News in November 2017 that a nuclear plume from a reactor leak in Russia took 2 months to get some media in the UK, thanks to French institute IRSN. However initially it was not - according to the Russian authorities - an accident in a reactor as such, and was apparently not harmful to human kind, being Ruthenium 106 which is however produced while splitting atoms. Clear as mud ? It took two months to get heard about after several European monitoring bodies recorded a release level for the R106 which if recorded in France would have required evacuation and sheltering of people in a radius of several kilometers from the accident site (Guardian Nov 10 & FT Nov 25/6.
Curious to learn more, SAGE came across an important piece of nuclear accident history also from Russia (then a Soviet Union republic) which is reckoned by Wikipaedia experts to have been the world's third most serious nuclear accident. Except no-one was told about it at the time - 1957 - by either the Soviets or the West, who knew, of course, because both sides feared the public might panic and upset the politics of the cold war nuclear crisis/stalemate of those years. It happened at Mayak, in the Urals, was a level 6 nuclear disaster (scale 1 to 10) just behind level 7s for Fukushima in Japan and Chernobyl in the Ukraine in 1986. The Mayak disaster is also known as the Kyshtym disaster. 270,000 people in Mayak got radio-active contamination across an area of 20,000 square miles. A cooling system failed, releasing 70-80 tons of liquid "waste' which, left unrepaired, caused a chemical explosion of 70-100 TNT tons equivalent. 10,000 people were evacuated within a week, but other people had to wait almost two years.