Expo 2010 Annex "White Elephant (Monju) Pavilion" is a pavilion themed on the fast breeder reactor, Monju built in Tsuruga Peninsula (Fukui Prefecture) in Japan. Twenty-two years have passed since the first criticality, and after only 250 days of operation, the maintenance cost per day was over 50 million yen. The nuclear fuel cycle plan was abandoned, and the cost of decommission is estimated to be 375 billion yen, which was too large, and the white breeder reactor on the beach was indeed a giant white elephant.