The Carter administration yesterday unveiled a strategy for solving an impending shortage in nuclear waste storage sites, one which could force the shutdown of nuclear reactors in the 1980s.

The plan, jointly developed by the Departments of Energy and State, would enable the federal government to take title to spent nuclear fuel rods and store them in existing and new sites scattered around the United States.

Unless new storage sites are found, federal experts concluded in a recent study, as many as 23 nuclear power plants may have to begin closing operations starting in 1979.

Administration officials are uncertain about the program's ultimate cost, where the wastes will be stored and whether the program will be managed by the Energy Department or private industry.

The Unites States now has 65 commercial light water nuclear reactors, and Department of Energy officials estiamte that there will be as many as 300 conventional reactors in operation by the end of the century.

Currently there ar 2,000 metric tons of spent nuclear fuel rods stored at nuclear reactor sites across the country (a metric ton contains 2,200 pounds). The uranium dioxide rods, covered with a "cladding" of a metal called zircalloy, are currently stored for periods of 5 to 15 years in water-filled "swimming pools" after leaving te reactor piles.

John Ahearne, senior nuclear adviser to Energy Secretary James R. Schlesinger Jr., said the new plan calls for storage and disposal fees which would be charged by the federal government. These fees, he said, would result in a 2.5 per cent rate increase in nuclear-generated electrical power costs.

Nuclear power-generated electricity now costs the consumer about 40 mills per kilowatt hour, slightly more expensive than conventionally generated power.

By the end of this year there will be 3,400 metric tons of spent fuel in storage, according to Nuclear Regulatory Commission estimates. Commercial waste is expected to mount at the rate of 1,000 metric tons a year.

George W. Cunningham, who heads the Energy Department's nuclear waste program, said the government will encourage private industry to provide and operate the storage sites, and has begun exploratory talks with some companies.

Two plants in existence that could be suitable with modifications include General Electric's Morris, Ill., plant, and Allied General Nuclear Service's plant at Barnwell, S.C. If industry does not operate the program, Ahearne said, the Energy Department would do it.

A commercial storage plant would have to licensed by the Nuclear Regulatory Commission. Energy Department officials say a federally operated plant would not have to go through the safety licensing process, but that it would be available for NRC "review."

There are three options for storing or disposing of nuclear wastes: "reprocessing" wastes into usable nuclear fuel, interim storage in "swimming pools," and disposal in deep underground rock salt or hard rock formations. President Carter ruled out commercial reprocessing in the United States when he announced his sweeping nonproliferation policy earlier this year. Reprocessing produces a byproduct which can be used to fabricate nuclear weapons.

The Energy Department has a budget of $123.5 million to evaluate potential nuclear waste burial sites in 36 states.

State Department officials say that the storage policy complements the President's nonproliferation policy, because it offers foreign countries an alternative to nuclear reprocessing. Yesterday an international conference with participants from 33 countries got under way in Washington to discuss nuclear waste and issues associated with nonproliferation.

Reaction tothe Carter waste plan was generally favorable.

Rep. Jonathan B. Bingham (D-N.Y.) said he favored the plan, adding, "The fact is that despite the blind assurances of te AEC, ERDA, and DOE, we have no safe demonstrated method for permanently disposing of nuclear wastes."