The Amazing Colossal Man.

Lt. Colonel Glenn Manning (Glenn Langan) survives an atomic bomb blast. Surviving the blast, Manning is treated by specialist Dr. Paul Linstrom (William Hudson) and military scientist Dr. Eric Coulter (Larry Thor) at the base hospital. Glenn's exposure to the plutonium blast has caused his old cells to stop dying and his new cells to multiply at an accelerated rate, resulting in his growing proportionately 8 feet in height a day. The military, headed by Colonel Hallock (James Seay), conducts a 10-mile-wide search for Glenn, but with no results.