The development of spent-fuel reprocessing technology as well as mixed-oxide (MOX)fuel conversion and fabrication is indispensable to the establishment of the fast breeder reactor (FBR) fuel cycle. Ninety-two tons of MOX was fabricated in the Tokai Plutonium Fuel Fabrication Facility from 1966 until March 1988. The Tokai Plutonium Fuel Production Facility (PFPF) was completed in 1987. Since then, uranium and plutonium test runs for fuel fabrication have been continued at PFPF. Production of MOX fuel for the experimental Joyo FBR started in the second half of 1988, and for the prototype Monju FBR, production is scheduled to begin in 1989. A plutonium conversion facility with a capacity of 10 kg of MOX per day was finished in 1983 and coconversion is going well after cold and hot test operations. Continuous processing is also being tested to scale up the conversion throughput. The conceptual design of the FBR Fuel Recycling Pilot Plant was completed in 1986. A decision was made to construct a new hot test facility, the Recycling Equipment Test Facility. This facility will be equipped with plant-scale test components and equipment for testing irradiated FBR fuel and collecting hot data. In the Chemical Processing Facility, 11 experimental campaigns have been carried out using irradiated MOX fuel. Many cold tests in the Engineering Development Facilities have been continued. Recognizing the importance of international cooperation in developing FBR fuel recycling technology, Power Reactor and Nuclear Fuel Development Corporation actively exchanges information and carries out joint research with its counterparts in the United States, the United Kingdom, and the Federal Republic of Germany. Especially with the United States, collaboration was begun in 1988 in the areas of head-end process, extraction process, remote technology, and facility design.