CREATE TABLE table_14315 ("Reactor Unit" TEXT, "Type" TEXT, "Average Output" TEXT, "Rated Power" TEXT, "Began construction" TEXT, "Finish construction" TEXT, "Commercial operation" TEXT, "Close of reactor" TEXT)

What is the rated power for the reactor that ended construction on May 10, 1978?
SELECT "Rated Power" FROM table_14315 WHERE "Finish construction" = 'may 10, 1978'
SELECT "Rated Power" FROM "table_14315" WHERE "Finish construction" = 'may 10, 1978'