Nuclear Regulatory Commission [3] chair Dale Klein "said he supports the 'groundwater protection initiative,' a self-policing effort proposed in May by the Nuclear Energy Institute [4] trade organization. 'I think as a nation we need to be cautious about putting unneeded regulations in place,' Klein said." He spoke at the Braidwood nuclear power plant in Illinois, "where tritium in groundwater spread beyond plant boundaries, sparking state and federal legislation, three lawsuits and an Exelon cleanup effort being monitored by state and federal agencies." Tritium contamination of groundwater has been found at at least 10 U.S. nuclear plants, most recently Wisconsin's Kewaunee [5] and California's defunct San Onofre [6] plants. Tritium is a low-energy nuclear isotope readily cleared by the body, though in high concentrations it has been linked to cancer and birth defects.