[en] As a part of the feasibility study (FS) on commercialized fast reactor (FR) cycle systems, the design studies and the technical assessments for various advanced reprocessing systems have been carried out. In this study, plant design study for the advanced aqueous system and the two non-aqueous systems (oxide electrowinning method and metal electrorefining method) and development of some evaluation - code systems were conducted. This report describes the results of the first-year study of FS phase II. (1) For future detailed plant design study of the advanced aqueous system, - based on the plant design at phase I, issues are made clear by checking the material transfer routes and their interference. - how to mix core fuels with blanket fuels is examined to obtain fuel products of designed plutonium contents. - the quantity of corrosion products generated from the reprocessing equipments and tanks is estimated to be not so much that its effect on the fuel product and the number of high-level vitrified waste form would be negligible small. (2) As for alternative aqueous reprocessing systems, - amine extraction method, which could not co-extract uranium and transuranium elements, is promising as a process for miner actinides recovery. - supercritical fluid direct extraction method will not provide serious safety problems within design-base events by providing adequate safety measures. (3) In the plant design study of oxide-electrowinning and metal-electrorefining methods, - measures of process rationalization are examined. - material handling system is investigated for smooth transferring of solid materials. - structures of main equipments such as electrorefiner are examined in more detail. (4) As for alternative reprocessing systems the results of investigations on fluoride volatility method, LINEX method, hybrid reprocessing and so on are presented. (5) Statuses of developments of the following code systems are described: 1. mass balance evaluation, 2. simulation of plant operation, 3. material transfer capability evaluation, 4. criticality safety analysis, and 5. construction cost estimation. (author)