Establishment of vitrification technology in Rokkasho Reprocessing Plant. The result of the active test of Rokkasho vitrification facility, the current status of new glass melter development

Reprocessing plant is one of the important issues from the viewpoints of the establishment of Japan's nuclear fuel cycle technology and the use of long-term stable nuclear energy. The Rokkasho Reprocessing Plant started a test for the vitrification of high-level radioactive liquid waste in 2007. Vitrification process, which is a domestic technology in Japan, was completed in 2013 after overcoming a number of encountered problems. The glass melter of the Rokkasho Reprocessing Plant adopted a ceramic melter system (LFCM system: Liquid Fed Ceramic Melter) that uses Joule heating through direct electrification. In order to achieve a more stable processing operation, the development of a new type of glass melter has been started. In this development, a full-scale test glass melter was fabricated, and a mock-up test using a simulated waste liquid is being held. The present stage is the second half of the test phase II, and operational performance under design conditions and the maximum processing capacity are being tested. For the design of a new glass melter, the results of this test will be reflected. In the field of software, a specific program for heat balance evaluation, and a manual preparation for operation purpose are under development. (A.O.)