The 1982 Nobel Peace Prize was awarded yesterday to two campaigners against nuclear weapons, Sweden's Alva Myrdal and Mexico's Alfonso Garcia Robles, for their "central role in the United Nations' disarmament negotiations" and for publicizing "the threat mankind faces in continued nuclear armament."

Both have been prominent critics of U.S. and Soviet policies on nuclear weapons and arms control.

Myrdal, 80, started her efforts to curb the world arms race in 1962 as head of the Swedish delegation to the U.N. disarmament conference in Geneva. Her 1976 book, "The Game of Disarmament," denounced the growth of the U.S. and Soviet nuclear arsenals during years of arms-control talks between the two superpowers.

Garcia Robles, 71, a career diplomat active in U.N. affairs since the organization's 1945 founding conference in San Francisco, was cited specifically as "the driving force" behind the 1967 Tlatelolco Treaty which declared Latin America a nuclear-free zone.

The prize committee appointed by the Norwegian Parliament said the two winners represented both "the patient and meticulous work undertaken in international negotiations on mutual disarmament" and "the work of the numerous peace movements." The award was made in hopes of encouraging the spread of "the climate of peace that has emerged in recent years, first and foremost in the Western world," across "still more boundaries," the Nobel committee said.

The winners were chosen from among 60 individuals and 19 organizations nominated this year. They included Lech Walesa, interned leader of Poland's Solidarity labor movement, U.S. Middle East negotiator Philip C. Habib, jailed Soviet activist Yuri Orlov and Bishop Desmond Tutu, a leading spokesman for South African blacks.

Last year's prize went to the office of the U.N. High Commissioner for Refugees. The last individual winner was Argentina's Adolfo Perez Esquivel, in 1980.

Both Myrdal and Garcia Robles said they were surprised and delighted by the award. "It will make the cause of disarmament heard again," Garcia Robles said in Geneva, where he heads the Mexican delegation to the U.N. Disarmament Committee. In Stockholm, Myrdal noted the award's "symbolic importance . . . for all those who strive for a reduction in nuclear arms and a political relaxation in the world."

Myrdal spent 11 years as Sweden's disarmament negotiator in Geneva, and from 1966 to 1973 was also minister for disarmament and church affairs. She is chairman of Sweden's Peace Forum movement and with her husband, economist Gunnar Myrdal, helped start the Stockholm International Peace Research Institute. The Myrdals won a West German peace award in 1970. In 1980, she was the first winner of the Albert Einstein Peace Award. When she was passed over for the Nobel Peace Prize last year, Norwegian peace groups raised $62,500 to award her a special "People's Peace Award."

Her early career was in family issues. Her first book, published with her husband in 1934, warned of a population crisis and advocated child allowances and sex education. She went on to direct a Stockholm teachers' college for 12 years before becoming head of the U.N.'s Social Division in 1949.

In 1955, Sweden named her its first ambassador to India. On her return, in 1961, she was elected to Parliament as a Social Democrat. The following year she began her disarmament work in Geneva.

Her husband, an expert on Third World development, shared the 1974 Nobel Prize for economics. The Myrdals are the fourth couple to win Nobels and the first to win in separate fields.

While Alva Myrdal's writing and speeches have made her an international public figure, Garcia Robles has avoided the limelight during most of his career. A diplomat since 1939, he led the Mexican delegation to the first U.N. conference in 1945. For the next 12 years, he worked in the U.N. bureaucracy as director of the political affairs division.

As ambassador to Brazil in 1964, Garcia Robles began his work on keeping nuclear weapons out of Latin America. The Treaty of Tlatelolco, signed in Mexico City in 1967, was the result.

In 1971 he returned to the U.N. as Mexico's ambassador, and four years later he was named foreign minister. In 1977 he went to Geneva as Mexican representative to the U.N. Disarmament Committee. The following year, as head of the Mexican delegation to the U.N. General Assembly's first special session on disarmament, Garcia Robles won agreement on a joint program for disarmament which is yet to be carried out.

The award he shares with Alva Myrdal is worth $157,000 this year. Because the prize is funded in Swedish kronor, it was reduced 16 percent last week by the new Swedish government's devaluation of the krona.