The provision would allow spent nuclear fuel to be consolidated at temporary storage sites, as long as it stays in a state that has commercial nuclear power. Nevada and Utah would be explicitly ruled out as a storage site.

But governors in northeastern states, where many commercial nuclear reactors are located, don't like the change.

"We are deeply concerned and must strongly oppose language . . . that would suddenly shift long-established national policy on nuclear waste disposal by requiring commercial spent fuel at local or regional federal consolidated facilities in up to 31 states across the nation," Rhode Island Gov. Donald Carcieri and Vermont Gov. James Douglas wrote on behalf of the Coalition of Northeastern Governors.

The governors also say the bill sets up an aggressive timetable to set up the storage sites that doesn't give enough time to evaluate safety, security and environmental impacts.

The waste would presumably be kept at the storage site until the Energy Department develops technology to recycle the nuclear material, or it can be buried at a permanent site at Yucca Mountain, Nev.

Building a system of temporary storage sites could undermine the push for a permanent repository, the governors argue in their letter, sent last week.

The nuclear storage language was added to the bill by Energy Committee Chairman Pete Domenici, R-N.M.; Senate Minority Leader Harry Reid, D-Nev.; and Sen. Bob Bennett, R-Utah. Bennett had hoped to have the bill through the Senate before senators left for their month-long August recess, but it was pushed back and Bennett said last week he doesn't anticipate it will be a top priority when senators return in September.

Anti-nuclear and environmental groups also oppose moving the waste to centralized facilities, arguing that the temporary facilities would become permanent that lack the necessary security and safeguards and that state governors would be cut out of the process.