Progress in the development of insulator coating for liquid lithium blankets

The National Institute for Fusion Science (NIFS), which was established in 1989, promotes academic approaches toward the exploration of fusion science for steady-state helical reactor and realizes the establishment of a comprehensive understanding of toroidal plasmas as an inter-university research organization and a key center of worldwide fusion research. The Large Helical Device (LHD) Project, the Numerical Simulation Science Project, and the Fusion Engineering Project are organized for early realization of net current free fusion reactor, and their recent activities are described in this paper. The LHD has been producing high-performance plasmas comparable to those of large tokamaks, and several new findings with regard to plasma physics have been obtained. The numerical simulation science project contributes understanding and systemization of the physical mechanisms of plasma confinement in fusion plasmas and explores complexity science of a plasma for realization of the numerical test reactor. In the fusion engineering project, the design of the helical fusion reactor has progressed based on the development of superconducting coils, the blanket, fusion materials and tritium handling.

Section: Simulation Science Projectmentioning

confidence: 99%

Recent Fusion Research in the National Institute for Fusion Science

Komori

Sakakibara

Sagara

et al. 2011

“…The functional layers such as a tritium permeation barrier and an electrical insulation layer coated on the structural materials of the blanket systems are the essential ones for the liquid breeder blankets [2].…”

Section: Introductionmentioning

confidence: 99%

Electroplating of Erbium on Steel Surface in ErCl3 Doped LiCl-KCl

Kondo

Tanaka

Muroga

et al. 2012

The electroplating of Er metal on the reduced activation ferritic martensitic steel, JLF-1 (Fe-9Cr-2W-0.1C), in a molten salt was studied. The specimen was immersed in the molten ErCl 3 doped LiCl-KCl electrolyte. The electroplating was carried out by a constant potential electrolysis method and a pulsed current electrolysis method. It was found that the Er metal was deposited on the specimen surface due to the electrochemical reaction.

“…For self cooled V/Li blanket concept, with liquid metal circulating in the direction perpendicular to the strong magnetic field, the effect of magnetohydrodynamic pressure drop (MHD effect) can be a potential problem [1]. To mitigate the MHD effect the surface of V-alloy should be electrically separated from the liquid Li by means of insulator coating.…”

Section: Introductionmentioning

confidence: 99%

“…Limited number of oxides and nitrides possessed the required insulating properties and thermodynamic stability in the liquid Li at the same time. Er 2 O 3 and Y 2 O 3 oxides and AlN nitride are considered as main candidates [1]. The in-situ formation of Er 2 O 3 layer on the surface of V-alloy is a promising technology to form the multi-functional coating (insulator, corrosion and tritiumpermeation barrier) on the inner surfaces of channels with complex shape directly in the liquid Li.…”

Section: Introductionmentioning

confidence: 99%

“…The in-situ formation of Er 2 O 3 layer on the surface of V-alloy is a promising technology to form the multi-functional coating (insulator, corrosion and tritiumpermeation barrier) on the inner surfaces of channels with complex shape directly in the liquid Li. This technique requires pre-charging of V-alloy with oxygen in gaseous medium before immersion in Li while liquid metal should be doped by active impurity (Er) [1]. Insulator Er 2 O 3 coating was successfully formed in-situ on the surface of V4Ti-4Cr alloy (NIFS HEAT 2) and the phenomenological model of oxide layer growth and evolution was developed [2][3][4][5].…”

Section: Introductionmentioning

confidence: 99%

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Effect of Lithium Purity on In-Situ Formation of Er2O3 Oxide Layer on V-4Ti-4Cr Alloy

Tsisar

Yeliseyeva

Muroga

et al. 2012

Effect of Li purity with respect to N on the features of in-situ formation of Er 2 O 3 oxide coating on the surface of V-4Ti-4Cr alloy was investigated. Samples of V-4Ti-4Cr alloy (NIFS HEAT 2) were pre-charged by oxygen in Ar-7%O 2 at 700• C. The hardened zone with needle shaped Ti-O net structure was formed in the near-surface layers of V-alloy after oxidation. Oxygen pre-charged samples were exposed to N-containing Li (C N[Li] ≤ 0.2 wt%) at 700• C and Li pre-cleaned by getter (Zr) at 650• C for 100 h. Both melts were doped with active Er impurity. It was shown that in-situ formation of E 2 O 3 oxide coating on the surface of V-alloys depends strongly on the purity level of Li with regard to the N. In N-containing Li the coating was not formed on the surface of V-alloy, while whole oxygen pre-stored in V-matrix was dissolved by Li. On the contrary, in Li precleaned with respect to N by Zr getter, the insulating oxide film was formed.