced
0:10:25 > 0:10:30if every one of the billion trillion uranium nuclei split in our sample.
0:10:31 > 0:10:36Just think what might be possible if this experiment could be scaled up.
0:10:41 > 0:10:45Within just four weeks of Hahn splitting the first uranium atom,
0:10:45 > 0:10:49a scientist in Washington drew a diagram on a blackboard.
0:10:49 > 0:10:51The diagram was of a new kind of weapon,
0:10:51 > 0:10:55and the scientist was Robert Oppenheimer.
0:10:55 > 0:10:58The creator of the atomic bomb.
0:11:05 > 0:11:10Six years later, his nuclear weapons brought the Second World War
0:11:10 > 0:11:11to an abrupt end.
0:11:14 > 0:11:16So where did that leave Britain?
0:11:18 > 0:11:22If it was to be a superpower alongside America and Russia,
0:11:22 > 0:11:23it needed a bomb of its own.
0:11:29 > 0:11:34So, far away from prying eyes, deep in the Cumbrian countryside, near a
0:11:34 > 0:11:40hamlet called Sellafield, plans were afoot to join the nuclear arms race.
0:11:45 > 0:11:50In fact, the government first built all of this as a top secret
0:11:50 > 0:11:52military research facility.
0:11:52 > 0:11:54It was called Windscale.
0:11:55 > 0:12:00And its aim - to make plutonium for a British atom bomb.
0:12:03 > 0:12:07In here is the prize the Windscale scientists were after.
0:12:08 > 0:12:10This is plutonium.
0:12:10 > 0:12:14Just like uranium, when atoms of plutonium split or fission,
0:12:14 > 0:12:16they release a massive burst of energy.
0:12:20 > 0:12:21But there's a catch.
0:12:22 > 0:12:28Virtually the only way plutonium can be made is out of uranium
0:12:28 > 0:12:30in a nuclear reactor.
0:12:41 > 0:12:46So, for four straight years, 5,000 people toiled day and night
0:12:46 > 0:12:48to build one.
0:12:53 > 0:12:57The science was so new and experimental that the plans
0:12:57 > 0:12:59would change almost daily.
0:13:06 > 0:13:11But despite this, in October 1950, just ten days behind schedule...
0:13:13 > 0:13:17..the Windscale nuclear reactor was finished.
0:13:38 > 0:13:41This is the heart of it.
0:13:41 > 0:13:44Otto Hahn's experiment on a massive scale.
0:13:48 > 0:13:50This is the reactor itself.
0:13:50 > 0:13:54Over 20 metres high...
0:13:54 > 0:13:58weighing over 2,000 tonnes...
0:13:58 > 0:14:02containing over 70,000 uranium rods.
0:14:05 > 0:14:10Inside this reactor, the scientists hoped to turn uranium into
0:14:10 > 0:14:12plutonium for their bomb.
0:14:14 > 0:14:17But to do that, they needed to trigger a chain reaction.
0:14:21 > 0:14:25Inside this box are 120 primed mouse traps,
0:14:25 > 0:14:28each one with a ping-pong ball on top.
0:14:28 > 0:14:32Let's see what happens when I drop this single ball in the top.
0:14:40 > 0:14:43One ball triggers more and more mouse traps.
0:14:44 > 0:14:46This is a chain reaction.
0:14:50 > 0:14:53The Windscale scientists believed their reactor would trigger
0:14:53 > 0:14:56a chain reaction, that, in the process,
0:14:56 > 0:14:59would turn some of the uranium into plutonium.
0:15:01 > 0:15:05As each uranium atom splits, it also releases neutrons.
0:15:07 > 0:15:10And just like the ping-pong balls triggering the mouse traps,
0:15:10 > 0:15:14these neutrons could split new uranium atoms.
0:15:16 > 0:15:20So, if they got it right, the uranium would trigger a massive
0:15:20 > 0:15:25nuclear chain reaction, producing enough neutrons to turn some
0:15:25 > 0:15:28of the uranium into plutonium for the bomb.
0:15:33 > 0:15:37Very nice. That's the genius of the chain reaction.
0:15:38 > 0:15:43That was the theory, but nobody knew for sure if it would actually work.
0:15:45 > 0:15:51The development work that should have been done was all cut
0:15:51 > 0:15:55short by the extreme political and military pressure on them,
0:15:55 > 0:15:59the very, very tight deadlines they were given.
0:15:59 > 0:16:05You did feel that we were in the vanguard of being something
0:16:05 > 0:16:06really new.
0:16:06 > 0:16:10Everybody was on a learning curve there, really, from, you know,
0:16:10 > 0:16:13ground floor to top level.
0:16:17 > 0:16:22In October 1950, the Windscale reactor was finally started up.
0:16:31 > 0:16:33This was the moment of truth.
0:16:39 > 0:16:43Inside the reactor, the chain reaction began.
0:16:45 > 0:16:46It worked.
0:16:46 > 0:16:49In the space of just four years, we'd gone from a basic
0:16:49 > 0:16:53understanding of nuclear fission to a working nuclear reactor.
0:16:57 > 0:17:00The uranium started to turn into plutonium.
0:17:02 > 0:17:06But, frustratingly, the process was agonisingly slow.
0:17:08 > 0:17:11It took six months in the reactor until there was enough
0:17:11 > 0:17:14plutonium to begin to extract it.
0:17:17 > 0:17:20I broke down the reaction vessel myself, scrambled around
0:17:20 > 0:17:23amongst calcium fluoride, to see if I could find anything.
0:17:23 > 0:17:27And there I found a piece of plutonium about this size, about
0:17:27 > 0:17:33the size of a 50p piece, 132 grams, and that was our very first piece.
0:17:38 > 0:17:42But by 1952, they'd managed to get enough to make
0:17:42 > 0:17:44the first British nuclear weapon.
0:17:57 > 0:17:59And it was detonated in Montebello Island
0:17:59 > 0:18:01in Western Australia.
0:18:04 > 0:18:06That lethal cloud, rising above Montebello,
0:18:06 > 0:18:10marks the achievement of British science and industry.
0:18:10 > 0:18:13At last, Britain had entered the nuclear age.
0:18:16 > 0:18:19These weapons had revealed just how much energy there was
0:18:19 > 0:18:21within the atom.
0:18:24 > 0:18:27But for the nuclear physicists there was another realisation,
0:18:27 > 0:18:30that the same science that had split the atom
0:18:30 > 0:18:35and produced the bomb could also be used for the betterment of humanity.
0:18:35 > 0:18:38That it also had the potential to produce almost limitless
0:18:38 > 0:18:43cheap energy, energy to power our cities, light our homes
0:18:43 > 0:18:45and forge a secure future for everyone.
0:18:47 > 0:18:51Because as well as producing plutonium, the reactor produced
0:18:51 > 0:18:54heat, and that heat could be harnessed.
0:18:58 > 0:19:01The dream was that the power of the atom would come out of the
0:19:01 > 0:19:05shadow of the bomb and into our living rooms...
0:19:07 > 0:19:09..as electricity.
0:19:12 > 0:19:16And, once again, Sellafield was at the very heart of the story.
0:19:18 > 0:19:23Here, in 1952, work began on an ambitious experiment in power
0:19:23 > 0:19:26generation that would shape the modern world.
0:19:30 > 0:19:33It was called Calder Hall.
0:19:36 > 0:19:40And when it opened in 1956, the nation celebrated.
0:19:43 > 0:19:47This new power which has proved itself to be such a terrifying
0:19:47 > 0:19:52weapon of destruction is harnessed for the first time,
0:19:52 > 0:19:55for the common good of our community.
0:19:57 > 0:20:01This is the control room of Calder Hall Reactor One,
0:20:01 > 0:20:02the nerve centre
0:20:02 > 0:20:05of the world's first commercial nuclear power station.
0:20:05 > 0:20:08On the 27th of August, 1956,
0:20:08 > 0:20:11heat generated from a nuclear chain reaction
0:20:11 > 0:20:14was used to turn water into steam,
0:20:14 > 0:20:17which drove a turbine that generated electricity.
0:20:17 > 0:20:21That electricity now poured into the National Grid.
0:20:21 > 0:20:24Britain had become a nuclear-powered nation.
0:20:32 > 0:20:34Within ten years,
0:20:34 > 0:20:38eight new nuclear power stations were turned on across the country.
0:20:40 > 0:20:42Puffed up with scientific zeal,
0:20:42 > 0:20:46politicians announced that nuclear power was so cheap
0:20:46 > 0:20:49they wouldn't even bother metering the electricity.
0:20:53 > 0:20:56At its peak, Calder Hall provided enough electricity
0:20:56 > 0:20:59to supply hundreds of thousands of homes.
0:21:06 > 0:21:10Today, I'm being allowed inside Calder Hall.
0:21:11 > 0:21:14I'm about to see something that as a theoretical physicist
0:21:14 > 0:21:16I've only ever imagined,
0:21:16 > 0:21:21the core of a nuclear reactor, where the uranium rods actually sit.
0:21:25 > 0:21:29Well, I'm at the heart of Calder Hall Reactor One
0:21:29 > 0:21:32and down here...
0:21:32 > 0:21:34beneath my feet is the core itself.
0:21:36 > 0:21:40'Just ten metres below me are thousands of radioactive
0:21:40 > 0:21:42'uranium fuel rods.'
0:21:43 > 0:21:45SIREN
0:21:49 > 0:21:51'I'm with the inspection team
0:21:51 > 0:21:54'that's going to check the state of these fuel rods,
0:21:54 > 0:21:57'and that means opening up the core itself.'
0:21:58 > 0:22:01So, what exactly will we see today?
0:22:01 > 0:22:03- When I take the blank off...- Right.
0:22:03 > 0:22:05..and then we'll take the shield plug out,
0:22:05 > 0:22:08put a spiral camera down and you'll be able to see into the reactor.
0:22:08 > 0:22:10What sort of things do you hope to see with the camera?
0:22:10 > 0:22:13Top of the fuel elements.
0:22:13 > 0:22:15To make sure that there's no nasties in there.
0:22:15 > 0:22:18That's right, yeah, there's no obstructions or anything like that.
0:22:20 > 0:22:21I'm, I'm feeling the,
0:22:21 > 0:22:25the usual combination of excitement and nervousness.
0:22:27 > 0:22:28Right, so we should get out of the way now?
0:22:28 > 0:22:31- Er, yes!- Right, OK!
0:22:36 > 0:22:38This is the protective shield plug
0:22:38 > 0:22:41that sits just above the core itself.
0:22:42 > 0:22:45This reactor was shut down 12 years ago,
0:22:45 > 0:22:48but despite that the core is still hot,
0:22:48 > 0:22:51with radioactivity, which they monitor closely.
0:22:52 > 0:22:54DISTANT SIREN
0:22:54 > 0:22:57- When the plug came out... - INDISTINCT
0:22:57 > 0:22:58..gamma, beta-gamma.
0:22:58 > 0:23:01That's something like, I guess how much,
0:23:01 > 0:23:03a dose you'd get from a C-Scan or something like that.
0:23:03 > 0:23:07- That's your dose for the year.- Your dose for a year in one...- Yeah.
0:23:07 > 0:23:09- OK, right.- Yeah.- So, still...
0:23:09 > 0:23:12- Still a... - ..full of radioactivity there.
0:23:12 > 0:23:14SIREN CONTINUES
0:23:14 > 0:23:19The team also regularly monitors the physical state of the rods.
0:23:19 > 0:23:24'And the only way to do that is by remote control camera.'
0:23:24 > 0:23:27This is us going down through standpipe,
0:23:27 > 0:23:29heading down into the reactor floor.
0:23:29 > 0:23:31- It's a long way down. - Yeah, it's 20 feet.
0:23:31 > 0:23:32DISTANT SIREN
0:23:35 > 0:23:37OK, Robert, can we stop there?
0:23:37 > 0:23:39Whoa. Here are the channels.
0:23:39 > 0:23:41- Those are the channels within the standpipe.- Yeah.
0:23:41 > 0:23:44And each channel, that's where the fuel rods...
0:23:44 > 0:23:45That's where the fuel rod is
0:23:45 > 0:23:49and there's either five or six fuel elements in each channel.
0:23:49 > 0:23:50The flashes on the picture
0:23:50 > 0:23:54are the effects of the powerful radiation on the camera.
0:23:54 > 0:23:55Just here,
0:23:55 > 0:23:59that's the glimmer of the top of a fuel element you can just see there.
0:23:59 > 0:24:02Just about see them shining.
0:24:03 > 0:24:08Eventually, all these uranium fuel rods will be removed.
0:24:08 > 0:24:12Not many people get to look down into a reactor core
0:24:12 > 0:24:13staring at a fuel rod.
0:24:18 > 0:24:20BIRDS TWEET
0:24:21 > 0:24:26Calder Hall has, without doubt, been a scientific success story.
0:24:27 > 0:24:30It proved that nuclear power really worked.
0:24:34 > 0:24:37But just over a year after it opened,
0:24:37 > 0:24:40this age of optimism came to an end.
0:24:44 > 0:24:48The nuclear forces that Otto Hahn unleashed back in 1938
0:24:48 > 0:24:51had unexpected consequences.
0:24:51 > 0:24:54Inside the Pandora's box of the atomic nucleus,
0:24:54 > 0:24:57along with the hope of unlimited energy,
0:24:57 > 0:24:59- was a dark secret... - MUFFLED SIREN
0:24:59 > 0:25:02..that these forces were hard to control.
0:25:04 > 0:25:07And this became terrifyingly apparent
0:25:07 > 0:25:10in the Windscale fire of 1957.
0:25:15 > 0:25:18Monday, 7th of October,
0:25:18 > 0:25:21the Windscale reactor was shut down for routine maintenance.
0:25:23 > 0:25:26But then, something strange happened.
0:25:27 > 0:25:31Instead of cooling, the temperature inside started to rise.
0:25:33 > 0:25:37My grandfather was part of the team working here. Um...
0:25:37 > 0:25:40the evidence and the information that was being relayed to them
0:25:40 > 0:25:42indicated something was amiss.
0:25:44 > 0:25:49I walked up on to the top of the pile
0:25:49 > 0:25:52and I saw a monitor up there
0:25:52 > 0:25:57and he said, "It's too hot. There's too much radiation."
0:25:58 > 0:26:01Eventually, someone peered into the core itself
0:26:01 > 0:26:05from a hole at the top of the reactor just here.
0:26:05 > 0:26:09They saw something no-one had ever considered possible.
0:26:09 > 0:26:11The core itself was on fire.
0:26:13 > 0:26:16I got a phone call from the General Manager.
0:26:16 > 0:26:18He said, "Tom, Pile One's on fire."
0:26:18 > 0:26:21I said, "Good God, you don't mean the core?"
0:26:21 > 0:26:22He said, "Yes."
0:26:22 > 0:26:25And we didn't know what we could do to stop it.
0:26:25 > 0:26:26DISTANT ALARM
0:26:26 > 0:26:29The fire raged for three days.
0:26:29 > 0:26:33Workers risked terrible radiation burns trying to push the fuel
0:26:33 > 0:26:37out of the reactor, using anything they could lay their hands on.
0:26:37 > 0:26:41But despite this, the fire continued to burn.
0:26:41 > 0:26:44So, they came up with a new plan...
0:26:44 > 0:26:46they'd flood the core
0:26:46 > 0:26:50and turn off the cooling fans.
0:26:50 > 0:26:52It was a huge risk.
0:26:52 > 0:26:54If you look at the size of the reactor face,
0:26:54 > 0:26:56each one of these tubes has fuel in,
0:26:56 > 0:27:00so the risk of setting them all on fire is immense.
0:27:00 > 0:27:06If they were wrong, the whole reactor might explode.
0:27:06 > 0:27:07You've got this blazing inferno
0:27:07 > 0:27:11with these flames belting out and hitting the back wall.
0:27:11 > 0:27:15Mankind had not faced anything like this ever before.
0:27:15 > 0:27:19- ALARM - They had no alternative.
0:27:19 > 0:27:21They hit the switch.
0:27:24 > 0:27:27The air goes off and psst...
0:27:27 > 0:27:28just like that.
0:27:28 > 0:27:30Absolutely incredible.
0:27:32 > 0:27:34The fire was finally out.
0:27:36 > 0:27:39But a new danger became apparent.
0:27:42 > 0:27:46Flames had melted the casing surrounding the nuclear fuel
0:27:46 > 0:27:48and some of the elements had burst.
0:27:48 > 0:27:52Radioactive material escaped out and up the chimney.
0:27:52 > 0:27:57A cloud of smoke began to fall over the area.
0:27:57 > 0:28:02As the wind blew it eastwards, it seemed catastrophic.
0:28:02 > 0:28:05Thousands of square miles might be contaminated.
0:28:05 > 0:28:07Hundreds of people could die.
0:28:10 > 0:28:13But it didn't happen.
0:28:13 > 0:28:14Thanks to one man.
0:28:26 > 0:28:31I'm now in the lift, climbing the 120-metre high chimney
0:28:31 > 0:28:33that was built to release the air
0:28:33 > 0:28:36used to cool the nuclear pile down below.
0:28:36 > 0:28:39Now, at the time, no-one imagined that releasing this air
0:28:39 > 0:28:42out into the atmosphere was in any way hazardous.
0:28:42 > 0:28:44Well, almost no-one.
0:28:50 > 0:28:54Seven years earlier, the Windscale Project had been masterminded
0:28:54 > 0:28:57by a physicist called John Cockcroft.
0:28:57 > 0:29:00He'd made his name in 1932,
0:29:00 > 0:29:03when he'd knocked together the world's first atomic accelerator.
0:29:03 > 0:29:06It was made out of packing cases and tinfoil
0:29:06 > 0:29:08and eventually won him the Nobel Prize.
0:29:15 > 0:29:19After this chimney was built, Cockcroft had a moment of doubt.
0:29:19 > 0:29:22What if the cooling air became contaminated?
0:29:22 > 0:29:26Now, no-one on his team believed this could actually happen,
0:29:26 > 0:29:28but Cockcroft was intransigent.
0:29:28 > 0:29:31He demanded that his engineers build a filter here
0:29:31 > 0:29:35at the very top of the 120-metre chimney.
0:29:35 > 0:29:39They laughingly called his idea "Cockcroft's Folly."
0:29:40 > 0:29:42Of course, he got his way.
0:29:42 > 0:29:45You can still see where the filters were slotted in
0:29:45 > 0:29:48across the top of the open chimney.
0:29:49 > 0:29:53As the cloud from the fire below belched out of the chimney,
0:29:53 > 0:29:58Cockcroft's Folly trapped almost all of the radioactivity.
0:30:02 > 0:30:07Designed by a maverick genius, built on a whim, this basic filter
0:30:07 > 0:30:10saved the North West and beyond from a terrible fate.
0:30:19 > 0:30:22This was the world's first nuclear accident
0:30:22 > 0:30:27and it served as a powerful warning that harvesting nuclear energy
0:30:27 > 0:30:33could lead to some unexpected and potentially lethal consequences.
0:30:33 > 0:30:35In the decades that have followed,
0:30:35 > 0:30:38there have been other more serious incidents at nuclear plants
0:30:38 > 0:30:40around the world.
0:30:41 > 0:30:44Three Mile Island,
0:30:44 > 0:30:45Chernobyl
0:30:45 > 0:30:46and Fukushima.
0:30:51 > 0:30:55Now, terms like contamination and radioactive leak
0:30:55 > 0:30:58are for ever etched in the public consciousness.
0:31:02 > 0:31:05I think what haunts us about radioactivity
0:31:05 > 0:31:08is that it's invisible,
0:31:08 > 0:31:10it's intangible
0:31:10 > 0:31:13and sometimes deadly.
0:31:13 > 0:31:16At Sellafield itself, it's something of an obsession.
0:31:16 > 0:31:18BELL RINGS
0:31:18 > 0:31:21Every time I leave a building,
0:31:21 > 0:31:26I'm checked and re-checked for any signs of radioactive contamination.
0:31:28 > 0:31:31But what exactly is radioactivity?
0:31:32 > 0:31:36Radioactivity is, in fact, three different processes,
0:31:36 > 0:31:38each one dangerous in its own particular way.
0:31:38 > 0:31:41They're called alpha, beta and gamma.
0:31:41 > 0:31:44Let me show you with this radioactive source.
0:31:44 > 0:31:46Now, this is a mineral called pitch blend
0:31:46 > 0:31:49which emits all three types of radioactivity.
0:31:49 > 0:31:52The first type is alpha radiation.
0:31:52 > 0:31:56Now, these are the emission of tiny lumps of nuclear matter
0:31:56 > 0:32:00made up of two protons and two neutrons called alpha particles.
0:32:00 > 0:32:03They're spat out from a nucleus, like uranium.
0:32:03 > 0:32:06Now, alpha radiation is very short-ranged
0:32:06 > 0:32:09so I have to bring this detector very close to the source
0:32:09 > 0:32:11to pick them up.
0:32:13 > 0:32:18And even a thin sheet of paper will stop them almost completely.
0:32:18 > 0:32:21Of course, alpha radiation is still dangerous
0:32:21 > 0:32:23when it comes into contact with skin
0:32:23 > 0:32:25or if you breathe it in or ingest it.
0:32:25 > 0:32:29The second type of radioactivity is called beta radiation.
0:32:29 > 0:32:31Now, these are tiny particles, electrons,
0:32:31 > 0:32:33or their cousins, the positrons,
0:32:33 > 0:32:36that are spat out of a nucleus at very high speed.
0:32:39 > 0:32:42When I switch my detector to beta radiation,
0:32:42 > 0:32:45we see that these particles are more penetrating,
0:32:45 > 0:32:47passing straight through paper...
0:32:49 > 0:32:52..but a sheet of aluminium blocks them.
0:32:55 > 0:32:58But beta radiation is also very dangerous -
0:32:58 > 0:33:01in fact, if exposed to it, it can burn the skin.
0:33:01 > 0:33:03Beta particles can even penetrate the skin
0:33:03 > 0:33:05and burn the tissue beneath.
0:33:06 > 0:33:08The third type is gamma radioactivity.
0:33:08 > 0:33:12Now, this is the emission not of particles of matter at all,
0:33:12 > 0:33:14but tiny lumps of light -
0:33:14 > 0:33:17high energy photons that fly out from the nucleus.
0:33:20 > 0:33:22Now when I look for gamma radiation,
0:33:22 > 0:33:25I see it passes easily through the aluminium,
0:33:25 > 0:33:29but a sheet of dense metal like lead effectively blocks them.
0:33:33 > 0:33:36To show you just how damaging gamma radioactivity can be,
0:33:36 > 0:33:38I've got these two plants.
0:33:38 > 0:33:40Now, one I'm going to place safely out here
0:33:40 > 0:33:44and the other inside this radiation furnace.
0:33:47 > 0:33:52This will blast the plant with a huge radiation dose -
0:33:52 > 0:33:56about the same as that given off by a spent nuclear fuel rod.
0:34:02 > 0:34:07Within minutes, the powerful radiation starts to affect the plant
0:34:07 > 0:34:08and our camera.
0:34:10 > 0:34:14The white snow is due to the radiation striking the camera's sensor.
0:34:26 > 0:34:30After an hour, the plant is transformed.
0:34:30 > 0:34:32Oh, wow!
0:34:32 > 0:34:34Look at that -
0:34:34 > 0:34:38the leaves are hanging limply, some of the flowers have fallen off.
0:34:38 > 0:34:42Compared with the healthy specimen, that looks a real mess.
0:34:47 > 0:34:49Under the microscope,
0:34:49 > 0:34:51we can see the damage done to the irradiated sample.
0:34:51 > 0:34:56Now, this is what a healthy sample should look like -
0:34:56 > 0:35:01beautiful, clearly defined cells, nice clean cell walls.
0:35:01 > 0:35:05And here is our irradiated sample -
0:35:05 > 0:35:09the cells are burnt, the cell walls have been damaged...
0:35:09 > 0:35:12and all this from just radioactivity.
0:35:16 > 0:35:19It explodes as energy...
0:35:19 > 0:35:22In the 1960s and '70s,
0:35:22 > 0:35:26public understanding about the effects of radioactivity grew...
0:35:27 > 0:35:32..and so, too, did their unease with the nuclear industry itself.
0:35:32 > 0:35:38The cosy, optimistic, clean image of the '50s had changed.
0:35:38 > 0:35:40Hey, hold it!
0:35:40 > 0:35:43But the government kept faith with the nuclear programme
0:35:43 > 0:35:45and pushed ahead.
0:35:46 > 0:35:53Here at Sellafield, they built the Windscale Advanced Gas Reactor
0:35:53 > 0:35:55and, across the country, there were others -
0:35:55 > 0:35:57Chapelcross,
0:35:57 > 0:35:58Dungeness,
0:35:58 > 0:35:59Sizewell.
0:36:01 > 0:36:05By the mid-'70s, over a dozen nuclear power stations
0:36:05 > 0:36:08were producing a quarter of Britain's electricity...
0:36:11 > 0:36:15..but they were also producing huge amounts of radioactive material.
0:36:21 > 0:36:26Virtually all of it was sent here, to Sellafield, for storage.
0:36:26 > 0:36:30And as we now know, this is nasty stuff.
0:36:30 > 0:36:33So, what on earth were they going to do with it?
0:36:42 > 0:36:47Back then, some of it was simply stored deep underwater
0:36:47 > 0:36:49in these vast open-air storage ponds.
0:36:51 > 0:36:55Hundreds of tonnes of spent fuel rods and radioactive waste
0:36:55 > 0:36:57were effectively dumped.
0:36:59 > 0:37:03Worryingly, there wasn't a long-term plan for any of it.
0:37:08 > 0:37:10By the 1980s,
0:37:10 > 0:37:13one of the defining issues for opponents of the nuclear industry
0:37:13 > 0:37:16was radioactive waste.
0:37:16 > 0:37:20Low-level waste should be the easiest to dispose of.
0:37:20 > 0:37:23In fact, it's simply dumped,
0:37:23 > 0:37:26left to the rain to leach it away, perhaps into local streams.
0:37:28 > 0:37:30Opposition to the nuclear industry grew
0:37:30 > 0:37:34over fears about the amounts of radioactive material
0:37:34 > 0:37:37they felt was being moved around the country.
0:37:40 > 0:37:41By the early '80s,
0:37:41 > 0:37:45there was a battle for the hearts and minds of public opinion.
0:37:46 > 0:37:50Nuclear power is not safe, not economic, not needed
0:37:50 > 0:37:52and certainly not worth the risk.
0:37:53 > 0:37:57The focus of the argument was the disposal of nuclear material.
0:37:59 > 0:38:01The environmentalists on one side,
0:38:01 > 0:38:04trying to stop its movement around the country...
0:38:06 > 0:38:08..the nuclear industry on the other...
0:38:10 > 0:38:12The flask wasn't significantly damaged...
0:38:12 > 0:38:16If they distrust us, we've said, "All right, well, we'll show them."
0:38:16 > 0:38:19..going to extreme lengths to try to prove how safe it was
0:38:19 > 0:38:22when it was being moved.
0:38:22 > 0:38:25But dropping the flask wasn't enough.
0:38:29 > 0:38:32It had remained intact and totally safe for the public
0:38:32 > 0:38:35had it contained actual radioactive materials.
0:38:42 > 0:38:46And all the time, radioactive waste and spent uranium fuel rods
0:38:46 > 0:38:50were still arriving at one place -
0:38:50 > 0:38:51Sellafield.
0:38:53 > 0:38:57It was gaining a reputation as Britain's nuclear dustbin.
0:38:59 > 0:39:02Then, on the 18th of November 1983,
0:39:02 > 0:39:06something happened here that damaged Sellafield's reputation irrevocably,
0:39:06 > 0:39:09so badly, in fact, that many people questioned
0:39:09 > 0:39:12whether the plant should be closed down altogether.
0:39:16 > 0:39:19That morning, scientists at Sellafield looked out to sea
0:39:19 > 0:39:22and saw an inky black slick.
0:39:22 > 0:39:25It was a slick of waste pouring out of Sellafield.
0:39:27 > 0:39:29Something had gone wrong.
0:39:29 > 0:39:32Highly radioactive waste went into this tank by mistake
0:39:32 > 0:39:34and much of it was discharged to the sea.
0:39:36 > 0:39:39Now, it's easy to point the finger in retrospect
0:39:39 > 0:39:43but, without doubt, a certain complacency had set in at Sellafield -
0:39:43 > 0:39:47a day-to-day lack of forethought and safety.
0:39:47 > 0:39:49Due to basic miscommunication,
0:39:49 > 0:39:53stored radioactive water was accidentally released out into the sea.
0:39:55 > 0:39:58Suddenly, more than ever before,
0:39:58 > 0:40:01their safety record was a matter of public concern.
0:40:03 > 0:40:07Greenpeace had been monitoring the discharges when the slick appeared.
0:40:07 > 0:40:08They sent the dinghy
0:40:08 > 0:40:11to the Government's Radiation Protection Board for tests...
0:40:11 > 0:40:15The local environmental pressure group wants Sellafield closed.
0:40:15 > 0:40:20This incident appeared to confirm the environmentalists' worst fears -
0:40:20 > 0:40:24accidents like this were bound to happen.
0:40:27 > 0:40:31The future of Sellafield appeared to hang in the balance.
0:40:34 > 0:40:38But, actually, plans were already in place to change the way
0:40:38 > 0:40:42they dealt with radioactive waste and the spent fuel rods.
0:40:43 > 0:40:47The most ambitious of all...
0:40:47 > 0:40:49was this -
0:40:49 > 0:40:53the Thermal Oxide Reprocessing Plant, Thorp.
0:41:01 > 0:41:06Costing more than £2 billion, it opened in 1994.
0:41:07 > 0:41:12It's one of the world's largest nuclear reprocessing plants,
0:41:12 > 0:41:15designed to deal with spent fuel rods safely...
0:41:18 > 0:41:22..and to commercially extract the uranium from them to be used again.
0:41:25 > 0:41:29In the '70s and '80s, when uranium was thought to be scarce,
0:41:29 > 0:41:30this was a huge idea
0:41:30 > 0:41:34because this uranium can then go back into nuclear power stations.
0:41:37 > 0:41:41Reprocessing had been done at Sellafield before
0:41:41 > 0:41:43but nothing like on this scale.
0:41:46 > 0:41:49This is the receipt pond.
0:41:49 > 0:41:51It's here that the spent fuel canisters arrive
0:41:51 > 0:41:54from power stations all around the world.
0:41:54 > 0:41:56It's in this pond that they're first opened up
0:41:56 > 0:42:01and the spent fuel rods removed and then taken to the storage pond.
0:42:08 > 0:42:11Then, the empty flasks are lifted up, taken away
0:42:11 > 0:42:13and washed to be used again.
0:42:22 > 0:42:26Meanwhile, the spent fuel is moved here -
0:42:26 > 0:42:28a massive storage pond.
0:42:30 > 0:42:32The water acts as a shield,
0:42:32 > 0:42:34blocking the radioactivity while it cools down...
0:42:37 > 0:42:39..a process that can take up to five years.
0:42:43 > 0:42:46Once the fuel rods have cooled down underwater,
0:42:46 > 0:42:49they're ready for the reprocessing to take place.
0:42:49 > 0:42:52Now, first of all, they have to be monitored because we have
0:42:52 > 0:42:55to make sure that they contain what they say on the tin.
0:42:55 > 0:42:58These rods come from reactors from all round the world.
0:43:03 > 0:43:07Once that's done, they can be taken up through that entry there
0:43:07 > 0:43:09into what's called the sheer cave.
0:43:09 > 0:43:11Once they're in there,
0:43:11 > 0:43:14they're behind two metres-thick concrete walls
0:43:14 > 0:43:16and they're beyond any human contact.
0:43:19 > 0:43:21Through metre-thick glass,
0:43:21 > 0:43:24you can see the machinery used to cut up the rods
0:43:24 > 0:43:29before being dissolved into boiling nitric acid.
0:43:35 > 0:43:38The next stage is to extract the pure uranium.
0:43:40 > 0:43:42Each one of these machines is an agitator
0:43:42 > 0:43:44and it just has a stirrer on the bottom
0:43:44 > 0:43:47which mixes up the nitric acid feed with the solvent.
0:43:47 > 0:43:51In my plant, the uranium is contacted with solvent
0:43:51 > 0:43:54and we get just pure uranium.
0:43:54 > 0:43:57The entirety of my system happens behind two metres of concrete.
0:43:57 > 0:44:01I can never touch or never go anywhere near the vessels in my system.
0:44:01 > 0:44:04The actual equipment attached to this motor is metres beneath me,
0:44:04 > 0:44:07in a tank that, until we decommission the plant,
0:44:07 > 0:44:09no-one will ever see again.
0:44:11 > 0:44:15Thorp reclaims the uranium as well as plutonium
0:44:15 > 0:44:18from the spent fuel, so that it can be used again.
0:44:20 > 0:44:23This isn't disposal - it's reprocessing.
0:44:26 > 0:44:31Thorp gave a much-needed boost to Sellafield.
0:44:31 > 0:44:36Attitudes to safety appeared very different from the '70s and '80s.
0:44:36 > 0:44:39It seemed to be taking waste management seriously.
0:44:48 > 0:44:52But although 97% of the spent nuclear fuel is recycled
0:44:52 > 0:44:57here at Sellafield, that still leaves 3% as waste...
0:44:59 > 0:45:01..and that 3% is a problem
0:45:01 > 0:45:05because it's very, very toxic.
0:45:10 > 0:45:14When Otto Hahn carried out his experiment in 1938,
0:45:14 > 0:45:18his fissioned uranium famously produced barium,
0:45:18 > 0:45:20but there were other products, too -
0:45:20 > 0:45:24krypton, strontium, caesium, iodine, xenon
0:45:24 > 0:45:29and exotic heavy metals like americium, berkelium and curium.
0:45:29 > 0:45:32Some of these are powerfully radioactive,
0:45:32 > 0:45:36others have half-lives of thousands or hundreds of thousands of years.
0:45:36 > 0:45:39This cocktail is the most toxic end product
0:45:39 > 0:45:42of the entire nuclear industry.
0:45:46 > 0:45:49This nuclear waste is so dangerous
0:45:49 > 0:45:52that exposure to it would kill you within hours.
0:45:57 > 0:46:01In the '90s, Sellafield designed a process that -
0:46:01 > 0:46:04while it wouldn't render it harmless -
0:46:04 > 0:46:05would at least lock it away.
0:46:07 > 0:46:10Currently, this is the end of the road
0:46:10 > 0:46:12for this foul and dangerous stuff.
0:46:12 > 0:46:16To render it safe and stable, it's vitrified,
0:46:16 > 0:46:18which means it's encased in glass,
0:46:18 > 0:46:21and that process takes place in here...
0:46:27 > 0:46:30..albeit behind a metre of lead glass
0:46:30 > 0:46:33that shields me from the intense radiation.
0:46:33 > 0:46:35The process is simple enough -
0:46:35 > 0:46:40the highly radioactive waste is first dried to a powder.
0:46:40 > 0:46:43It looks a bit like this, strangely like coffee granules.
0:46:43 > 0:46:46Then, glass granules are added to the mixture
0:46:46 > 0:46:49and it's heated to about 1,100 degrees.
0:46:49 > 0:46:53It melts and is poured into those containers in there.
0:46:53 > 0:46:56Now, the important thing about vitrification
0:46:56 > 0:46:59is that it then solidifies as it cools
0:46:59 > 0:47:01so there's no chance of leakage.
0:47:01 > 0:47:03It looks a little bit like this.
0:47:03 > 0:47:07So, the radioactive waste is now not encased in the glass,
0:47:07 > 0:47:10it becomes part of the glass itself.
0:47:10 > 0:47:14Those containers are then sealed, they're decontaminated
0:47:14 > 0:47:16and taken away for storage.
0:47:18 > 0:47:22And this is where the containers of vitrified waste are brought.
0:47:22 > 0:47:26Under this floor, they're stacked up to ten deep.
0:47:26 > 0:47:29They're air-cooled and monitored 24 hours a day.
0:47:33 > 0:47:37The radiation produced by the waste down below is so intense,
0:47:37 > 0:47:40it produces heat that I can feel up here on the surface,
0:47:40 > 0:47:44even though I'm shielded by over two metres of concrete.
0:47:44 > 0:47:51This is where several thousand tonnes of the most toxic waste in the world is stored,
0:47:51 > 0:47:53and here is where it'll currently remain.
0:47:57 > 0:48:01But, ultimately, what makes this nuclear waste so deadly
0:48:01 > 0:48:04is not just the high level of radioactivity,
0:48:04 > 0:48:07but the length of time it remains that way.
0:48:11 > 0:48:14Every isotope is different -
0:48:14 > 0:48:16some are active for just seconds,
0:48:16 > 0:48:19others remain radioactive for millions of years.
0:48:19 > 0:48:21This facet of their character
0:48:21 > 0:48:24is captured by something called the half-life.
0:48:24 > 0:48:26SIREN BLARES
0:48:31 > 0:48:35To show you what I mean, I've set up an experiment.
0:48:35 > 0:48:39I'm bombarding a sample of quartz with a proton beam.
0:48:40 > 0:48:42This will make it radioactive.
0:48:48 > 0:48:51It's produced an isotope of nitrogen that is radioactive.
0:48:51 > 0:48:53It's producing beta particles
0:48:53 > 0:48:56and these are counted by this device here.
0:48:56 > 0:48:59Now, to give you an idea of what a half-life means,
0:48:59 > 0:49:04I'm going to record the activity every minute for half an hour.
0:49:04 > 0:49:08OK, so it's now showing that 1,400 beta particles per second
0:49:08 > 0:49:10are being emitted.
0:49:12 > 0:49:16So, that's 1,150 counts after one minute.
0:49:22 > 0:49:24Dropping right down.
0:49:24 > 0:49:27Now down to just under 700 after five minutes.
0:49:33 > 0:49:36So, here's what my graph tells me.
0:49:36 > 0:49:41My sample started off with a count rate of 1,400 per second.
0:49:41 > 0:49:44After eight or nine minutes, that had dropped by a half
0:49:44 > 0:49:47and then by a further half after another nine minutes.
0:49:47 > 0:49:51This period of time over which the count rate drops by a half
0:49:51 > 0:49:54is called the half-life.
0:49:54 > 0:49:58And this is important because, unlike my sample -
0:49:58 > 0:50:00which has a half-life of nine minutes -
0:50:00 > 0:50:02some of the material at Sellafield
0:50:02 > 0:50:05has a half-life of hundreds of thousands of years.
0:50:07 > 0:50:11In other words, it won't be safe for thousands of generations.
0:50:15 > 0:50:19And this means that much of the work here is now about finding ways
0:50:19 > 0:50:23to store this material safely for a very long time.
0:50:32 > 0:50:35In the early days, they built nuclear reactors
0:50:35 > 0:50:40with little thought of what to do when they came to the end of their working lives.
0:50:43 > 0:50:48For instance, this experimental reactor built here at Sellafield in the '60s
0:50:48 > 0:50:50was finally shut down in 1981.
0:50:52 > 0:50:57Sellafield decommissioned this core by building a giant robotic arm
0:50:57 > 0:51:01that reached inside and cut it up into fragments.
0:51:01 > 0:51:03It then put all those dangerous radioactive pieces
0:51:03 > 0:51:07into large steel reinforced concrete boxes.
0:51:13 > 0:51:16And those boxes are stored here at Sellafield,
0:51:16 > 0:51:18in this air-conditioned warehouse.
0:51:20 > 0:51:25This, then, is the decommissioned core of a nuclear reactor.
0:51:29 > 0:51:31It's very unnerving hearing the radiation detector
0:51:31 > 0:51:33making so much noise.
0:51:33 > 0:51:36In fact, these levels are completely safe -
0:51:36 > 0:51:40still, it's eerie being so close to something so deadly.
0:51:42 > 0:51:45These concrete blocks will contain the radioactivity
0:51:45 > 0:51:49until it's relatively harmless, some 100 years from now.
0:52:03 > 0:52:05But just across the road
0:52:05 > 0:52:10is one of the most controversial problems facing Sellafield today -
0:52:10 > 0:52:12cleaning up the waste from the legacy ponds.
0:52:15 > 0:52:19This is the First Generation Magnox Storage Pond,
0:52:19 > 0:52:21acknowledged by Sellafield themselves
0:52:21 > 0:52:24as one of the most dangerous buildings in Western Europe.
0:52:26 > 0:52:29And that's because the ponds that nuclear waste was dumped in
0:52:29 > 0:52:33for decades are deteriorating.
0:52:33 > 0:52:36Contaminated water is seeping through the internal walls.
0:52:39 > 0:52:42Sellafield's current plan is to remove the waste
0:52:42 > 0:52:45from these ageing ponds, mix it with concrete
0:52:45 > 0:52:47and then store it in steel containers.
0:52:51 > 0:52:53They're already using a remote-controlled vehicle
0:52:53 > 0:52:57to start that process.
0:52:57 > 0:53:00You can see some of the components have come apart.
0:53:00 > 0:53:02What sort of stuff is down here?
0:53:02 > 0:53:05We have a significant amount of spent nuclear fuel.
0:53:05 > 0:53:10There are quite a lot of reactor components and isotope cartridges.
0:53:10 > 0:53:13Do you want to try and lift that one up, Helen?
0:53:13 > 0:53:15- No pressure!- No pressure.
0:53:15 > 0:53:19How long has that component been in the pond?
0:53:19 > 0:53:23Erm, that's the first time it's been touched in probably 51 years.
0:53:23 > 0:53:26It seems a whole range of different things are there -
0:53:26 > 0:53:29why were they all put in the pond together like this?
0:53:29 > 0:53:33The pond was there supporting the effort towards getting us a bomb together.
0:53:33 > 0:53:35It was rushed,
0:53:35 > 0:53:38We had to get that bomb ready for the early '50s
0:53:38 > 0:53:41to prove that we had it, and, once we had the bomb,
0:53:41 > 0:53:44I guess things got forgotten about.
0:53:44 > 0:53:48Right. Well, now that you've sort of made me somewhat nervous,
0:53:48 > 0:53:51I still would like to have a go.
0:53:51 > 0:53:54Give it to me when you know I can't do any harm!
0:53:54 > 0:53:57- So can I look inside what's in here?- Yeah.
0:53:57 > 0:54:01This one has got isotope cans that have corroded.
0:54:01 > 0:54:04- So all of that is...- It's started to bow and overflow.
0:54:04 > 0:54:06It's like...
0:54:06 > 0:54:09the nastiest kind of buried treasure you could imagine!
0:54:11 > 0:54:13How dangerous is this stuff?
0:54:13 > 0:54:16In situ, as it stands with a five-metre water covering,
0:54:16 > 0:54:18it's less dangerous than you would imagine.
0:54:18 > 0:54:21The dose rates coming off it are minimal.
0:54:21 > 0:54:25However, if some of the material were allowed to dry out,
0:54:25 > 0:54:26that would be a different matter -
0:54:26 > 0:54:29it could cause a major contamination hazard.
0:54:29 > 0:54:32The fact that this stuff is down there and is so nasty -
0:54:32 > 0:54:35for many people, this is an argument against nuclear power,
0:54:35 > 0:54:37"Look, this is the sort of mess that it creates."
0:54:37 > 0:54:42This is certainly an argument against the way things were dealt with 50, 60 years ago,
0:54:42 > 0:54:44but we have a duty to clean it up.
0:54:44 > 0:54:47We can't just leave the hazard for yet another generation.
0:54:54 > 0:54:58And yet, in some way, I can't help feeling we are still leaving it
0:54:58 > 0:55:02for another generation, just in safer stores.
0:55:04 > 0:55:07The waste from the ponds will be stored in steel containers.
0:55:09 > 0:55:13The dead reactors are just stored in concrete blocks.
0:55:15 > 0:55:17And the most radioactive material of all,
0:55:17 > 0:55:20the vitrified high-level waste,
0:55:20 > 0:55:23is still in a warehouse on site here at Sellafield.
0:55:26 > 0:55:29I think we do need long-term options for this waste.
0:55:29 > 0:55:33Can we store it safely in places like this for 100 generations?
0:55:34 > 0:55:39The current long-term plan is to bury it deep underground,
0:55:39 > 0:55:40locking it away for ever...
0:55:42 > 0:55:45..but this plan continues to divide opinion.
0:55:49 > 0:55:51Personally, I believe that if we do bury it,
0:55:51 > 0:55:54we have to have the option of being able to retrieve it
0:55:54 > 0:55:55at some point in the future
0:55:55 > 0:55:58because if we're to have a nuclear industry -
0:55:58 > 0:56:00and I think we should -
0:56:00 > 0:56:03we need to deal with this waste permanently.
0:56:03 > 0:56:06And one possible option that fascinates me
0:56:06 > 0:56:08is to find a way to transmute it -
0:56:08 > 0:56:12bombard it with a high energy, high intensity beam of neutrons
0:56:12 > 0:56:16that smashes it up into far less harmful fragments.
0:56:16 > 0:56:19I think this is an option worth exploring
0:56:19 > 0:56:22because I believe nuclear power, alongside renewables,
0:56:22 > 0:56:25is crucial for our future energy needs.
0:56:34 > 0:56:38The story of Sellafield is the story of the British nuclear age.
0:56:43 > 0:56:49Sellafield began as a headlong rush to develop nuclear weapons and nuclear power
0:56:49 > 0:56:51with little thought to the future.
0:56:53 > 0:56:55It appeared to be a success...
0:56:57 > 0:57:00..then the cracks started to show -
0:57:00 > 0:57:03leaks and the fire released deadly radioactivity
0:57:03 > 0:57:05out into the air and sea.
0:57:07 > 0:57:10And successive governments and, indeed, the public themselves
0:57:10 > 0:57:14demanded that the nuclear industry clean up its act.
0:57:18 > 0:57:19With massive investment,
0:57:19 > 0:57:22Sellafield seemed to enter a more responsible phase
0:57:22 > 0:57:24in managing nuclear waste.
0:57:24 > 0:57:27And, as we deal with the issues of climate change,
0:57:27 > 0:57:31it seems we might be on the cusp of a new nuclear age.
0:57:35 > 0:57:38Where I'm walking now is a proposed site
0:57:38 > 0:57:41for the next generation of nuclear power stations,
0:57:41 > 0:57:43just a few hundred metres from Sellafield -
0:57:43 > 0:57:46so in the shadow of the very first.
0:57:47 > 0:57:49This seems a poignant place
0:57:49 > 0:57:52to ponder the lessons we can take from Sellafield.
0:57:52 > 0:57:56We've understood, slowly and not without mistakes,
0:57:56 > 0:57:58that if we are to have a nuclear industry,
0:57:58 > 0:58:01then we have to think in the long term -
0:58:01 > 0:58:05not just for the quick buck or because of political pressure,
0:58:05 > 0:58:08but in terms of the many decades, even centuries,
0:58:08 > 0:58:13it takes from conception all the way through to the end of clean-up.
0:58:13 > 0:58:16And this is an important lesson, not just for the nuclear industry,
0:58:16 > 0:58:19but for any of mankind's more ambitious projects -
0:58:19 > 0:58:22be they scientific, engineering, political -
0:58:22 > 0:58:25we must take the long view.
0:58:25 > 0:58:28Otherwise, well, we have learnt nothing.