Civilian federal agencies have found at least 1,882 potential hazardous waste sites on their property but have studied only half of them to determine whether a cleanup is necessary, according to a report by the General Accounting Office released yesterday.

The report found that 934 of the sites had been examined closely and that 511 of them had been determined to need a cleanup. Of those, waste has been removed or contained at 78 locations, about 15 percent of the total so far.

More than two-thirds of the potentially hazardous sites, 1,326, belong to the Department of Energy. Of these, 1,061 sites were at facilities used for the production of nuclear materials and weapons.

Only four of the 11 agencies studied had finished searching for chemical dumps on their lands by September 1986, when the figures were compiled, even though the 1980 "Superfund" law required complete lists to be submitted to the Environmental Protection Agency by June 1981.

The study is a follow-up to a 1984 survey that found that five of 16 agencies had not searched for hazardous waste sites on their land. The report focused on the 11 agencies that owned more than 95 percent of the sites identified in 1984.

By law, federal agencies are required to submit a list of potential hazardous waste sites they own to the EPA every two years, but there is no deadline for the agencies to locate all waste sites on their property.