Immediately after the attacks, the federal Nuclear Regulatory Commission ordered a suspension of such visits due to security concerns.

The agency is working with Pacific Gas and Electric Co. to find a way to restore the visits without compromising heightened security precautions at the plant, said Victor Dricks, an NRC spokesman.

For their part, PG&E officials are eager to get public tours going again. Such visits are an important public-education tool, said Jeff Lewis, plant spokesman. For example, it allows the public to see firsthand the plant's armed guards and some other security measures.

"We think it's very important that we have public access even if it is in a limited venue," he said. "It helps demystify what is going on out at the plant." Diablo Canyon is only visible from boats on the ocean or airplanes.

The mystery of the plant, coupled with the fact that it has been in the news a lot lately because of the utility's proposal to build an aboveground storage facility for highly radioactive used reactor fuel, has created pent-up public interest in visiting Diablo Canyon.

Earlier this month, the Diablo Canyon Independent Safety Committee took a busload of 22 people to the plant. It took only an hour for the sign-ups to fill.

"We could have easily filled two or three buses," said Robert Rathie, with the safety committee office in Monterey. "The community has demonstrated a real interest in the plant." If allowed, the free tours would be similar to the safety committee's excursion, Lewis said. There would be stops at an overlook above the plant, the site of the proposed storage facility, reactor control-room simulators and the intake structure for the plant's ocean-water cooling system.

Like before the Sept. 11 attacks, the tours would not go into the security area immediately surrounding the reactor containment domes. They would be canceled during times of heightened national security risk.

PG&E officials hope to have an agreement soon.