The movie was made for TV and sadly lacking in plot, but the Nuclear Regulatory Commission watched transfixed yesterday as the camera focused lovingly on shiny metal rods, a tray of cables and a few railings. The inside of the damaged Three Mile Island nuclear power plant was on television for the first time.

"We really see no damage of any kind," said Richard H. Vollmer, chief of the NRC's task force overseeing cleanup of the March accident's aftermath.

As the camera panned slowly past the tops of the reactor control rods, the electrical connections and the maneuvering cranes and hooks, everything looked shiny and new. The only action was provided by a few falling water droplets, the result of condensation on the containment building's walls. w

The damage is out of sight, under the shiny rods and within the reactor vessel itself. The video tape doesn't show the intensely radioactive gases loose in the reactor building as a result of the overheating of the core. Nor does it reveal the six feet of water in the building basement.

Instead, it suggests that the much-discussed "pressure spike" within the containment, which was thought to have been a small explosion of hydrogen gas, left visible marks. There are no signs of burning anywhere the camera could see.

Vollmer explained that the tape was made Nov. 10 by Metropolitan Edison Co., owners of Three Mile Island, through a six-inch opening in the containment building wall about 65 feet above the floor. The opening was a spare among the many holes that admit pipes and electrical cables, so a box was built around it outside and a remote-control camera hooked up. Special lights were also inserted.

The result was a two-hour videotape of very little drama but much scientific interest. The version the NRC saw was a nine-minute collection of highlights.

Vollmer and his deputy, John Collins, told the three commissioners present that an NRC decision on how to deal with the radioactive gases in the containment could speed or slow the final reactor cleanup by at least 20 months.

Metropolitan Edison, Vollmer said, had proposed a cleanup schedule that finishes at the end of 1982, but does not include preparation of environmental impact statements. The earliest of Vollmer's alternatives ends in mid-1983 and the latest, which he said is still conservative, in August 1984. That does not include refitting to bring the plant back into operation.