The Nuclear Regulatory Commission has directed its staff to revise within 24 months a key nuclear-waste rule and develop a general environmental impact statement in response to a recent federal court ruling.

The regulation deals with "waste confidence," a generic finding that spent nuclear fuel can be stored for decades beyond a reactor's licensed operating life without significant environmental harm. NRC says the rule enables it to license or renew the license of a reactor without examining the effects of extended waste storage at the individual site.

In its June 8 ruling, the U.S. Court of Appeals for the District of Columbia Circuit said the NRC should have considered new or renewed reactor licenses' potential environmental effects under a scenario in which a permanent waste repository is never built. The court found other deficiencies with NRC's consideration of leaks and fires involving spent-fuel pools.

The court also barred NRC from issuing final combined construction-and-operating licenses for reactors until its concerns are addressed.

In a Sept. 6 memo, NRC's commissioners urged its staff to move swiftly to develop a generic environmental impact statement to support developing an updated waste-confidence rule. NRC also said that individual, site-specific environmental analyses were appropriate but only in limited circumstances.