 NAICC submitted its inquiry report to both houses on July 5, 2012.The 10-member commission compiled its report based on more than 1,167 interviews and 900 hours of hearings.It was a six-month independent investigation, the first of its kind with wide-ranging subpoena powers in Japan's constitutional history, which held public hearings with former Prime Minister Naoto Kan and Tokyo Electric Power Co's former president Masataka Shimizu, who gave conflicting accounts of the disaster response.