As Pacific Gas & Electric attempts to get regulatory preapproval for $706 million to replace steam generators at the Diablo Canyon nuclear facility, critics charge that PG&E needs to invest instead in heading off potentially dangerous problems due to aging parts other than the steam generators. The utility is also coming under fire for not falling in line with a host of other utilities that have filed lawsuits against steam generator manufacturer Westinghouse. According to PG&E, delaying replacement of eroding steam generators at the 2,200 MW plant could increase risk of early shutdowns and prolonged outages due to stepped-up inspections and maintenance. Installing the requested equipment by 2009 will save ratepayers more than $1.2 billion, maintains the utility, compared with costs of replacing the capacity and energy output of Diablo with new gas-fired plants. The overhaul is expected to extend Diablo?s shelf life until 2025. Since 2002, ratepayers no longer automatically subsidize operating costs for the nuclear plant. The discussion came in a raft of testimony filed this week at the California Public Utilities Commission. ?A substantial body of experience in the nuclear power industry indicates that age-related degradation of structures and equipment, not related to steam generator degradation, is a significant, often undetected problem that necessitates costly repairs and lengthy outages, and that could challenge reactor safety margins,? stated David Lochbaum, nuclear safety engineer with the Union of Concerned Scientists. Lochbaum represents San Louis Obispo Mothers for Peace, the Sierra Club, Public Citizen, Greenpeace, and Environment California. For instance, Lochbaum cited a fire and 33-hour loss of off-site power to Diablo unit 1 in 2000 sparked by the same electric transformer that had exploded in 1995. In addition to transformers, Diablo has ?miles? of cables used for power and control of electrical equipment. The aging cable system is often ignored until some failure is detected, said Lochbaum. The scientist stressed that PG&E has neglected the potential for prolonged reactor outages from factors other than steam generators. In the past 20 years, he noted, 27 reactors have encountered delays of a year or more in restarting; none of the outages was initiated by steam generator age-related problems. Leveling similar charges, David Schlissel, senior consultant for Synapse Energy Economics, said PG&E faces the ?unpleasant surprise? of planning for the replacement of reactor vessel heads at the Diablo units separate from the steam generators. According to PG&E, these units will cost approximately $67 million. The breakdown of reactor vessel heads is a serious industrywide problem not anticipated five years ago, said Schlissel, representing The Utility Reform Network. These costs need to be factored into future plant capital additions, he said. No one is saying that it will just take $706 million to keep Diablo operational, responded John Nelson, PG&E spokesperson. The utility conducted a cost-benefit analysis that accounted for future operational and capital costs, and Nelson said that ratepayers would ?still come out ahead to the tune of $1.2 billion.? Diablo?s reactor vessel heads are in good condition, Nelson said, but the utility is aware they may need to be replaced in the future and has factored that into plans. Consumer and environmental groups are pushing PG&E to beef up protections at Diablo against potential terrorist attacks in the wake of September 11. They cite findings that the Nuclear Regulatory Commission requires only light defense of U.S. nuclear plants and spent fuel, making them vulnerable to attack. Costs arising from such an attack at Diablo would be no less than $100 million per year, say the Sierra Club and other groups. In another issue in the case, intervenors contend that PG&E should sue Westinghouse?the maker of the installed steam generators at Diablo. Between 1978 and 1996, a dozen utilities across the country filed lawsuits against Westinghouse over faulty steam generators. Some suits alleged fraud by the manufacturer. For example, the 1990 complaint by Duke Power charged that prior to signing contracts with the company, Westinghouse ?knew or disregarded? information showing that tubes in steam generators would be susceptible to corrosion and cracking. TURN argues that PG&E needs to press for cost recovery through a suit against Westinghouse. The Office of Ratepayer Advocates said PG&E probably knew before Diablo?s commercial operation that there were significant problems with tubing in the units? steam generators. Since PG&E has failed to pursue any claim against Westinghouse, ORA recommends that the commission calculate a discount into overhaul cost, based on an assumption of what the company would refund PG&E. Nelson disputed ORA?s claim, saying PG&E was aware of changes to water chemistry from the generators and adjusted Diablo?s plant design to accommodate the components when they were installed. ?In fact, these steam generators have lasted as long or longer than any other similar model in the U.S.,? said Nelson. PG&E doesn?t agree that the components are defective, he stressed, saying they have lasted 20 years so far, well beyond their contracted warranty. PG&E is conducting competitive bidding to get the best deal for replacement steam generators, said Nelson. However, the utility is maintaining a relationship with Westinghouse, awarding the company a $14 million sole-source contract in February for replacement parts and service at Diablo. The new equipment will be supplied to support the nuke?s fall 2005 and spring 2006 refueling outages.