Thirty one years ago today Reactor No 4 at Chernobyl, Ukraine, blew up. Eventually fifty tons of radioactive material were blown over the Soviet bloc and Western Europe. Ironically both sides of the Iron Curtain manifested a government reflex to conceal. France averaged out radioactive hotspots over a wide area, to dilute the data and reassure the French people nuclear power was safe. The Politburo upped the permitted radioactivity levels to ten times their normal exposure – and much worse. Belarus authorities threaten journalists today asking about highly radioactive milk. It has taken brave and persistent people like Ukranian journalist Alla Yaroshinskaya to find out and expose the truth. Understorey recalls some of Chernobyl’s secrets, and its tragedies, also speaking with John Croft, deep ecologist campaigner and international trainer.