Complex sentence: Seven experimental weapon assemblies and six cores were delivered to San Pedro, California, and loaded on the weapon assembly ship USS "Curtiss", in February 1948, but the Atomic Energy Commission only gave permission for the expenditure of three cores in the tests.
Split into simpler sentences: Seven experimental weapon assemblies and six cores were delivered to San Pedro, California, and loaded on USS "Curtiss", the weapon assembly ship in February 1948. However, the Atomic Energy Commission only gave permission for the expenditure of three cores in the tests.