The list of methods to commit the perfect homicide has been lenghtened here with the accidental discovery of what may well be the world's first attempted atomic murder.

Three highly irradiated pieces of magnesium used to handle radioactive uranium bars were placed under the driver's seat of a car belonging to a shift foreman at the French Atomic Energy Commission's nuclear Wastes reprocessing plant at La Hague in Normandy.

The foreman, Guy Busin, 39, was saved from slow death only because he had an accident with his car that made it unusable.

When discovered, the magnesium was still emitting 10 rads of radiation an hour. International nuclear safety regulations provide that atomic workers should be allowed to receive only 5 rads a year at work.

Busin wrecked his car in November, and had it towed to his yard. He discovered the irradiated magnesium only late last month when he started taking the car apart.

Suspicion immediately centered on the 15 men in Busin's crew. He was known as a taskmaster, some way a martinet. There had already been attempts to sabotage his car with sugar in the gas tank and sulfuric acid in the fuel line.

But it took intensive police work to figure out which of the 15 was the most highly motivated to commit atomic murder.

Finally, suspicion centered on a member of the crew who was the man Busin least suspected.

It was Noel Lecomte, 27, father of two children and a member of the Busin team for two years. Interrogated three times in 24 hours, Lecomte confessed and was arrested Wednesday.

"Guy Busin persecuted me," Lecomte was quoted by the newspaper France-Soir as saying. "He was authoritarian and a nitpicker. He would disturb me constantly over nothing. He was always on my back. I wanted to avenge myself."

Lecomte described how he beat the nuclear factory's security system to the irradiated material out. It just involved walking out one day with the magnesium in a plastic bag and putting it under the seat of Busin's car in the parking lot.

A surprised Busin said he had had minor difficulties with Lecomte at first but he thought that had been sorted out long ago. The magnesium was apparently under the seat from August to November.

If Busin had continued to use the car the radiation would eventually have been fatal. He said he had felt "tired" at one point. Atomic Energy Commission doctors who checked him over say he seems fit now. Lecomte is charged with "attempted poisoning."