At this point, scientists don't know what pumping hundreds of kilotons of SO2 into the stratosphere continually for decades or even centuries would do to the atmosphere. (scholarsandrogues.com)
In the worst case, based on a 100 - kiloton blast at a depth of 700 metres close to the edge of the atoll, radioisotopes could reach the ocean in 25 to 50 years. (newscientist.com)
According to the NukeMap, a weapon with a 20 - kiloton yield produces a fireball with a radius of 260 meters, making its total width the size of 5 football fields. (businessinsider.com)