The explosion was a result of a rocket engine test over the border of Norway in Russia. A nuclear-powered engine was being tested near to the village of Nyonoksa, which is to the west of Severodvinsk. Russia’s state nuclear agency, Rosatom, has said that five people killed in the blast worked for the agency and the accident involved “isotope power sources”.
The five Rosatom workers who were killed are to be awarded high state honours.
The radioactive iodine had been detected as far as Svanhovd, which is by the Russian border.


The agency said only tiny amounts of iodine had been detected and the level is so low that it poses no harm to people or the environment.
The sample was taken during the period of 9-12 August.
Russia’s weather service has also revealed that radiation levels in the city of Severodvinsk had spiked up to 16 times last Thursday.
Scientific director of Russian Federal Nuclear Centre, Vyacheslav Soloviev, said: “We are analysing the whole chain of events to assess both the scale of the accident and to understand it causes.”
President Donald Trump said the U.S. “is learning much from the failed missile explosion in Russia” and added that “we have similar, though more advanced, technology.
This blast was the latest in deadly accidents that Russia has suffered in recent months.
One person was killed and 13 others injured following a huge explosion at a Siberian military depot.
The side effects of radioactive iodine are nausea, neck tenderness, loss of taste and swollen salivary glands.
The explosion caused panic among locals with many people rushing to buy medical iodine to limit the effects of iodine.