NRC NEWS

 U.S. NUCLEAR REGULATORY COMMISSION 

 Office of Public Affairs Telephone: 301/415-8200

 Washington, DC 20555-001 E-mail: opa@nrc.gov 

 Web Site: http://www.nrc.gov/OPA

No. 01-112 September 21, 2001

NRC REACTS TO TERRORIST ATTACKS

In light of the recent terrorist attacks, U.S. Nuclear Regulatory Commission officials and staff

have been working around the clock to ensure adequate protection of nuclear power plants and nuclear

fuel facilities. This has involved close coordination with the Federal Bureau of Investigation, other

intelligence and law enforcement agencies, NRC licensees, and military, state and local authorities.

Immediately after the attacks, the NRC advised nuclear power plants to go to the highest level of

security, which they promptly did. The NRC has advised its licensees to maintain heightened security. 

The agency continues to monitor the situation, and is prepared to make any adjustments to security

measures as may be deemed appropriate.

In view of the recent unprecedented events, Chairman Richard A. Meserve, with the full support

of the Commission, has directed the staff to review the NRCís security regulations and procedures.

A number of questions have come in from reporters and members of the public since the tragic

events of September 11. The following questions and answers are offered in response:

Q: What would happen if a large commercial airliner was intentionally crashed into a nuclear

power plant?

A:. Nuclear power plants have inherent capability to protect public health and safety through

such features as robust containment buildings, redundant safety systems, and highly trained operators. 

They are among the most hardened structures in the country and are designed to withstand extreme

events, such as hurricanes, tornadoes and earthquakes. In addition, all NRC licenses with significant

radiological material have emergency response plans to enable the mitigation of impacts on the public

in the event of a release. However, the NRC did not specifically contemplate attacks by aircraft such as

Boeing 757s or 767s and nuclear power plants were not designed to withstand such crashes. Detailed

engineering analyses of a large airliner crash have not yet been performed. 

Q: What measures have the NRC and its power plant licensees taken in face of this potential

threat?
A: Immediately after the attacks, the NRC advised licensees to go to the highest level of

security, which all did promptly. The specific actions are understandably sensitive, but they generally

included such things as increased patrols, augmented security forces and capabilities, additional security

posts, heightened coordination with law enforcement and military authorities, and limited access of

personnel and vehicles to the sites.

Q: What, precisely, did the NRC do in response to the attacks?

A: At 10 a.m. on September 11, the NRC activated its Emergency Operations Center in

headquarters and assembled a team of top officials and specialists. The same was done in each of its

four regional offices. In addition to communicating with its licensees about the need to go to the highest

level of security, the NRC established communications with the FBI, the Department of Energy, and

the Federal Emergency Management Agency, among others. NRC personnel were dispatched to the

FBIís Strategic Information Operations Center. The NRC has also established close communications

with nuclear regulators in Canada and Mexico.

Q:What would happen if a large aircraft should crash into a spent fuel dry storage cask?

A: The capacity of spent fuel dry storage casks to withstand a crash by a large commercial

aircraft has not been analyzed. Nonetheless, storage casks are robust and must be capable of

withstanding severe impacts, such as might occur during tornadoes, hurricanes or earthquakes. In the

event that a cask were breached, any impacts would be localized. All spent fuel storage facilities have

plans to respond to such an emergency, drawn up in consultation with local officials.

Q: What if a large aircraft crashed into a spent fuel transportation cask in a heavily populated

area?

A: Again, the capacity of shipping casks to withstand such a crash has not been analyzed. 

However, they are designed to protect the public in severe transportation accidents. The cask must be

able to withstand a 30-foot drop, a puncture test, exposure to a 30-minute fire at 1475 degrees

Fahrenheit, and submersion under water for an extended period. Moreover, the location of loaded

casks is not publicly disclosed and such a cask would present a small target to an aircraft . 

If an airliner crashed into a cask, there could be some localized impacts. Regulations require

special accident response training of those involved in shipping, as well as coordination with state, local

and tribal emergency response personnel. In addition, redundant communications must be maintained

during shipment with the transporter vehicle; this would facilitate emergency response, if necessary.

Q: Could such a crash into a nuclear power plant, or a storage or shipping cask trigger a nuclear

explosion?

A: No. 

Q: What are the consequences if an airliner crashed into a uranium fuel cycle facility?

A: Because of the nature of the material, there would likely be only minimal off-site radiological

consequences. Some such facilities use chemicals similar to those found at many industrial facilities. 
In the event of a release, comprehensive emergency response procedures would be immediately

implemented.

Q: Have nuclear power plants been subject to attack in the past?

A: There has never been an attack on a nuclear power plant. On very rare occasions there have

been intrusions. For example, there was a 1993 car crash through the gates of Three Mile Island plant

by an individual with a history of treatment for mental illness. Such intrusions have not resulted in

harm to public health or safety.

Q: What are the normal security measures at commercial nuclear power plants.

A: Licensees are required to implement security programs that include well-armed civilian guard

forces, physical barriers, detection systems, access controls, alarm stations, and detailed response

strategies. NRC routinely inspects security measures as part of its normal reactor oversight process and

periodically undertakes various exercises, including force-on-force exercises, so as to assure that any

vulnerabilities are exposed and corrected . 

Q: Is an attack using an airplane part of the NRCís design basis threat against which its licensees

have to defend?

A: No. The NRC has been in close and continuing contact with law enforcement and the

military regarding such a threat. 

Q: What exactly is the so-called design basis threat?

A: The details of the design basis threat are classified, but it includes the characteristics of a

possible sabotage attempt that NRC licensees are required to protect against. The agency continually

assesses the adequacy of the design basis threat in consultation with local law enforcement and federal

intelligence agencies.

Q:Is the NRC contemplating a modification of the design basis threat?

A: The agency will continue to coordinate with law enforcement and intelligence agencies to

assess the implications of this new manifestation of terrorism. If the NRC determines that the design

basis threat warrants revision, such changes would occur through a public rulemaking.

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