South Carolina Gov. Richard W. Riley yesterday urged Congress to mandate that states producing low-level nuclear waste assume responsibility for its disposal.

Riley, who is chairman of the State Planning Council (a group appointed by President Carter to study waste-disposal issues) spoke before a Kennedy School of Government seminar on "Nuclear Wastes and the States."

"We take the benefits of nuclear development in such areas as medical research, electrical power and nuclear weapons, and we must now be willing to assume the responsibility of disposing the wastes," Riley said, calling on Americans to bear the burdens of their own policies.

Kiley's state houses the Chem Nuclear Corporation's low-level waste disposal site, which until recently received more than 80 per cent of all solid waste produced in the United States.

South Carolina will reduce the amount of low-level wastes entering the state for burial at the Chem Nuclear site "to force other states to take their share of responsibility in wastes disposal," Riley said.

Riley said he hopes to reduce the level of waste accepted at the Chem Nuclear site--one of three operating in the country--from 250,000 in 1979 to 100,000 cubic ft. per month by late 1981. He added that the two-year time period would allow nuclear-waste-producing states to establish their own burial sites.

States should be given the authority to enforce compliance of safety regulations governing the handling of nuclear wastes within their boundaries, Riley said. He added, "States must have the ability to protect the health and safety of their citizens."

Riley outlined steps that Congress, the Department of Energy and the State Planning Council should take in formulating a comprehensive national plan for the disposal of wastes. He said they should:

*resolve the issue of location and procedures for permanent high level waste burial sites;

*resolve the issue of whether high level wastes should be "glassified" or otherwise immobilized before burial;

*delineate the responsibilities inherent in various other technological methods of disposal.

He added that the federal government should have authority over the disposal of high level wastes and spent reactor fuel