Strong international opposition was voiced at the tenth World Energy Conference today to President Carter's proposals to curb the spread of nuclear weapons and reduce the risk of nuclear terrorism by limiting fast-breeder reactors and the use of plutonium for nuclear fuel.

Fast-breeders and plutonium were favored unanimously by delegates from Britain, Canada, France, India, Italy, Sweden, Japan the United States and West Germany, who called them safe, efficient and able to meet future world energy needs.

John Hill, chairman of Britain's Atomic Energy Authority, said plutonium produces only "soft" radiation that could be stopped by a piece of paper of rubber gloves.

The director of France's Atomic Energy Commission, Michel Pecquer, said fast-breeders can produce 60 times more energy then thermal reactors.

A spokesman for the International Atomic Energy Agency said the Carter restraints are pointless as "The technological cat is alrealy out of the bag."

Speaking for American private enterprise, W. Kenneth Davis, vice president of Bechtel Power Corp., said the United States would not be able to meets its nuclear fuel requirements in the year 2,000 without plutonium fast-breeders.

The Carter administration opposes proliferation of fast-breeder reactors on the ground that his could lead to the spread of nuclear weapons. It is against plutonium because it is an inert metal that can be transported easily and, therefore, is easy for terrorists to steal.

The panel discussion on plutonium use - Soviet delegates refused to take part because it is a governmental issue - came on the third day of the five-day conference, which is attended by more than 4,000 government officials, energy-industry executives, economists, scientists and engineers from 70 countries.

Earlier in the day, the conference's conservation commission stated that uranium requirements for nuclear fuel production could be reduced by 50 per cent by recycling plutonium in heavy-water reactors and warned that crudeoil prices could rocket uncontrollably after 1985 unless alternative supplies of energy as available.

"Conventional petroleum reserves are running out," reported the commission, which was set up at the ninth World Energy conference in 1974 in Detroit. "The years 1985 to 1995 seem critical. If demand for petroleum continues at that time, that is, if there is not sufficient coal and nuclear electricity, there will probably be a shortage and oil prices are likely to rocket uncontrollably,"

The survey of petrolum resources, which was based on a poll of 29 governments, oil companies and energy-industry experts, estimated ultimate worldwide reserves of crude oil at around 1.75 trillion to 2 trillion barrels.

But, the report said, "The annual rate of growth of reserves in slowing down. Between 1970 and 1975, only 8.5 billion barrels of oil wer discovered per year whereas world consumption was 19.4 billion barrels."

The survey estimated world reserves of non-conventional oil, such as deep offshore and polar deposits, shale oil and sand tar, at between 1.5 trillion and 2 trillion barrels and urged governments to help finance development of these sources.

At present prices, the report said, non-conventional petroleum would cost $20 to $25 a barrel to recover, but government aid in developing recovery processes could reduce this to $15