CREATE TABLE table_53327 ("Unit" CLOB, "Reactor Type" CLOB, "Net Capacity" CLOB, "Gross Capacity" CLOB, "Construction Start" CLOB, "Grid Connection" CLOB, "Commercial Operation" CLOB, "Status" CLOB)

When was the Hamaoka-4 unit commercial operation date?
SELECT "Commercial Operation" FROM table_53327 WHERE "Unit" = 'hamaoka-4'
SELECT "Commercial Operation" FROM "table_53327" WHERE "Unit" = 'hamaoka-4'