In an October 17 hearing on Pacific Gas & Electric's Diablo Canyon nuclear plant, Ninth Circuit Court of Appeals judges asked Nuclear Regulatory Commission attorney Charles Mullins tough policy questions but posed only technical questions to environmental attorney Diane Curran. The San Luis Obispo Mothers for Peace and the Sierra Club are suing the NRC. They claim the agency violated federal law by refusing to grant a hearing on whether the National Environmental Policy Act (NEPA) requires consideration of the environmental impacts of terrorist attacks during spent reactor fuel storage and transportation. Attorneys general for California, Washington, Utah, and Massachusetts are supporting their case. "NEPA did not require" a hearing, Mullins told the judges' panel. He explained that earthquakes are predictable, but not terrorist attacks. Therefore, the agency doesn't need a public hearing on the latter. "But suppose you have a pronouncement from Bin Laden-you know there's going to be an attack?" queried judges Stephen Reinhard and Sidney Thomas. They grilled Mullins and PG&E attorney David Repka as to why the agency could not quantify risks from a potential attack. Repka argued that the issue is a procedural matter. At stake, he said, is whether on-site radioactive waste storage should be licensed, which is apart from the issue of radioactive releases as a result of terrorist attacks. He said the cause-and-effect issue in the procedural matter is not the same as what environmentalists argue. A radioactive release would be "the effect of a terrorist act, not a licensing action." PG&E plans to expand its current radioactive waste storage from spent-fuel pools at the Diablo Canyon plant to the use of dry casks, which will be placed above ground at the site. Environmentalists are concerned that the planned 140 casks will be exposed to potential threats without berms or other protection. "The NRC refuses to consider mitigation measures," stated Curran.