Complex sentence: Power was the main branch of industry: the country's only nuclear power plant, one of the world's most powerful, is situated near Visaginas, it ceased operations in December 2009 over safety concerns, and is currently being decommissioned.
Split into simpler sentences: Power was the main branch of industry: the country's only nuclear power plant, one of the world's most powerful, is situated near Visaginas. It ceased operations in December 2009 over safety concerns and is currently being decommissioned.