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Volume 7, Issue #4 • January 30, 2003


 

A Nuclear 9/11: Imminent or Inflated Threat?

Mark Burgess, CDI Research Analyst, mburgess@cdi.org

The possibility that terrorists might crash a hijacked airliner into a nuclear power plant is one of the more nightmarish scenarios to have surfaced since the al Qaeda attacks on the Pentagon and the World Trade Center on Sept. 11, 2001. However, disagreement remains as to whether a plant could survive such an attack as well as the likely consequences.

Consequences

According to a January/February 2002 article in the Bulletin of the Atomic Scientists, an average nuclear power plant contains 1,000 times as much long-lived radioactivity than was released by the Hiroshima bomb. The spent fuel pools at such a plant are said to contain "some multiple of that – several Chernobyl’s worth." However, unlike an atomic bomb, any damage from a terrorist attack on a nuclear power plant would result almost entirely from the release of radioactivity, not the initial blast, although casualties would be similar. According to a Nuclear Regulatory Commission (NRC) study, a meltdown at one of Southern California’s San Onofre reactors could cause: 130,000 ‘prompt’ fatalities; 300,000 latent cancers; and 600,000 cases of genetic defects. Another study carried out for the NRC in 1980 estimated that such an incident would cost up to $314 billion (around $700 billion in today’s dollars).

Others remain less convinced of the dangers posed by such an incident. One controversial September 2002 article in Science magazine by Douglas M. Chapin and 18 other members of the National Academy of Engineering, claims that the implications of the 1986 Chernobyl accident are not applicable to American reactors, as on that occasion the fissile materials were mainly dispersed into the atmosphere by burning graphite. This article also goes on to claim that: "The terrible and widespread consequences of that accident – increased suicide, alcoholism, depression, and unemployment, plus 100,000 unnecessary abortions – were caused primarily by fear of radiation and by poor planning based on that fear." Such findings contrast with those of the United Nations, which highlights a 25-fold increase in childhood thyroid cancers in some cities in Belarus, and explicitly link this to the accident at Chernobyl. Another study, by Richard L. Garwin, estimates that some 24,000 unidentified deaths are likely to be caused by the radioactive material released at Chernobyl.

Nuclear Power Plant Survivability

Nuclear power plants are designed to withstand extreme events such as hurricanes, tornadoes and earthquakes, but not necessarily to survive attacks by terrorists using large airliners such as Boeing 757s or 767s as ballistic missiles. The Nuclear Control Institute (NCI) -- an organization often critical of safety at nuclear plants -- estimates that a direct, high-speed hit by a large commercial passenger jet would "have a high likelihood of penetrating a containment building" that houses a power reactor. According to the NCI, such an incident could cause a significant release of radiation into the environment and result in tens of thousands of cancer deaths.

The authors of the September 2002 Science article disagree, citing a 1988 test in which an unmanned plane was flown at around 480 mph into a 12-foot thick concrete wall. The plane was destroyed by the impact, its engines only piercing the structure by a couple of inches, while the main body penetrated even less. The article also concluded that the greater impact of larger planes was offset by their absorption of more energy in their collapse, and that higher speed, while increasing the impact, would not do so "enough to matter."

However, a report by Sandia National Laboratories -- which conducted this test -- says it was meant to measure the jet’s impact not the strength of the wall. Moreover, the wall in question was not embedded in the ground as would be the case with that of a nuclear power plant. Consequently, according to the official test report, "the major portion of the impact energy went into movement of the target and not in producing structural damage." For their part, while Chapin et al concede that the test was not intended to measure the survivability of a concrete structure in such an incident, they maintain that it nonetheless confirms that large aircraft disintegrate on impact, causing little penetration. This appears to ignore that fact that the F-4 Phantom fighter used in the tests is considerably smaller and lighter than a large civilian airliner. It also does not address the dangers posed should an aircraft be crashed into a plant’s spent fuel pool rather than its reactor.

Spent Fuel Pools

Such pools, generally around 40-feet deep, are made of reinforced concrete walls four or five feet thick with stainless steel liners. They are used to store and cool spent nuclear fuel, and can hold five to ten times more long-lived radioactivity than the reactor core itself. The biggest risk with such pools is said to stem from water loss.

If this happens the spent fuel can become exposed to air and steam. Its zirconium cladding would then react exothermically (giving off heat) and catch fire at 1,000 degrees Celsius. Ironically, this process may be aided by the pools’ safety equipment that is packed between fuel assemblies to guard against the risk of criticality by controlling water chemistry and absorbing neutrons. According to the NRC, this safety equipment could restrict air and water flow to exposed spent fuel assemblies in the event of a terrorist attack that compromised the integrity of the cooling pool.

This could release up to 100 percent of the highly dangerous isotope cesium 137 contained in the pool. A 1997 study for the NRC estimates that a severe pool fire could cause up to 28,000 cancer fatalities, render some 188 square miles of territory uninhabitable, and cause $59 billion in damage. Moreover, as the NRC acknowledges, the risk of a zirconium fire cannot be dismissed even years after spent fuel has been moved into storage.

The Wrong Threat?

Such risks notwithstanding, recent computer analyses conducted by the Electric Power and Research Institute (EPRI) on behalf of the Nuclear Energy Institute -- a trade association of utilities and nuclear energy firms -- found that a used fuel pool, the reactor containment structure, used fuel ‘dry’ storage facilities, and used fuel transportation containers would all survive a direct impact from a fuel laden airliner. Some, such as NCI President, Edwin Lyman, dispute such findings, claiming "we can’t take anything the [nuclear] industry says at face value."

Underlying the seeming interminable nature of such disagreement is the fact that the debate often appears less about the risk posed by a terrorist attack on a nuclear power plant than more general safety concerns over such plants. These concerns pre-date the terrorist attacks of Sept. 11, 2001, and may be distorting the actual risks posed by a terrorist kamikaze attack on such a target by a large airliner.

The willingness of al Qaeda and their fellow travelers to commit such an act cannot be doubted after the attacks on New York and the Pentagon. Similarly, while as outlined above, consensus does not exist as to the damage any breech of a nuclear reactor would entail, the weight of scientific opinion suggests that such an event could be catastrophic -- more so if the spent fuel pool is the target of the attack. However, not only does the recent EPRI study conclude that nuclear power plants are structurally secure against attack by terrorists crashing airliners into them, but ‘Silent Vector’ -- an exercise conducted by the Center for Strategic and International Studies (CSIS) that examined the vulnerability of America’s energy industry to terrorist attack – concluded that nuclear power plants were relatively secure. According to CSIS President John Hamre, "Nuclear plants remain the best-defended parts of the energy infrastructure." Conversely, chemical storage sites and liquefied natural gas facilities were found to “remain a problem.” As such findings indicate, the risk of terrorists crashing a hijacked airliner into a nuclear plant is not the only potential threat facing America’s energy infrastructure. Nor is it necessarily the greatest.

Moreover, by storming their hijackers and causing the plane to crash before reaching its target, United Airlines flight 93’s passengers showed that hijacking an American airliner for use as a ballistic missile will never again be as easy as it once was. In addition, according to a Dec. 8, 2002, New York Times article, 19 percent of guards at the Indian Point nuclear facility allegedly do not believe they provide sufficient protection for the plant against terrorist attack. As this shows, an attack using an airliner is not the only danger when considering plant security, and probably not the most likely.

Looked at together, all these factors suggest that only an independent study of the vulnerabilities of America’s entire civilian infrastructure can give a true picture of the threat posed to it by terrorists. Huge though such an undertaking might be, it is the only way to comprehensively assess and prioritize the terrorist threat to American soil.


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