By Andreas Rinke, Riham Alkousaa and Tom Käckenhoff BERLIN (Reuters) -German Chancellor Olaf Scholz has asked the economy, environment and finance ministries to lay the legal framework to keep the country’s three nuclear power plants operational until as late as April 15, 2023, a letter seen by Reuters showed on Monday. Germany had planned to complete a phase-out of nuclear power by the end of this year, but a collapse in energy supplies from Russia because of the war in Ukraine has prompted the government to keep two plants on standby. Lengthy disagreements within the ruling coalition governm…