The Department of Energy has agreed to study moving the controversial Rocky Flats nuclear weapons plant from its present site 16 miles northwest of downtown Denver.

DOE indicated that the two-year study, costing up to $5 million and focusing initially on safety standards for workers, might simply result in upgrading the safeguards on the nuclear operations. Rocky Flats manufactures plutonium "triggers" for all U.S. nuclear bombs and is a key research and production site for the neutron weapon.

But according to Dr. Carl Z. Morgan, professor at Georgia Tech and former director of safety operations at the government's radiation laboratories in Oak Ridge, Tenn., "the Rocky Flats installation should never have been built so close to a city, and should be shut down or relocated as soon as possible, preferably deep inside a mountain."

The reassessment of possible phase-out of operations was recommended nearly five years ago by a task force representing Colorado's Gov. Richard Lamm and Rep. Tim Wirth (D).

Over the years, since a $45 million fire and release of toxic plutonium into the atmosphere brought the plant's mission into public view, Rocky Flats has been a point of controversy. A year ago 5,000 antinuclear protesters demonstrated at the plant and more than 200 were arrested for blocking railroad access. Protesters have been denied permission by DOE to hold another demonstration April 28 and the American Civil Liberties Union has taken their case to federal court.

According to Rep. Wirth, fears and misgivings about the plant persist. Conflicts between agencies over acceptable standards have been well publicized. Disclosure of the impact of Nevada testing 20 years ago on civilians downwind, as well as questions raised by Three Mile Island, add to the unease.

Possible alternative sites were mentioned in a draft environmental impact statement on Rocky Flats completed last year.Among them were the former Nevada test range and the site of the Pentax facility outside Amarillo, Tex., where final assembly and dismantling of nuclear weapons takes place.