The estimated radionuclide spreading calculated using the HYSPLIT software. Open source data were used for the calculation.
On 8 August, around 12 am Moscow time, the sensors of the Automated Radiation Monitoring System (ARMS) in Severodvinsk (Russian Federation) recorded an increase in radiation background. Within half an hour, it was about three times higher than the permissible value. The equivalent dose rate of gamma radiation was 2 µSv/h.
The increase in radiation background occurred due to the explosion of a liquid rocket engine in the military area near Arkhangelsk, where the military training area for testing ballistic missiles for nuclear submarines is located. Because of the incident, two people died and six people were injured with varying degrees of severity.
Later, Serhii Kozub, Deputy Captain of the Arkhangelsk Seaport, imposed a ban on navigation in the Dvina Bay for a month at the request of the Ministry of Defense.
The media reported that the Ministry of Defense did not allow the Ministry of Emergencies of the Russian Federation to place of incident and it carried out all the measures on the mitigation of emergency consequences by its own forces. In addition, the Russian media published information that the Ministry of Defense of the Russian Federation made details of the catastrophe secret. At the same time, the agency denies the fact of release of harmful substances and states that “no emissions of harmful material to the atmosphere were recorded and the radiation background is normal”.
The International Ecological Protection Organization Greenpeace in Russia appealed to the Federal Service for the Oversight of Consumer Protection and Welfare to determine the cause of increased radiation background, since the value of 2 µSv/h exceeds normal background level according to environmental activists. Such an increase of radiation background may be an indicator of the presence of alpha- and beta-emitting radionuclides in the air that are dangerous in the view of internal exposure (for example, by inhalation of radioactive gases or aerosols).
The state of the environment is currently under monitoring and information is constantly updated.