If Russia deploys nuclear weapons in Ukraine, tactical nuclear weapons, then we will probably hardly notice them. The impact will be limited for the Netherlands. Which wrote Het Parool on 14 March after consultation with the RIVM. At the request of the Authority for Nuclear Safety and Radiation Protection, RIVM had made some calculations based on the use of Russian nuclear weapons and it looked good. The nuclear bombs only had a devastating effect locally. The first results of the calculations had already been shared with the radiation authority.
Limited impact: very reassuring, the Authority will have thought. A bit like Chernobyl: keep cows inside, spin spinach and you’re there. Annoying of the local devastation.
Tactical Nuclear Weapons are nuclear weapons that are deployed on or near the battlefield and that have a direct effect on the course of the battle. Strategic nuclear weapons are different, targeting targets far beyond the battlefield, such as other strategic nuclear weapons or cities, factories and airports. counter force and counter value†
Tactical nuclear weapons can be delivered by missiles, cruise missiles and aircraft, yes even by howitzers. They have also been constructed as mines. The weapons have an explosive power, a yield, which is often less than ten percent of the bombs dropped on Hiroshima and Nagasaki in 1945, which were small nuclear bombs by modern standards, equivalent in effect to the explosion of 12 and 18 kilotons of TNT. In modern reflections on the effects of nuclear weapons, the one megaton bomb is often the reference.
The usefulness of tactical nuclear bombs is not immediately clear to the outsider, but the Americans used to sell them in the past. If the Soviets advance in closed tank formations to the west, we will stop them with tactical nuclear weapons, was the idea. Later, fears grew that ‘low-yield weapons’ were lowering the nuclear threshold and they were abolished again, except for the B61 aerial bomb. But Russia retained a large and varied arsenal of tactical weapons and would have developed policy to force a decision in a deadlocked conflict with conventional weapons: ‘escalate to de-escalate’. The Last AmericanNuclear Posture Review(2018) considers such a Russian ‘limited nuclear first use‘ with tactical weapons as a real danger and therefore insists again on expanding the arsenal of tactical nuclear weapons. Tailored Deterrence† Rather a tailor-made response than a plunge into total nuclear war.
Hiroshima and Nagasaki
It is not clear how devastating the deployment of tactical weapons would be, because, say, little experience has been gained with it. The bombs on Hiroshima and Nagasaki caused so many victims because they were dropped on densely populated cities. But the heavy damage did not extend further than 5 kilometers from the hypocenter (ground zero). For the smaller tactical weapons it will be proportionally less.
What would create radioactive fallout? That depends not only on the weight of the weapons, but also on their composition. The so-called Enhanced Radiaton Weapon, the infamous neutron bomb, was considered a fairly clean weapon. It was a small type of hydrogen bomb that produced relatively many extra neutrons. The practical advantages of the concept turned out to be limited and the Americans no longer have it in stock.
The decisive factor is the height at which a nuclear weapon explodes. The destructive power of nuclear weapons and other heavy bombs is greater if you detonate them above the ground rather than on top. Then the direct pressure wave and the pressure wave reflected by the earth’s surface can combine to form an extra heavy pressure wave (the Mach Voice effect† The optimum height is determined by the weight of the bomb. With the bombs of Hiroshima and Nagasaki it was about 600 meters, for a bomb of 1 kiloton it would be 220 meters.
But nuclear bombs that explode low to the ground are dirty bombs: they induce a lot of radioactivity in the top soil layer (‘activation’) with their neutron pulse and moreover easily suck it high into the air. The soil dust combines with the bomb’s radioactive fission products, is carried off by the wind and can later rain down. The 25 kiloton plutonium bomb of the Trinity test (July 16, 1945) in New Mexico exploded at a height of just 100 feet, causing up to 150 kilometers away dangerous fallout† Hardly any fallout has been measured around Hiroshima. On the other hand, the fallout of the hydrogen bomb (Castle Bravo) which exploded in March 1954 near Bikini Atoll, causing health damage from a distance of 350 kilometers. That was a 15 megaton bomb that exploded near the earth’s surface.
It is also not certain how quickly a site will recover from the deployment of a nuclear weapon. For the first hours after the Trinity test, “ground zero” was so radioactive that you were in great danger even in a lead-lined sealed Sherman tank. But already in September journalists were received. Hiroshima (August 6, 1945) was killed just a month after the attack visited by American researchers who, with the Geiger counter in hand, were able to claim that there was no longer any imminent danger. (The late effects were yet to come.) It’s bittersweet, but it seems Ukraine’s wheat and sunflower crops don’t even have much to fear from nuclear weapons.
A version of this article also appeared in NRC Handelsblad of 26 March 2022
A version of this article also appeared in NRC on the morning of March 26, 2022