An increase in electricity charges in Japan may be required to cover the enormous costs of disposing of high-level radioactive waste produced during the reprocessing of spent nuclear fuel, according to a report released Thursday by an advisory group to the international trade and industry minister. The entire process of disposing of high-level radioactive waste from nuclear power plants is estimated to cost between 2.7 trillion yen and 3.1 trillion yen, the report said. It added that it is the responsibility of both current and future generations that benefit from atomic energy to bear disposal costs. The group estimated that disposal costs would increase the monthly electricity bill of an average, four-member family by 7 yen to 30 yen.