Kyshtym disaster

A decision was made to resettle villagers within a radius of about 130 kilometers northeast of the epicenter of the blast.

An excerpt from the article 42 facts about Kyshtym disaster

Approximately 12,000 people lived in the evacuation area, and roughly 2000 in the area of the highest concentration of radiation. Resettlement decisions were not made immediately, and for some settlements it took as long as several weeks. Many residents at the time of resettlement had already absorbed a dose of radiation sufficient to develop radiation sickness.

Four villages - Bierdianysh, Saltykovo, Galikayevo, and Kirpichiki were evacuated within 7-14 days, and another 20 villages were evacuated within 8-22 months of the disaster.