Tuesday's serious radiation exposure accident at a nuclear research facility in eastern Japan occurred when workers were handling a metal plutonium container that had been kept sealed for 26 years and never once opened for periodic checks, officials of the Nuclear Regulation Authority said Thursday.The container was opened Tuesday morning for an inspection based on an instruction from regulators after they found the long-term storage of radioactive materials at locations other than their designated areas in Japan Atomic Energy Agency facilities, including its Oarai Research & Development Ce…READ FULL ARTICLE