Tuesday marks the 30th anniversary of the Chernobyl nuclear disaster, when an explosion at the power plant near the town contaminated a wide area.
During the catastrophe, two people died immediately, while 29 more died within weeks. It is estimated thousands more have died from cancers and other illnesses in the ensuing years.
More than 200 tons of uranium are still inside the reactor site, fueling fears that new radiation leaks could occur in the area.
International donors on Monday pledged an additional $99 million in aid toward completing a newer, safer fuel storage facility for Chernobyl.
Since 2011, tourists have been allowed to visit Chernobyl. Much of the Chernobyl exclusion zone provides a snapshot of Cold War tensions, frozen in time in 1986.