Radiation levels rose sharply in the city of Severodvinsk with nearly 200,000 inhabitants following the explosion, which should have occurred on August 8.
According to Russia's weather institute, radiation levels of between four and sixteen times the normal were recorded, stated the state-controlled Russian news agency Tass.
"Went south and west"Less than a week later, the Swedish Radiation Safety Authority stated that the preliminary measurement results showed that there were no elevated levels of radioactive substances in Sweden. The Authority also makes this assessment in its final analysis.
- The scatter calculations we have made show that any emissions from the incident mainly went south and east, and thus did not affect Sweden, says Jonas Boson, an investigator at the Radiation Safety Authority.
- If any part of the emission hit Sweden, it would have happened during the week after the incident.
Samples in Sweden have been conducted by the Swedish Defense Research Institute (FOI). The measurements were made at FOI's measuring stations in Gävle, Kiruna, Ljungbyhed, Stockholm, Umeå and Visby.
- The air filter measurements are very sensitive and can detect extremely low levels of radioactive substances in the air. There is no risk that we would miss an emission with consequences for Sweden, says Jonas Boson.
According to Russian data, seven people were killed as a result of the accident - both military and top scientists.
The researchers worked at the state of Rosatom, which is responsible for everything that has to do with nuclear technology. In addition to nuclear power plants, Rosatom is also responsible for developing nuclear warheads for Russia's Ministry of Defense.
The fire and subsequent explosion occurred when testing a robot on an offshore platform, Tass reported a few days after the accident.
US data later claimed that the explosion occurred when a nuclear-powered robot would be recovered from the seabed after a test shooting in the Barents Sea over a year earlier.
FOI's expert Fredrik Westerlund has previously told SVT that the information is too scarce to say anything about the cause of the accident.
260 measuring stations in FinlandThe Finnish radiation safety authority Stuk reports daily measurements of radioactivity at about 260 measuring stations. Stuk has analyzed radioactive substances in the outdoor air when it "would have been theoretically possible that radioactive substances would have come to Finland after the accident".
- Nothing abnormal was observed in measurements. According to the results, no radioactive material from the accident has entered Finland, says Risto Isaksson of the Finnish Radiation Safety Authority Stuk.