The UK Government has published official guidance on how to respond to a radiation emergency, advising people to "follow this guidance as much as you can." The guidance lists three critical actions to take "straight away": go inside, stay inside, and tune in.
Go inside, stay inside, tune in
The first step, according to the Government, is to "go indoors and stay there." People are told to "close the windows and doors to the outside" and "try to stay away from the outside walls."
The second step is to stay inside. "Staying inside protects you from radiation," the Government says. "Turn off fans and air conditioning if you have them. You will be told what to do next. You might need to stay inside for one or two days."
The third step is to tune in. "Check the news to find out what to do next," says the Government. "Official advice might be given on the radio, television, internet, social media or by the police. The government will put advice online at GOV.UK."
Evacuation and official guidance
The emergency services may instruct people to evacuate. "This is called evacuation," the Government states. "Get ready to leave in case you are told to. Only leave if you are told to. Going outside might mean your body gets more radiation."
The official guidance relates to a "radiation emergency," which is an incident that could expose people to elevated radiation levels. The UK Government cites scenarios such as a nuclear power station accident or an incident during the transportation of radioactive materials as examples. It emphasises that such incidents are rare and does not reference a nuclear attack in the guidance. Nevertheless, nuclear weapons also generate lethal radiation levels, which persist longer and spread more extensively than the immediate devastation caused by their explosion.
What happens if a nuclear weapon explodes?
The International Campaign to Abolish Nuclear Weapons (ICAN) states: "Nuclear weapons are the most destructive, inhumane and indiscriminate weapons ever created. Both in the scale of the devastation they cause, and in their uniquely persistent, spreading, genetically damaging radioactive fallout, they are unlike any other weapons."
The Nobel Peace Prize-winning organisation continues: "A single nuclear bomb detonated over a large city could kill millions of people. Several nuclear explosions over modern cities would kill tens of millions of people. Casualties from a major nuclear war between the US and Russia would reach hundreds of millions."
ICAN describes what happens when a nuclear bomb detonates: the fireball from the explosion would reach its maximum size in 10 seconds; it releases vast amounts of energy in the form of blast, heat and radiation; an enormous shockwave reaches speeds of many hundreds of miles an hour; the blast kills people close to ground zero, and causes lung injuries, ear damage and internal bleeding further away; people sustain injuries from collapsing buildings and flying objects; thermal radiation is so intense that almost everything close to ground zero is vaporized; extreme heat causes severe burns and ignites fires over a large area, which coalesce into a giant firestorm; even people in underground shelters face likely death due to a lack of oxygen and carbon monoxide poisoning.
"In the long-term, nuclear weapons produce ionizing radiation, which kills or sickens those exposed, contaminates the environment, and has long-term health consequences, including cancer and genetic damage," says ICAN.
How likely is nuclear war?
Global tensions are mounting. NATO has warned that Russia is becoming increasingly reckless, with the country accused of targeting specific locations in Germany, Poland and Estonia, alongside its continuing deadly offensive in Ukraine.
The UK Government has begun revising its so-called "war book," which has not been updated for decades, according to the BBC. The UK's most senior soldier, Sir Richard Knighton, said the threat posed by Russia meant Britain was living through the "most dangerous" period of his 35-year career in the armed forces.
This does not mean nuclear conflict is likely, of course, given the extreme nature of such a scenario. In fact, any confrontation may not even involve boots on the ground, with one expert telling the BBC that "it's not the tanks you need to worry about - it's the cutting of cables on the ocean floor, it's the hacking into systems on which so many things depend. The possibility for asymmetric war, for cyber war, is growing by leaps and bounds."
Professor Anthony Glees, a security expert and academic at the University of Buckingham, said: "The list of attacks and overflying by drones we strongly believe have been launched against us by Russia grows daily."
He added: "We are told that NATO chiefs are convinced Putin knows that if Russia crosses into NATO territory to start even a limited ground offensive against a NATO member, Article 5 will kick in and he risks a nuclear war with NATO which he cannot win and will end with his destruction."
