Part 3: What would happen if Putin used a nuclear weapon in Ukraine?

The physical consequences for Ukraine, and for the rest of Europe, would be catastrophic, if Putin were to approve a nuclear strike. Kyiv, the capital of Ukraine, is home to over 3 million people as of 2022. Using a current model of nuclear warhead, the Topol (SS-25), in the Russian nuclear arsenal, we can predict these consequences. A single bomb dropped on the city would cause 560,660 fatalities and another 982,690 injuries, according to Dr. Alex Wellerstein’s nuclear explosion model NUKEMAP. Destruction would reach more than half the population. At first, the nuclear blast would cause a fireball with a 0.97-km radius, where anything inside would vaporize due to the extreme heat. Then, the fireball would expand into a moderate blast damage radius of about 6-km, which has enough force for residential buildings to collapse and cause instant fatalities. The moderate blast damage would expand further into a thermal radiation zone of about 11-km radius around the fireball, which is strong enough to cause third degree burns.

Finally, a 18-km radius of light blast damage with enough force to cause windows to break. In an attack, the fatalities and injuries would result from the immediate impact of the nuclear bomb, which collapses buildings, causes fires, and spreads radiation. Furthermore, residents of Kiev must worry about the dangers of secondary effects which include a lack of functioning hospitals or medical systems nearby.

The effects of a nuclear bomb would vary by the size of the weapon and whether it explodes closer to the ground or in the air above Kiev. You can use the Nuclear Bomb Blast Simulator developed by Dr. Alex Wellerstein at the Steven’s Institute of Technology, to simulate dropping a nuclear bomb for visualization of the true radius of such an attack.

This scenario alone would be devastating, with a single bomb causing the loss of over 800,000 innocent lives in mere minutes. However, this does not include the aftermath of such an attack, such as an escalating nuclear war, or the broader military and political implications of a nuclear attack.