Maine Electricity and Waste Inventory, Baseline and Model Inputs
For Electricity and Waste Destruction
Transcript of For Electricity and Waste Destruction
Molten Salt Reactors (MSRs)For Electricity and Waste Destruction
Dr. Charles ForsbergOak Ridge National Laboratory
P.O. Box 2008; Oak Ridge, TN 37831-6180Tel: (865) 574-6783; E-mail: [email protected]
Presentation of Generation IV Nuclear Energy System Conceptto Office Of Nuclear Energy (DOE/NE-1)
U.S. Department of EnergyWashington, D.C.
June 7, 2002
The submitted manuscript has been authored by a contractor of the U.S. Government under contract DE-AC05-00OR22725. Accordingly, the U.S. Government retains a nonexclusive, royalty-free license to publish or reproduce the published form of this contribution, or allow others to do so, for U.S. Government purposes. File name: MSR.NCTWG.March.2000
Molten Salt Reactors (MSRs) Use a Molten Salt Coolant Containing Dissolved Fuel
• Thermal Neutron Reactor− Molten salt (71.6% 7LiF, 16% BeF2, 12% ThF4, 0.4% UF4)− Fuel and fission products dissolved in fluoride salt− Graphite moderator
• The Molten Salt Breeder Reactor (MSBR) was the backup for the LMFBR (1960s)− 1000-MW(e) conceptual design developed− Lower breeding ratio (1.033) compared with the LMFBR
• Fuel cycle (primarily at reactor site)− 233U–Thorium fuel cycle (breeder fuel cycle)− Other possible fuel cycles (actinide burner, once-through)− Batch or on-line removal of selected fission products− No fuel fabrication, qualification, or irradiation damage
Traditional Molten Salt Reactor
ORNL DWG 99C-6888R
HeatExchanger
Reactor
GraphiteModerator
SecondarySalt Pump
Off-gasSystem
PrimarySalt Pump
PurifiedSalt
ChemicalProcessing
Plant
Turbo-Generator
FreezePlug
Critically Safe, Passively Cooled Dump Tanks(Emergency Cooling and Shutdown)
Steam Generator
NaBF _NaFCoolant Salt
4
72LiF _Th
Fuel Salt_BeF F _UF4 4
566 Co
704 Co
454 Co
621 Co
538 Co
The Molten Salt Reactor Experiment Demonstrated the Concept
U-235 fuel operation• Critical June 1, 1965• Full power May 23, 1966• End operation Mar 26, 1968
U-233 fuel operation• Critical Oct 2, 1968• Full power Jan 28, 1969• Reactor shutdown Dec 12, 1969
Hours critical 17,655
Circulating fuel loop time hours 21,788
Equiv. full power hrs w/ 235U fuel 9,005
Equiv. full power hrs w/ 233U fuel 4,167
MSRE power = 8 MW thermal Core volume < 2 cubic meters
Molten Salt Reactors Have a Different Safety Approach that Allows Passive Safety in Large Reactors
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Reactor
GraphiteModerator
PurifiedSalt
ChemicalProcessing
PlantFreeze
Plug
Critically Safe, PassivelyCooled Dump Tanks(Emergency Cooling andShutdown)
Low accident source term withcontinuous removal of mobilefission products
Low pressure (molten saltboiling point ~1400 C)o
Low chemical reactivity
Passive cooling by dumpingfuel to cooled tanks
FuelSalt
566 Co
704 Co
MSRs Have Advantages For Waste Burning:No Fuel Fabrication, Multiple Target/Fuel Recycle
Avoided, And Low Actinide Inventories
Thermal Reactors(with Pu recycle)
Thermal Reactors(with Pu recycle)
Fast Reactors(with Pu recycle)Fast Reactors
(with Pu recycle)
Pu, MA, ThI-129, Tc-99Pu, MA, ThI-129, Tc-99
Molten SaltBurner Reactor
MiningMining
EnrichmentEnrichment
Final Form Product DisposalFinal Form Product Disposal
Enriched Uranium Depleted Uranium
Pu
Fuel Cycle Advocated in Kurchatov Study
RussiaEC (CEA-France)Edf (France)KoreaCzech RepublicU.S. (Academic)
Ongoing Molten-Salt Transmutation Programs
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Extended Molten Salt Reactor Family
Molten Salt Fueled Molten Salt Cooled
• Aircraft Nuclear Propulsion Program (1950s)
• Molten Salt Breeder Reactor Program (1960s)
• Molten salt burner (Russia, France, etc.)
• Molten salt space reactor (ORNL and MSFC)
• Advanced High-Temperature Reactor
• Special reactors• Fusion reactors (Tritium
production with 6Li)− Inertial− Magnetic
Fluoride Molten Salt R&D Activities in the United States
• Basic Energy Sciences (ORNL)• Fuel processing (ORNL, ANL, INEEL)
− Ongoing fluoride salt processing programs at ORNL• Materials (ORNL)
− Hastelloy N (1970s)− Chemical redox control (1980s)− High-temperature test loops (current)
• Space reactors (ORNL)• Advanced High-Temperature Reactor (ORNL, SNL)• Actinide burning (University of California)• Fusion (University of California, LLNL, etc.)• Special reactors
Areas for R&D
• Major areas for R&D− Actinide solubility limits in multi-component systems
• Higher actinide concentrations in burner MSRs• Alternative fluoride salts (Be or Li free)
− Fission-gas control (tritium, etc.)− Waste processing and waste form
• Other areas− Accident evaluations− Higher-temperature materials− Nonproliferation analysis− Alternative power cycles (gas turbines, etc.)− New separations technologies− Understanding graphite limitations
Conclusions
• Molten salt test reactor built in the 1960s• GIF interest in molten-salt-fueled reactors
− Efficient fuel resources− Waste burners (Primary interest)
• Growing programs in Europe and Russia• Base technology used by multiple programs• R&D issues reasonably well understood
Molten Salt Characteristics
• Molten fluoride salts preferred− Low nuclear cross section− Chemical stability
• Choice of salt depends upon mission− Breeder (low absorption cross section: Li, Be
fluorides− Waste burner (high solubility: all actinides)− Hydrogen production (low tritium production: Zr,
Na fluorides)• Extensive industrial experience
− Aluminum metal made using molten fluoride salt
ORNL Molten Salt Loop Evaluates High-Temperature Material/Salt Performance
Hastelloy N loop material– Compatible with salts– Stable to 1255°K
Maximum temperature 1073°K
Temperature differential: 50 to 100°K
Molten salt flow due to differences in densities with temperature
~2 liters total volume
Thermal Convection Loop Establishes Compatibility for the
Most Realistic Conditions
Insert line drawing A and Picture B
Rationale for Using MSRs for Waste Burning Is Based on Engineering,
Cost, and Operational Issues• Recycle and fabrication of minor-actinide solid fuels are
very expensive and difficult• Waste burning has excessive impacts on conventional
reactors (high actinide inventory to destruction rate)• Molten Salt Reactors
− Add actinides to salt− Actinides remain in salt until full burnout − Fission products removed from salt− For waste burner applications, ~10% of nuclear
electricity from MSRs used for waste destruction• R&D is required to define the best waste burning strategy
MSR Fuel Cycles
• Thermal neutron (233U/Th) breeder reactor• Denatured low-conversion breeder reactor• Denatured once-through fuel cycle • Actinide burning (intrinsic to concept)
The Proliferation-Resistant Characteristics of the MSR Are
Different Than Those of Other Systems
• Low total fissile inventory• With added 238U, 233U made non-weapons-
usable• Very poor plutonium isotopics (primarily
242Pu)
Advanced High-Temperature Reactor (AHTR):(Solid Fuel and Salt Coolant for Hydrogen Production)
• Goals− Hydrogen production− Efficient electricity production
• Requirements for hydrogen production define reactor design− Low pressure− Heat delivered at a high, almost-constant temperature− No tritium− Isolation of reactor from chemical facility
• AHTR design characteristics− Solid coated-particle fuel (similar to gas-cooled reactors)− Molten salt coolant (Na/Zr fluoride, etc.)
The AHTR Uses a Multi-Reheat Brayton Cycle for High-Efficiency Electricity Production
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ControlRods Hot Molten Salt
Cooling Water
Generator
Recuperator
GasCompressor
Hot Air Out
AirInlet
Fuel(Similar toMHTGR)
ReactorVesselGuardVessel
ReactorElectric Power Cycle
Multi-Reheat Helium Brayton CyclePassive DecayHeat Removal
AHTR Liquid Cooling Allows All the Heat to Be Delivered at Near Reactor Exit Temperatures(Match Thermochemical Hydrogen Production Requirements)
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PWR
LMFBR
AGR
HTGR-GT
AHTR
Hydrogen Production
AHTR
0
200
400
600
800
1000
InletDelivered Heat
Outlet
LiquidGas
Tem
pera
ture
(°C
)
(General Atomics)
(Hinkley Point B)
(Super Phenix)
(Point Beach)
925°C
675°C
491°C
395°C
310°C
299°C
545°C
319°C
665°C
750°C
850°C
1000°C