Ozyorsk

Ozyorsk or Ozersk (Russian: Озёрск) is a closed town in Chelyabinsk Oblast, Russia. Population: 82,268 (2010 Census preliminary results); 91,760 (2002 Census).

Ozyorsk was and remains a closed town because of its proximity to the Mayak plant, one of the sources of Soviet plutonium during the Cold War, and now a Russian facility for processing nuclear waste and recycling nuclear material from decommissioned nuclear weapons.