AD-2 nuclear reactor was shut down without incidents. Underground nuclear reactor AD-2 was put in operation in 1964 and became the main source of the heat for Zheleznogorsk. At the moment the coal and black oil boilers provide the heat and hot water for the town. Such scheduled works take place at the reactor several times a year according to the technical requirements. The previous shut down for maintenance took place last winter and went without incidents. The current repair works are scheduled to last for 20 days.