One of the most serious nuclear accidents at SGCE[further explanation needed] occurred on April 6, 1993, when a tank containing a highly radioactive solution exploded (see § Tomsk-7 explosion).

As was the tradition with Soviet towns containing secret facilities, the designation "Tomsk-7" (like its predecessor "Pyaty Pochtovy") is simply a postal code which implies that the place is located close to the city of Tomsk.

Upon leaving Seversk, residents had to surrender their special entry passes at the checkpoint and it was forbidden to discuss where they worked or lived.

Visitors can apply for entry passes at the main checkpoint; prior to May 2007, they needed to visit a special office in Tomsk.

There was a nuclear accident at the Tomsk-7 Reprocessing Complex on April 6, 1993, when a tank exploded due to formation of red oil, while nitric acid was being added to a plutonium-uranium mixture.

The cloud was dispersed northwards by the wind, with some of the radioactive material settling over the neighboring village of Georgiyevka.

[citation needed] There is also a nonprofit organization, Ostrovsky House of Culture,[11] and a cinema called Mir.

[12] There is a major post-secondary school in the city, the Seversk State Technological Academy, a branch of Moscow Engineering Physics Institute.