Simplify the following text for a Grade 10 native English-speaking person.
Original: The Chernobyl disaster was a nuclear accident that occurred on 26 April 1986 at the Chernobyl Nuclear Power Plant in the Ukrainian SSR ( now Ukraine ) .
Simplified: The Chernobyl disaster occurred on 26 April 1986 at the Chernobyl nuclear power plant in Pripyat , Ukraine .