Southern California Edison formally requested an outside audit of Mitsubishi Heavy Industries’ “books, accounts, relevant correspondence, specifications, time cards, drawings, designs, and other documentation” for the steam generators that engendered shutting down the San Onofre Nuclear Generating Station in January 2012. The 2,100 MW plant was permanently retired by its owners Edison and San Diego Gas & Electric in June. “Mitsubishi’s unjustified interpretation” of the steam generators’ contract underscores “suspicion that Mitsubishi refuses to be transparent,” Edison president Ron Liztinger wrote to Mitsubishi’s executive vice president Shigero Masamori. The letter was revealed by the utility Oct. 7. Mitsubishi did not respond to a written request for comment.