[en] This progress report is a quarterly report in which the work achievement of the Engineering Section and the operational results of the Joyo have been reported for two years since April, 1980. From April, 1982, this is changed to the report of whole Fast Experimental Reactor Division. The test items of the performance test of the MK-2 core and the characteristic test of the irradiation bed and the schedule were decided after the coordination among the sections concerned. The analysis of the nuclear-thermal characteristics of the MK-2 core (0-th cycle) and the planning of fuel replacement from first to 10th cycle were carried out. The subcriticality monitoring work during the transition period to the MK-2 core was started in February, 1982. General progress, the achievement in reactor technology, the activities of various committees in the Division, the plan of the studies on reactor technology, the foreign information on FBRs, the reports published by the Engineering Section and the presentation of papers to outside, and the plan of the performance test of the MK-2 core are reported. It is scheduled to perform the performance test of the MK-2 core and attain the continuous 100 hours operation at 100 MW output by March, 1983, thus obtain the certificate. (Kako, I.)