On February 17, the Nuclear Regulatory Commission (“NRC”) adopted a final rule requiring applicants for new nuclear plants to assess the design of their reactor to avoid or mitigate the effects of a large commercial airplane crash.

Since the September 11 terrorist attacks, the NRC has adopted several rules aimed at improving security at existing nuclear power facilities. In February 2002, the NRC issued an order requiring all existing nuclear plants to develop and adopt procedures to deal with large fires and explosions, including “beyond-design-basis” aircraft impacts. In March 2007, the NRC required both existing and proposed new reactors to defend against more realistic threats. In December 2008, the NRC codified these requirements in a separate rule for all existing and proposed nuclear facilities.

The new rule expands previous rules that require new nuclear power plants to be designed under very strict requirements so that they can shut down safely after “design-basis events” such as large fires, floods, earthquakes and hurricanes, as well as unlikely equipment malfunctions. These requirements include having two redundant systems to accomplish each safety function.

Under the new rule, a design feature or functional capability of a proposed nuclear reactor that is solely designed to comply with the rule will be exempt from NRC design-basis regulations, such as regulations for redundancy. Such design features must address core cooling capability, containment integrity, spent fuel cooling capability, and spent fuel pool integrity following an airplane crash into a nuclear generating facility.

Specifically, the rule requires that the design of a proposed nuclear reactor include features that will keep the reactor core cooled in the event of an airplane crash or that the reactor containment shell will remain intact to contain any radiation released from a crack in the core. Additionally, new plant designs must show that the plant’s spent fuel cooling system or spent fuel pool would remain intact so that no radiation would be released after an airplane collision.

The NRC noted that nuclear power plant operators are not required to prevent the impact of large commercial aircraft because that is the responsibility of the federal government. However, if such an unlikely event were to occur at a new plant designed in accordance with the new rule, the plant will be better able to withstand such a crash.

The rule does not apply to existing nuclear power facilities. However, utilities seeking to build already approved projects will have to demonstrate compliance with the new rule as part of their construction and operating license.