Dismantling Sellafield: the epic task of shutting down a nuclear site

The story of Sellafield began long before the Earth was formed. Tens of thousands of giant stars exploded after running out of fuel. The matter in the stars' core was mashed together by the force of the detonations. trillions of tonnes of uranium were flung out by such explosions and wound up near the sun.

The violent tectonics of the young Earth pushed the uranium not towards its hot core but up into the folds of its crust, as a result of the space dust and debris cohering to form our planet. Within reach, so to speak, of the humans who eventually came along circa 300,000BC, and who mined the uranium beginning in the 1500s, who learned about its radioactivity in 1896 and began feeding it into their nuclear reactor for 70 years.

Sellafield is a place where multiple time spans drift in and out of view. Sellafield is a small town with over a thousand buildings, roads and a rail siding that is owned by the government. The end of a road on the Cumbrian coast is where Sellafield is located. The sea is just beyond as you pass cows drowsing in pastures. After driving through a high security gate, you are surrounded by towering chimneys, pipework, chugging cooling plants, and everything dressed in steampunk. The sun hits metal. The noise of machinery can be heard in some places. It feels like it's been there a long time.

Sellafield has had different responsibilities since it started. plutonium was used to make nuclear weapons. It generated electricity for the national grid. After the life cycles of nuclear fuel rods have ended, it is possible to extract plutonium and Uranium from them. On the day before I went to Sellafield, the reprocessing ended. It was the first time that it had happened. From an operational nuclear facility, Sellafield turned into a full-time storage depot filled with toxic nuclear waste.

Sellafield has ceased to produce anything anymore. I went to Sellafield to understand how it is preparing for its end. The spent fuel rods, scraps of metal, radioactive liquids, and a miscellany of other debris are parked in concrete silos, artificial ponds, and sealed buildings. The industry calls some of these structures intolerable because of the sea air, radiation and time itself. Cumbria's soil and water will be poisoned if they degrade too much.

The waste must be hauled out, the silos destroyed, and the ponds filled with soil to prevent that disaster. The buildings that will be built on the site will be secured. A few decades is how long that will last. Nuclear waste doesn't have respect for time periods. The UK plans to build a subterranean vault later this century and moving it into it is the best way to protect it. The waste will be left alone for tens of thousands of years. The Grandchildren of those who work on the site will not see the end of the race to deal with all the radioactive waste. It will cost at least £121 billion.

Sellafield has only been in existence for a single lunch break in a human life. Even though it has lasted almost the entire atomic age, it has seen both its earliest and continuing mistakes. Nuclear energy will make electricity too cheap to meter according to the chair of the US Atomic Energy Commission. The forecast hasn't aged as well as it could. The main reason power companies and governments don't like nuclear power is that it's too expensive to produce and it's hard to find.

Many people are held captive by one measure of time and can't really comprehend another. The short-termism of policymaking neglected any plans that had to be made for the long-term survival of radioactive waste. At Sellafield, I was told that science is still trying to correct the decisions made in haste three decades ago. The head of operations at one of Sellafield's two waste storage ponds said that many of the earliest structures weren't built with Decommissioning in mind.

Sellafield's scientists are having to invent the process of winding the site down because they don't know enough about it. They don't know what to look for in the ponds. They don't know how long it will take to dispose of all the waste, or what Sellafield will look like after that. The programme is filled with assumptions and guesses. From now on, it will be finished. In order to keep Sellafield from falling apart, they will dismantle it while keeping it intact.

You have to put a lot of other things together before you disassemble an old nuclear facility. There are new technologies and new buildings to replace the intolerable ones. The price tag may go even higher. The geological disposal facility (GDF), bored hundreds of metres into the Earth's rock, is a project that could cost as much as $560 billion. If a GDF gets its first deposit in the 20th century, the waste has to be put away and filled by the 22nd century.

This state of temporariness could make you feel like a frequent flyer. Sellafield has a lot of radioactivity and the thought of a catastrophe is always present. A member of the Sellafield team pointed out several different waste storage facilities when we walked through the site. He said that the spot where we stood was the most dangerous in Europe.

There are different types of waste at Sellafield. The spent fuel rods and metal are submerged in open, rectangular ponds where the water cools them and absorbs their radiation. The skips have been holding radioactive material for a long time. Nuclear sludge is mixed with degraded metal and radioactive dust. The silos were partially sunk into the earth and filled with rubble. The reactor that caught fire in 1957 has been sealed off and left alone ever since, making it even more dangerous. 140 tonnes of plutonium has been stored at Sellafield over the course of the last 50 years. It is the largest amount of plutonium in the world, but it is also a waste because no one wants it for weapons anymore.

Nuclear policy has been stagnant for a long time. After the disaster at the nuclear plant in Japan, several countries began shutting down their reactor and tearing up their plans for new ones. They were much more expensive to build and maintain than solar and wind installations. In the UK, the fraction of electricity generated by nuclear plants has fallen steadily. Only one of the five nuclear stations will remain operational past the year 2028. The cost of building the first new nuclear plant in a generation has ballooned to more than 25 billion dollars.

The governments felt the need to redo their sums when sanctions on Russia caused a shortage of oil and gas. Wealthy nations began to worry about winter power cuts. Governments are reverting to their old habits in the current crisis. The deadline for abandoning nuclear fuel in Germany was extended in October. Sizewell C, a nuclear power station to be built in Suffolk, was given the go-ahead by the UK despite the US allocating $6 billion to save struggling plants. Japan will commission new plants just a decade after it was hit by a nuclear disaster. As Sellafield cleans up after the first round of nuclear enthusiasm, another is getting underway.

There is a soundtrack to the time spent in Sellafield. Soft Cheeps were let off by the radiation trackers as radioactivity levels changed around us. Before we left the building, we ran the Geiger counter over ourselves to make sure we didn't miss anything. Our tracker went crazy at one point. Staff planted 10 feet of lead into the ground around the cracked pipe to protect the people from the radiation. My guide told me it was safe. We were able to power walk past.

It was the hottest day in the UK. We were very warm before we went to the reprocessing plant to see the spent fuel that had been removed. I heard a sound every second on the four floors that make up the plant. Some of the people who joined at 18 have been here for more than 40 years. Her husband is a firefighter and her father was a welder. She gets to meet aunts and cousins on her shifts. She is saying that Sellafield is a big family.

When the spent fuel rod emerged from the reactor, it was half as hot as the surface of the sun. There are hundreds of rods of fuel in a reactor. A stream of neutrons is sent into the pile. The process of generating more neutrons out of the Uranium atoms is what leads to the huge amount of heat that can turn water into steam.

The heavier atoms of plutonium are the stuff of nuclear weapons. plutonium was used to set up the UK's earliest reactor, called Magnox, which was set up to produce electricity. There were 26 such reactor built by the government. They are either being decommissioned or waiting to be demolished. If you weren't interested in making plutonium nukes to blow up cities, Magnox was a pretty inefficient way to light up homes and power factories.

Reprocessing was one of Sellafield's main tasks for most of the 20th century. It was thought that once used fuel rods were removed, they could be safely stored and used for other purposes. Cumbria received spent rods from plants in the UK, Italy and Japan. Sellafield has taken in more spent fuel than any other place in the world. The rods arrived at Sellafield by train and were stored in the shape of flasks. The walls of the flasks are a third of a meter thick. In 1984 the government arranged for a speeding train to collide with a flask in response to concerns about how strong the containers were. The video is stunningly beautiful. A part of the locomotive blew up and the train derailed at 100mph. There were a few scratches and dents on the flask.

The rods were first cooled in ponds of water at Sellafield. They were dissolved in nitric acid. The plutonium and Uranium were separated from the liquor. The acid to powder cycle lasted up to 36 hours, but it hadn't improved efficiency since she'd been there. The only change was the decreasing number of reactor rods.

The day before I met him, technicians fed the last of the spent fuel into acid. Sellafield transitioned from an operational facility to a depot dedicated to storage and containment. After hours of technical problems, the rods went in late in the evening. You didn't hear anything after they dropped through. It was like, 'OK, that's it'. "'Let's go home' She felt sad when I met her the next day. Everybody is wondering what to do. There is no fuel in the building. I don't think it's hitting the team yet.

The reprocessing plant was going to end. Many steam lines from the 1960s remained fractured. There was a shortage of spare parts that weren't manufactured anymore. In the last 16 days, I have only had 16 days of running the plant. To conduct repairs, clean the machines and take them apart is the best way to close it down. The reprocessing plant will be left alone for decades for its radioactivity to dwindle, but at last it will be placed on a "fire watch" to make sure nothing happens in the building.

Much of the radioactivity is turned into nuclear waste. A paper towel or a shoe cover can absorb radioactivity, but they are graded as low-level waste and can be left outdoors. Cement protects against radiation. The phrase "when in doubt, grout" is used in the nuclear waste industry. The paper towel needs a long time to be safe. Radiation tends to change time all out of proportion.

High-level waste is so radioactive that it will give off heat for thousands of years. Over time, it will be harmless, but the scale of that time is not human. Every 16 years, the number of radioactive atoms in the kind of iodine found in nuclear waste decreases. 7,000 years ago, a determined pedestrian could set out from the Humber estuary in northern England and walk to the Netherlands and then to Norway. The drift of continents and the next ice age have to be considered when planning for the disposal of high level waste.

There is a search for stability. Most of the atoms in our daily lives are stable. Nuclear particles are crammed into the atoms of some elements in a way that makes them radioactive. When these atoms decay, they throw off particles and energy for a long time. Nuclear fuel and waste are both radioactive, but only time can make them harmless.

Waste can travel undetected and cause fatal consequences: radioactive atoms carried by the wind or water can enter living bodies and cause cancer. The reactor fire at Sellafield in 1957 created a radioactive cloud from the top of the chimney. Some of the particles were found as far away as Germany and Norway. In the weeks after the fire, samples of milk taken from the dairy cows in the meadow near Sellafield showed 10 times the allowable level of radioactivity. The government had to dump milk in the Irish Sea because it couldn't afford to buy it.

Authorities lied from the beginning. For three days, no one in the area was told about the accident or that they should stay indoors. The Daily Mirror reported at the time that Sellafield workers were persuaded to walk off the job because they were worried about their health. The report of the government inquiry was not made public until 1988. Few people knew that the fire dispersed polonium, a much more deadly radioactive substance. The death toll from cancer has been continually revised upward. The old name, Windscale, and the memories of the fire were erased when Sellafield was renamed in 1981.

There is invisibility of radiation and the government is not transparent. Since the 1957 fire, Sellafield has not suffered an accident of the same magnitude, but the fear that some radioactivity is leaking out of the facility has not gone away. A Sellafield line discharged radioactive solvent into the sea in 1983. The government firm that ran Sellafield was fined ten thousand dollars. A documentary crew discovered higher incidences of leukaemia among children in some areas. Radiation from Sellafield wasn't to blame according to a study. The study suggested that the leukaemia may have been caused by an infectious cause.

There was a lot of spent fuel rods on Sellafield's site. This was a lot of money. Half of the reprocessing plant's income was from overseas. The pursuit of commercial reprocessing turned Sellafield and a similar French site into "defacto waste dumps" according to the journalist. The Sellafield needs 2 billion dollars a year to maintain. Back in the 1950s, a smart line of business looked like it would work out. Maintaining the world's costliest rubbish dump becomes more and more calamitous over time.

The expenditure goes up because structures are more prone to accidents. There was 83,000 litres of radioactive acid that dripped out of a pipe in 2005. The plant had to be shut down for two years in order to clean up the mess. A waste pond had a leak in a sump tank that had to be shut down. There was an old crack in the waste silo. When I visited, it was still dripping liquid into the ground. For no other reason than to allow for waste to be tipped in, the silos are made of concrete. It's a certainty that their further degradation is going to happen. It made me think of a man who built a house of ice in the deepest part of the winter, only to have it all melt and fall on him.

The laser snake is not an industrial machine. After it's fat, six-metre-long body slinks out of its cage-like housing, it can rear up in a hurry. The accordion folds make it stretch and compress. The snake has a mouth that fires a purple shaft of light and it is the size of a dinner plate. The beam of the laser blisters the metal as it slices through it. This instrument took two years to develop. The laser snake would haunt them if Philip K Dick designed them.

The creators of the snake put it to use in a demo. The first reprocessing facility at Sellafield was called B204 and it was filled with radioactive gas in 1973. The building was immediately closed after 34 workers were contaminated. Humans haven't entered the cells since they turned so lethal that gas, fuel rods and radioactive equipment were all left there. The snake could get in through a hole drilled into a cell wall and up to a two-metre high steel vat. The vat was radioactive. It was too large to be taken apart in a single piece.

Sellafield's engineers prepared for the task by practicing on a 3D model, ventilating the cell, and setting up a stream of air to blow away the molten metal. The snake was able to cut up the vat quickly. The pieces were put in the cell. They didn't know how to remove them. The snake hasn't been put to use since 2015.

One employee called thepoky stick approach to tackling Sellafield's nuclear waste a curious mix of sophistication and ingenuity. The laser snake was conceived especially for Sellafield. Phil Atherton, a manager working with the silo team, told me that the process of emptying a wheelie bin felt crude and time consuming. Once the waste is removed new forms of storage have to be created. They can't be irretrievably secure and robust because scientists are still developing better ways to deal with waste. "You don't want to do anything that leads to a solution that isn't there." The future can't be discounted.

We climbed onto the roof of the silos. Intermediate-level waste is more harmful than low-level paper towels because it is submerged in water. Swarf was the skin on the fuel rods that was broken into smaller pieces. A machine as big as a studio apartment, designed from scratch over two decades and built at a cost of 100 million dollars, was what Atherton wanted to show off. It has 13,500 working parts. It was positioned above an uncapped silo so that it could be moved.

An operator sits inside the machine and reaches into the silo to catch waste. He said that cameras don't offer much help in the water. The team was able to fill four skips after pulling out enough waste. The megafauna cousins of those fairground soft-toy grabbers will one day be in the silos. It will take a long time to empty all the silos. At some point in the future, the skips of extricated waste will be sequestered in the ground and moved into another Sellafield warehouse.

I met John Cassidy, who has worked at Sellafield for more than 30 years, so long that a colleague called him "the oracle". The pond in Cassidy's is larger than the one in the industrial park. In the water, the skips full of used fuel rods were stacked three deep, and when one was placed in or pulled out, the rods would fall on to the floor of the pond.

A small part of the pond was built over a staircase. We stopped to look at the remotely operated vehicle that was floating in the water. The little arm is at the end. Cassidy made a statement. It will float down to the bottom of the pond and pick up a nuclear rod that fell out of a skip. A human touch is needed sometimes. Professional divers from the US will be hired by Sellafield. Nuclear plants keep so much water on hand that a class of specialist divers only works in the ponds and tanks at these plants, inspecting and repairing them. Nuclear divers in Sellafield will clean up the pond floor and put on radiation-proof suits.

An employee of Sellafield sat in a gaming chair on the second floor and worked on his laptop. He had an ROV fitted with a toilet brush that was reinforced with a plastic tube. The skip's flank was painted black with the digits "9738" appearing on it. During the heyday of reprocessing, the skips were unloaded into pools so hastily that Sellafield is now having to build an underwater map of what is where. One more addition to Sellafield's knowledge of itself was made by Skip No 9738.

Edward Teller was the father of the hydrogen bomb. It was only in theory that he was correct. By the 1970s, the US government began considering burying reactor waste in a GDF because of the utility of water, steel and concrete. The cost of keeping waste safe, the duration over which it has to be maintained, the accidents that could befall it, and the consequences of those accidents were all glossed over. Not a single GDF has started up in the world over the last four decades. The complete solution is a hypothesis.

Although to a lay person, even these seem to have been conceived by a scientist. The high-level waste needs to be cooled in giant tanks. It is mixed with glass beads and sugar and turned into a block of glass. The sugar makes the waste less volatile. Eva Watson-Graham is an information officer at Sellafield. Each container has been stacked 10 high in a warehouse since 1991. You can still feel warmth on the soles of your shoes if you stand on the floor above them.

This is not enough in the long run. Sellafield's infrastructure is at risk of being destroyed by fire or flood. The nuclear material could be used by terrorists. Money runs out when governments change. The nations have ceased to exist. The glass degrades The sea and land are made of the same material. When the industry was in its infancy, scientists didn't do contingency planning like they do now. The GDF was created to hold waste until its dangers have dried up.

Beneath Finland there is a glimpse of such an endeavor. If you drive 250 km west, you will see a tunnel called Onkalo. A salt caverns in New Mexico opened in 1999 and will last 10,000 years. It will be the world's first GDF for spent fuel and high-level reactor waste if Onkalo begins operating on time. It will cost over $5 billion and will be safe for a million years. It has only been around for a third of the time for the species that is building it.

Onkalo was built by a firm called Posiva and is located on the island of Olkiluoto. There was a hot blush on Olkiluoto when I was there. The air was clear and odorless. In a van, we went down a steep, dark ramp for a quarter of an hour until we reached the lowest level, and here I caught the smell of a closed space in which heavy machinery has been running for a long time. The rock's surface was like butter, but at a distance, the walls were like stucco. We followed a tunnel and then turned around and drove back up. Even after all these years, Sanna Mustonen still gets lost. After Onkalo takes in its waste, the caverns will be sealed with a clay that absorbs water and can be found in cat litter.

The location of the GDF was decided in four decades. Mustonen said that a lot had to be considered. The bedrock below the site is 1.9 billion years old. It is below ground. Will the waste be stable in these rocks? What are the probabilities of earthquakes and earthquakes. The sea will rise. If a kilometer or two of ice forms on the surface, how will the rock hold up? There had to be models of accidents. After fifteen years after the New Mexico site opened, a drum of waste burst open, leaking radiation up an exhaust shaft and then for a kilometer or so above ground. Someone put wheat-based cat litter into the drum instead of bentonite, which caused the problem. Posiva submitted all of its studies and contingency plans to the government of Finland. The document was 17,700 pages long.

Once it has been filled, Onkalo will be turned over to the state. Nuclear waste from other countries will be put into GDFs. Switzerland and France are trying to find a spot for their country. Plans for the UK are at an earlier stage. Nuclear Waste Services, a government agency, is studying locations and talking to people who live there. "If the geology is simple, and we are disposing of just high- and intermediate-level waste, then we're thinking £20 billion," said Jonathan Turner. For now, the ceiling is over fifty billion dollars. Turner said it was a major project similar to the Olympics.

Nuclear Waste Services is talking to several communities about the possibility of a GDF. Sellafield would have come full circle if the GDF ended up in this area. The idea that atomic energy will be both easy and cheap is the very idea that drove the creation of Sellafield.

On one of my afternoons in Sellafield, I was shown a half-made building that was supposed to be used to pack plutonium into canisters for shipment to the GDF. We got into the main hall after ducking through half-constructed corridors. Someday, the plant will be taller than the abbey, and it will be torn down once it's done. I was riveted by the sight of a building going up even as it was being demolished, and I was trying to imagine a future in which all of Sellafield would be returned.