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Title: COMPATIBILITY OF MULTI-LAYER, ELECTRICALLY INSULATING COATINGS FOR THE VANADIUM-LITHIUM BLANKET

Abstract

The objective of this work is to demonstrate that a multi-layer, electrically insulating coating will acceptably reduce the magneto hydrodynamic (MHD) pressure losses in a lithium-cooled blanket. Coatings of Er{sub 2}O{sub 3} or Y{sub 2}O{sub 3} with an overlying coating of vanadium have been fabricated by physical vapor deposition. Coatings have demonstrated acceptable as-received resistivity at 800 C in vacuum and at 600 C in contact with Li. When the Y2O3 coating was completely covered with a 10 {micro}m vanadium layer, it survived exposure to Li for 100 h at 800 C without degradation. The interaction between V alloys and Li at {le} 800 C is now the critical compatibility issue and a loop test is being constructed. New ceramic materials based on the Y-Ti-O system also are being explored.

Authors:
 [1];  [1];  [2];  [2]
  1. ORNL
  2. Lawrence Livermore National Laboratory (LLNL)
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
931619
DOE Contract Number:
DE-AC05-00OR22725
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Nuclear Materials; Journal Volume: 367-370; Journal Issue: 2
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; BREEDING BLANKETS; LITHIUM; VANADIUM; COATINGS; COMPATIBILITY; MAGNETOHYDRODYNAMICS; PHYSICAL VAPOR DEPOSITION; ERBIUM OXIDES; YTTRIUM OXIDES; ELECTRIC CONDUCTIVITY

Citation Formats

Pint, Bruce A, Moser, Jeremy L, Jankowski, Alan, and Hayes, J. COMPATIBILITY OF MULTI-LAYER, ELECTRICALLY INSULATING COATINGS FOR THE VANADIUM-LITHIUM BLANKET. United States: N. p., 2007. Web. doi:10.1016/j.jnucmat.2007.03.208.
Pint, Bruce A, Moser, Jeremy L, Jankowski, Alan, & Hayes, J. COMPATIBILITY OF MULTI-LAYER, ELECTRICALLY INSULATING COATINGS FOR THE VANADIUM-LITHIUM BLANKET. United States. doi:10.1016/j.jnucmat.2007.03.208.
Pint, Bruce A, Moser, Jeremy L, Jankowski, Alan, and Hayes, J. Mon . "COMPATIBILITY OF MULTI-LAYER, ELECTRICALLY INSULATING COATINGS FOR THE VANADIUM-LITHIUM BLANKET". United States. doi:10.1016/j.jnucmat.2007.03.208.
@article{osti_931619,
title = {COMPATIBILITY OF MULTI-LAYER, ELECTRICALLY INSULATING COATINGS FOR THE VANADIUM-LITHIUM BLANKET},
author = {Pint, Bruce A and Moser, Jeremy L and Jankowski, Alan and Hayes, J.},
abstractNote = {The objective of this work is to demonstrate that a multi-layer, electrically insulating coating will acceptably reduce the magneto hydrodynamic (MHD) pressure losses in a lithium-cooled blanket. Coatings of Er{sub 2}O{sub 3} or Y{sub 2}O{sub 3} with an overlying coating of vanadium have been fabricated by physical vapor deposition. Coatings have demonstrated acceptable as-received resistivity at 800 C in vacuum and at 600 C in contact with Li. When the Y2O3 coating was completely covered with a 10 {micro}m vanadium layer, it survived exposure to Li for 100 h at 800 C without degradation. The interaction between V alloys and Li at {le} 800 C is now the critical compatibility issue and a loop test is being constructed. New ceramic materials based on the Y-Ti-O system also are being explored.},
doi = {10.1016/j.jnucmat.2007.03.208},
journal = {Journal of Nuclear Materials},
number = 2,
volume = 367-370,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
}
  • The self-cooled lithium blanket concept with a vanadium structure offers a potential for high performance with attractive safety and environmental features. Based on blanket design studies, it became apparent that electrically insulating duct walls would be required to reduce the magnetohydrodynamic (MHD) pressure drop for liquid metal-cooled blankets for high magnetic field fusion devices. As a result, development of insulator coatings was recommended as the most appropriate approach for resolving this issue. Oxides such as CaO, Y{sub 2}O{sub 3}, BeO, MgO, MgAl{sub 2}O{sub 4}, and Y{sub 3}Al{sub 2}O{sub 12} and nitrides such as AlN, BN and Si{sub 3}N{sub 2} weremore » initially considered potential candidate coating materials. Based on results of scoping studies, CaO and AlN have been selected as primary candidates for further development. Progress on the development of CaO and AlN coatings, including in-situ formation and electrical properties measurements, are summarized in this paper.« less
  • The blanket system is one of the most important components in a fusion reactor because it has a major impact on both the economics and safety of fusion energy. The primary functions of the blanket in a deuterium/tritium-fueled fusion reactor are to convert the fusion energy into sensible heat and to breed tritium for the fuel cycle. The liquid-metal blanket concept requires an electrically insulating coating on the first-wall structural material to minimize the magnetohydrodynamic pressure drop that occurs during the flow of liquid metal in a magnetic field. Based on the thermodynamics of interactions between the coating and themore » liquid lithium on one side and the structural V-base alloy on the other side, several coating candidates are being examined to perform the insulating function over a wide range of temperatures and lithium chemistries.« less
  • A neutronics-based investigation was carried out for self-cooled Blanket Test Modules in ITER with coolant of liquid lithium and structural materials of V-4Cr-4Ti. The design feasibility was demonstrated for the test module having the purpose to validate the tritium self sufficiency for DEMO Li/V blanket without neutron multiplier Be.
  • Several experiments were conducted to develop electrically insulating CaO coatings on a V-4Cr-4Ti alloy for application in an Li environment. The coatings were developed by vapor phase transport external to Li, and also in-situ in an Li-Ca environment at elevated temperature. In the vapor phase study, several geometrical arrangements were examined to obtain a uniform coating of Ca on the specimens, which were typically coupons measuring 5 to 10 x 5 x 1 mm. After Ca deposition from the vapor phase, the specimens were oxidized in a high-purity argon environment at 600 C to convert the deposited metal into oxide.more » The specimens exhibited insulating characteristics after this oxidation step. Several promising coated specimens were then exposed to high-purity Li at 500 C for 48--68 h to determine coating integrity. Microstructural characteristics of the coatings were evaluated by scanning electron microscopy and energy-dispersive X-ray analysis. Electrical resistances of the coatings were measured by a two-probe method between room temperature and 700 C before and after exposure to Li.« less
  • No abstract prepared.