Sen. Gary Hart (D.-Colo.), chairman of the Senate subcommittee on nuclear regulation, says he will introduce a bill this week that calls for an end to nuclear power plant construction if by Jan. 1, 1985, the federal government does not have a licensed burial site for radioactive waste.

Hart's bill also would require a 10 percent reduction in power output by existing nuclear plants for each year after Jan. 1, 1985, that a nuclear waste burial site is not licensed.

The bill would impose a further mandatory 10 percent power reduction on the nuclear industry for each year after Jan. 1, 1992, that a licensed burial site is not opened by the federal government. The bill is independent of any halt to nuclear construction that might be called in the wake of the Three Mile Island accident.

"It is time to pay off the mortgage." Hart said in a statement he plans to read on the Senate floor today when he introduces his bill. "We cannot plan to store nuclear waste indefinitely."

In Hart's bill is a measure to prevent the continued storage of spent nuclear fuel at "swimming pools" alongside power plants. The measure would forbid the Nuclear Regulatory Commission to approve any plan to store spent fuel at an "away-from-reactor" site until it has licensed a permanent waste burial site.

Hart's bill would give the NRC licensing Authority over all new disposal and storage facilities, except those for the short-term storgae of wastes that accumulate from the production of nuclear weapons. The NRC does not now have licensing authority over any federal waste disposal facilities.

The Hart bill also would give states the right to disapprove a construction permit or operating license issued by the NRC for a burial site. At the same time, the bill would allow for a presidential "veto" of a state's rejection of a site "if he determines both that the facility meets the health and safety standard and that not building the facility would significanty impair the nation's energy interest."