RICHLAND, Wash. (AP) _ Radioactive ants, flies and gnats have been found at the Hanford nuclear complex, bringing to mind those Cold War-era B horror movies in which giant, mutant insects are the awful price paid for mankind's entry into the Atomic Age.

Officials at the nation's most contaminated nuclear site insist there is no danger of Hanford becoming the setting for a '90s version of ``Them!,'' the 1954 movie starring James Arness and James Whitmore in which huge, marauding ants are spawned by nuclear experiments in the desert.

Although Hanford is working to eradicate its ``hot'' insects, officials said the radioactivity the pests carry is slight and no threat to neighboring communities.

``We're not dealing with an insect that would leave and all of a sudden start to give birth to these malformed, horrible insects,'' said a chuckling Richard Zack, an entomologist at Washington State University in Pullman.

The situation came to light in September when red harvester ants found underground near some old waste pipes were discovered to be radioactive. Then, earlier this month, workers discovered radioactive flying insects around cans where the staff's day-to-day nonradioactive garbage is thrown away.

That led Fluor Daniel Hanford, the company that manages Hanford for the Energy Department, to check the town dump where Hanford garbage is taken. Workers found trash that had apparently become radioactive from contact with the bugs, and sent 210 tons of it back to Hanford for burial.

Still, a person would have had to stand next to a spot contaminated by radioactive bugs for an hour to get the level of exposure equal to a dental X-ray, said Mike Berriochoa, spokesman for Fluor Daniel Hanford.

And the house-size ants of ``Them!'' are ``physical impossibilities'' and just the stuff of science fiction, Zack said.

Zack and Berriochoa said they are not aware of any pattern of genetic mutation in the insects around Hanford. And if the insects were to develop mutations, the abnormalities would be along the lines of a short antenna or an extra leg, Zack said.

And because the insects' range is short _ for fruit flies, it's a few hundred yards to a half-mile _ the chances of their leaving the 560-square-mile complex are slim, he said.

Hanford said radioactive pests are to be expected at a place that produced 40 years' worth of plutonium for the nation's nuclear weapons, including the bomb dropped on Nagasaki, Japan, in 1945.

With all manner of burrowing creatures in the desert, including mice, rabbits and snakes, there's always the potential something will get contaminated, Berriochoa said. When contaminated mouse or rabbit droppings are found at Hanford, traps are set for the animal, and it is destroyed.

Hanford stopped producing plutonium at Hanford in the 1980s, but some areas remain highly radioactive. Billions of dollars are being spent to clean up the site along the Columbia River.

Julie Petersen, 22, who works at Sunburst Video in Richland, does not spend a lot of time worrying about mutant bugs.

``I'm sure I get more radioactivity from my microwave,'' said Ms. Petersen, whose friends outside the area still ask her if she glows. ``It's just something we deal with every day. It's the way most people live.''