UN chief Ban Ki-moon arrives in Japan on Sunday, where he plans to visit the Fukushima nuclear disaster zone. Thesecretary-general will visit hard-hit Fukushima prefecture in the evening as one of the most senior foreign leaders to go to the area after a magnitude 9.0 earthquake and tsunami on March 11 triggered the catastrophe. Tomorrow, Ban will meet some of the 85,000 peoplewho have evacuated to shelters from areas around the plant after whathas become the worst nuclear disaster since Chernobyl 25 years ago.Ban will also meet Prime Minister Naoto Kan and Foreign Minister Takeaki Matsumoto on Monday,