Institute for Space and Nuclear Power Studies

Jean-Michel Tournier

Assistant Research Professor

Institute for Space and Nuclear
Power Studies
MSC01-1120, FEC 234
1 University of New Mexico
Albuquerque, NM 87131-0001
Phone: 505.277.7961
Fax: 505.277.2814
tournier@unm.edu

Education:

Ph.D. Engineering, University of New Mexico, 1996

P.E. École Centrale des Arts et Manufactures de Paris, France, 1988

M. S. Applied Mathematics, University PARIS XIII, France, 1986.

Research Projects:

Since he joined ISNPS as a Research Assistant Professor, Dr. Tournier has been involved with a number of exciting research projects. For three years, he served as the Task Leader of a Grant awarded by the Space Vehicles Technologies Directorate of the Air Force Research Laboratory, Kirtland AFB, Albuquerque, NM, entitled "Experimental Investigations, Modeling, and Analyses of Alkali-Metal Thermal-to-Electric Converters (AMTEC) for Space Applications." The goal of this program was to evaluate the readiness of AMTEC technology for flight on the NASA Pluto/Express Flyby and other future space missions. As part of this effort, Dr. Tournier developed comprehensive performance models of vapor-anode, multi-tube AMTECs and appropriate thermal models of the experimental setups for benchmarking the models, analyzed experimental data and provided technical feedback and recommendations for improving the test setup and the design of next generation AMTEC devices.

During the Fiscal Year 1999, Dr. Tournier participated in an exploratory effort sponsored by the Department of Energy, performed jointly by Sandia National Laboratories, Sholtis Engineering & Safety Consulting and ISNPS, on investigating the potential of plutonia coated-particle fuel for use in advanced radioisotope power systems (RPSs) and heater units (RHUs). The ZrC-coated 238PuO2 fuel particles offer a promise for enhanced safety and higher specific power than current state-of-the-art Light Weight Radioisotope Heater Units (LWRHUs). The fuel kernels are intentionally sized (> 300 μm) to prevent any adverse radiological effects. They are non-respirable, non-inhalable, and if ingested, would simply be excreted with no radiological effects. In addition, this coated fuel form offers excellent design flexibility as the fuel compact could be made into different shapes and sizes to provide thermal power from milli-watts to tens or even hundreds of watts.

During this exploratory effort, the fabrication technologies of coated plutonia particles and the release mechanisms of helium gas in small-grain, large-grain and polycrystalline (sol-gel) plutonia fuels were reviewed and examined. Design and functional requirements for coated particle fuel were established based on the review of credible launch and reentry accident environments that the fuel could potentially experience. A design and performance model of coated particle fuel compact (CPFC) was developed to evaluate the effects of fuel temperature, storage time before launch, helium gas release fraction from the plutonia fuel kernels, and the use of single-size and binary-size fuel particles on the RHU thermal power and specific power, and compare them with those of the current LWRHU.

Dr. Tournier is currently involved with two projects, a NERI Grant in collaboration with Westinghouse Electric Corporation on developing a novel, integrated terrestrial reactor/power conversion system that uses Alkali-Metal Thermal-to-Electric Converters (AMTEC), and a Grant from Bechtel-Bettis Atomic Power Laboratory on designing, modeling and analyzing a small-size AMTEC cell with corrugated BASE. Under the NERI Grant, a conceptual design of a modular static converter has been developed for use in high energy utilization, small nuclear power plants, to provide electricity and co-generation power for a multitude of applications, including space heating (< 400 K), seawater desalination (~ 400 K), and/or high temperature process heat or steam (> 850 K). The reference converter, which delivers > 50 kWe at ~300 V DC, consists of a multi-BASE AMTEC operating between 1000 K and 650 K, that is thermally coupled to a thermoelectric (TE) bottom cycle operating between 650 K and 390 K. The heat rejected from the TE bottom cycle is removed by natural convection of ambient air and used for industrial or residential space heating. The reference AMTEC/TE converters are integrated into modules, each generating ~ 1 MWe at 6.6 kV AC. The optimization analyses of the potassium-AMTEC/TE converter demonstrated a net conversion efficiency > 30%, for delivering electricity to the Grid at 6.6 kV AC, while providing co-generation thermal energy for space heating.

These AMTEC/TE static converters were used in performance analyses of one Gas Cooled Reactor (GCR) and three Liquid Metal Cooled Reactor (LMR) small power plants. Additional static converters employed in these plants included segmented thermoelectrics (STE) of high figure-of-merit materials, used in conjunction with seawater desalination modules. Analysis results showed that LMR and GCR power plants with static conversion could achieve a total utilization of the nuclear reactor's thermal power in excess of 92%. Based on the results of these analyses, it might be argued that small nuclear power plants with static conversion could indeed be a valuable choice for providing the appropriate mix of electricity and co-generation power needed in underdeveloped countries and in remote communities, with no or limited electrical Grid, and little or no access to reasonably priced fossil fuels. Although such small, high energy utilization nuclear power plants may not compete with large commercial nuclear power plants in electricity cost in metropolitan areas, they could meet, at comparative prices, the electrical and thermal energy needs for a variety of applications, and where large power plants are neither economical nor practical. These small nuclear power plants could be designed and built with emphases on simplicity, low maintenance, inherent safety, passive cooling, non-proliferation, and long life, and could provide both electricity and process heat for a variety of uses, creating jobs and stimulating economical growth.

Areas of Expertise:

Thermal management of nuclear power systems for space and terrestrial applications: reactor thermal-hydraulics, Thermo-Electric electroMagnetic (TEM) pumps, transport phenomena and classical fluid dynamics, heat pipes, conduction and radiation heat transfers.

Modeling and experimental investigations of advanced static energy conversion systems for space and terrestrial applications: Thermo-Electric converters (TE), Alkali-Metal Thermal-to-Electric Converters (AMTEC), electrochemical processes in fuel cells.

High energy utilization, small nuclear power plants with static (AMTEC, TE) energy conversion, to provide electricity and co-generation thermal power in underdeveloped countries or remote areas, for a multitude of applications, including industrial or residential space heating (< 400 K), seawater desalination (~ 400 K), and/or high temperature process heat or steam (> 850 K).

Plutonia coated-particle fuel for use in advanced radioisotope power systems (RPSs) and heater units (RHUs): granular (using powder metallurgy) and polycrystalline (using sol-gel fabrication techniques) microstructures of oxide fuels, gas release mechanisms and retention in oxide fuels, thermal and performance analysis of advanced RPSs and RHUs.

Analysis of thermal energy storage units for solar dynamics power systems, and experimental investigations and modeling of low-temperature and high-temperature heat pipes, including startup from a frozen state: flow in porous media, solid-liquid, liquid-vapor and solid-vapor phase changes, non-continuum (transition and free-molecule) vapor flow regimes, thermophysics and interfacial phenomena in microgravity and reduced gravity environment (capillary effect, thermo-capillary or marangoni convection).

Numerical techniques: finite elements, control volume and finite-difference techniques; some experience and interest in mathematical models of turbulence for calculating combustion chambers, and parallelization algorithms for most efficient use of super-computers.

Honors:

Recipient of the STAIF-1998 Outstanding Paper Award (for entire conference), at the 1998 Space Technology and Applications International Forum, Albuquerque, NM.

Recipient of the 1996 Manuel Lujan, Jr. Best Student Paper Award at the 1996 Space Technology and Applications International Forum, Albuquerque, NM.