On Thursday, CNBC published an Amanda Macias story “US intel report says mysterious Russian explosion was triggered by recovery mission of nuclear-powered missile, not a test” about the mysterious August 8 weapons-testing accident that killed at least seven people at Nyonoska, a remote Russian Navy weapons range on the shores of the White Sea of the Arctic Ocean. Macias reported that US intelligence found that the explosion occurred during a mission to salvage a nuclear-powered missile from the floor of the White Sea.
Mark Krutov, Sergei Dobrynin, and Mike Eckel followed up with report on RFE/RL with more detail, including a lead photo taken from a closed chat room on VK, a Russian social media platform, along with other photos. Although I won’t reproduce the photos here due to copyright restrictions, they are well worth a look-see. The lead photo was captioned “This is what death looks like” (in Russian), and depicts two pontoon platforms supporting damaged blue six-meter shipping containers of the type used by Ekomet-C, a St. Petersburg, Russia shipping company that advertises them for “storage and transport of solid radioactive waste”. The RFE/RL report also contains satellite imagery matching the photos, along with Russian chat-room discussion likely by local fishermen indicating that one witnessed a 100-meter column of water that burst into the air.
According to a report by Andrew E. Kramer in the New York Times, the Russian weather agency Rosgidromet said on Monday that it found strontium-91 (half-life 9.3 hours), barium-139 (half-life 83 minutes), barium-140 (half-life 12.8 days), and lanthanum-140 (half-life 40 hours) in samples it took in Severodinsk, about 20 miles from the accident. This indicates that the accident involved a nuclear reactor explosion, rather than nuclear material escaping from an isotope source as Russian authorities had originally asserted. The accident also likely released plutonium, cesium-137 or radioactive iodine, though these materials were not reported. Rosgidromet says that cities near the accident now have normal radiation levels.
The RFE/RL report concludes:
In a post to Twitter, Edwin Lyman, a nuclear expert at the Union of Concerned Scientists in Washington, D.C., said that the speculation of a botched salvage mission, coupled with the earlier announcement by Rosgidromet, pointed to the possibility that a reactor rod that would have kept a nuclear reaction under control might have dropped out of the core, causing “inadvertent criticality.”
Inadvertent criticality, also called a “critical excursion”, a “divergent chain reaction”, or a “criticality accident”, is uncontrolled nuclear fission. Although frequently lethal to nearby humans, it is smaller than the nuclear explosion produced by a fission bomb. The last known fatality due to inadvertent criticality in the US was a 1964 accident in a nuclear processing facility in Wood River Junction, Rhode Island.