Pacific Gas & Electric is justifying its proposal to spend $706 million on retrofitting Diablo Canyon's steam generators by citing the facility?s lack of carbon dioxide emissions and its cost-effectiveness. PG&E fails to mention, however, the lack of radioactive spent-fuel storage and low-level waste burial for continued operation of the plant. In a January 9 filing with the California Public Utilities Commission for a new proceeding to vet the capital additions spending, the utility said the units would have to be shut down early?between 7 and 12 years before their licenses expire?if the new steam generators are not installed. With new steam generators, the plants could run for decades longer but PG&E would have to renew its license with the Nuclear Regulatory Commission. The NRC rarely rejects such requests, allowing owners to continue operating plants 20 years beyond their original licenses. According to Jeff Lewis, PG&E spokesperson, ?The company has not made a decision on whether to seek such a license extension.? PG&E claims that spending more than $700 million?an amount ratepayers will have to pay back with interest?will produce ?net benefits? worth $1.77 billion. PG&E said the amount was arrived at by using a ?Monte Carlo? analysis for potential replacement costs. If the additions cost more than the projected $706 million, PG&E said, it would be ?at risk for the additional amount.? If the 2,200 MW output of the nuclear plant were to be replaced by fossil-fueled generation, PG&E estimates that it would add 7 million tons of carbon dioxide, a greenhouse gas, to the air every year. The utility provided no estimate of pollution savings if the facility were replaced by renewable energy projects. If Diablo Canyon continues operations, additional radioactive waste will need to be stored or buried. Currently, PG&E has a proposal at the Nuclear Regulatory Commission to place spent fuel in aboveground storage on site while long-term burial at Yucca Mountain, Nevada, is under consideration. Meanwhile, San Luis Obispo Mothers for Peace is suing the utility in the Ninth Circuit Court of Appeals over expanding its on-site radioactive waste storage. Along with the Sierra Club and a county supervisor, Mothers for Peace is set to file its briefs March 8. The groups claim federal regulators have not taken into consideration potential terrorism attacks on the nuclear plant.