WASHINGTON - A government defense plan for nuclear power plants assumes an attack would come from fewer than half the number of Sept. 11 hijackers, and they would not be armed with rocket-propelled grenades or other weapons often used by terrorists overseas.
Such assumptions, say critics of the largely classified security document, could make plants vulnerable to a terrorist takeover even though the industry has pumped more than $1.2 billion (?1 billion) into defenses at its 64 reactor sites in 31 states since the al-Qaida attacks in 2001.
Because of the sensitive nature of security, NRC officials refused in interviews to discuss details of the defense plan. They said the requirements, expected to be final later this year, will demand a level of security from a civilian guard force that is "reasonable."
"I'm not going to get into numbers," said Michael Weber, deputy director of the NRC's office of security and incident response> He has been involved closely in the development of the defense plan, known as the Design Basis Threat, or DBT.
Various sources, including congressional investigators, private watchdog groups and industry representatives with access to NRC officials, say the defense plan assumes an attack force of roughly double the number that had been used in government planning before the 9/11 attacks. Back then, plants were required to anticipate no more than four adversaries, including an "insider" accomplice.
Nineteen al-Qaida terrorists were involved the attacks on Sept. 11, 2001, against the World Trade Center, the Pentagon and an unknown third target. The third plane was brought down in a Pennsylvania field by a passenger revolt.
The NRC "should require defenses against attacks ... by groups at least as large as that involved in the 9/11 attacks," attorneys general from seven states wrote the agency last year, worried that the upgraded defense plan falls well short of that number.
Their states have 31 of the nation's 103 commercial power reactors.
"Instead of sizing the DBT on the actual threat, the NRC bases security standards on what the NRC, or perhaps the nuclear industry, believes a private guard force can be expected to handle," said Peter Stockton, a former security adviser at the Energy Department who now is with the Project on Government Oversight, a private watchdog group.
Stockton said he has learned the commission rejected staff recommendations to require guard forces at reactors to be capable of defending against an attack force armed with a variety of weapons including rocket propelled grenades, powerful "platter" explosive charges capable of penetrating six feet of concrete, homemade torpedoes and .50-caliber armor-piercing ammunition.
Those NRC decisions were confirmed by industry and congressional sources who are familiar with deliberations on the defense plan but spoke on condition of anonymity because of the sensitive nature of the details.
Stockton produced an unclassified Energy Department training film for security at its nuclear sites that says such weapons are readily available to terrorists and suggests ways to defend against them.
"I can't discuss it," NRC spokesman Eliot Brenner said Wednesday, which also was the deadline for public comment on the defense plan.
Weber, the NRC security official, said detailed information about the size of a potential attack force or its firepower could be exploited by terrorists and therefore could not be discussed publicly.
Weber acknowledged that the crafting of the DBT "takes into account not only what is the threat but what is reasonable for a private security force to protect against." The NRC assumes there could be a larger threat than outlined by the guard-force DBT, and the defense plan includes provisions to get police and military reinforcements to a plant.
"If a larger threat shows up, then the security force that's on site has to be able to hold that site long enough so the cavalry can respond," says Weber.