Proliferation-Proof Uranium/Plutonium Fuel Cycles Safeguards and Non-Proliferation

Transcription

1 Proliferation-Proof Uranium/Plutonium Fuel Cycles Safeguards and Non-Proliferation SUB Hamburg by Gunther KeBler A 2012/7138 Scientific Publishing

2 id- Contents 1 Nuclear Proliferation and IAEA-Safeguards Historical Developmenta Safeguards Implementation Arms reduction initiatives Amounts of reactor-grade plutonium in the world Amounts of reactor-grade americium and neptunium in the world Neptunium and americium Nuclear fuel cycle concepts New scientific results and further developments 9 References Section Technical applications of nuclear power reactors Nuclear reactors operating in the world in The nuclear fuel cycle Natural uranium ores Uranium resources Thorium resources Concentration of uranium Purification of uranium Uranium conversion Natural uranium consumption and needs by the nuclear power industry Natural uranium consumption by different reactor types Future need for natural uranium 20 References Section 2 ' 22 3 Uranium enrichment Introduction Enrichment technologies Enrichment and cascade theory Ideal cascade Number of stages for an ideal cascade Inputs and Outputs of the enrichment process Separative work of the enrichment process Gaseous Diffusion Technology Gas centrifuge Gas centrifuge technology Russian centrifuge design Rotor dynamics Laser enrichment The AVLIS enrichment technology 35

3 Molecular Laser Isotope Separation (MLIS) Conversion of UF6 into UO2 powder 36 References Section Neutron and reactor physics Fission process Neutron reactions Reaction rates Spatial distribution of the neutron flux in the reactor core Criticality factor keff Design of a reactor core Fuel burnup and transmutation during reactor operation The conversion and breeding process Uranium-plutonium cycle Thorium-uranium cycle Conversion and breeding process Fuel utilization Radioactive Inventories in spent fuel Inherent Safety Characteristics of Converter and Breeder Reactor Cores Reactivity and Non-Steady State Conditions Temperature Reactivity Coefficients Reactor Control and Safety Analysis 61 References Section Nuclear reactors with a thermal neutron spectrum Introduction and historical development European Pressurized Water Reactors (PWRs) Core with fuel elements and control elements Reactor pressure vessel Primary coolant pumps, pressurizer and piping Steam generators Safety injection and residual heat removal system In-containment refuelling water storage tank (IRWST) Emergency feed water system (EFWS) Emergency power supply systems (EPSSs) EPR safety concept and containment system Russian Light Water Reactors Main design characteristics Safety concept of VVERs Boiling Water Reactors (BWRs) Core, Pressure Vessel and Cooling System The SWR-1000 inner containment system Safety relief valve system 79

4 5.4.4 Emergency condensers Containment cooling condensers Passive Pressure Pulse Transmitter Residual Heat Removal and Active Core Flooding Systems Safety Shutdown Systems Cooling after a severe core melt Emergency power supply SWR-1000 safety concept and containment system Other Types of Fission Reactors Pressurized Heavy Water Reactors Gas-cooled Reactors Molten Salt Thermal Breeder Reactor (MSBR) Limitation to LWRs and LMFBRs 83 References Section Fast Neutron Reactors (FRs) Breeding process Development of FRs Sodium coolant properties Demonstration SFRs Large scale deployment of SFRs Commercial size SFRs BN-600 in Russia Commercial size SFR design Lead-Bismuth cooled FRs Lead-bismuth coolant properties Design proposals for Lead-bismuth FRs The Integral Fast Reactor (IFR) 96 References Section The Nuclear Fuel Cycles Storage of Spent Fuel Elements after Discharge Transport of Spent Fuel Elements Intermediate Storage of Spent Fuel ElementslOl 7.2 The Uranium-238/Plutonium Fuel Cycle Reprocessing of Spent UO2Fuel Elements LWR Fuel Element Disassembly and Spent Fuel Dissolution Gas Cleaning and Retention of Gaseous Fission Products Chemical Separation of Uranium and Plutonium (PUREX process) Mass flows and radioactivities in a reprocessing facility Reprocessing capacity for spent UO2 fuel Conditioning of waste from LWR fuel reprocessing] Storage and cooling of liquid high level waste concentrates (HLWC) 109

5 7.3.2 Solidification of the HLWC by vitrification Conditioning of solid HLW from reprocessing plants Conditioning of solid organic waste from reprocessing plants, refabrication plants and nuclear reactors Ill Conditioning of liquid organic MLW Transport and Storage of HLW and MLW Long Term Waste Disposal Low level waste disposal without long-lived a-emitters Repositories for low heat producing HLW/MLW Repositories for HLW in deep geological formations Direct Disposal of Spent Fuel Mixed Oxide Fuel Fabrication MOX fuel refabrication capacity in the world The Uranium/Plutonium Fuel Cycle of Fast Breeder Reactors Ex-Core time Periods of FBR Spent Fuel Mass Flow in an FBR Fuel Cycle FBR Spent Fuel Reprocessing FBR Fuel Fabrication Status of FBR Fuel Reprocessing and Refabrication The Closed Nuclear U/Pu MOX Fuel Cycle for PWRs Plutonium Recycling as Plutonium Uranium Mixed Oxide (MOX) Fuel in the SGR mode Plutonium incineration in PWRs during several recycling steps Balance of plutonium inventories and incineration of plutonium Neptunium and Americium generation in the SGR plutonium recycle scenario Plutonium incineration in a MOX-PWR or FR burner or ADS strategy Chemical separation (partitioning) of minor actinides Joint chemical separations of plutonium and neptunium Aqueous chemical separation of americium and curium Chemical separation of Americium/Curium from the Lanthanides Chemical separation of Americium from Curium Pyro-metallurgical methods for the separation of Uranium, Plutonium and Minor Actinides Fuel refabrication for incineration of actinides Intermediate storage of Curium Incineration of minor actinides in nuclear reactors 132 References Section The IAEA Safeguards System Material Balance Measurements Significant quantities of fissile materials and timely detection Methods of Safeguards Techniques Material Balance Areas (MBAs) Advanced Safeguards Approaches Safeguards Measurement Technologies 144

6 8.1.6 Containment and surveillance methods Anti-Neutrino measurement Unattended monitoring systems Safeguards Application to the Different Parts of the Nuclear Fuel Cycle 155 References Section Safeguards concept of uranium enrichment plants Introduction Inspection techniques Unattended safeguard systems for enrichment plants Containment and surveillance Environmental sampling 162 References Section Safeguards for Light Water Reactors (LWRs) and spent fuel pools Light Water Reactors and fresh fuel elements Safeguards surveillance of spent fuel elements Gamma-ray spectroscopy Active and passive neutron interrogation methods Advanced antineutrino measurements 167 References Section Safeguards survey of large scale reprocessing plants Spent fuel storage pool Safeguards measurement for the accountancy tank Separation of fission products and actinides Near real time accountancy Safeguards measurements in product storage areas Waste streams Containment and Surveillance (C/S) IAEA resident inspectors Material balance areas for a large scale spent fuel reprocessing plant 172 References Section Nondestructive assay of residual fuel on leached hulls and dissolver sludge 176 References Section MOX fuel fabrication process MOX fuel fabrication plant Safeguards approach 178 References Section Assessment of Criticism of Safeguards for Large Scale Reprocessing Plants Introduction Basis of Criticism Material Accountancy, Near Real Time Accountancy and Containment and Surveillance 181 References Section Countercriticism and potential solution by proliferation-proof civil nuclear fuel cycles Proliferation-resistant or proliferation-proof? 183 References Section

7 9 Reactor-grade plutonium as a proliferation problem Introduction Nuclear characteristic data of plutonium which are important for the assessment of the plutonium proliferation problem Isotopic compositions of weapons plutonium and reactor-grade plutonium The potential nuclear explosive yield of reactor-grade plutonium Introduction and scientific approach Earlier analysis of the potential nuclear explosive yield Design principle and geometrical dimensions of early NEDs Scientific basis for the discussion of the potential nuclear energy of reactor-grade plutonium Equations describing superprompt critical power excursion and explosion 197 9!7.1 Numerical Solution of the Coupled System of Equations Recalculation of the Sandmeier Case Dimensions for initial conditions Neutron Lifetime, leff Rossi alpha Initial Power and Temperature at t = Materials Data and Equation of State Results of Recalculation of the,,sandmeier Example" Verification of Serber's Relation, Y ~ ~^~ Calculation of explosion yields of HNEDs with reactor-grade plutonium Initial conditions for shock compression by outer chemical high-explosive lenses Hydrodynamic shock compression Equation of state (EOS) data for compression of Pu and U metal Calculations of Hydrodynamic Shock Compression in HNEDs Shock compression during implosion of a hollow spherical Pu shell with a Unat reflector Effect of Spherical Compression on keff Reactivity increase as a function of compression time Spontaneous fission neutron source multiplication Pre-ignition by spontaneous fission neutrons in HNEDs with higher Pu-238 contents Pre-ignition as a consequence of strong spontaneous fission neutron sources Pre-ignition as a consequence of strong spontaneous fission neutron sources and sigmoidal Rossi alpha, a(t) Pre-ignition of hybrid HNEDs Calculation of Explosion Yield for HNEDs with Reactor-grade Plutonium Compression Shock Waves and Initial Power Initial power at t = 0 for calculation of explosive yield Power Excursion How Far Can the Shock Wave Penetrate into the Pu-sphere? Detailed results of the calculations of explosion yield for the 0.06 TPa and 0.11 TPa cases Sensitivity of calculations of the nuclear explosion yields 235

8 Nuclear explosive yield of hollow reactor-grade plutonium HNEDs Discussion of this results compared to those of Mark Conclusions from the analysis of the explosive yields of HNEDs based on reactor-grade plutonium Categorization of different isotopic compositions of plutonium Integral pre-ignition probability and nuclear explosive yield Numerical evaluation of the integral probability for pre-ignition for different isotopic compositions of plutonium The US test of 1962 with reactor-grade plutonium 246 References Section Thermal analysis of HNEDs at different levels of technology Definition of different levels of technology Geometric dimensions for different levels of technology High explosives for different classes of technology Low technology high explosives Medium technology high explosives Very high technology high explosives The one-dimensional conservative approach for the thermal analyses Temperature profile within an HNED Outer temperature at the casing of the HNED Radial temperature distribution within the HNED for constant thermal conductivity Radial temperature distribution in a bare solid Pu-sphere Comparison with IAEA definitions Temperature profile in an assembled HNED Results of thermal analyses Radial temperature profiles in an HNED with reactor-grade plutonium with an alpha-particle of kw Radial temperature profiles for reactor plutonium from spent fuel with an alpha-particle heat power of kw Radial temperature profiles for reactor plutonium with an alpha-particle heat power between and kw HNEDs with other implosion geometries Conclusions for the results of the thermal analyses Low Technology Medium Technology Common assessment of the neutronic and the thermal analysis Limits of alpha-particle heat power for proliferation-proof plutonium Additional remarks on the low and medium-technology cases Outside cooling of the HNEDs Coolability of HNEDs Metal strips of high thermal conductivity Coolability of very high technology HNEDs Effects of cooling low-technology and medium technology HNEDs 275

9 10.13 Solution of the steady state and transient heat conduction problem with temperature dependent thermal conductivities and specific heats Formulation of the heat conduction problem Numerical solution for the transient temperature distribution Thermal conductivity and specific heat at cryogenic temperatures Specific heat data at cryogenic temperatures Cooling of low technology HNEDs by liquid nitrogen or liquid helium Numerical results for medium technology HNEDs Conclusions for low and medium technology HNEDs Technical difficulties for cooling by liquid nitrogen or liquid helium Numerical results for high technology HNEDs Steady state and transient temperature distributions for cooling of the HNED by internal rods of high thermal conductivity Outline of the approximate method for determining the steady state temperature distribution in an HNED with cooling by aluminum rods Calculated results for low technology HNEDs (steady state temperature profile) Transient temperature distribution if the aluminum rods will be replaced by high explosive material Technical difficulties Installing the reactor grade plutonium sphere prior to detonation Conclusions 292 References Section Proliferation Resistance of Americium Originating from Spent Irradiated Reactor Fuel Introduction Some nuclear physics data of the three americium isotopes Am-241, Am-242m and Am Am-241 from the decay of Pu Am-242m production Considerations on pre-ignition, alpha-particle heat power and critical mass of americium Critical mass of reactor americium metal based Hypothetical Nuclear Explosive Devices Gun type HNED with metallic americium Spherical implosion type HNED with metallic americium Critical masses for gun type HNEDs and spherical implosion type HNEDS Critical masses for gun type systems Critical masses for spherical implosion type systems Pre-ignition for reactor-americium based gun type and spherical implosion type HNEDs Pre-ignition of metallic americium based gun type systems Results of pre-ignition analysis for gun type systems Results of pre-ignition analysis for spherical implosion HNEDs 309

10 11.8 Geometric dimensions, alpha particle heat power and material characteristics for the thermal analysis of spherical americium based implosion type HNEDs Geometric dimensions of a reactor-americium based spherical implosion type HNED for the thermal analyses Material properties for high explosives Outside temperature of the reactor americium based HNED Temperatures of a metallic reactor americium bare sphere and gamma radiation problems Outside casing temperature of americium based HNEDs Inside temperature profile in the americium based HNED Radial temperature profile for a reactor-americium sphere HNED (option G, PWR) Radial temperature profile for a reactor-americium HNED (Option H LMFBR) Radial temperature profile for a reactor-americium HNED (option K, ADS) Radial temperature profile for a reactor-americium HNED (option L, 100% Am-241) Radial temperature profile for a reactor-americium HNED (option M Am-242m breeding) Discussion of the results of the thermal analyses and uncertainties Characteristics of material data Coolability of the reactor americium HNED Conclusions 319 References Section Fuel cycle options for the production of denatured, proliferation-proof plutonium Introduction Review of earlier research Analysis of fuel cycle options for the production of proliferation-proof plutonium Fuel cycle options for the production of denatured, proliferation-proof plutonium Results of physics calculations for the selected fuel types Results for fuel type A; UO2 from reenriched recycled uranium Results for fuel type B Results for fuel type C Results for fuel type D Results for fuel type E; MOX fuel with thorium, uranium, plutonium and minor actinides Moderator density and Doppler reactivity coefficients for the fuel type A, B, C, D, E Long term behavior of denatured, proliferation-proof fuel in PWRs and FRs Long term behavior of denatured plutonium in LWRs Long-term irradiation behavior of denatured plutonium in fast reactors Destruction of denatured fuel type C in a PWR Peculiarities of the fuel cycle and of the PWR design for production and recycling of denatured proliferation-proof plutonium Conclusions 335

11 13 Neptunium as a proliferation problem and fuel cycle options for avoiding neptunium production Neptunium as a proliferation problem Neptunium-free nuclear fuel cycle Model of a neptunium-free nuclear fuel cycle Future proliferation-proof, neptunium-free fuel cycles Initial fuel composition for proliferation-proof plutonium and neptunium-free fuel cycles Selection of fuel composition for neptunium-free proliferation-proof fuel cycles Isotopic compositions of the fuel during burnup Reactivity coefficients relevant to PWR safety Peculiarities and technical modifications required for the PWR design Conclusion for incineration of proliferation-proof plutonium in PWR cores Fast reactor fuel cycle for utilizing americium as well as denatured proliferation-proof plutonium but avoiding neptunium production Results of the FR core calculations Plutonium incineration and breeding Americium incineration and production of curium Conclusion for FRs operating with proliferation-proof plutonium and americium, but avoiding neptunium 357 References Future civil proliferation-proof fuel cycles Introduction Plutonium incineration by a multi-recycling strategy Needed capacity of reprocessing and Pu/U refabrication plants Fuel cycle plant capacity in the world in Transition phase for the production of proliferation-proof plutonium Different levels for non-proliferation criteria of reactor-grade plutonium Scientific proposal for level I criterion for non-proliferation Scientific proposal for level II criterion for non-proliferation Alpha-particle decay of Pu-238 in proliferation-proof reactor-grade plutonium Can proliferation-proof plutonium be converted to weapon grade plutonium Centrifuge enrichment technology Decomposition of PuF6 by alpha-particle radiation Atomic vapor Laser isotope enrichment Future civil Pu/U fuel with proliferation-proof, reactor-grade plutonium Incineration of proliferation-proof, reactor-grade plutonium in PWRs Incineration of proliferation-proof reactor-grade plutonium in FRs Future international proliferation-proof nuclear fuel cycles Effect on Safeguards and Non-proliferation Issues in Future Civil Uses of Nuclear Power of the Proposed Concept of Upper Limits for Non-proliferation Not Included In This Proposal 373 References Section