San Diego — With war brewing in the Middle East and new domestic terror strikes threatened, America is battening down the hatches. Targets are being hardened, nuclear power plants are under close watch, and all manner of precautions are being taken to safeguard dangerous nuclear materials from foreign attack. A key concern is in La Jolla, where one of the nation's most prominent defense contractors is harboring a tidy cache of plutonium and uranium, enough to cause thousands of cancer cases if terrorists ever managed to make off with the material or to blow up the containment building. Once alone on a finger canyon, the site, though surrounded by a security fence, is crowded by biotechnology research buildings and busy parking lots.

Two months before the September 11, 2001, terrorist attacks, security at the site was beefed up under a plan approved by the federal Nuclear Regulatory Commission, which today maintains that those and other top-secret precautions are adequate to protect the nuclear waste, left over from almost 40 years of reactor research.

But others familiar with the situation are not so sanguine about the pre-9/11 security plan and believe that National Guard troops may be necessary to ring the site in case of war and its aftermath. The location, they maintain, may be vulnerable from the air. In the end, these sources say, safety will only be guaranteed when the nuclear material is removed.

The location is on the outer perimeter of the industrial campus of General Atomics, maker of the Predator, the unmanned aerial vehicle that has played a conspicuous role in Bosnia, Afghanistan, and now, with the approach of full-scale war against Saddam Hussein, in Iraq. The Predator has been used as an airborne intelligence-gathering platform, equipped with television cameras to monitor military maneuvers and troop buildups. But it has a more lethal role.

Armed with Hellfire missiles by the CIA, the Predator has been responsible for killing at least a dozen alleged al-Qaeda operatives, including a top leader, Qaed Salim Sinan al-Harethi, and five others in a strike last November that vaporized their car as it drove down a remote road in Yemen. Also reported killed in that attack was Kamal Dirwish, an American citizen identified by the Bush administration as the head of an alleged al-Qaeda sleeper cell in Buffalo, New York. Six alleged members of that cell were subsequently arrested by the FBI, which said it couldn't rule out that others might still be on the loose.

Besides Predator, General Atomics contracts with the Department of Defense to provide the government with Navy power systems, guidance devices, and computer integration. It owns uranium mines in Australia, does research for the U.S. government's nuclear fusion project, and is involved in top-secret "black budget" projects for the Pentagon. The company is owned by two wealthy brothers, Air Force veterans with close ties to the CIA, Linden and Neal Blue, who acquired it from Chevron Oil in 1986, when it was called GA Technologies. But 40 years before that, the firm, which started life in the mid-1950s as General Atomics, was one of America's nuclear pioneers.

GA and its portfolio of nuclear power ventures was the brainchild of physicist Frederic de Hoffman, a Harvard graduate from Vienna, who during World War II played a pivotal role in the development of the first atomic bomb at Los Alamos. After the war he went to work for the new Atomic Energy Commission, set up by the U.S. government to oversee nuclear development. In 1955, he was recruited by John Jay Hopkins, chairman of General Dynamics, the largest defense contractor in America, which was seeking to branch into atomic energy.

After its founding in July of that year, GA went looking for a headquarters and found it in San Diego after Mayor Charles C. Dail, always eager for new industry, offered the company 320 acres of city-owned land on Torrey Pines Mesa, just west of the Torrey Pines state park. In the fall of 1956, city voters approved Proposition H, which formalized the transfer, by a 6-1 margin.

In June 1959, the new General Atomics complex, named the John Jay Hopkins Laboratory for Pure and Applied Science, was officially dedicated. Newspaper publisher Jim Copley lauded the event with a special section in the Sunday edition of his San Diego Union. "Atoms for Peace," said one headline. "The Atom at Work for Better Living," said another. "Progress is Goal of the GA Team and its Lab Reflects this Purpose," said yet another. Seventy-five-year-old Danish quantum physicist Niels Bohr, Nobel laureate and a father of the Manhattan Project who keynoted the ceremony, was said to "bestride the world of atomic physics like a shy colossus."

In an article under his byline, de Hoffmann extolled the benefits of atomic energy and described for readers the laboratory's first invention; the TRIGA nuclear reactor, "named for training, research and isotopes -- the GA is for General Atomics."

Most of the hoped-for breakthroughs touted by de Hoffmann -- including Project Orion, a spaceship to Mars to be powered by detonating a series of atomic bombs behind the craft -- fell by the wayside, derailed by cost overruns, failures of technology, and, in the case of the nuclear rocket ship, fear of atmospheric fallout. Many of General Atomics' brave schemes to commercialize the atom also turned out to be embarrassing duds.

But the firm lived on as a center for federally funded nuclear and defense research and development. The company was unloaded by General Dynamics, which sold it to Gulf Oil. It was inherited by Chevron Oil in a merger with Gulf before winding up in the hands of the Blue brothers, who diversified from the company's traditional nuclear businesses by buying the rights to the Predator from the bankrupt Israeli national who invented the craft. The company's board of directors was populated with retired CIA operatives and old Department of Defense hands such as ex-defense secretary Harold Brown.

Meanwhile, the reactor had taken on a life of its own. Developed by Los Alamos veterans Edward Teller and Freeman Dyson beginning in 1956, when GA was still headquartered in an old schoolhouse near Lindbergh Field, the reactor relied on uranium fuel alloys to control its nuclear reaction. Not designed to produce electricity, it turned out specialty products, such as medical isotopes, and was also employed by academics in physics research. By 1958, the first of more than 65 reactors to be eventually built by GA was sold.

In June 1959, the first of three reactors to be operated on GA's Torrey Pines campus was demonstrated for Bryant Evans, a reporter with the San Diego Union. "One of the interesting things about the [reactor] flash is that it is safe enough for people to watch from the rim of the reactor," he wrote. "At Thursday's test, there was a brilliant flash of blue light. Then things were as they were before. The heat slowly passed to the water that surrounded the fuel elements. It was slow enough to prevent the water's boiling."

The Union reported in February 1960 that a second reactor had begun operating at GA. "Start of the device's chain reaction was announced by Frederick de Hoffmann, General Dynamics senior vice president and president of General Atomics. He said the new device would be used in new fields of nuclear research and testing. De Hoffmann did not specify any particular experiments."

In May 1965, the Union reported that the Atomic Energy Commission had approved yet another reactor on Torrey Pines Mesa. "The AEC said the company plans to use the reactor for research on high-energy neutron and gamma radiation. The third reactor would be located in a new extension planned for the General Atomics plant. The AEC said it has determined that operation of the new reactor would not endanger public health and safety." La Jollan William Whittemore, who says he managed the TRIGA facility for decades, notes that the third reactor, designated the Mark 3, was used to research the feasibility of employing nuclear energy to produce electrical power for space probes. The Mark 3, he says, was fueled with highly enriched, bomb-grade uranium. The special fuel, 70 percent enriched with Uranium 235, was made in the days before there was a concern for terrorists. "The reactor has to have very much increased security. When the project went dead, the reactor was decommissioned about 20 years ago." The fuel was then moved to the Mark F, he says.

But setting up the reactors has proved far easier than dismantling them and getting rid of the accompanying radioactive waste. Even though the reactors have been off-line for more than six years, their legacy of nuclear fuel, including at least a gram of deadly plutonium (euphemistically referred to by the government as "special nuclear material"), remains stored on GA's La Jolla site. The reason, say regulators, is that GA is still negotiating with the government over the terms of disposal at a federal nuclear waste site.

The reactors were shut down and decommissioned by the federal government's Nuclear Regulatory Commission beginning in the mid-1990s. "All special nuclear material in the TRIGA Mark I reactor was transferred to the TRIGA Mark F reactor and is possessed under that license."

The reactors themselves were dismantled and their parts were disposed of offsite. But because GA was still haggling with the government over what to do with the radioactive waste, one of the reactor's water-filled pools was left behind to hold the spent fuel, ostensibly protected from intruders by top-secret measures spelled out in a "physical security plan" the company filed with the NRC.

In July 2001, two months before the September 11 terrorist attacks, the agency says, GA amended the security procedures to make them tougher. "On June 29, 2000, GA submitted the 'Safeguards Contingency Response Plan for the General Atomics TRIGA Reactors Facility' for NRC review and approval, and proposed changes to the 'Fixed Site and Transportation Plan for the Protection of Special Nuclear Material at the General Atomics TRIGA Reactors Facility,' " according to a July 11, 2001, NRC document.

"GA submitted the proposed amendment in response to specific changes in the long-term storage and physical protection of spent TRIGA fuel at the site. The amendments apply primarily to physical barriers, security practices, and administrative procedures....

"Access controls, physical barriers, communications, and alarm monitoring capabilities have been enhanced to provide greater assurance that unauthorized access into the material access area can be detected, assessed, and delayed until a proper and timely response can be accomplished."

The GA plan is intended to thwart anyone who tried to bring a bomb into the facility or spirit away nuclear fuel, according to the document.

"The administrative access control commitments made by GA provide adequate assurance that attempts to introduce unauthorized materials into, or remove materials from, the MAA can be detected," according to the document. Precautions include "maintaining and updating authorization lists, providing positive key and lock controls, and searching all personnel, packages, and vehicles.

"Testing and maintenance commitments provide an adequate level of assurance that the intrusion detection system will be capable of performing its intended function when called upon.

"As stated in a letter dated May 22, 2001, GA will ensure that suitable alternate communication capabilities are maintained if primary communications with outside support and response agencies are lost."

According to an NRC official in Washington, GA is currently licensed to have "up to" 30 kilograms of uranium and one gram of plutonium, a reaction by-product, at the site of La Jolla reactors. He says that the company and the federal Department of Energy, which oversees disposal of nuclear waste, "is trying to come up with some kind of agreement" to transport the material off the premises and to an atomic waste dump.

He says the agency is satisfied with current security arrangements at GA. Because the plan is classified, adoption of further protective measures in a time of war, such as troop deployments or additional guards, weaponry, or monitoring systems, would not be made public.

"I would say that the NRC takes its responsibility regarding security very seriously," said the NRC official. "There has not been a credible threat against a specific licensee. Even before 9/11, nuclear facilities were required to have very strict security plans for protecting facilities. They are among the most carefully and closely guarded facilities in the country. And since 9/11 we have required upgrades of that."

Whittemore, the former TRIGA manager, says that the risk to the public is virtually nonexistent. He says that even in the unlikely event that terrorists got their hands on the material, they could not build a true atomic bomb but could merely assemble a so-called "dirty bomb" to scatter radiation haphazardly. A direct hit on the fuel-storage facility from the air would be unlikely to successfully disperse any radioactivity, he insists.

"Everybody has been ratcheted up whether security is needed or not because of 9/11," he says. "The fuel was safe before [additional security precautions were implemented] and is safe now. The fuel is not a security issue as far as the company is concerned. It's simply a white elephant. You don't want too many white elephants around." Shipment of the fuel to a final resting place at a nuclear dump in Idaho has been delayed for almost ten years, he contends, because of interference from anti-nuclear activists and overzealous federal regulators. "It's a deplorable situation. The fuel is incapable of causing nuclear damage, and yet it has to be shipped like it was the most dangerous commodity. That runs the cost up. When we went into this business 50 years ago, the government agreed to be a repository for the fuel. Now they won't take it."