U.S. Secretary Jennifer Granholm listens to Dr. Arati Prabhakar, Director of White House Office of Science and Technology Policy during a U.S. Department of Energy news conference to announce that scientists at the Lawrence Livermore National Laboratory (LLNL) have made a breakthrough on fusion energy, the process that powers the sun and stars that one day could provide a cheap source of electricity in Washington, U.S., December 13, 2022. REUTERS/Mary F. Calvert