nuclear-news

The explosion blew out the reactor’s twelve-ton lid—and fuel rods—and ruptured the pressure hull. The reactor core was destroyed, and eight officers and two enlisted men standing nearby were killed instantly. A the blast threw debris was thrown into the air, and a plume of fallout 650 meters wide by 3.5 kilometers long traveled downwind on the Dunay Peninsula. More debris and the isotope Cobalt-60 was thrown overboard and onto the nearby docks.

According to Nuclear Risks, the accident scene was heavily contaminated with radioactivity. Gamma ray radiation was not particularly bad; at an exposure rate of five millisieverts per hour, it was the equivalent of getting a chest CT scan every hour. However, the explosion also released 259 petabecquerels of radioactive particles, including twenty-nine gigabecquerels of iodine-131, a known cause of cancer. This bode very badly for the emergency cleanup crews, especially firefighters who needed to get close to the explosion site, and the nearby village of Shkotovo-22. Forty-nine members of the cleanup crew displayed symptoms of radiation sickness, ten of them displaying acute symptoms…….

While the Chazhma Bay region appears contaminated to this day with radiation, it is unknown how much of it is the result of the K-431 incident and how much the result of the many nuclear-powered submarines that were junked and forgotten in the area.

The K-431 incident was one of several involving Soviet submarine reactors. Ten Soviet submarines experienced nuclear accidents, and one other, K-11, also suffered a refueling criticality………. https://news.yahoo.com/1985-nuclear-submarine-explosion-contaminated-213000521.html