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After announced reviews, some Diablo Canyon nuclear plant emergency measures were found deficient in case of a disaster like the earthquake and tsunami that caused meltdowns at the Fukushima Daiichi facility. San Onofre Nuclear Generating Station and Palo Verde units were rated more acceptable. Nuclear Regulatory Commission results were released May 13. While California’s operating nuclear plants are designed to hold up in a 7.5 earthquake (Diablo Canyon) and 7.0 temblor (San Onofre), Nuclear Regulatory Commission investigators found vehicles are in the path of emergency response and at Diablo Canyon hoses for water to cool an overheated reactor are short. At San Onofre, inspectors discovered some staff were deficient in training. Inspection results include: Diablo Canyon-- During the NRC’s inspection, a portable long-term cooling pump did not operate, and hoses to transport emergency reservoir water could not be connected. In the case of fire, investigators noted that staff lack required training. Further inspections are required, according to the NRC, to “evaluate the impact of high radiation and worker dose” and “effects of a prolonged station blackout on starting diesel generators.” Inspectors also were concerned that “operator access to important areas of the plant would be limited after core damage occurred.” All Diablo’s backup diesel generators are of the same design and thus “could be susceptible to a common made failure because of similarities,” according to inspectors. Owned and operated by Pacific Gas & Electric, the 2,200 MW plant sits on the coast within a half-mile from the Shoreline fault and lies about three miles from the Hosgri fault. Coincidentally, May 17, there was a loss of power to Diablo unit 1 “that caused all unit 1 emergency diesel generators to start in standby mode,” according to a NRC report. The emergency generators started “as designed,” according to the report. San Onofre Nuclear Generating Station--Inspectors at the facility found severe accident procedures “were generally in place and executable.” The report added that 5 percent of personnel in the emergency response organization hadn’t received training. In total, inspectors identified 45 deficiencies, but none “would be expected to impact the success of any severe accident action,” although they reported that firefighting equipment could be “impacted by a seismic event.” Southern California Edison (the plant operator) owns 78.2 percent of the facility, San Diego Gas & Electric 20 percent, and Riverside, 1.8 percent. Units 2 and 3 have a 2,200 MW capacity. Unit 1, at 436 MW, was shut down in 1992 but remains on site as its owners were unable to dispose of the reactor in a long-term storage facility. The plant sits about five miles from the Inglewood-Newport-Rose Canyon fault. That’s estimated to pose the hazard of a 7.2 earthquake. Palo Verde--The 3,600 MW Arizona nuclear plant is 16 percent owned by Southern California Edison. In this inspection, the backup generators to power the plant in an external power blackout were operating. Flooding is not an issue with the desert power plant, noted inspectors, yet drain and sump valves were operational. The plant is also remote from most seismic activity. Regulators did note that “non-seismic valves” could fail “allowing water intrusion” On a nationwide level, Rep. Ed Markey (D-MA) reported May 12 that the NRC inspections found “widespread malfunctions and inoperability of emergency diesel generators” and that seismic safety requirements are “outdated.” He called for a moratorium on license extensions, like the one pending for Diablo Canyon. Markey introduced legislation March 29 to effect such a moratorium. In related news, the NRC met with industry representatives May 18 to discuss obtaining new seismic data on power plants. At issue is what kind of earthquake modeling should be used, what kind of risk assessment analysis is appropriate, and whether there should be priorities on some nuclear facilities--like the ones closest to earthquake faults.

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