The Department of Energy violated federal regulations by orchestrating extensive lobbying by a private firm and nuclear weapons scientists against a possible congressional ban on nuclear tests, the General Accounting Office (GAO) concluded in a draft report yesterday.

Detailing a yearlong "program to influence the Congress" on the nuclear testing issue, GAO said DOE had paid a local contractor, RDA Logicon, several hundred-thousand dollars and brought employes of three national nuclear weapons laboratories to Washington to help conduct the lobbying campaign, violating not only its guidelines but those of the federal Office of Management and Budget.

The lobbying was aimed at blocking legislation approved by the House in May but recently rejected by the Senate that would bar all but a few nuclear tests as part of an effort to constrain the nuclear arms race, the GAO report said.

The department, which manages U.S. nuclear weapons research and production, has been a leader of the administration's opposition to a testing limit, arguing it would harm the U.S. arsenal.

C. Anson Franklin, a DOE spokesman, said yesterday that the agency would withhold detailed comment until it had carefully reviewed the report. But he acknowledged that the agency had been "very much involved in issues affecting nuclear testing" and defended its "right and responsibility to work with the Congress on issues affecting administration policy."

The GAO indicated the effort began in mid-1986 with an internal memorandum by Edward Badolato, then DOE deputy assistant secretary for security affairs and defense programs, recommending "a broad effort to promote DOE views on nuclear testing in . . . Congress and before the . . . public through various methods, including an extensive media effort."

The report said the campaign was coordinated by an arms control "working group" directed by three DOE assistant secretaries but staffed by officials of the Lawrence Livermore, Los Alamos and Sandia national laboratories on loan to DOE headquarters in Washington.

The group initially discussed using "pro-defense public interest groups to influence members of the Congress," the report said, which would have violated a criminal statute against federal lobbying activities. But DOE and laboratory officials quoted by the GAO said it was never approved.

Instead, the group requested and approved efforts by lab employes to influence nuclear testing legislation by conducting more than 100 briefings for members of Congress and their staffs, picked in part because they had a DOE facility in their home district.

During most briefings, the lab workers were accompanied by DOE officials who assisted in ranking legislators on a numerical scale according to their support for the administration's position and their willingness to "help the DOE cause."

The GAO concluded that this violated federal rules against using contractor employes in "managerial roles" and barring consultants from influencing pending legislation.

But it did not violate regulations barring contractor use of federal funds for lobbying activities, because DOE rewrote them last January, effectively exempting the national laboratories, the GAO concluded.

After the lobbying activities were reported by The Washington Post last May, triggering congressional demands for the GAO investigation, DOE further amended the regulations to exempt "situations where DOE requests the contractor to present information to Congress while accompanied by a DOE official."

Although these changes were considered "within DOE's discretion," the GAO recommended that DOE eliminate its exemption for national laboratories and other contractors. It also said Congress may want to overturn a provision in the 1988 DOE budget bill, already approved by the Senate Appropriations Committee, which maintains the labs' exemption.

Several congressional aides said the new legislative provision had been included in the bill at the request of senior laboratory officials this summer. It was not mentioned in the committee's staff report.

Sen. J. Bennett Johnston (D-La.), the provision's author, said in an interview that it was not drafted to permit the labs to continue lobbying against a nuclear test ban, but to ensure that the laboratories were able to offer advice on other military matters.

But one congressional aide criticized the provision because it would "blow away restraints against improper lobbying."