A troubled reactor at the Savannah River Plant won't resume producing nuclear weapons material until engineers are sure longtime safety problems have been corrected, an Energy Department spokesman said Saturday.

"I think we are all disturbed by what we have seen," said John Ahearne, chairman of the Advisory Committee for Nuclear Facilities Safety, one of two Energy Department bodies investigating the sprawling facility near Aiken, S.C.Richard W. Starostecki, deputy assistant energy secretary for safety, health and quality assurance, also has started a new review of events at the Savannah River Plant, said department spokeswoman Chris Sankey.

Plant managers have been rocked over the past week by disclosure that up to 30 significant mishaps occurred at the facility over the past three decades and that many had not been reported to Washington headquarters or disclosed to the public.

All three reactors at the plant have been shut down since August when a mishap idled the P-Reactor.

Spokesman Doug Elmets said the department will not restart the reactor "until we are completely satisfied with all the safety procedures."

Sankey said Friday the department had set a Nov. 1 target date for restarting the P-Reactor, but Elmets said Saturday that Sankey was in error and that no timetable has been set.

The plant produces two materials used in nuclear weapons, plutonium, which the government has in adequate supply, and tritium, which decays more quickly. Officials say the amount of tritium on hand and the date by which they must resume production are classified.

Sankey also had said that if the Savannah River Plant cannot resume production in time, the department might restart the N-Reactor at the Hanford nuclear reservation in Washington state in order to guarantee an adequate supply of tritium.