Lydiaa wrote:
chernobyl...
Even the residue could kill ya
Chernobyl was not a nuclear explosion. In fact, it was actually way worse in terms of fallout than most any single nuclear explosion unless you made one with, say, cobalt tampers to increase long-term fallout. Even then it would still depend heavily on burst height and yield.
Chernobyl involved several explosions and a fire that spread large amounts of radioactive material in a large plume over time. Nuclear explosions, on the other hand, invest far more of their energy in blast, fireball, and short-term radiation such as gamma rays which move at the speed of light. In addition, the fusion portion in thermonuclear (hydrogen) types of warheads produces far less radiation, proportionally speaking.
For comparisonQuote:
On 26 April 1986 at 01:23 a.m. (UTC+3) reactor number four at the Chernobyl plant, near Prypiat in the Ukrainian Soviet Socialist Republic, exploded. Further explosions and the resulting fire sent a plume of highly radioactive fallout into the atmosphere and over an extensive geographical area. Four hundred times more fallout was released than had been by the atomic bombing of Hiroshima.[2]
Quote:
According to official estimates, about 95% of the fuel (about 180 tonnes) in the reactor at the time of the accident remains inside the shelter, with a total radioactivity of nearly 18 million curies (670 PBq). The radioactive material consists of core fragments, dust, and lava-like "fuel-containing materials" (FCM) that flowed through the wrecked reactor building before hardening into a ceramic form.
Part of the reason for so much fallout at Chernobyl was the ample supply of radioactive material; 180 tons of radioactive material is far larger than any nuclear weapon; as large as most weapons plus their entire delivery system. In fact a B-52 loaded is between 132 and 244 tons, so we're talking about as much radioactive material in terms of weight as a nuclear bomb, plus its entire case and systems, plus the airplane carrying it.
The Hiroshima bomb by various measures was 12 to 20 kilotons total yield, so in order to produce the same amount of radiation, a nuclear warhead would need to be 4.8 to 8 megatons in total yield, assuming that radiation production scaled up evenly. That is not, however, a safe assumption. Once weapons pass about 500 kilotons, pure fission designs become impractical and a fission-fusion design (thermonuclear, or a "hydrogen bomb" as often known) is needed. In fact, the largest weapon ever tested, Tsar Bomba, weighed in at 50 megatons by most sources and still produced less radiation (it was scaled down from a planned 100 megaton test and while the Soviet Union of the 50s is less than sterling in terms of safety, it's also safe to say that they did not wish to turn their own nation into a radioactive mess); in fact in terms of radiation compared to yield it was one of the cleanest detonations ever as well.
With most nuclear detonations, initial radiation would be quite high but it would fall off fairly rapidly, especially for an airburst. A ground burst would produce much more fallout because of the ground material being incorporated into the fireball and contaminated. A subsurface explosion produces the most, but is also best contained.
One would therefore expect to see high levels of radiation around hard targets such as missile silos following an exchange. Those targets would be attacked mainly by ground or subsurface burst to knock them out. Softer targets such as airfields and cities would be attacked by airburst, and therefore probably have less persistent radioactivity (in very general terms, since yield and number of weapons utilized would matter as well). This would be no free lunch though, sicne an airburst would maximize blast damage.