With the world marking 80 years since the atomic bombings of Hiroshima and Nagasaki, the threat of nuclear weapons remains a stark reality. Russia’s arsenal now includes missiles capable of unleashing blasts tens of times more powerful than those historic attacks. What would happen if one of these modern warheads struck a city like Vilnius?
On August 2, 1939, Albert Einstein signed a letter warning then-US President Franklin Roosevelt about German advances in developing a new type of weapon: the atomic bomb. This began with the Manhattan Project.
By the end of 1945, 210,000 people had died in the two cities, and many others later developed cancer or chronic illnesses.
This year marks 80 years since the United States dropped atomic bombs on the Japanese cities of Hiroshima and Nagasaki. Around 70% of buildings were destroyed in Hiroshima, 40% in Nagasaki.
This was the only time atomic bombs were used in conflict rather than for testing. The 1970 Treaty on the Non-Proliferation of Nuclear Weapons requires non-nuclear states not to develop or acquire nuclear weapons, while nuclear-armed states are obliged to negotiate disarmament in good faith.
As of today, the US, Russia, China, France and the United Kingdom are all signatories of the treaty and officially recognised as nuclear-armed states. However, according to the International Campaign to Abolish Nuclear Weapons (ICAN), four other countries – Pakistan, India, Israel and North Korea – either possess or are developing nuclear weapons. Iran is also believed to be developing nuclear weapons.
What do we know about modern nuclear weapons – and why, despite developing them, do we fear them so greatly?
Nuclear and thermonuclear bombs
The letter addressed to Roosevelt and signed by A. Einstein, stated that “the element uranium may soon become a new and important source of energy” and that it could be used to “construct extremely powerful new types of bombs. One such bomb, delivered by ship and detonated in a harbour, could destroy the entire port and part of the surrounding area.”
Dr Mažena Mackoit-Sinkevičienė, a researcher at Vilnius University and the Centre for Physical Sciences and Technology, says that the isotopes used in nuclear reactors and nuclear weapons are typically produced through the fission (splitting) of atomic nuclei. These can include uranium-235 (U-235), plutonium-239 (Pu-239) and uranium-233 (U-233).
[Isotopes are atoms of the same chemical element with the same nuclear charge but different masses – LRT note.]
Thermonuclear (hydrogen) bombs, meanwhile, release energy through fusion – the merging of hydrogen isotopes (deuterium and tritium) into helium nuclei.
“It is a process similar to what happens in the core of the Sun,” the physicist explains.
She adds that the construction of nuclear weapons is a highly complex process, noting that even minor flaws can prevent a full nuclear explosion, resulting only in a chemical blast that destroys the bomb without a nuclear detonation.
Hiroshima and Nagasaki
Stephen Walker’s book Shockwave: Countdown to Hiroshima includes interviews with those involved in the creation and deployment of the bombs.
Over Hiroshima, the Americans dropped an atomic bomb called Little Boy, which was made using uranium-235 (U-235). In a 2004 interview, Theodore “Dutch” Van Kirk, the navigator on board the Enola Gay, shared his memories of the Hiroshima “mission” on 6 August 1945:
“The moment the bomb left the aircraft, we made a sharp turn… Later, we turned back to look at Hiroshima. But it was gone from sight. It was covered in smoke, dust, and debris. Within three minutes, the city was no more – it was completely destroyed.”
Three days later, on 9 August, a second bomb, known as Fat Man, was dropped on Nagasaki. It was made from plutonium-239 (Pu-239).
Pilots and crew who returned to the devastated Nagasaki described scenes of horror.
According to Stephen Walker’s book, just three weeks after the strike on Nagasaki, pilot Paul Tibbets, navigator Theodore Van Kirk and others returned to the devastated city.
“We arrived… It was frightening. Very frightening. (…) It chills you to the bone,” Van Kirk recalled.
Charles “Don” Albury, a 24-year-old pilot, visited a Nagasaki hospital and saw charred bodies lying outside. “It was terrible. I can’t go back there,” he said.
He ended his interview with quiet words: “Never again.”
Modern nuclear weapons – up to 60 times more powerful
Yet the words “never again” hold little meaning for some. Today, not only are atomic bombs still being developed at full capacity, but they are also vastly more powerful than those dropped on Japan.
“The two atomic bombs dropped on Japanese cities at the end of the Second World War had explosive yields equivalent to roughly 15 kilotonnes (Hiroshima) and 20 kilotonnes (Nagasaki) of TNT. In today’s nuclear arsenals, such weapons are considered ‘low-yield’,” explains Dr Mackoit-Sinkevičienė
According to the physicist, a single US-made B61-13 bomb could be up to 24 times more powerful than the one dropped on Hiroshima.
Meanwhile, Russia’s arsenal includes Topol-M intercontinental ballistic missiles, “each capable of carrying a single nuclear warhead with an explosive yield of around 800 kilotonnes of TNT – roughly 50 to 60 times more powerful than the Hiroshima bomb,” Mackoit-Sinkevičienė notes.
According to ICAN, the US and Russia together hold nearly 90% of the world’s nuclear warheads, with Russia possessing 5,449 and the US 5,277.
Simulations show a full-scale nuclear war between the US and Russia could trigger a nuclear winter, with global temperatures falling by about 9°C and taking years to recover, drastically affecting agriculture worldwide.
Even a limited nuclear war between India and Pakistan could reduce average global temperatures by 1.8°C for five years, cut rainfall by 8%, and reduce crop yields by 11%.
If a nuclear bomb exploded over Vilnius
But what would happen if Russia were to launch a Topol missile carrying an 800-kiloton warhead over the Lithuanian capital?
Although the impact of a nuclear bomb is difficult to assess as it depends on multiple factors, a simulation can nevertheless be run. Dr Mažena Mackoit-Sinkevičienė used the NUKEMAP website, created by Alex Wellerstein, to model the potential effects of such an explosion.
The simulation assumed a south-westerly wind of 24 km/h. “Lithuania’s wind conditions are typical of the temperate climate zone of Central Europe, where prevailing westerly and south-westerly winds – so-called westerlies – blow in from the Atlantic,” the physicist explained.
Typically, about 35% of a nuclear explosion’s energy is released as heat and light. The intense flash can temporarily blind people nearby for several minutes. It’s estimated that at the centre of a 1-megaton nuclear blast, temperatures can reach nearly 100 million degrees Celsius – around five times hotter than the core of the Sun, reports ScienceAlert.
“The fireball radius [in the simulation] is 1.28 km – the largest size of a nuclear fireball. Its effect on the ground depends on the height of the explosion. If the fireball touches the ground, the amount of radioactive fallout greatly increases. Everything inside the fireball is essentially vaporised,” explains Dr Mažena Mackoit-Sinkevičienė.
According to the simulation, the radius of thermal radiation could extend up to 9.7 km. “Third-degree burns, which affect all layers of the skin and are often painless because the nerves are destroyed, are typical. Such burns can cause severe scarring or disability, and amputations may be necessary.”
But heat is not the only concern. A nuclear explosion also pushes air outwards, causing a sudden and intense increase in air pressure that can crush objects and demolish buildings.
Within a 2.02 km radius, the mortality rate is almost 100%. Most residential buildings would collapse within a 4.25 km radius. “There is a high likelihood of fires breaking out, and damaged buildings greatly increase the risk of fire spreading.”
Even those living 10.9 km from ground zero would not be spared – windows would shatter from the blast, causing many injuries. Prompted by the initial flash, people are likely to approach the windows just as the shockwave reaches them.
Those who survive would suffer severe radiation exposure. According to the simulation, if an 800-kiloton atomic bomb were to strike Vilnius, the radius affected by radiation would be 2.43 km.
“Those exposed to ionising radiation are likely to die within about a month. Around 15% of survivors later die from cancer caused by the radiation,” explains Dr Mažena Mackoit-Sinkevičienė. Since the simulation assumes a south-westerly wind, radioactive particles would spread towards Latvia.
Following the atomic bombings of Hiroshima and Nagasaki, a strange phenomenon was observed in nearby regions – ‘black rain’.
“Black rain consists of radioactive particles that rise into the atmosphere along with soot, dust clouds, vapour, and moisture, then fall back to the ground as a dark, sticky rain occurring minutes or hours after the explosion in nearby areas (up to hundreds of kilometres away, depending on the wind),” the physicist explains.
Dr Mackoit-Sinkevičienė states that if an 800-kiloton bomb exploded at ground level over Vilnius with a 24 km/h wind, radioactive fallout would affect approximately 22,970 square kilometres within an hour of the blast.
Still, radioactive particles may travel even further. In one study, traces of radioactive carbon from Cold War nuclear tests were found in the deepest place on Earth – the Mariana Trench.
How far radioactive dust can spread is clearly illustrated by another NUKEMAP simulation, where Russia uses the RT-2PM ‘Topol’ ballistic missile system to launch an 800-kiloton (TNT equivalent) warhead at Warsaw with a 24 km/h south-westerly wind. In this scenario, radioactive particles would drift towards Vilnius, reaching Druskininkai and Varėna.
What if the Zaporizhzhia Nuclear Power Plant exploded?
“A direct hit on an operational nuclear reactor or a loss of electrical power could cause a reactor core meltdown, as happened in Fukushima and Chernobyl. In such an event, a large amount of radioactive fission products would be released into the environment, necessitating the evacuation of residents within a radius of hundreds of kilometres,” warns Dr Mažena Mackoit-Sinkevičienė.
However, Dr Mackoit-Sinkevičienė reassures that Lithuanians would have little cause for concern even if an accident occurred at the Zaporizhzhia nuclear power plant.
If contamination were to enter groundwater, consumption of agricultural produce from some areas would be prohibited. Should an incident cause radioactive materials to enter the atmosphere, the scale of contamination would depend on many factors, primarily weather conditions. Due to prevailing wind directions, the southern regions of Ukraine, Crimea, and possibly parts of Moldova, Romania, and Bulgaria would be most affected. Lithuania would likely experience minimal impact, unless a very large-scale incident occurred alongside unfavourable meteorological conditions.
The likelihood of this latter scenario is extremely low, as all reactors at Zaporizhzhia are currently shut down.
“The Zaporizhzhia nuclear power plant is currently not operational and contains no radioactive iodine. The greatest probable risk is water contamination, if other radionuclides (such as uranium) were to enter the Dnieper River or groundwater – which would constitute an environmental problem,” concludes Dr Mažena Mackoit-Sinkevičienė.
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