managed by ut-battelle for the department of energy using lead-bismuth eutectic in merit syringe...
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Managed by UT-Battellefor the Department of Energy
Using Lead-Bismuth Eutectic in MERIT Syringe Pump
Van Graves
October, 2007
2 Managed by UT-Battellefor the Department of Energy
Goal
Feasibility study to evaluate use of Lead-Bismuth Eutectic (LBE) free jet as a high-power target
Repeat of MERIT Hg jet experiment at CERN– 20m/s, 1cm dia jet in 15T magnetic field
– High-speed optical diagnostics
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Some LBE References
Handbook on Lead-bismuth Eutectic Alloy and Lead Properties, Materials Compatibility, Thermal-hydraulics and Technologies– Nuclear Energy Agency document– http://www.nea.fr/html/science/reports/2007/nea6195-handbook.html
Thermophysical properties of lead and lead-bismuth eutectic– Sobolev, Journal of Nuclear Materials, V362 (2007), p235-247
Expansion of solidified lead bismuth eutectic– Glasbrenner et al, Journal of Nuclear Materials, V343 (2005), p341-348
Lead-bismuth eutectic recrystallization studies for the Megapie target– Zucchini et al, Journal of Nuclear Materials, V336 (2005), p291-298
Review of liquid metal corrosion issues for potential containment materials for liquid lead and lead-bismuth eutectic spallation targets as a neutron source– Park et al, Nuclear Engineering and Design, V196 (2000), p315-325
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Hg – LBE Liquid Comparison
Parameter Unit Hg (@293K) LBE (@423K)
Melting temperature K 234 397.7
Latent heat of fusion kJ/kg 11.6 38.6
Boiling temperature K 630 1943
Latent heat of vaporization kJ/kg 295 854
Density kg/m^3 13540 10536
Sound velocity m/s 1407 1766
Isobaric specific heat J/kg-K 139 149
Dynamic viscosity Pa-s 1.53E-03 2.94E-03
Electrical resistivity Ohm-m 0.96E-06 1.08E-06
Thermal conductivity W/m-K 2.0 9.7
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Heating/Cooling Issues
LBE solidification – Groeshel paper gives recommended cooling rate of 0.02 °C/min to prevent container damage (expansion rate reduced to 0.05%)
Entire primary flow path should be heated– Air temperature/pressure issues– Expansion cooling at nozzle– Precipitation/deposition on walls/windows
Hydraulic cylinder operation at 150 °C
Flange loosening from thermal cycles
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Thermal Input
Energy required to heat LBE from 20C to 150C– Assumed volume = 15 L (158 kg)
– Latent heat of fusion = 38.6 kJ/kg
– Specific heat = 149 J/kg-K
Raise temp from 20C to 125C E=m*c*dt 2470 kJ
Solid to liquid E=m*q 6100 kJ
Raise temp from 125C to 150C E=m*c*dt 590 kJ
Total 9160 kJ(8700 BTU)
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MERIT Syringe Pump Layout
Entire primary containment would have to be heated
Major safety issue if nozzle solidifies
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Other Issues
Wetting – LBE on sapphire windows
Oxide formation
Seal compatibility – Viton seals used for Hg pump
Complete fluid removal from system
Filling/draining – flow path and containers should be heated
Containment materials
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Health/Safety Considerations
Lead is the primary hazard
From LBE Handbook,– Permissible LBE exposure level 50-100μg/m3
– Maximum allowable concentration 100-150 μg/m3
Elevated temperatures for LBE handling
Systems we have in place for Hg vapors should be sufficient for LBE, perhaps different filters
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Approach
Determine feasibility– Check design/materials/heating issues– Preliminary engineering concepts
LBE Wettability Study– Rudimentary experiments to verify compatibility with
sapphire, lexan, etc.– Expect minimal amount of experimental hardware to be
procured– Internal ORNL safety issues with handling LBE resolved
Fully developed engineering models, choose vendor parts
Detailed fabrication drawings
No hardware procurements in this phase