After years of accusations of creating a 'chilled work environment,' Nuclear Regulatory Commission Chairman Gregory Jaczko resigned this morning (PDF). His largest achievement was perhaps killing the Yucca Mountain waste repository, and he oversaw the certification of the AP1000 reactor. It is unknown whether a new chairman will be appointed from within the NRC. Quoting the Washington Post: "The reason for his resignation is unclear. He is stepping down before the release of a second inspector general report rumored to be into allegations of Mr. Jaczko's misconduct. NRC spokesman Eliot Brenner told The Washington Times that the report had no impact on the timing of Mr. Jaczko's resignation announcement. Mr. Jaczko's statement was vague, saying that it 'is the appropriate time to continue my efforts to ensure public safety in a different forum. This is the right time to pass along the public safety torch to a new chairman...' While his statement did not specifically touch on the embarrassing revelations of his tyrannical approach to the job or its impact on NRC staff, he did sound a defiant note by claiming the NRC was 'one of the best places to work in the federal government throughout my tenure.'" Today also marks the start of the annual nuclear industry conference.