A Freak Atomic Accident Destroyed a Russian Nuclear Missile Submarine in 1985

This wasn't a "freak" atomic accident. That would imply that it was something unforeseeable, that came out of the blue.

But it was neither.

The reactor vessel head was being lifted...with control rods still attached, which was lifting the control rods for the entire reactor core. They KNEW this was happening, because they PLANNED for it, putting a limiting device over the vessel head to prevent it during the evolution.

But they didn't position it correctly, didn't engineer it properly in order to adequately prevent lifting the vessel head (and control rods) too high and didn't engineer it properly with both a physical means and a procedural means to stop the evolution if things went beyond the scope of authorized work parameters.

Not to mention they deliberately designed and implemented a process which required lifting the vessel head with the control rods still attached in the first place.

It was a total f*ck-up from start to finish.

The result was the core went prompt critical, generated an incredible amount of heat in a short period of time, and virtually vaporized all the water in the reactor vessel, causing a steam explosion which destroyed the core and rather dramatically propelled the vessel head some distance into the air.

And, of course, killing a number of people and contaminating the environment with radioactive debris.

Fortunately, it was a new reactor core, which hadn't been operated to the end of it's useful life. Had this been the case, the radioactive footprint would have been significantly larger, and longer lived.

It was really bad. We have had close calls, and I can tell you from first hand experience that our yards are not perfect at handling reactors, but because of the system that Adm Rickover put in place, we have rigorous checks and balances and strict adherence to procedure that have stood us well...

I agree that the USN Sub Navy does a much better job, however, I do have to disagree with one of the lines in the article. "The U.S. Navy’s nuclear submarine fleet, by contrast, suffered zero nuclear accidents—not only during the Cold War but all the way up to the present day." I am not so sure that we can really exclude Thresher from the zero nuclear accidents in reality. I KNOW that the theory is that a brazed fitting gave out allowing sea water to enter and causing loss of power, but that has and never will be proven. The boat broke up into at least 6 major sections as she passed test (crush) depth. So maybe we have had no nuclear accidents, maybe not.