Exactly 40 years ago today, the Chernobyl nuclear power plant was destroyed in the worst nuclear disaster the world has ever seen.
A combination of poor planning and human error led to an enormous steam-powered explosion that spread radioactive material across the planet.
The blast rendered the surrounding land uninhabitable for hundreds of years, forced the evacuation of over 200,000 people, and led to thousands of deaths from cancer.
But what would happen if a similar disaster occurred in the UK today?
Experts say that a Chernobyl-scale explosion at one of the UK’s nine operational nuclear reactors is highly unlikely, if not impossible.
However, were one of the reactors to blow, the results would be disastrous for millions of Brits.
More than 1,000 square miles (2,800 km squared) surrounding the reactor could be rendered uninhabitable by intense radiation.
Meanwhile, clouds of wind-driven radiation could spread over vast regions of the UK, contaminating the food supply for decades to come.
While it’s easy to lump the effects of a nuclear disaster together as ‘radiation’, the reality is much more complicated.
When Chernobyl‘s Reactor 4 overheated and blew, it released a column containing over 100 different radioactive materials.
Some of these, such as extremely dangerous radioactive iodine, have a very short half-life – meaning they break down and become safe in just weeks.
In contrast, elements like uranium-235 and plutonium-239 take thousands or even millions of years to break down.
How much of each element is released, how far they spread, and how the government reacts is what really determines how devastating the disaster will be.
Eduardo Farfan, Professor of Nuclear Engineering at Kennesaw State University who has studied the spread of radiation around Chernobyl, told the Daily Mail: ‘If there were a very large off-site release, some form of restricted or exclusion area would almost certainly be needed around the plant, at least initially.’
He added: ‘Radioactive materials can travel very long distances, potentially hundreds to thousands of kilometres, but the most serious contamination is usually much closer to the source and is highly uneven.’
After the Chernobyl disaster, some 58,000 square miles of Belarus, Ukraine, and Russia were contaminated in an area that stretched up to 200 miles (500 km) north of the site.
After the Chernobyl disaster, some 58,000 square miles of Belarus, Ukraine, and Russia were contaminated with over 100 different radioactive materials
Initially, authorities created an exclusion zone covering an 18-mile (30 km) radius around the site.
Everything within the smaller 6-mile (10-km) radius immediately surrounding the reactor, known as the black zone, was deemed permanently uninhabitable.
If a similar exclusion zone were to be put in place around the Sizewell B reactor, homes as far as the outskirts of nearby Ipswich could be evacuated.
However, in the following years, the exclusion zone was greatly expanded to cover 1,600 square miles (4,143 square km) – an area about two and a half times the size of London.
If a disaster at a UK power plant followed a similar pattern, Professor Farfan says that the area would need to be closed to humans for ‘months to decades’ depending on the radiation dose.
Weather modelling using the National Oceanic and Atmospheric Association’s HYSPLIT Trajectory Model suggests that an explosion at Sizewell B would largely drive material westwards.
Simulations show that radioactive particles could be pushed over Oxford and London before travelling west to cover large parts of Devon and Cornwall.
Depending on the weather conditions, parts of these areas could be contaminated sufficiently to require temporary evacuation or constant radiation monitoring for years to come.
If there were a nuclear disaster at Sizewell B, weather models suggest that the radioactive particles could be driven westwards over Oxford, London, and Cornwall
Previous models suggest that a release of radiation on the scale of Chernobyl at Sizewell B could lead to heavy contamination of areas in the South Downs, Norwich, and Cornwall
‘Chernobyl shows that some heavily contaminated areas required long-term exclusion and relocation, while Fukushima shows that some evacuated areas can be reopened after monitoring,’ he says.
‘The key point is that “uninhabitable” is not one uniform condition; some zones may reopen relatively quickly, while hotspots and forested areas can remain problematic.’
Of course, the real impact would be on the people exposed to this radiation during and immediately after the disaster.
Exposure to extremely high doses of radiation, like those experienced by workers at the power plant, causes acute radiation syndrome.
Symptoms begin with severe nausea, vomiting, and diarrhoea shortly after exposure, followed by bone marrow destruction, infection, and potential damage to the gastrointestinal tract and brain.
However, even during a disastrous nuclear meltdown, these cases are rarely fatal.
During the Chernobyl disaster, there were 134 cases of acute radiation syndrome in people onsite and involved in the cleanup, which led to only 28 deaths.
Likewise, no-one outside the plant at the time of the disaster was exposed to a high enough dose of radiation to cause acute radiation syndrome.
The most severe effects would be felt by the site workers and those tasked with clearing up the radioactive material, known during the Chernobyl disasters as ‘liquidators’. Pictured: A liquidator on the Chernobyl disaster site
There were 134 cases of acute radiation syndrome in people onsite and involved in the cleanup, which led to 28 deaths. Pictured: The Chernobyl nuclear site as seen in 1986
In a modern nuclear power plant, better shielding and safety planning would likely reduce these initial fatalities even further.
This means the biggest risk to most of the population would actually be from low-level environmental contamination rather than acute exposure.
In the days and weeks immediately following a disaster, the biggest danger would be from highly radioactive iodine isotopes distributed into the environment.
Professor Jim Smith, an expert on the Chernobyl disaster from the University of Portsmouth, says: ‘Iodine decays very fast, but if you don’t stop people consuming iodine in those few weeks people get a very high dose to the small thyroid gland in the neck.’
After Chernobyl the Soviet authorities didn’t act quickly enough to stop people, and especially children, from eating food contaminated with radioactive iodine, leading to a big spike in thyroid cancer cases.
The United Nations Scientific Committee on the Effects of Atomic Radiation concluded that there were around 5,000 thyroid cancer cases linked to Chernobyl, leading to 15 fatalities.
By contrast, Professor Smith says that Japanese authorities in the wake of the Fukushima disaster acted quickly and prevented contaminated food from being consumed.
If radioactive material is deposited on British farmland, these food restrictions could stay in place for years.
The biggest danger after the disaster is from food contaminated with radioactive iodine, which caused 5,000 thyroid cancer cases after Chernobyl, leading to 15 fatalities. Pictured: A 17-year-old girl recovering from surgery to remove her cancerous thyroid in Kyiv, Ukraine
After Chernobyl, nearly 10,000 farms and four million sheep in the UK were placed under restrictions and radiation monitoring due to caesium-137 contamination.
These restrictions on British produce were only lifted in 2012, almost 30 years after the Chernobyl, despite the disaster taking place hundreds of miles away.
‘After Chernobyl, restrictions on produce continued for over 20 years in some areas,’ Professor Smith points out.
However, with proper controls and planning in place, the risk to public safety after a major nuclear disaster is actually far smaller than you might expect.
About 700 million people received a dose of radiation after Chernobyl, but Professor Smith estimates this only led to 15,000 early deaths across the entire world.
Even among the ‘liquidators’, emergency workers drafted in to clean up the reactor, cancer rates were determined to a much greater extent by smoking and alcoholism than exposure to radiation.
For comparison, Professor Smith points out that there are an estimated 25,000 early deaths every single year in the UK alone due to air pollution.
‘I think if the response was done correctly, as the Japanese largely did after Fukushima, then there wouldn’t be a really significant cancer risk,’ says Professor Smith.
After the Fukushima nuclear disaster (pictured), authorities prevented people from eating contaminated food. This significantly lowered the risk of thyroid cancer
‘I think the biggest problems would be in the social, economic and mental health impacts of a large-scale nuclear accident.
‘Large-scale and potentially permanent evacuations have a big impact on people.’
Could a disaster like Chernobyl happen in the UK today?
Thankfully, experts agree that a disaster like the one at Chernobyl is ‘extremely unlikely, perhaps impossible’.
Taking Sizewell B as an example, there are several key differences between this modern reactor and Chernobyl.
The RBMK reactor used at Chernobyl was particularly dangerous, with several critical design flaws and very few safety precautions in place.
‘Chernobyl had a potentially dangerous reactor design, almost no safety culture and no strengthened containment building,’ says Professor Smith.
To make matters worse, the explosion in the disaster triggered a graphite fire that continued to drive radioactive material into the atmosphere.
Experts say that a disaster at a modern British nuclear reactor, such as Sizewell B, is ‘extremely unlikely, perhaps impossible’ due to significant design improvements and safety planning
In comparison, modern reactors are different in almost every way.
‘Sizewell B is designed and operated much more safely than Chernobyl was,’ says Professor Smith.
‘It has a “secondary containment” building which is a strengthened dome designed to withstand external and internal shocks.’
Likewise, UK nuclear emergency planning is built around pre-defined areas called Detailed Emergency Planning Zones and, for some sites, Outline Planning Zones for extremely unlikely but more severe events.
This means that the UK is already poised to implement radiation controls in the event of a disaster.
Professor Farfan says: ‘The UK would make decisions using real-time radiological monitoring and site-specific emergency plans, so protective actions would likely be more targeted.
‘That does not mean the consequences would be trivial if a severe accident occurred, but it does mean the pathway to a wide, uncontrolled release like Chernobyl is much less plausible in the modern UK context.’
WHAT IS THE CHERNOBYL EXCLUSION ZONE?
In 1986 an explosion at the Chernobyl power plant in the former Soviet Union town of Pripyat leaked radioactive material into the environment.
The explosion was caused by a fire in one of the nuclear reactors and the surrounding area was evacuated as a result.
Around 116,000 people were permanently evacuated from the exclusion zone around the power plant, with villages and towns left to go to ruin.
While radiation levels in the region is still considered too high for humans to return, wildlife has moved back into the 1,600 square mile (4,300 square km) Chernobyl Exclusion Zone (CEZ) and is flourishing.
While radiation levels in the region is still considered too high for humans to return, animals such as wolves (pictured) have moved back into the area and is flourishing
Many argue that the region should be given over to the animals which have become established in the area – creating a radioactive protected wildlife reserve.
Studies of the animals and plants in the area around Chernobyl are now providing clues as to what the world would be like should humans suddenly disappear.
Scientists are monitoring the health of plants and animals in the exclusion area to see how they react to chronic radiation exposure.
Camera traps set up by researchers have captured a stunning array of local wildlife, including wolves, lynx, mouse, boars, deer, horses, and many others, as they wander through the area.
It shows that three decades on from the disaster, the area is far from being a wasteland. Instead life is thriving there.
