Run! Superman’s tearing up buildings! The cover story of Superman 89 (May 1954) features Luthor as the villain.
Schwartz, Boring and Kaye aim for a thriller in this story, which opens with Luthor producing a small kryptonite bomb. Superman allows himself to be exposed to it, and the blast does injure him. Luthor threatens to explode a much larger one in an hour.
Superman spends the story frantically searching Metropolis for the bomb, until he realizes it must be in a lead container, kept among other lead containers, and raids the hospital radium vaults until he finds it.