Panel Still Considering Alternatives To Nuclear Blast Off S. Africa Coast

Members of a committee formed by the White House to investigate evidence of a nuclear explosion off the coast of South Africa last September 22 yesterday disputed a published report that had "ruled out almost every other explanation for the event."

Several members of the seven-man committee, which includes two Harvard professors, indicated that although some theories had been dismissed, other natural explanations were being "actively investigated."

A United States Vela reconnaisance satellite monitored two rapid, bright flashes of light off the coast of South Africa on the night of September 22 which U.S. government analysts attributed to a nuclear explosion. South Africa denied detonating a nuclear device.

At the request of President Carter, the White House set up a committee to search for any evidence to back up the initial conclusion, investigate alternative possibilities and determine whether a malfunction aboard the satellite could have produced the observations.

After nearly two months of work, the panel met in Washington .D.C. for the third time on Dec. 21 to discuss its findings. The Washington Post reported Tuesday that while no corroborating evidence of a nuclear explosion had been found, the committee had "ruled out almost every other explanation for the event," eliminating the "superlightening bolt" or satellite malfunction theories for the twin pulse of light observed on Sept. 22.

However, several scientists on the committee stressed yesterday that it had reached no final conclusions and was still looking into number of explanations, including the possibility that the satellite observed a disintegrating meteorite or flaking of the satellite itself.

The chairman of the committee is Jack P. Ruina, Massachusetts Institute of Technology professor of electrical engineering and computer sciences. The two Harvard members are Riccardo Giacconi, professor of Astronomy and an expert in X-ray astronomy, and Richard L. Garwin, professor of Public Policy and a specialist in particle physics. The White House has refused to confirm the identities of committee members, and asked committee members not to comment on its findings.

Some experts said the Post story implied that the committee had virtually concluded that an atomic explosion was the sole explanation for the Sept. 22 event. One committee scientist termed that implication "a distortion."

Another, Luis W. Alvarez, emeritus professor of physics at Berkeley and a Nobel laureate, said the Post story "seems to me to be backwards." He refused further comment.

In addition to Alvarez, Wolfgang K.H. Panofsky, a physicist at the Standford Linear Accelerator Center in California, and two other scientists are on the committee.

John Marcum, senior advisor to the president for technology and arms control, said yesterday the committee hoped to conclude its work by the end of this month