The test took place on a sea platform during a period of work related to the engineering and technical support of “isotopic power sources” in a “liquid propulsion system,” the agency said. Some were wounded and exposed to radiations. Rosatom said three of its employees were treated for burns.The agency said the accident occurred during tests of a jet propulsion system that runs on an atomic battery. Radioactivity in the region spiked in the nearby city of Severodvinsk for about a half an hour but the nuclear safety authority in Norway, near Arkhangelsk, said it had not detected any evidence of increased radiation from the blast.
Inhabitants in Arkhangelsk had began to stockpile iodine. Arms control expert Jeffrey Lewis wrote on Twitter that the blast could have been linked to tests of a Russian 9M730 nuclear cruise missile, known as Burevestnik in Russian and SSC-X-9 Skyfall by NATO, which was unveiled last year. If the accident happened on tests for Burevestnik, the blast would represent one of the worst accidents by Russia’s military in years.