Radiation safety

New details on Russia's mysterious missile disaster suggest a nuclear reactor blew up

A mysterious explosion at a Russian weapons testing site earlier this month released various radioactive isotopes, creating a cloud of radioactive gases that swept across a nearby town, the country's state weather agency said Monday, and experts said the mixture removes all doubt about what blew up.

The deadly August 8 blast at the Nyonoksa military weapons testing range released a handful of rapidly decaying radioactive isotopes — strontium-91, barium-139, barium-140, and lanthanum-140 — which have half-lives ranging from 83 minutes to 12.8 days, the Roshydromet national weather and environmental monitoring agency said in a statement on test samples.

"These are fission products," Joshua Pollack, a leading expert on nuclear and missile proliferation, told Insider. "If anyone still doubts that a nuclear reactor was involved in this incident, this report should go a long way toward resolving that."