"JOYO" irradiation test engineering progress report for period from april 1 to september 30, 1979

not registered; not registered; not registered; Miyakawa, Shunichi; not registered; Arii, Yoshio*; not registered

This report describes the progress made in Irradiation Test Engineering at the JOYO Experimental Fast Reactor Division during the period Apri1 1 - September 30, 1979. Highlights of the activities performed are summarized below. (1)A report on the Irradiation Rig Assembling Facility (IRAF) was submitted to the government to support the granting of a Construction Permit. Simultaneously, an explanation was presented to officials of the district government, Ibaraki prefecture, and Oarai town. (2)Purchase specifications of the IRAF building structures and internal equipments were completed based on the conceptual design work performed last fiscal year. Bids are now being evaluated. (3)In accodance with the JOYO irradiation test plan, fourteen core components have been sent to the post Irradiation Examination (PIE) facilities. These include six (6) core fuel subassemblies, two (2) blanket subassemblies, four (4) regulating rods, one (1) neutron source and one (1) pile oscillator rod. (4)The JOYO MK-II irradiation test plan was reviewed and updated. Some modifications were made in the reactivity estimation and the fuel fabrication schedule. (5)A detail design report and purchase specification for the MK-II irradiation test subassembly B type was campleted. Contracts for fabrication of parts and materials are being evaluated. (6)In accordance with the PNC/DOE Dosimetry Exchange Agreement, PNC dosimeter sets were sent to EBR-II for irradiation. Similar dosimeter sets which are to be irradiated in JOYO during the first 75 MWt duty cycle have been encapsulated and sent to the irradiation rig manufacturer. (7)Neutronic irradiation condition data have been established for the standard equilibrium core of the JOYO MK-II configuration. The data package will be published this autumn in a special publication. The package includes the axial distribution of neutron flux, fission and absorption rates, and gamma and neutron heat rate in each row.