"Only 1400 kilograms of uranium and graphite mixture would have needed to hit the water to set off a new explosion. Our experts studied the possibility and concluded that the explosion would have had a force of 3 to 5 megatons. Minsk...would have been razed." - Vassili Nesterenko, director of the Institute of Nuclear Energy at the National Academy of Sciences of Belarus.

I am not a nuclear physicist, but at least some people who are did not find this to be "clearly nonsense."