The raid happened at the end of February and the heavy water plant was back up and running by the end of April. Not to take anything away from these courageous men and women who executed the raid with great pains and sacrifice.
There’s a good book on the raid called Skis Against the Atom which also describes a secondary raid on the ferry transporting the supply of heavy water when the original installation was closed down after Allied bombing raids a year later. That, perhaps, was even more important in keeping the Nazis from acquiring a nuclear weapon.
My notes on the book are at https://www.dailykos.com/stories/2014/6/28/1310235/-Why-the-Nazis-Never-Built-an-Atomic-Bomb
