Patent Number: 
Section: claims

1. A transportable nuclear generator, comprising:a reactor power module comprising a nuclear core, control systems, and coolant flow reversing structure, wherein the reactor power module is configured to burn a nuclear fuel to generate thermal energy in a coolant/working fluid;a power conversion module comprising turbo-machinery equipment and heat exchangers, wherein the power conversion module is configured to receive the thermal energy from the coolant/working fluid from the reactor power module and to generate mechanical energy; anda power generation module comprising a fast generator-motor, electronic controllers and uninterruptable power sources, wherein the power generation module is configured to receive mechanical energy from the power conversion module and to generate electrical energy,wherein the reactor power module, the power conversion module, and the power generation module are configured to be thermo-hydraulically coupled to one another to form an operational nuclear reactor as a single vessel. 2. The transportable nuclear generator of claim 1, wherein the reactor power module, the power conversion module, and the power generation module are configured to be interchangeably assemblable in a horizontal or vertical configuration. 3. The transportable nuclear generator of claim 1, wherein the reactor power module, the power conversion module, and the power generation module are further configured to be passively cooled via natural coolant-circulation across heat transfer surfaces. 4. The transportable nuclear generator of claim 1, wherein the reactor power module, the power conversion module, and the power generation module are further configured to operate as a self-contained unit without requiring external piping or equipment. 5. The transportable nuclear generator of claim 1, wherein the reactor power module comprises a melt-proof thermally conductive ceramic nuclear core. 6. The transportable nuclear generator of claim 1, further comprising coolant pathways defined by internal fins with low fluid-dynamic drag that provide core structural support while ensuring transfer of decay thermal energy from the core to external fins by conduction heat transfer mechanisms, wherein the coolant pathways are configured to safely and passively transfer decay thermal energy to an environment surrounding the transportable nuclear generator even in the total absence of coolant. 7. The transportable nuclear generator of claim 1, wherein the reactor power module further comprises at least one of the following reactivity control systems:(1) control rods or rotary control drums in a neutron reflector, containing neutron absorbing and reflecting materials configured to be passively engaged in absorbing mode for safety;(2) an array of in-core control rods;(3) an emergency shutdown system that injects neutron poison into the core through a passive system. 8. The transportable nuclear generator of claim 1, further comprising an inert gas as coolant and working fluid for the power conversion module. 9. The transportable nuclear generator of claim 1, wherein the reactor power module, the power conversion module, and the power generation module are further configured to perform a regenerative Brayton cycle to generate electricity. 10. The transportable nuclear generator of claim 1, further comprising:a primary loop fully enclosed in the reactor power module;water as a coolant and moderator circulating in the primary loop;one or more integral separation heat exchangers configured to provide thermal coupling between the primary loop in the reactor power module and a secondary loop in the power conversion module;water circulating in the secondary loop that receives thermal energy from the primary loop to generate superheated steam, wherein water in the secondary loop transfers thermal energy to the integral turbo-machinery in the power conversion module in the form of superheated steam to generate electricity according to a Rankine power cycle; andan integral condenser, wherein after expanding in the turbo-machinery, steam is vented to the integral condenser which passively transfers thermal energy to internal and externally extended cooling fins of the power conversion module to condense the steam. 11. The transportable nuclear generator of claim 10, further comprising one or more pumps that re-pressurize condensed steam and pump the resulting sub-cooled water at an inlet of a secondary side of the separation heat exchanger into the secondary loop. 12. The transportable nuclear generator of claim 1, further comprising:a primary loop fully enclosed in the reactor power module;liquid metal as coolant actively circulated by recirculation pumps in the primary loop;one or more integral separation heat exchangers configured to provide thermal coupling between the primary loop in the reactor power module and a secondary loop in the power conversion module;gas or water circulating in the secondary loop,wherein when gas is circulating in the secondary loop, the turbo-machinery is configured to satisfy the requirements of a regenerative Brayton power cycle, andwherein when water is circulating in the secondary loop, the turbo-machinery is configured to satisfy Rankine power cycle requirements. 13. The transportable nuclear generator of claim 1, further comprising:rotary components forming the turbo-machinery in the power conversion module;rotary components forming a generator-motor of the power generation module;a rotary shaft that connects the rotary components forming the turbo-machinery in the power conversion module and the rotary components forming a generator-motor of the power generation module in the form of a direct mechanical coupling so that the rotary components forming the turbo-machinery and the rotary components forming a generator-motor rotate with a common speed,wherein the rotational speed of the shaft is determined by the thermal-hydraulics of the power conversion system, loading conditions and settings of the electronic control system regulating the electric generator-motor machine, andwherein a frequency and other electrical parameters of the generator power are controllable by integral electronic conditioning circuits. 14. The transportable nuclear generator of claim 13, wherein:the generator-motor generates electricity during operation of the transportable nuclear generator,the generator-motor drives the turbo-machinery of the power conversion module during startup and after shutdown, andstartup power is provided to the generator-motor during startup through uninterruptable power sources or an external source of electric power. 15. The transportable nuclear generator of claim 1, wherein the reactor power module is further configured to allow removal of a reactor power module containing fresh or spent nuclear fuel and replacement with a new reactor power module having fresh nuclear fuel. 16. The transportable nuclear generator of claim 1, further comprising heat exchangers for the production of low-and/or high-grade process heat to be distributed to equipment dedicated to desalination, bio-fuel processing, district heating, or other industrial uses. 17. A method of generating electricity, comprising:providing the transportable nuclear generator of claim 1; andoperating the transportable nuclear generator in one of the following modes:(1) according to a regenerative Brayton power cycle to generate electricity using an inert gas as a working fluid;(2) according to a Rankine power cycle to generate electricity when water is used as a working fluid. 18. The method of claim 17, further comprising operating the transportable nuclear generator in a horizontal or vertical configuration. 19. The method of claim 17, wherein the transportable nuclear generator further comprises:integrated heat exchangers formed by internal and external fins configured to provide passive cooling; andan emergency shutdown system that injects neutron poison into the core through a passive system if other systems fail. 20. A method of refueling a transportable nuclear generator, the method comprising: providing the transportable nuclear generator of claim 15;removing a first reactor power module having fresh or spent nuclear fuel; and replacing the first reactor power module with a second reactor power module having fresh nuclear fuel. 21. The transportable nuclear generator of claim 5, wherein the melt-proof thermally conductive ceramic nuclear core further comprises:monolithic fuel elements (MTF) comprising tri-structural isotropic (TRISO) fissile fuel sealed in SiC pellets. 22. The transportable nuclear generator of claim 21, wherein the SiC pellets are nano-infiltration and transient eutectic-phase (NITE) sintered pellets. 23. The transportable nuclear generator of claim 21, wherein the MTF elements comprise the TRISO fissile fuel SiC pellets sealed into SiC or SiC-composite elements. 24. The transportable nuclear generator of claim 21, wherein the TRISO fuel pellets further comprise a layer of unfueled SiC surrounding a fueled region. 25. The transportable nuclear generator of claim 21, wherein the TRISO fuel pellets further comprise an oxide, carbide, oxy-carbide or a nitride of uranium, plutonium, thorium or other fissile isotope. 26. The transportable nuclear generator of claim 21, wherein the TRISO fuel pellets further comprise a burnable poison rare earth oxide comprising erbia or gadolinia incorporated in the SiC pellets. 27. The transportable nuclear generator of claim 21, wherein the melt-proof thermally conductive ceramic nuclear core further comprises non-fuel coated particles comprising a burnable poison. 28. The transportable nuclear generator of claim 21, wherein the melt-proof thermally conductive ceramic nuclear core further comprises fuel elements comprising a composite structure of unidirectional fiber-reinforced NITE-sintered SiC with SIC fibers. 29. The transportable nuclear generator of claim 21, wherein the TRISO fuel pellets further comprise a high-density non-porous SiC coating. 30. The transportable nuclear generator of claim 21, wherein:the MTF elements comprise rectangular blocks, hexagonal blocks, or quarter-circle plates, andwherein the MTF elements comprise holes that provide flow pathways for a coolant. 31. The transportable nuclear generator of claim 30, further comprising:neutron reflector elements comprising carbon or SiC,wherein the neutron reflector elements are geometrically configured to correspond to the geometric configuration of the MTF elements. 32. The transportable nuclear generator of claim 30, wherein the MTF elements are spaced so as to eliminate gaps between MTF elements to thereby enhance the thermal conductivity of the conductive ceramic core and to enhance core passive heat transfer properties. 33. The transportable nuclear generator of claim 21, wherein the melt-proof thermally conductive ceramic nuclear core further comprises:pressure plates provided at an inlet and outlet of the core,wherein the pressure plates comprise matching coolant holes that provide flow pathways for a coolant, andwherein the pressure plates are configured to provide a compressive force that keeps the core under compression. 34. The transportable nuclear generator of claim 21, wherein the melt-proof thermally conductive ceramic nuclear core further comprises:fuel rods containing nuclear fissile material in the form of oxide, nitride, or metal, with metallic or ceramic cladding and arranged in bundles. 35. The transportable nuclear generator of claim 34, wherein the bundles are geometrically arranged so as to have favorable heat transport properties relative to a coolant. 36. The transportable nuclear generator of claim 21, wherein the melt-proof thermally conductive ceramic nuclear core further comprises loose fuel elements in the form of spherical pebbles. 37. The transportable nuclear generator of claim 21, wherein the melt-proof thermally conductive ceramic nuclear core is configured to allow passive cooling even in the absence of a coolant. 38. The transportable nuclear generator of claim 21, wherein the melt-proof thermally conductive ceramic nuclear core further comprises control rods, made of a sintered mix of SiC-Gd203 and Er203 and control rod sleeves. 39. The transportable nuclear generator of claim 21, wherein the melt-proof thermally conductive ceramic nuclear core further comprises control rod channels made of fiber-reinforced carbon or SiC composite materials. 40. The transportable nuclear generator of claim 21, wherein the MTF elements comprise partial cuts to allow for controlled fracturing of the MTF elements without cracks propagating into the TRISO fuel pellets in the event that the transportable nuclear generator is subjected to severe kinetic stresses or impacts.