I was watching a program and the narrator made mention of the "The disaster at Sibirskaya Nuclear Power Plant"...and then added nothing to it.
So I decided to do some of my own research on it, (I googled it) and didn't really find a lot of information on it, other than a short summary of the events that didn't explain a lot and TIME Magazine calling it the one of the world's worst nuclear disaster. The most detailed the short excerpts get is "A tank blew up inside the plant, dispersing a cloud of radioactive material".
On the historical timeline, this was after Chernobyl. So what exactly happened at Sibirskaya? What were the consequences of the disaster? How did it affect the local population?
Seversk is still has a population of 100,000+, but an article in the BBC had a short entry that said several other villages had to be evacuated and remain empty. They're still uninhabitable because of radioactivity.
Does anyone have a more detailed explanation of what happened?
The Tomsk-7 accident was an accident at a nuclear reprocessing plant. This is not a nuclear reactor — it was a plant used to extract plutonium from spent nuclear fuel.
A tank exploded and vented some radioactive gases (fission products and heavy actinides). There was a fire. The contamination levels were very low. The IAEA ranked it as a Level 3 on the International Nuclear Event Scale (INES), "namely, a 'serious incident' but one in which there was no overexposure to personnel." By comparison, Fukushima and Chernobyl were ranked Level 7 and Three Mile Island Level 5.
As for effects on the population and remediation:
Parts of the SCE site and a considerable area of the surrounding countryside to the north of the complex, including the village of Georgievka and part of the trunk road linking Samus with Tomsk, were contaminated with radionuclides. Although the level of contamination was relatively low, considerable effort was expended in decontaminating buildings and land on the SCE site, as well as farm land and areas within the locality of Georgievka. Food was imported for both the local population and animals to avoid consumption of contaminated food. Some of the measures introduced in the surrounding area were not strictly warranted by the level of contamination but were carried out to provide reassurance to the local population and to reduce their concern and stress.
All together it seems pretty minor as far as nuclear accidents go. There were high levels of radiation around the building with the accident, but the levels offsite are very low. The villages do not seem to have been fully evacuated. They are also small enough that low-levels of radiation are unlikely to produce probabilistic effects in the population (the main one that was contaminated had only 75 people living in it). The BBC report seems exaggerated to say the least. If this really ranks as one of the world's worst nuclear disasters, it speaks for the relative drop-off in "worst" that you get once you get outside of the top 5 or so.
Link to IAEA report: http://www-pub.iaea.org/mtcd/publications/pdf/p060_scr.pdf
It's normally called the "Tomsk-7 Accident," so that's why you had a hard time finding info on it.
It was a very, very minor accident in comparison to Mayak and Chernobyl. A tank used in reprocessing exploded due to an unforeseen reaction and spewed fission products about the countryside. The contaminated area was limited, and decontamination efforts were initiated rapidly.
The dose to workers was very limited according to the IAEA report:
"The highest recorded external dose to a worker was 7 mSv and the firemen who extinguished the fire received about 2 mSv."