Advanced Atomic Energy Research Section

概要

Main objective of our research section is to realize advanced energy systems for the sustainable develop- ment under global environmental constraints. We have shown a Zero-emission energy scenario based on fu- sion energy with biomass-based recycling system where biomass waste is converted into liquid fuel or hydrogen. And further we now propose an innovative Negative emission scenario. to isolate CO2 in the at- mosphere by a carbonization process. Our research section focuses on development of hydrogen isotopes fuel circulation system, breeding blankets , fusion ma- terial R&D, feasibility study for fusion-biomass hy- brid power system, conversion of biomass waste, and fusion neutron generation/measurement. Followings are main research achievements in the fiscal year of 2021 .

-Hydrogen permeation quantification through a struc- ture material and the effect of the existence of ceramic breeding material.

-Development and successful operation of liquid lith- ium lead droplet system for efficient recovery of hy- drogen isotope using a heat and mass-transfer loop. -Development of hydrogen isotope pumping system using proton conducting ceramics for the divertor ex- haust in a fusion system.

-Upgrade of a compact fusion neutron source for ra- diography

2. Hydrogen permeation through structural material Understanding the permeation behavior of trit-ium from a pebble bed breeding blanket is essential for establishing a self-sufficient fuel cycle in a nu- clear fusion reactor. It is known that double corro- sion layers forms on reduced activation ferritic- martensitic (RAFM) steel surface by gas release from a ceramic breeder material, however, its effect on hydrogen permeation behavior has not been elu- cidated. In-situ measurement of hydrogen permea- tion through an F82H RAFM wall of a ceramic breeder pebble bed was performed using a new ex- perimental set-up (Fig. 1). The corrosion layer formed on the F82H sample had a dense microstruc- ture , which reduced hydrogen permeation flux at least by one order of magnitude. The permeation re- duction factors were 20-50 at the water-coolant temperature of a blanket. A self-repairing ability is expected for the surface oxide layer as the corrosion occurs spontaneously inside a breeding blanket.

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