A team of U.S. government nuclear experts is visiting South Africa to discuss how full-scope international inspection of this country's nuclear-enrichment facility would be carried out.

The visit reciprocates an unannounced three-day visit in August by a delegation of technicians from the South African Atomic Energy Board to an American enrichment plant under construction in Portsmouth, Ohio.

The exchanges suggest that progress has been made in negotiations aimed at seeking a compromise resolution of the nuclear dispute that has led to a cutoff of U.S. nuclear fuel supplies to Pretoria.

Technical discussions on safeguards appear to indicate that South Africa is reconsidering its rejection of international inspection. The talks are taking place as the Reagan administration is carrying out a comprehensive review of U.S. antiproliferation efforts. There have been suggestions that reassessment could result in an easing of U.S. policy and legislative requirements on countries, including South Africa, that seek American nuclear supplies.

Under the Carter administration there appeared to be little willingness to develop a compromise. The two visits are evidence that there has been some movement from South Africa in response to a new approach.

South Africa presently cannot buy American slightly enriched (3 percent) uranium for its two French-built 1,000-megawatt power plants under construction near Cape Town. A 1978 U.S. law prohibits the export of all nuclear fuel to countries that do not submit their nuclear facilities to full-scope international safeguards.

In a further effort to curb nuclear-weapon proliferation, the Ford and Carter administrations also refused to supply highly enriched uranium for a small research reactor and demanded that it sign the Nuclear Nonproliferation Treaty. The United States has indicated strong suspicion that South Africa was developing a nuclear weapon.

South Africa has submitted its research reactor and power plants to safeguards but has refused to do the same with its enrichment plant, saying it fears that its secret enrichment process might be compromised. It has also declined to sign the treaty, which would commit it to disavowing any future development of a nuclear weapon.

The U.S. fuel cutoffs already have forced South Africa to reduce its research program, and the threatened delay in the opening of the power plants could cost them over $1 million a day.

If Washington dropped the policy requirement that South Africa sign the nonproliferation treaty, and Pretoria agreed to full-scope safeguards on its enrichment plant, South Africa would then be in a situation similar to Spain, Brazil and Argentina -- accepting safeguards but not the treaty.

The team now here will visit Valindaba, the restricted site west of Pretoria where the pilot enrichment plant is being expanded into a small commercial facility to fill domestic needs.

But it is not known if the four U.S. officials from the State Department, the Department of Energy and the Arms Control and Disarmament Agency will be given direct access to the plant itself. Even some limited access would signal a measure of trust from the South Africans. No U.S. access to the plant has ever been acknowledged. In 1979, three U.S. Embassy officials were expelled by Pretoria after allegations that they had taken clandestine aerial photos of the site.