Larsson was Sweden’s technical attaché to Washington, D.C., by the time of the Three Mile Island accident and is a former manager of a division of the Swedish nuclear technology agency and a former environment and energy policy manager of the Swedish National Federation of Industry. Between 1997 and 2000, he was the manager of the nuclear reactor safety department of the EBRD, and subsequently he managed the bilateral Swedish nuclear safety aid to Eastern Europe. He works as a consultant in the firm "SiP Nuclear Consulting AB".