Non-civilian : In addition to the civilian accidents described above , several accidents at early nuclear weapons facilities – such as the Windscale fire , the contamination of the Techa River by the nuclear waste from the Mayak compound , and the Kyshtym disaster at the same compound – released substantial radioactivity into the environment . The Windscale fire resulted in thyroid doses of 5 – 20 mSv for adults and 10 – 60 mSv for children . The doses from the accidents at Mayak are unknown
Kyshtym disaster
Kyshtym disaster
Background radiation