Legislation to limit insurance and other aids to development on the nation's barrier islands will be among Senate Republicans' top environmental priorities this year, according to Sen. John H. Chafee (R-R.I.) new chairman of the Senate environmental pollution subcommittee.

There will be no major reexamination, however, of the so-called superfund that was set up last year to deal with toxic chemical dumps and spills. Still, Chafee said in an interview, he is "very upbeat" about the chances for further environmental progress in the new administration, and he chided conservationists for talking "as though they might have to go into an air raid shelter."

Ronald Reagan, he said, is justly proud of his environmental record in California, where as governor he received credit for a strong clean air act, and "is going to be just as environmentally conscious" as president.

The barrier islands -- Miami Beach, Galveston, Tex., Rehoboth Beach, Del., and North Carolina's Outer Banks, among others -- are in danger of destruction from beachgoers' effects to make them into permanent homes. Chafee said he would introduce a bill within the next month "to limit federal expenditures and financial assistance, such as flood control insurance . . . to discourage development there."

There is "lots of support," Chafee said, for protecting the barrier islands, which form a necklace offshore from Maine to Mexico and survive best when natural wave action is allowed to move and reshape them. Nearly $500 million in federal funds was spent on island projects between 1976 and 1978, and far more could be spent in the wake of a major hurricane, which most of the major developed islands have not experienced.

Chafee said that the subcommittee will draft an oil spill cleanup bill to attach to last year's "super-fund," a $1.8 billion industry-federal fund to pay for the cleanup of toxic waste dumps and spills. However, "don't expect to see the overall superfund reopened except for this oil-spill thing," Chafee warned -- apparently dooming the hopes of environmentalists and several senators who have promised efforts to enlarge the fund and broaden its liability provisions.

Other environmental priorities will include reauthorization of the Clean Water Act, in which Chafee said he will "thoroughly examine" the huge construction grants program that builds sewers and treatment plants. "Of the $25 billion obligated, only $2.1 billion has been spent on finished projects," while up to 75 percent of existing plants do not meet discharge requirements, he said.

He also wants to strengthen the Lacey Act, which bans interstate traffic in contraband birds and animals, and to set up within a Wildlife Resources Conservation Act an international conservation corps to help developing nations with their wildlife management.

The Clean Air Act reauthorization, which is expected to be the major environmental controversy of the coming year, will be handled by the Environment and Public Works Committee, of which Sen. James Jeffords (R-Vt.), one of the act's chief defenders, is chairman.