CREATE TABLE table_12983929_1 (shut_down VARCHAR, commercial_operation VARCHAR)

What's the shut down state of the unit that's been in commercial operation since 01.02.1984?
SELECT shut_down FROM table_12983929_1 WHERE commercial_operation = "01.02.1984"
SELECT "shut_down" FROM "table_12983929_1" WHERE "01.02.1984" = "commercial_operation"