The Carter administration has ordered a review of U.S. efforts to halt the spread of nuclear weapons amid indications of a tougher position on the issue from the White House and State Department.

Among the items to be considered are U.S. efforts to block or modify the West German sale to Brazil of a nuclear fuel reprocessing plant, which would be capable of manufacturing weapons material from used nuclear fuel.

The German-Brazilian deal was among the subjects discussed by Vice President Mondale and German Chancellor Helmut Schmidt on Tuesday in Bonn, and is the topic of continuing discussions between Secretary of State Cyrus R. Vance and Peter Hermes, a senior official of the German Foreign Ministry.

The Ford administration also opposed German's sale of reprocessing technology and equipment to Brazil, though some of its opposition evidently was only for form's sake.

Then-Secretary of State Henry A. Kissinger supposedly protested the sale in a meeting with German Foreign Minister Hans-Dietrich Genscher in June. 1975, shortly after the deal was signed, but senior German officials later publicly denied the subject had come up.

According to a knowledgable diplomatic source the topic actually was not discussed, except for brief comment by Kissinger to the Germans just before a press briefing that "something will have to be said to satisfy the press and Congress" about the Brazilian sale.

In an interview with the Associated Press and United Press International last weekend, President Carter called for use of "all diplomatic means" to restrain the spread of nuclear weapons capability, and said "we are quite concerned" about the reprocessing of reactor fuel into weapons material.

Even before inauguration day, Carter reportedly gave personal approval to the government review of anti proliferation policy, one of 15 immediate foreign policy studies set in motion by the National Security Council as the new administration came into office. The "presidential review memorandum" ordering the study calls for its completion by Feb. 28, informed sources said.

Joseph Nye, a Harvard expert on international relations and energy policy, is expected to be working chairman of the study group. Nye has joined the State Department as chief of anti proliferation policy, to be centered in the office of former League of Women Voters president Lucy W. Benson. Benson has been named under secretary of state for security assistance, science and technology, a job previously known as under secretary for security assistance.

An interagency study ordered by President Ford last summer culminated in an Oct. 28 announcement making more firm the U.S. antiproliferation stance. The new study is expected to lead to a considerable additional stiffening of the U.S. position.

It is considered significant that the Ford study was headed by Robert W. Fri, then deputy administrator of the generally pro-nuclear Energy Research and Development Administration (ERDA), while the Carter study is to be headed by Nye, a State Department official whose major responsibility is blocking the spread of nuclear capabilities abroad.

The Nuclear Regulatory Commission, which regulates overseas sales of U.S. nuclear fuel, technology and equipment, is to take a much larger role in the new study than in the earlier one. The nuclear industry, on the other hand, is expected to have a smaller role than before.

Among the items to be studied are future U.S. policy in the semisecret London conference of nuclear suppliers, the renegotiation of "agreements for cooperation" in nuclear matters that the United States has signed with foreign countries, the future of the proposed atomic reactor sales to Israel and Egypt supported by former Presidents Nixon and Ford, licensing of new shipments of U.S. nuclear fuel to India, and broader questions of overall policy.

Another matter to be studied is an 11th hour decision by Ford's National Security Council to permit the commercial reprocessing in Europe of shipments of U.S.-supplied nuclear fuel owned by Japan, Spain and Switzerland.

The decision which was not publicly announced, first came to light in the nuclear industry press. The Natural Resources Defense Council, a non-profit environmental group, obtained details under a Freedom of Information Act request.

Decision papers provided under the FOI request indicated that the Arms Control and Disarmament Agency sought unsuccessfully to hold up reprocessing of the Swiss fuel, and that the State Department in November withdrew its earlier approval of reprocessing of the Spanish fuel. However, the National Security Council approved the reprocessing for all three countries in the last week of December.

The Oct. 28 Ford declaration included a shift of U.S. policy against commercial reprocessing, partly because of the danger that the plutonium produced by such an operation can be used in atomic bombs.

Neither Japan, Spain nor Switzerland is a nuclear weapons state, although the countries where the commercial reprocessing is to be done (England and France) have made and exploded nuclear weapons. Under agreements with the United States, any plutonium extracted from the recently approved shipments of nuclear waste cannot be transferred back to Japan, Spain or Switzerland without additional U.S. approval.

U.S. approval is required if U.S.-supplied nuclear material is to be retransferred to a different country from the one that purchased it originally. Some 575 retransfers of U.S.-supplied material were approved from 1961 to 1974, but only a few of these, if any, were for commercial reprocess- [TEXT OMMITTED FROM SOURCE]