he owner of the damaged Three Mile Island atomic power plant said today that the first televised look inside the reactor did not produce "evidence" that the uranium oxide fuel had melted when the core was exposed three years ago during the nation's worst nuclear accident.

"What we have seen does not suggest . . . that there was actual melting of fuel," said Robert C. Arnold, president of the nuclear division of General Public Utilities. "We are not saying that there was no melting of fuel because we can't prove that at this point, but no one will know until we get the raw material out to look at it."

Arnold made the statement during a news conference at which officials who took part in Wednesday's two-hour inspection--the first look inside the reactor since the March 28, 1979, accident--agreed that the central portion of the core of the reactor had been reduced to "a bed of rubble."

"The big thing that came out of this look was that the top five feet of the center of the core wasn't there," said William Hamilton, head of the technology assessment and advisory group that assisted GPU with the inspection. "There had been various estimates. There were some who felt the core was in pretty good shape. No one would say that now. It is severely damaged. There is no question about that."

But Hamilton, who had told The Washington Post Wednesday night that the televised look at the central region of the core showed that "the uranium oxide fuel had melted," backed away from that statement at today's news conference and said he agreed with Arnold that no conclusions of that kind could be drawn "until we get some material under a microscope."

"I think melting was the wrong way to describe it," Hamilton said. "I think damage is a better way to describe it."

The question of whether uranium fuel melted during the accident--or whether the soaring temperatures in the reactor melted only the zirconium alloy cladding of the fuel rods--is significant because uranium melts at a much higher temperature.

The melting of fuel, if confirmed, would indicate that the level of danger at the time of the accident--and the risk of a radioactive release that would have required evacuation of the area around Three Mile Island--might have been greater than previously believed.

"Many of these questions are beyond the ability of the information right now to answer," Arnold insisted yesterday. "As to what actually occurred on March 28, 1979, all of us are going to have to wait for a while to find out."

"We are going to try to get some samples of materials so we can find out the answers to questions like this," Hamilton said.

During the news conference, Dr. James Thiesing, a Bechtel official serving as project manager for the ultimate removal of the damaged core from the Three Mile Island reactor, said that when the miniature television camera was lowered into the area that would normally be the top of the core, "nothing was visible."

The camera was then lowered five feet into the reactor. There, he said, it encountered a pile of "rubble consisting of degrees of fuel, oxidized cladding and other structural materials that were deposited there during the accident."

As Thiesing spoke, GPU officials showed a 14-minute videotape that had been pieced together from the two-hour inspection. The rubble resembled televised scenes of the lunar landscape.

Officials involved with the televised inspection emphasized that the primary purpose of the so-called "quick look" was not to draw conclusions about what happened during the accident, but to gain information that would be useful in planning the ultimate removal of the core.