OCEANSIDE -- A recent letter calling for new nuclear plants to be designed with potential attacks from commercial airliners in mind has caused the anti-nuclear activist community to ask fresh questions about the safety of the nation's 101 existing nuclear plants, including the San Onofre Nuclear Generating Station north of Oceanside.

Rochelle Becker, a founding member of the California-based Alliance for Nuclear Responsibility activist group, said she believes that the nuclear industry's call for new plant design guidelines to consider commercial aircraft attack is an admission -- whether intentional or unintentional -- that current plants are vulnerable.

"That's what the public has been saying for six years since (the Sept. 11, 2001, terrorist attacks)," Becker said.

She said the alliance, and other national anti-nuclear groups, will compare notes in a conference call Wednesday and will determine whether to file a fresh request with the Nuclear Regulatory Commission, calling for better protection against intentional commercial airliner attacks.

The Nuclear Regulatory Commission has rebuffed previous proposals from anti-nuclear activist organizations calling for a range of safety enhancements, including the suggestion to shield each plant with a giant steel cage.

Representatives from both the Nuclear Energy Institute, the nuclear industry's lobbying arm which wrote the letter that has riled the anti-nuclear community, and the Nuclear Regulatory Commission, the federal agency in charge of making sure plants are safe, said they disagree with any attempt to link the design process for new plants with safety at existing plants.

Tony Pietrangelo, vice president for regulatory affairs at the energy institute, said the letter, mailed to nuclear regulators Dec. 8, was simply meant to make sure that all potential security threats are considered during new plants' design phases, not after the fact -- such as what was done at existing plants in the wake of 9/11.

Pietrangelo said the institute harbors no uncertainties about existing plants' abilities to withstand a direct strike from a commercial airliner.

"I think we convinced ourselves that the containment buildings and the fuel pools are adequate," he said.

Becker said she and many others see the fuel pools as the weak link in most reactor systems. Each of San Onofre's two operating reactors has a 45-foot-deep pool that stores hundreds of highly radioactive spent uranium fuel assemblies. According to Southern California Edison, the assemblies must be stored under water for seven to 10 years before they are cool enough to be moved to dry storage in nearby concrete vaults near the plant's twin containment domes.

Though today Edison will not specify the exact dimensions of San Onofre's spent-fuel pools, the company told the North County Times in 2002 that they are below ground. Company spokesman Ray Golden said the pools are surrounded by a reinforced concrete wall that is "several feet thick" and that those walls are capped by a concrete roof of similar heft.

Golden added that the pools are tucked between the plant's tall containment domes and its metal electrical distribution lines, making a direct plane strike more difficult.

Golden said that Edison has conducted its own technical review of the pools and is confident they could withstand a direct hit from a commercial airliner.

Scott Burnell, a spokesman for the Nuclear Regulatory Commission, dismissed any attempt to link new plant design guidelines to existing plant security as tenuous at best.

He said that the commission's governing board has long shied away from addressing attacks from commercial aircraft in its official design guidelines, because defending from such a threat requires more resources than a private plant owner could muster.

"The commission has repeatedly said that commercial aircraft are outside the realm that a private facility should be required to defend against," Burnell said.

He added that the commission believes, like Edison and the nuclear institute, that the nation's plants can withstand the large explosions and fires that such a strike could generate.

Contact staff writer Paul Sisson at (760) 901-4087 or psisson@nctimes.com.