31 results about "Subcritical reactor" patented technology

The invention discloses a passive natural-circulation lead bismuth heat exchange device for heat transfer by a lead bismuth fluid and a method for discharging heat out of reactor core, belonging to the field of nuclear energy heat exchange equipment. The heat exchange device particularly comprises two natural-circulation heat transfer loop structures, namely a round loop and a square loop, and is a device which realizes natural-circulation heat transfer at two sides. The inner ring of an inner ring pipe is a primary side lead bismuth alloy fluid passage, and a secondary side fluid passage is arranged between the outer ring of the inner ring pipe and the inner wall of an outer ring pipe. Heat generated by a subcritical reactor of an ADS (accelerator driven system) is transferred to coolants of the two loops by the liquid lead bismuth alloy through the inner ring pipe of the device, the lead bismuth alloy flows through the device to exchange heat with a secondary side fluid. The primary side heat exchange fluid and the secondary side heat exchange fluid form natural circulation under the driving of a density difference, and the high-efficiency, energy-saving, safe and reliable passive characteristic is achieved. The device is simple and easy to operate, is free of a complicated lead bismuth pump, is in no need of a power source and has the characteristics of energy conservation, high safety and high reliability. The passive natural-circulation lead bismuth heat exchange device and the method for discharging heat out of the reactor core comply with the current policy of energy conservation and emission reduction and are easy in market promotion.

The invention relates to a radial-power-flattened efficient nuclear waste transmutation subcritical reactor core and a design method thereof. The reactor core sequentially comprises an outer neutron source region (1), a first transmutation fuel zone (2), a second transmutation fuel zone (3), a third transmutation fuel zone (4), a reflective area (5) and a shielded area (6) from the center outwards. The transmutation fuel zones of the reactor core are arranged in three zones; the reactor core is arranged in a triangular shape, and is subjected to principle design and analysis by analyzing coupled neutronics and thermal-hydraulic principles and using mathematical methods; and aiming at each transmutation zone, specific geometry layer arrangement is performed from inside to outside based on the design principles, so that the power distribution of the transmutation fuel zones can be flattened in the radial direction. The reactor core can utilize fast neutron transmutation TRU (Transuranic) generated by exogenous neutron, is high in neutron utilization, good in radial power flattening, high in power generation efficiency and simple in structure, and has the functions of safety and high efficiency in nuclear waste disposal and economy.

The invention provides a subcritical degree reverse dynamic measuring method free of a space effect. Compared with other methods, the method is characterized in that subcritical degree online measurement free of the influence of the space effect is achieved, wherein a stationary source mode is selected to work out space positions with the neutron-flux density normalization shape function unchanged after the state of a reactor is changed to arrange detectors; the reference subcritical degree of a subcritical reactor and the neutron-flux density under the condition that a stable external source is available are measured based on a pulse neutron source method or a source jerk method, and an external neutron source item is scaled with a subcritical inverse dynamic formula; the subcritical degree is calculated on line according to time-sequence data read at the positions of the detectors. The method has the advantages that the influence of redistribution of the neutron-flux shape space is avoided when the subcritical degree is measured; the delay effect of delayed neutrons can be responded to; the subcritical degree can be measured online in real time regardless of low power or high power.

The invention relates to a method for monitoring sub-critical reactor reactivity. The method includes the steps: placing neutron detectors at two different positions of a reactor; effective multiplication constant gradually changing the reactor reactivity, and recording a specific value C and an effective multiplication constant keff of neutron counting rate at the same moment; fitting calibratingcurve graphs of the specific values C and the effective multiplication constants keff of the neutron counting rate of various moments; recording neutron counting rates of the two neutron detectors inreal time to obtain specific values of the two neutron counting rates, and substituting the specific values into the calibrating curve graphs to obtain effective multiplication constants of the effective multiplication constant when reactor reactivity is practically monitored. The neutron detectors are used for acquiring neutron counting rates, and the specific values C of the neutron counting rates recorded by two detectors represent characteristic parameters of neutron flux density space distribution shapes. Compared with a traditional method, the method is more visual, simple and convenient, on-line real-time monitoring of the reactivity change can be achieved, effects of external source intensity are omitted, and space effect correction of the traditional method under a deep sub-critical condition is avoided.

The embodiment of the invention provides a material changing system for an accelerator driving subcritical reactor and the accelerator driving subcritical reactor with the material changing system. The material changing system comprises a rotatable rotating plug (2) and a material changing machine (1), wherein the rotating plug (2) is arranged on a top cover of a reactor; the material changing machine (1) comprises a rotating rod (8), a cantilever (7) and a material changing grasping head (6); the cantilever (7) is connected with the lower end of the rotating rod (8); the material changing grasping head (6) is connected with the end part, far away from the rotating rod (8), of the cantilever (7); the rotating rod (8) is arranged on the rotating plug (2), can rotate around the self axial line and can vertically move. The material changing system according to the embodiment of the invention has the advantages that the structure is simple and compact; the material changing operation is simple and convenient after the material changing system according to the embodiment of the invention is used.

The invention discloses an experimental device for flow and heat transfer characteristics of a curved single passage of a subcritical energy reactor coolant. The experimental device comprises a curved heating single tube, wherein the two ends of the heating single tube are communicated with stabilizing straight tubes, and the stabilizing straight tubes are communicated with threaded joints, the threaded joint are sleeved with threaded flanges; the stabilizing straight tubes are welded with powered copper bars, and pressure diversion holes are formed in the stabilizing straight tubes; the heating single tube is an eccentric curved tube or a concentric curved tube; the center of an inside diameter circle of the eccentric curved tube is O1, the center of an outside diameter circle of the eccentric curved tube is O2, the distance between the O1 to the O2 is larger than zero, and a line segment for connecting the O1 to the O2 is O1O2; the eccentric curved tube is welded with a thermocouple, and a heat insulation protection structure is arranged on the outer wall of the eccentric curved tube; the center of an inside diameter circle of the concentric curved tube and the center of an outside diameter circle of the concentric curved tube are overlaid at a point X1, a plurality of thermocouples are welded on the outer wall of the concentric curved tube, and a heat insulation protection structure is arranged on the outer wall of the concentric curved tube. The experimental device can provide experiment support for the feasibility study on a thermo-hydraulic design of the subcritical reactor coolant.

The invention discloses a fused-salt fuel multi-reactor system. The fused-salt fuel multi-reactor system comprises a reactor module, a heat exchange module, a pump module and a fuel processing module,wherein the reactor module comprises a type I reactor module and a type II reactor module, which adopt the same kind of fused-salt fuel flowing therein; and the type I reactor module and the type IIreactor module are serially and/or parallelly arranged. The type I reactor module operates in an overmoderated region or near the optimal grid point, is used for realizing productivity and multiplication, and comprises a set of reactivity control system which is used for controlling reactivity variation of the rectors. The type II reactor module operates in an undermoderated region and non-moderated region, is used for multiplication and transmutation, belongs to a subcritical reactor, and comprises a set of neutron source systems for driving the reactors. The fused-salt fuel multi-reactor system disclosed by the invention fully utilizes the fluidity of the liquid fuel, and can realize the functions of productivity, multiplication, transmutation and the like in the same system.

The invention discloses a system for keeping the constant temperature of a target window of an accelerator driven sub-critical reactor. The system is composed of a current sensor, a DCCT, a target loop rack, a cock, a proton beam tube, a guide tube, an outer sleeve, a target fixing plug, an automatic temperature control electromagnetic induction coil, the target window, a sub-critical reactor core, a reactor container and a reactor-core lower grid tray. The system has the advantages that after proton beam currents of an accelerator suddenly disappear, as the beam current strength is reduced, working signals of the electromagnetic coil are triggered through current changes, the electromagnetic coil rapidly works, the bottom of the outer sleeve is heated, coolants located in the outer sleeve and below the target window are further heated, the temperature of the target window after the proton beam currents disappear is kept constant, it is guaranteed that after the proton beam currents of the accelerator disappear, the temperature of the target window can not drop obviously, heat stress changes, caused by beam disappearing, of the target window are greatly reduced, and the target window material fatigue fracture risk caused by the fact that the heat stress cycle of the target window is generated due to the proton beam currents of the accelerator frequently disappear is further lowered.

The invention discloses a spallation target of an accelerator drive sub-critical reactor of low proton beam intensity efficient transmutation nuclear waste, and relates to the technical field of nuclear energy. The spallation target is characterized in that reactor cores of the spallation target are arranged in a shape of a triangular grid, a proton beam (1), a liquid state heavy metal spallation target (2), a fission fuel region (3), an axial reflecting region (4), an axial shielding region (5), a radial reflecting region (6) and a radial shielding region (7) are sequentially arranged from center to outside. Based on the reactor cores adopting TRU dispersion metal fuels, the reactor physics principle and the spallation target physics principle are applied, and spallation target geometrical optimizing is carried out with the transmutation performance as evaluation indexes. Based on the optimized spallation target, in the state that structures and material component distribution of the reactor cores are not changed, the reactor cores of the spallation target can have the functions that the same transmutation performance is obtained in the fixed power operation mode, the proton beam intensity is reduced, energy gain factors of the reactor are improved, and the higher MA transmutation performance is obtained in the fixed proton beam intensity mode.

Subcritical reactor performance analysis method, system, apparatus and computer medium are disclosed. That method include: obtaining lambda fundamental conjugate neutron flux in a subcritical reactor;Obtaining the neutron flux of the instantaneous alpha fundamental wave in the subcritical reactor; calculating The absolute reactivity of subcritical reactor based on lambda-fundamental conjugate neutron flux and alfa-fundamental neutron flux. Based on the absolute reactivity of subcritical reactor, analyzing and acquiring the performance of subcritical reactor and the results. In a subcritical reactor performance analysis method disclosed herein, The absolute reactivity of subcritical reactor is calculated based on Lambda-fundamental conjugate neutron flux and alfa-fundamental neutron flux.It is proved that the analysis results of subcritical reactor performance based on absolute reactivity of subcritical reactor are more accurate. The invention discloses a subcritical reactor performance analysis system, a device and a computer-readable storage medium, which also solve the corresponding technical problems.

Now disclosing previously undisclosed aspects of the original accelerator-driven sub-critical reactor, whose since-then familiar parts and operation was first disclosed publicly starting in 1990: a more efficient accelerator-driven system is proposed which fully and completely implements the fundamental insights of the original invention and which realizes then a completely next-generation and practical and wave energy processing system, departing fundamentally from thermal-conversion/turbine based systems and moving much more completely to a fusion-like paradigm, as was originally conceived. Departing fundamentally from the conventional energy processing paradigm, proposed are more efficient energy collection and conversion systems “directly” collecting particle flows and wave radiation, converting them more efficiently to usably power for distribution, and recycling flows required for the accelerator-driven system. Thus, by those greater net efficiencies, thereby enabling a wider range of feedstock/fuel types and cycles generalized, while also providing: 1) a significantly more efficient Thorium-cycle system, in one configuration, 2) a more energy-productive nuclear waste reduction system, in another configuration, 3) accelerator driven systems for other fertile-fission candidate elements, and 4) which may be applied to fusion systems (substituting the fission unit in the proposed system class and category) in a way that may lower the break-even point for such systems and thus make the advent of practical fusion sooner than otherwise possible. 5) In addition and importantly, an optical-power processing and distribution is also enabled by the proposed, providing both optical power as base power for telecom, process energy for industrial uses, and lighting and other wavelengths for consumer and general business use.

The invention provides an emergency reactor-shutdown system and method suitable for accelerator driving for a sub-critical reactor system. The emergency reactor-shutdown system includes a first emergency reactor-shutdown subsystem used for controlling a reactor-shutdown circuit breaker to cut off a path between an accelerator proton source and an accelerator power source system according to an emergency reactor-shutdown signal emitted by a reactor protection system, and a second emergency reactor-shutdown subsystem used for controlling an accelerator chopper to set an accelerator proton beam current pulse duty ratio to a minimum value according to a transient signal which cannot realize emergency reactor shutdown emitted by the reactor protection system. The system and method provided by the invention can realize the emergency reactor shutdown by adopting the second emergency reactor-shutdown subsystem in the case that the first emergency reactor-shutdown subsystem fails to realize theemergency reactor shutdown, thereby greatly improving safety of a reactor.

The invention discloses a method for simultaneously removing VOCs and PM2.5. The method comprises the following steps: (1) pressurizing waste gas containing VOCs and/or PM2.5 by a compressor and thenconveying the waste gas to a mixer; (2) pressurizing water or hydrogen peroxide through a pressurizing pump, conveying the pressurized water or hydrogen peroxide to a mixer for mixing, and conveying an obtained mixture to a preheating-cooling device and a high-temperature preheater for heating; (3) performing water oxidation reaction in a supercritical/subcritical reactor to remove VOCs and PM2.5;(4) conveying high-temperature and high-pressure fluid flowing out of a turbo expander into a preheating-cooling device to heat the materials; (5) taking high-temperature and high-pressure fluid flowing out of the preheating-cooling device as a heat source of a waste heat boiler to generate superheated steam; and (6) conveying fluid flowing out of the waste heat boiler into a gas-liquid separatorafter pressure reduction, and carrying out separation of gas and liquid. The method provided by the invention does not need any adsorbent, flocculant or catalytic combustion, and the device is simpleto operate, energy-saving, environment-friendly and easy to implement.

The new features of an accelerator driven subcritical reactor disclosed by this invention include the multiple intake ports connected to the reactor vessel for delivering protons from one or more accelerators to accommodate the full length LWR spent fuels for furnishing the desirable neutron distribution in a subcritical core to incinerate nuclear wastes. This is based on the notion of adopting the spent fuels in intact form to feed directly to the newly designed subcritical core. External modulators in the proton intake ports have the ability of splitting the fluxes and adjusting their energy from one or more accelerators to form multiple proton streams arriving at different axial locations in the spallation target for creating multiple neutron sources. The new design could combine the cycles of reprocessing spent fuels, manufacturing fuels for reuse, and incinerating minor actinides into one single cycle.