Los Angeles is planning its biggest security operation to protect athletes and officials at the Olympic Games in 1984. But nobody is talking about the details.

So Peter Ueberroth, president of the organizing committee, yesterday tried to reassure the Olympic and international sports federation leaders who have been meeting and inspecting the competition sites this week.

"Our No. 1 priority has always been the athletes," Ueberroth said at a news conference. "But an equal priority is that we will see to it that the Games are safe for athletes and officials."

The executive board of the International Olympic Committee (IOC) put plenty of questions to Ueberroth and his team, who reported on progress in planning for the Games. It is only 10 years since the Munich Olympics were marred by the massacre of Israeli competitors by Palestinian guerrillas; Los Angeles is said to have more foreign exiles than any other city in the world.

Baseball: In Hermosillo, Mexico, Fernando Valenzuela was the winning pitcher as Mexico defeated the Ponce Lions of Puerto Rico, 14-0, in the second game of a Caribbean championship baseball series doubleheader. In the other game, the Caracas (Venezuela) Lions beat the Escogido (Dominican Republic) Lions, 7-3.

In Baltimore, the Orioles' Eddie Murray was honored by Mayor William Donald Schaefer for providing inspiration, and free baseball tickets, for city youth. At a City Hall ceremony, Murray was presented an award of merit citing his public service in buying 50 Orioles season tickets which are distributed to youngsters through the city's Human Services Coordinating Councils.