The Reactor (location)

The Reactor is the main power source of Chernobyl. During 1986 it had a major meltdown and the city of Chernobyl was rendered an "unlivable" wasteland.

This is not the whole story, however.

Beneath the Reactor was a research facility designed to discover the way to create limitless power using a substance known as the "Void." The massive amounts of radiation caused a negative reaction within the Void which caused it to be dispersed across the city. When a group of mercenaries and teenagers repopulated Chernobyl in 1993, they discovered this substance and used it to create various weapons and serums.

The "survivors" of the Disaster were horribly mutated due to the Void and essentially turned into mindless zombies.

In about 2005 the Void had dispersed enough that the surrounding area was essentially safe for all life.

In about 2007 the Reactor was safe enough to not be instantly killed upon entry.