A $16.75 million study to more precisely determine earthquake hazards surrounding the Diablo Canyon nuclear power plant needs an Environment Impact Report, according to the State Lands Commission, which serves as the lead agency on the study. The underwater survey is expected to create sound levels higher than a jackhammer. Determining whether underwater sounds used to study faults and small ersatz earthquakes harm the marine environment is part of the nuclear facility\u2019s California Environmental Quality Act review. At risk is the potential to engender radioactive releases due to seismic activity. The environmental review \u201ccould result in a sigh of relief\u201d for stakeholders, or it could \u201cmake people more freaked out,\u201d said Jennifer Deleon, Lands Commission project manager. \u201cIt\u2019s hugely contingent on lots and lots of things.\u201d The tests contribute to state knowledge to help protect public safety; they also may contribute to the federal 20-year license extension for the nuclear plant. Two processes to be used in gathering data for owner Pacific Gas & Electric--vibroseis and accelerated weight drop--may impact biological, recreational, and other resources, according to a July 21 public hearing. The data gathering techniques are the \u201chigh energy\u201d second phase of the seismic study, said PG&E spokesperson Cory Raftery. Testing with the two techniques require more than 2 kilojoules of sound energy underwater, he said. Vibroseis is a process that emanates a constant sound that delivers a bounceback to help map underwater geology. Accelerated weight drop is releasing a heavy load into the landscape to produce earthquake-like vibrations. In the past, the processes have been used for oil exploration. For Diablo Canyon, PG&E intends to map potential seismic hazards in detail. The utility is aware that the facility lies about three miles from the Hosgri fault. About two years ago, it was discovered that another fault--known as Shoreline--is about 1 kilometer from the nuclear power plant. Before the Fukushima Daiichi nuclear meltdowns, PG&E planned to take on the studies, for which the California Public Utilities Commission allowed up to $16.75 million in spending. After the Japan disaster, PG&E asked the Nuclear Regulatory Commission to consider whatever data the studies turn up as it weighs whether to extend the plant\u2019s license for 20 years. In an unusual move, the NRC announced it would try to include new seismic data--although that inclusion would not necessarily slow down the relicensing process. Federal regulators have extended licenses for 71 reactors out of a total of 103 units nationwide. Of those, five have been allowed since the Fukushima meltdowns.