An internal Energy Department investigation has uncovered critical weaknesses in computer security, protection of nuclear materials and reaction capability of the guard force at the Lawrence Livermore National Laboratory in California, according to congressional and administrative sources.

The Livermore lab is one of the major components of the nation's nuclear weapons research complex. The findings of lax external security there come in the wake of growing controversy over allegations of Chinese espionage at Livermore and at Los Alamos National Laboratory in New Mexico.

The new security problems were uncovered by an investigative team from a new office of security oversight set up by Energy Secretary Bill Richardson in response to the spying controversy. The team--which included active and retired FBI, CIA, Secret Service and military personnel--probed the Livermore lab's response to external security threats, such as attacks by terrorists or computer hackers, and determined it was not prepared for them.

Sources said the Energy Department investigators did limited performance testing of Livermore's contract guard force and determined it could not handle some physical assaults on the facility. In addition, the team said the guards' response times to other events were far slower than needed.

The investigation showed that foreign nationals residing in sensitive countries abroad and doing non-weapons work for Livermore have had remote dial-up access to the nuclear laboratory's main, unclassified computer. "They are unmonitored and may be able to gather sensitive information in the files of other individuals," said one source familiar with the inquiry.

The investigative team, which Richardson has described in testimony as his "junkyard dogs," also discovered some Livermore buildings that contained stored nuclear materials and parts did not meet Energy Department security standards.

The team's classified findings, completed last month, have been discussed with Livermore's management and will be delivered to members of the House Commerce Committee on Thursday, sources said. Livermore's director, Bruce Tarter, is also scheduled to be on hand to discuss with members what the reforms will be.

The problems of physical protection of the Energy Department's nuclear weapons research and production facilities, such as Livermore, have been the repeated subject of critical studies by the department and the General Accounting Office, but have gained new attention because of the recent controversy focused on internal security at the labs.

A congressional committee led by Rep. Christopher Cox (R-Calif.) charged in a report last month that the labs had failed to prevent or aggressively investigate security breaches by scientists working at Los Alamos and Livermore, including possible cooperation with Chinese espionage.

Richardson's internal probe expands the focus to include weaknesses in physical and cyber-security systems. Livermore and other facilities hold tons of plutonium and other nuclear bomb materials that past security reviews have found vulnerable to terrorist attack.

But key Republicans remain unconvinced that Richardson can solve the department's counterintelligence and security problems without creation of a semiautonomous agency within the Department of Energy to oversee all aspects of its nuclear programs, a move Richardson is strenuously resisting.

Richardson named retired Air Force Gen. Eugene E. Habiger as the department's first security "czar" two weeks ago, hoping to fend off congressional reorganization.

Rep. Thomas J. Bliley Jr. (R-Va.), chairman of the Commerce Committee, said last week that the Livermore inspection "was not favorable" and criticized Richardson for "trying so hard to keep this information from my committee." Bliley said yesterday in a statement that he intends "to keep the pressure on the department and Livermore to end the spin and correct this intolerable situation once and for all."

Edward J. McCallum, a retired Army Green Beret lieutenant colonel who served as DOE's director of safeguards and security until he was placed on paid administrative leave two months ago, said in an interview yesterday that Energy Department security forces are still inadequate. There are 4,000 security personnel for 50 facilities. "The major dozen or so facilities are well under strength; they're running 25 percent overtime on average."

While DOE SWAT teams used to protect nuclear facilities from terrorist attacks have been reduced by 50 percent since 1992, McCallum said, there has been increase of 30 percent in the amount of nuclear materials for which the department is responsible.

McCallum, who has been openly critical of the way the administration has handled DOE security, said he had been using Army Green Berets and Navy SEALS to help train department security personnel and to help pinpoint security vulnerabilities at the nation's nuclear facilities. He said that unlike himself, Glenn Podonsky, a longtime DOE employee who headed the new investigation called for by Richardson, could get the results of his investigations "to the secretary. I couldn't get it past the Office of Nonproliferation and National Security, an office formed in 1993 that separated us from the secretary's office."

Podonsky, who headed the new investigation, said in an interview that when he went to the Energy Department to do inspections and evaluations in the late 1980s, "I would get mild attention from assistant secretaries and the labs would push back on recommendations." Then-Energy Secretary Hazel R. O'Leary cut back on his budget and emphasized health and safety inspections, other sources said.

Besides physical security at Energy Department facilities, McCallum said, the department must also rectify serious cyber-security problems. "The classified systems have never been penetrated," McCallum said. "But the unclassified, sensitive computer systems have been, hundreds of times or more."

McCallum said he remains skeptical of Richardson's efforts to improve security. "I haven't seen much in the way of ongoing security reform," McCallum said. "I've listened to a lot of talk." McCallum questioned why Richardson did not stop and meet with DOE's security officials, gathered last week in Albuquerque for a conference, during his trip to nearby Los Alamos National Laboratory.

McCallum was placed on leave for allegedly divulging classified information to a former security official, a charge McCallum denies. McCallum has strong bipartisan support on the House Government Reform Committee.