Functional materials for breeding blankets—status and developments

Abstract

The development of tritium breeder, neutron multiplier and flow channel insert materials for the breeding blanket of the DEMO reactor is reviewed. Present emphasis is on the ITER test blanket module (TBM); lithium metatitanate (Li 2 TiO 3 ) and lithium orthosilicate (Li 4 SiO 4 ) pebbles have been developed by leading TBM parties. Beryllium pebbles have been selected as the neutron multiplier. Good progress has been made in their fabrication; however, verification of the design by experiments is in the planning stage. Irradiation data are also limited, but the decrease in thermal conductivity of beryllium due to irradiation followed by swelling is a concern. Tests at ITER are regarded as a major milestone. For the DEMO reactor, improvement of the breeder has been attempted to obtain a higher lithium content, and Be 12 Ti and other beryllide intermetallic compounds that have superior chemical stability have been studied. LiPb eutectic has been considered as a DEMO blanket in the liquid breeder option and is used as a coolant to achieve a higher outlet temperature; a SiC flow channel insert is used to prevent magnetohydrodynamic pressure drop and corrosion. A significant technical gap between ITER TBM and DEMO is recognized, and the world fusion community is working on ITER TBM and DEMO blanket development in parallel.

Anisotropic Diffusion of a Charged Tritium Interstitial in Li2TiO3 from First-Principles Calculations

“…Relative to all other candidates (such as Li 2 O, Li 4 SiO 4 , Li 2 ZrO 3 , LiAlO 2 , etc.) of breeder ceramics, Li 2 TiO 3 has reasonable lithium density, high melting temperature, low activation, good chemical stability, nice structure compatibility, and excellent tritium release performance, therefore Li 2 TiO 3 being considered as a very promising breeder material in fusion reactors [3][4][5][6][7].…”

Fundamental Study on Fretting Corrosion in Solid Breeder Blanket

“…Lithium titanate (Li 2 TiO 3 ) is candidate tritium breeder in the solid breeder blanket of fusion reactors [1,2]. The small pebbles of Li 2 TiO 3 are packed in the blanket box.…”

A Comprehensive Study on Li4si1-xtixo4 Ceramics for Advanced Tritium Breeders

“…Tritium breeding materials (TBMs) are taken as one of the key functional materials for fusion reactor blanket. Neutrons generated from the reaction between deuterium (D) and tritium (T) can react with Li element to produce tritium, thus achieving tritium self-sustaining of a D-T fusion reactor [1][2][3]. With preferable chemical stability, efficient tritium extraction, high temperature resistance and no magnetohydrodynamic effect, lithium-based ceramics have long been recognized as promising TBMs [2,[4][5][6].…”