Thursday, November 09, 2006

On Air Attack and Nuclear Power Plants

From today's edition of the New York Times:

With construction of many new nuclear reactors under discussion, the Nuclear Regulatory Commission is grappling with the question of whether they should be designed to withstand a Sept. 11-style airplane attack.

The commission has told its staff to study the vulnerabilities of the four new reactor designs, two of which it has already approved. But it has decided not to make the nuclear power industry meet security requirements any tougher than those for existing plants, which were designed before suicide airliner attacks, and even before the development of such airplanes.

Planes are not on the list of weapons that reactors must be prepared to survive. One of the five commissioners, Gregory B. Jaczko, has called for the panel to require design changes to reduce vulnerability, but the other four seem unpersuaded.
One of my colleagues, Adrian Heymer, is also quoted:
At the Nuclear Energy Institute, the industry's trade association, Adrian Heymer, senior director for new plant deployment, said designers had analyzed existing plants and made many changes that cost little but made the new designs more difficult to attack. But, in general, Mr. Heymer said, protecting against terrorism was a government function.

"“Refineries, tall buildings, those are the responsibility of federal government to protect,"” he said.
In 2002, EPRI conducted a study on the topic:
EPRI aircraft crash building integrity study uses advanced computer modeling and adverse assumptions. In 2002, the independent research organization EPRI undertook an advanced computer modeling study to determine if buildings at nuclear power plants can withstand the impact of an aircraft crash similar to the Sept. 11 terrorist attacks. A Boeing 767 was selected as the aircraft because its weight is greater than almost all other commercial jet airliners flown in the United States, and because over two-thirds of the commercial aircraft registered in this country are manufactured by Boeing. The location of the buildings and facilities where the aircraft would do the most damage was chosen as the place where the aircraft would strike. The study used the reasonable, controllable aircraft speed for the accuracy of the strike analyzed.

Nuclear plants are much smaller than the World Trade Center or the Pentagon, making them more difficult targets to strike by aircraft. Because nuclear plant structures are smaller than the buildings attacked on Sept. 11, they are more difficult to damage, because it is more difficult to aim the airplane such that it hits the structure at its most damaging point. In addition, used fuel storage pools are either deep within a building or the used fuel is located underground and thus not visible to a pilot from a plant'’s exterior. Also, intervening structures on the power plant site make it very difficult to reach these areas by plane. Finally, nuclear plant buildings and structures are so low to the ground that the ground begins to affect the wind currents produced by the plane, reducing a pilot'’s ability to control and maneuver the plane without slowing down.

The EPRI study demonstrates that the critical structures of a nuclear power plant will not be penetrated by a aircraft crash. The results of the EPRI study demonstrate that no parts of a Boeing 767 --—the engine, the fuselage, or the wings, nor the jet fuel -- —will enter the containment building, used fuel storage pool, used fuel dry storage facilities, or the used fuel transportation containers. This means that no radiation will leak from these structures even if hit by a Boeing 767 at the maximum plausible force and vulnerability.
For more on the study, which EPRI conducted at the request of NEI, click here. For more on safety and security at nuclear power plants, click here.

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8 comments:

Randal Leavitt said...

Let's face it - nuclear reactors are ugly and should be completely underground. A reactor in the rural areas should have a farm or a forest park on top of it. A reactor in the middle of the city should be below the subways. This approach also hides and minimizes transmission lines, and makes reuse of the exhaust heat feasible. Now, what is the concern about airplanes?

Anonymous said...

Randal, that sounds expensive. Why spend so much to solve a problem that doesn't exist?

Nuclear power is already overburdened with expenditure that just makes uninformed people feel better about chimeric threats.

Randal Leavitt said...

Hmmm ... I think a policy that requires all energy production plants and transmission lines to be hidden underground would favour nuclear energy.

How much is beauty worth?

Anonymous said...

The ultimate level playing field :-)

Anonymous said...

I see no discussion of the effects of burning jet fuel in this assessment. It looks more like impact forces only. The impact is not what took down the towers.

Also, there is the threat of RPGs and shoulder launched missles or even a jet loaded with explosives.

You have to rely upon the government to protect the facilities. If orchestrated correctly, an attack can be painful, both economically and radiologically.

Stewart Peterson said...

Does concrete burn?

David Bradish said...

No, concrete does not burn.

Eric McErlain said...

I got the following note from a colleague of mine at NEI, Doug Walters:

"Regarding fires, licensees implemented measures to deal with losses of large areas of the plant due to fire and explosions. In February 2002, the Commission, directed nuclear power plant licensees to develop specific plans and strategies to respond to a wide range of threats, including the impact of an aircraft attack. The NRC has conducted detailed, site-specific engineering studies of a limited number of plants to gain insights on potential vulnerabilities of nuclear power plants to deliberate attacks involving large commercial aircraft. The results of these studies have confirmed the effectiveness of the February 2002 NRC-ordered mitigative measures, and have identified the need for some additional enhancements. For the facilities analyzed, the studies confirm the low likelihood of both damaging the reactor core and releasing radioactivity that could affect public health and safety. Even in the unlikely event of a radiological release due to a terrorist use of a large aircraft against a nuclear power plant, the studies indicate that there would be time to implement the required on-site mitigating actions. These results have also validated the potential radioactive source term for off-site emergency planning basis. Nevertheless, on June 20, 2006, the NRC issued orders to appropriate power reactor licensees requiring the implementation of additional key radiological protection and mitigation strategies to reduce potential consequences from the loss of large areas of the plant due to large fires or explosions."

Further...

"We agree the defense of our nation’s critical infrastructure is a shared responsibility between the NRC, the DOD, the DHS, Federal and State law enforcement, and other Federal Agencies. A reasonable approach in determining the threat requires making certain assumptions about these shared responsibilities. Although licensees are not required to develop protective strategies to defend against beyond-DBT events, it should not be concluded that licensees can provide no defense against those threats."

Thanks to Doug for taking the time to address the question.