What Happened on the White Sea near Nyonoksa, Russia?

Something strange happened near Nyonoksa, Russia. There was an explosion. There was a radiation spike. At least five Russian nuclear personnel were killed. Information is dribbling out. The Russians are slowly fessing up to what happened. However, details are very, very elusive and there is an enormous amount of speculation.

Nyonoksa, Russia is in the Archangelsk Oblast (district) near Severodinsk and Archangels. It is located off the east shore of the White Sea and in the general vicinity of a lot of Russian naval bases. The accident or incident didn't happen at the town itself though, but rather at a site nearby. If the Russians are to be believed, it was out on the White Sea itself.

On August 8th, an accident took place. The accident was supposedly due to rocket fuel catching fire and at least five people have so far have died. The reports initially just stated there was an accident with a rocket. This happens rockets having far, far more energy stored in them than even a 747 and when precautions are not sufficiently taken, people die. It even happens here in the US: ask the Challenger astronauts or Virgin Galactic employees. It would have been a tragedy rather than a mystery.  This is not a strictly Russian thing.

But then...

Radiation counters spiked in in Nyonoksa, Russia and elsewhere. The radiation levels spiked to 20x the norm. And then returned to normal within days. Even possibly a day. The Norwegians reported no spike in Norway until several days later, but it was a spike of radioactive iodine. Previous radioative iodine spikes have been attributed to medical manufacturing in Russia in the past.

Therein lies the mystery.

Had this been a case where a nuclear weapon or whatnot had had a subcritical explosion, the fallout would have contaminated the area and the radiation would be persistent and VERY detectable with the cloud it would have generated in Norway with far more isotopes than merely the glowy-version of iodine. Yet it did not. Whatever caused the spike did so with a gas or something very transiently and easily dispersible.

The Moscow initially denied there was no radiation spike. They originally stated there was an explosion with a liquid fuel rocket engine. Now they are saying the stating the 7 killed were working on iso tope power sources' for new weapon systems. Yet, they still deny the radiation release: the city of Nyonoksa stated there was a radiation spike though and there was a run on iodine in town (iodine can protect the thyroid from radiation damage).  The Russians later announced and then cancelled an evacuation of Nyonoksa.

This has increased the speculation as to what happened. The Warzone (and others) have suggested there was an explosion related to the Burevestnik nuclear powered cruise missile the Russians have been working on: NATO calls the weapon 'Skyfall' which I find to be way more awesome, btw. This uses an exposed nuclear reactor to heat air into providing thrust. This was explored by the US in Project Pluto back in the 1960s/1970s. A premature or accidental test run would fit the profile for the radiation spike, but would not be a match for the description of an explosion: the engine exhaust can be radioactive even if no radioactive material from the engine is lost. The workers being present when the engine started and unexpectedly would also fit why they died and what they were doing.

However...

If the workers were killed in an accidental test, it would be a massive case of negligence. Worse than that, actually. Heads ought to be rolling so much that Putin could field a bowling team using the severed heads as bowling balls.

Burevestnik has been an air launched weapon. Russia has been testing it over in Siberia. Archangelsk's area is more naval. The location seems rather strange for the Burevestnik then unless they were working on it to integrate with naval assets. Possible, but strangely premature. The weapon is still in very early testing and the flight regime is still being expanded.   Adding the capability to, say, the Tu-144 Backfires, would be really dumb at this point. Likewise attempting to do the same with a sub or surface ship is also stupid: with money tight in the Russian defense budget, getting the missile working ought to come first and the Russians are far from stupid in that regard. This should have greatly decreased the possibility of the Burevestnik being the source of the radiation.  

But!

The engineers killed were related to the nuclear industry in Russia.  the Russians have copped to the explosion being related to their nuclear weapons development.  The US gov has stated they think the explosion was related to the Burevestnik.  In a weird and blatant twist, the Russians have been disabling radiation sensors in the area.  And doctors reported Cesium-137 in patients.

Other possibilities - unlikely ones - were a nuclear sub had to do an emergency reactor venting after an explosion.  Yet another possibility was the explosion and the radiation leak were from difference incidents.   Some have thrown out some crazy ideas based on the fact the Russians called the test as using a isotopic power source: a deliciously obfuscating phrase that covers nuclear reactors, RTGs and several other oddities.

The weirdness about the very transient nature of the radioactive cloud and Russia's obfuscations leave a lot of unknowns.  So, while, far less of a mystery than two weeks ago, the real nature of what happened continues to remain murky.

What caused the radiation spike? Why did it clear so quickly? What is going on on the shores of the White Sea?   We suspect, but don't know.