Nature joined the debate over the fate of the Diablo Canyon nuclear facility this week, striking central California with a 6.0 magnitude earthquake about 50 miles from the plant. The September 28 temblor hit during the midst of California Public Utilities Commission hearings to consider a potential $700 million investment in new steam heat exchangers for the plant. Stakeholders made hay with the timing, while the hearings shut out the public from learning details of arrangements between the nuclear plant?s owner, Pacific Gas & Electric, and its steam generation contractor, Westinghouse. During the hearings, administrative law judge Jeffrey O?Donnell rejected the Sierra Club and other environmentalists? bid to examine potential seismic retrofit costs during the CPUC proceedings. In August, O?Donnell agreed with PG&E that the Nuclear Regulatory Commission (NRC) has jurisdiction over seismic matters. At the same time, O?Donnell?s assertion that seismic review could effectively torpedo the utility?s move to replace steam generators implicitly acknowledged the damaging impact such review could have. Overall, PG&E maintains that delaying replacement of the eroding equipment could increase risks of early shutdowns and plant outages. At the hearings, PG&E conceded it hasn?t analyzed potential costs for injury, death, cleanup, or remediation efforts arising from accidental releases of radioactive materials from Diablo. Given the ?history of safe industry operations,? such accidents are not likely enough to prompt such consideration, the utility said in response to questions from The Utility Reform Network. Despite this assessment, Westinghouse, maker of installed steam generators at Diablo, has been slapped with lawsuits from a dozen utilities over faulty components (Circuit, August 6, 2004). At PG&E?s request, the public was shut out of the part of the hearings focusing on Westinghouse matters. The utility contends that making this information public could damage trade secrets. The closed hearings came on the heels of the recent passage of watered-down legislation on CPUC confidentiality reforms (see story on page 8). Meanwhile, on the ground at Diablo, Joseph Tapia, NRC senior resident inspector, said no damage to Diablo was found during inspections conducted after the quake. PG&E issued, then retracted, a press release stating that Diablo operated without a hitch through the event. According to the notice that was recalled, the utility declared an ?unusual event? after tremors were felt by Diablo?s control room personnel. PG&E offered no explanation for retraction of the message. Gregg Fishman, California Independent System Operator spokesperson, said the earthquake didn?t diminish output to the grid from Diablo or other plants. Still, critics of PG&E?s plans charge that the CPUC?s refusal to look at seismic issues for Diablo leaves California on shaky ground. Duke and Dynegy/NRG, which operate plants in the region, said their generating facilities experienced no service interruptions. A coalition of environmental and advocacy groups say the earthquake offers a wake-up call for the CPUC to stop ignoring requests for scrutiny of potential seismic retrofit costs. ?We?re living on borrowed time and have been lucky so far,? said Carl Zichella, regional staff director for the Sierra Club. ?Instead of extending [Diablo?s] life, we should be looking to move to alternatives,? said Zichella at a September 29 press conference. Diablo is located 2.5 miles from the Hosgri earthquake fault line. ?Lisa Weinzimer