A small modular molten salt reactor providing homogeneous flow

Abstract

The present invention relates to an optimized geometric design for Small Modular Molten Salt Reactors (SM-MSR) operating in the fast neutron spectrum. The SM-MSR of the present invention, incorporates a symmetrical structure with six input and six output points. The triangular curves between these inlets and outlets direct the flow of liquid fuel, optimizing the mixture and eliminating recirculation zones. The design ensures a homogeneous flow of liquid fuel salt within the reactor core, preventing the formation of recirculation zones. This feature improves the neutronic and thermo-hydraulic performance of the reactor, prevents thermal stresses that may occur in the blanket walls, and increases heat transfer efficiency.

Description

[0001] DESCRIPTION

[0002] A SMALL MODULAR MOLTEN SALT REACTOR PROVIDING HOMOGENEOUS FLOW

[0003] Technical Field of the Invention

[0004] The present invention relates to small modular molten salt reactors (SM-MSR) operating in the fast neutron spectrum. A geometric SM-MSR that ensures homogeneous flow of liquid fuel salt in these reactors is obtained with the present invention. In small reactors, recirculation regions resulting from geometric variations affect both the neutronic and thermal-hydraulic performance of the reactor. The present invention eliminates recirculation problems by ensuring homogeneous flow, prevents thermal stresses that may occur on the blanket wall, and provides more efficient heat transfer.

[0005] State of the Art

[0006] Nuclear energy is a discipline that plays a significant role in energy production and is constantly evolving with modem technologies. This field draws attention through research aimed at meeting energy needs in a safe, efficient, and sustainable manner. Nuclear reactor technologies are fundamental tools used in energy production, and different types of reactor designs offer various advantages. Generation IV reactors, in particular, have been developed with the goals of increasing energy efficiency, reducing waste, and maximizing safety.

[0007] Molten Salt Reactors (MSRs) stand out among Generation IV reactors as a type of reactor based on the use of liquid fuel. In these reactors, fuel in liquid form can be used for both energy production and cooling. Key advantages of molten salt reactors include higher fuel combustion rates, the ability to operate at low pressures, and ease of fuel reprocessing. Furthermore, the ability to optimize their neutronic and thermal-hydraulic performance ensures that these types of reactors are widely used in research and development activities.

[0008] Small Modular Reactors (SMRs) are among the designs that highlight the concept of modularity in nuclear energy technologies. These reactors aim to enable energyproduction units to be designed in smaller sizes and in a modular way, allowing them to adapt to different geographical and economic conditions. Modular reactors offer advantages such as portability, ease of installation, and flexible capacity management, providing new perspectives in energy production. The combination of SMRs with molten salt technology has great potential, both technically and economically.

[0009] One of the most fundamental technical challenges encountered in molten salt reactors is ensuring a homogeneous flow. Even distribution of liquid fuel within the reactor core is a critical parameter for balancing the thermal stress loads of the system and ensuring the stability of neutronic performance. When homogeneous flow cannot be achieved, localized temperature increases on the reactor walls increase thermal stresses, raising safety risks. Another challenge is the formation of recirculation zones. Within the reactor, the liquid fuel spending more time than necessary in certain regions is referred to as recirculation. This situation leads to the formation of local temperature differences, negatively affecting both fuel efficiency and thermo-hydraulic stability. Another problem is thermal stress caused by the interaction of the fluid with the walls. High temperatures, particularly those occurring in reactor blanket walls, can weaken the mechanical strength of materials, leading to structural degradation in the long term. Finally, the complexity of neutronic calculations also presents a significant technical challenge. In molten salt reactors, the constant movement of the liquid fuel makes neutronic calculations more complex. This complexity makes it difficult to ensure the accuracy of the calculations necessary to guarantee the reactor's safe and efficient operation.

[0010] The limitations and inadequacies of current technological solutions, such as the inability to ensure homogeneous flow in molten salt reactors, the high amount of recirculation, the occurrence of thermal stress, and the complexity of neutronic calculations, have made it necessary to develop a new approach in the field of molten salt reactors.

[0011] Brief Description and Objects of the Invention

[0012] The present invention relates to a specific geometric design that provides homogeneous flow for small modular molten salt reactors (SM-MSR) operating in the fast neutron spectrum. This design ensures that the liquid fuel is distributed evenlywithin the reactor core, eliminating recirculation zones. It offers a more efficient structure in terms of both thermal-hydraulic and neutronic performance by increasing the mixture of liquid fuel with the help of the geometric arrangement of the inlet and outlet points.

[0013] One object of the present invention is to obtain an SM-MSR that eliminates recirculation zones. The triangular curves between the inlet and outlet points allow the liquid fuel to move in a spiraling motion. This arrangement solves the recirculation problem by preventing the accumulation of fluid in stagnant areas within the core, enabling the flow to continue uninterrupted throughout the entire reactor.

[0014] Another object of the present invention is to obtain an SM-MSR in which the thermal stress generated in the reactor blanket walls is minimized. In particular, the use of inclined surfaces in the design and the swirling progression of the flow reduce temperature peaks at the wall surfaces. This prevents excessive thermal stresses that may occur in the blanket walls and ensures that the materials operate within safe limits. In addition, the invention aims to achieve an SM-MSR that simplifies neutronic calculations. The symmetrical placement of the entry and exit points allows the flow to move in an orderly manner, improving the accuracy of the data used in neutronic analyses. This allows neutronic calculations during reactor design to be performed with a smaller margin of error.

[0015] Another object of the present invention is to obtain an SM-MSR with improved thermal-hydraulic performance. Arranging flow paths helps to achieve more balanced temperature and pressure distributions. Furthermore, the arrangement of six inlets and six outlets makes the energy transfer of the fluid more efficient, maximizing the thermal-hydraulic performance of the reactor.

[0016] Another object of the present invention is to obtain an SM-MSR in which local temperature differences are prevented. The triangular structures between the inlets allow the fluid to rise in an orderly fashion by merging from different regions. This balances the temperature distribution within the core, minimizing temperature differences. Directing the flow in this way improves reactor performance and increases thermal-hydraulic efficiency.

[0017] Description of DrawingsFigure 1. Geometry of a Small Modular Molten Salt Reactor (SM-MSR) with six inlet / outlet ports (a: flow direction)

[0018] Figure 2. Cross-section of the SM-MSR wall (a: 0.26 m, b: 0.17 m, c: 1.69 m, d: 0.79 m, e: 0.90 m, f: 0.51 m, g: 0.40 m, h: 0.22 m, j: 0.15m) (Lengths are in meters (m)) Figure 3. Side projection of the geometry of the Small Modular Molten Salt Reactor (SM-MSR) (a: 0.17 m, b: 0.80 m, c: 1,50 m, d: 0,32 m, e: 0.14 m)

[0019] Figure 4. Bottom projection of the Small Modular Molten Salt Reactor (SM-MSR) geometry (R1: 0.41 m, R2: 0.53 m, R3: 0.32 m, R4: 0,79 m)

[0020] Reference Numbers

[0021] 1. Fluid inlet

[0022] 2. Triangular structure

[0023] 3. Body

[0024] 4. Fluid outlet

[0025] Detailed Description of the Invention

[0026] The present invention is a small modular molten salt reactor (SM-MSR) designed to provide a homogeneous flow for fuel salt. SM-MSR of the present invention comprises;

[0027] a. six L-shaped fluid inlets (1), which are integrated with the body (3) at the head end of the flow direction where the nuclear fuel enters the heat exchangers, to ensure the entry of fluid into the body (3),

[0028] b. twelve triangular structures (2) in total, one between each of the two fluid inlets (1) and one between each of the two fluid outlets (4) to ensure a homogeneous flow by the rotational rise of the fluid,

[0029] c. a cylindrical body (3) through which the fluid passes, integrated with fluid inlets (1 ) at the beginning of the flow direction and fluid outlets (4) at the end of the flow direction,

[0030] d. six fluid outlets (4) integrated with the body (3) on the end side of the flow direction, where the fluid exits the body (3).

[0031] Here, the direction indicated by "a" is the direction of flow. The fluid enters the body (3) through the fluid inlet (1) points, the fluid heated by nuclear reactions is connected toan external heat exchanger system for heat transfer through the fluid outlet (4) points. The fluid inlet (1) points of the reactor are the outlet connections of these heat exchangers. Likewise, the fluid outlet (4) points of the reactor are the inlet connections of the heat exchangers. Apart from that, everything else in the geometry is closed. The SM-MSR of the present invention, has a symmetrical structure with six fluid inlets (1) and six fluid outlets (4). The triangular structures (2) located between the inlets ensure that the liquid fuel combines, rotates, and rises homogeneously within the reactor core. This special design optimizes the liquid fuel mixture, improving the reactor's thermal and neutronic performance.

[0032] The SM-MSR described in the present invention improves fluid dynamics in the core region. Triangular structures (2) eliminate recirculation problems in wall areas by directing the flow of liquid fuel in a specific pattern. Preventing recirculation zones reduces thermal stress loads on the reactor while also preventing mechanical problems caused by temperature differences. These triangular structures (2) also allow the fluid to spiral from the fluid inlets (1 ) to the fluid outlets (4) without the need for any stirrers inside the reactor. These features contribute to the safe and long-term operation of the reactor.

[0033] The liquid fuel is mixed homogeneously over a large area with the help of the triangular structure (2) between the fluid inlets (1). Homogeneous flow reduces uncertainties in the thermal-hydraulic calculations of the reactor, while allowing for more predictable results in neutronic analyses. This design of SM-MSR offers significant advantages over traditional reactor designs in terms of both performance and safety. In particular, this type of flow control is a critical solution for increasing the efficiency of energy production in small-scale reactors.

Claims

CLAIMS1. A small modular molten salt reactor (SM-MSR) designed to provide a homogeneous flow for fuel salt, comprising;a. six L-shaped fluid inlets (1), which are integrated with the body (3) at the head end of the flow direction where the nuclear fuel enters the heat exchangers, to ensure the entry of fluid into the body (3),b. twelve triangular structures (2) in total, one between each of the two fluid inlets (1) and one between each of the two fluid outlets (4) to ensure a homogeneous flow by the rotational rise of the fluid,c. a cylindrical body (3) through which the fluid passes, integrated with fluid inlets (1 ) at the beginning of the flow direction and fluid outlets (4) at the end of the flow direction,d. six fluid outlets (4) integrated with the body (3) on the end side of the flow direction, where the fluid exits the body (3).

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