Patent Application
20250157678
The present disclosure relates to control drives for nuclear reactors. The present disclosure also relates to a method of reloading fuel assemblies in nuclear reactors.
Nuclear fission reactors generate heat via a process of neutron chain reaction. The operating state of the reactor is adjusted by changing the neutron absorption rate in the reactor core. In general terms, this is referred to as reactivity control. One of the established methods for reactivity control is to use movable control rods containing neutron absorbing material, such as cadmium or boron. Inserting the control rods deeper into the reactor core increases, and withdrawing the rods reduces neutron absorption.
The conventional technical solution for control rod systems is to place the rod drive mechanisms (i.e. the electric motors that move the rods up and down) outside the reactor pressure vessel. In pressurized water reactors (PWRs) the rod drives are attached on the top lid of the vessel. Control rods of boiling water reactors (BWRs) are operated from below, with the drive shafts penetrating the vessel bottom.
In some reactor concepts the control rod drive mechanisms are placed inside the pressure vessel. One of the advantages of using in-vessel rod drives is that the possibility of fast control rod ejection transients is eliminated by design, due to the lack of pressure differential over the drive mechanism. This is not a common solution, however, since the operating conditions can be challenging for electric components. The operating temperature in conventional light water reactors is around 300° C. PWRs operate at 12-15 MPa, and BWRs at around 7 MPa pressure, respectively.
In conventional PWRs core reactivity is in addition adjusted by changing the concentration of boric acid in the coolant water. This method, also known as boron shim, is in particular used for compensating the excess reactivity of fresh fuel assemblies placed in the reactor core at the beginning of each operating cycle. As the fuel is consumed, boron concentration is slowly reduced.
Some PWR concepts are designed to operate without soluble boron. The advantage of this approach is that the chemical and volume control system of the reactor is somewhat simplified, and reactivity transients related to boron dilution eliminated by design.
The drawback of boron-free operation is that reactivity control has to be managed by control rods alone, which complicates the core design. Further, maintaining the core in a sub-critical safe shut-down state during reloading operations becomes a technical challenge, since disassembling the core requires removing the control rod drives and associated structures before the fuel assemblies can be accessed. This is not an issue in conventional PWRs, in which the safe shut-down state is instead maintained by soluble boron, or in BWRs, in which control rods are inserted from below, and remain in place when the core is accessed from above.
In addition to reactivity control systems, the state of the reactor should be constantly monitored by various sensors and detectors that measure the relevant operating parameters, such as neutron flux and coolant temperature. In-core neutron detectors are placed in hollow instrumentation tubes that are part of the fuel assembly structure. Ex-core neutron detectors and temperature sensors are placed outside the core.
Nuclear reactors subject to boron-free operations are challenging due to managing reactivity control by control rods alone and tedious disassembling of the control rod mechanism while maintaining the reactor in safe shut-down state during refueling operations. In-vessel control rod drives may be a preferred solution for many reactors operating under natural circulation, in which case maintaining sufficient coolant flow requires considerable elevation between the reactor core and primary heat exchangers, which is also reflected in the overall height of the reactor pressure vessel and the length of the control rod shafts. This is in particular the case for low-temperature reactors, in which the operating conditions are less challenging for electric components. There is therefore a need to improve in-vessel control rod systems in reactor types where such configuration is an attractive option.
A novel fuel and control system is therefore herein proposed. The invention is defined by the features of the independent claims. Some specific embodiments are defined in the dependent claims.
According to a first aspect of the present disclosure, there is provided a fuel and control system featuring a drive motor, a control rod assembly, a fuel unit and a frame. The frame attaches the drive assembly to the fuel unit and provides a space for control movement of the control rod assembly so that the frame, the fuel unit, the drive assembly and the control rod assembly are integrated so that the fuel and control system is configured to be loaded into and unloaded out of the nuclear reactor as one unit.
One or more embodiments of the first aspect may include one or several features from the following itemized list:
According to a second aspect of the present disclosure, there is provided a nuclear reactor featuring a reactor core, a pressure vessel and a plurality of fuel and control system where the fuel and control system is contained inside the pressure vessel.
One or more embodiments of the second aspect may include one or several features from the following itemized list:
According to a third aspect of the present disclosure, there is provided a method for refueling a nuclear reactor featuring unloading a first fuel unit by removing a fuel and control system as one unit from the reactor core, and reloading a second fuel unit by inserting a fuel and control system as one unit into the reactor core.
One or more embodiments of the third aspect may include one or several features from the following itemized list:
According to a fourth aspect of the present disclosure, there is provided a method of operating the nuclear reactor featuring the fuel and control system where the reactor core is subject to a boron free operation.
Considerable benefits are gained with the aid of the novel fuel and control system. The fuel and control system ensures that at least the control rod assembly, the drive motor and the fuel unit move as one unit to allow for convenient removal of the fuel unit. The fuel and control system mitigates the criticality safety challenges associated with reactors operating without soluble boron primarily by eliminating the need to remove individual components such as the drive assembly, which could lead to the inadvertent removal of the neutron-absorbing control rods. This enables the fuel and control rod system to be designed in such way, that the reactor cannot become critical during reloading operations. This is ensured by two factors. First, the control rod assembly is maintained in the fuel unit when the fuel and control system is moved as a single unit. Second, the design of the components prevents the control rod assembly to be withdrawn from the fuel unit by actuating the drive unit, since the electric connections have to be disconnected before accessing the core. Further, the fuel and control system simplifies the reloading operations by integrating all reactivity control and instrumentation systems into a single modular component. The fuel and control system enables combining various attractive options in reactor design: boron-free operation and in-vessel control rod drives, the combination of which has been previously limited by conflicting constraints in known solutions.
In the following certain exemplary embodiments are described in greater detail with reference to the accompanying drawings, in which:
“Fuel unit” is known as a fuel assembly in the field of nuclear engineering. “Electrical connector” refers to an electrical connection, for example electrical leads or wires which may connect to a socket or other leads of another component. “Electrical connector counterpart” refers to a socket or another electrical connection, for example an electrical connection meant to connect the ends of electrical leads. “Attachment” without the connotation of “electrical” may refer to a physical attachment between surfaces or components and may refer to mating surfaces between surfaces or components.
In the present context expressions “fuel and control system” and “fuel and control module” can be used interchangeably.
According to the illustrated embodiment
According to the illustrated embodiment
As is shown in
According to at least some embodiments, at least a portion of the fuel and control system 100 is located under the grid plates 181, 182. A portion of the drive assembly 110 and the control rod assembly 140 may be located above the grid plates 181, 182, however the connector grid plate opening 188 and the support grid plate opening are openings where the entire structure of each of the drive assembly, the frame 130, the fuel unit 150, and the control rod assembly 140, cannot go through due to the size of these openings. According to at least some embodiments, the width of the grid plate opening 188 is smaller than the width of the frame 130 and the width of the drive flange 120.
The connector grid plate 182 has a main electrical connector 184, which connects to a main electrical connector counterpart 185. The nuclear reactor 170 may have a connector block 186 where, according to the illustrated embodiment
The following paragraphs describe the usage of components of the fuel and control system 100.
The nuclear reactor 170 as illustrated in
During operation, the drive motor and instrumentation electrical connector counterpart 187 is connected to the drive motor electrical connector 114 and the instrumentation electrical connector 133. While these connectors are connected, the main electrical connector 184 and the main electrical connector counterpart 185 are connected and therefore power and electrical connections are being supplied by the electric cables 183 to the drive motor 111 and the instrumentation via the main connector and the drive motor electrical connector 114. As a result, the connector grid plate 182, when installed, provides an electrical connection to the drive motor 111 and the electromagnet 119, provides transmission of data and other signals to and from the instrumentation, and provides electric current to power the instrumentation. The connector grid plate 182 has a body that is at least partially solid. According to at least some embodiments, when the connector grid plate 182 is installed, each of the drive motor and instrumentation electrical connector counterparts 187 connects to the corresponding drive motor electrical connector 114 and the instrumentation electrical connector 133 of each fuel and control system 100. This manner of connecting allows the electrical connections to be made all at once (due to the at least partially solid body of the connector grid plate 182), rather than having to connect the electrical connection individually. As a result, a function of the connector grid plate 182 is to make electric connections time-efficient. The connector grid plate 182 acts as a bridge between the electric cables 183 and the drive motor electrical connector 114 with the instrumentation electrical connector 133. Therefore, the installment and detachment of the connector grid plate 182 determines whether the electrical connections provided to the drive motor 111 and the instrumentation are connected or not. When the connector grid plate 182 is installed and providing power and electric connections, the connector grid plate 182 is in a connected state.
The connector grid plate 182 also allows signals of data to transmit from the instrumentation to a receiving device for receiving data which is located outside of the nuclear reactor 170.
The electric cables 183 may be connected directly to the main electrical connector counterpart 185 so that when the main electrical connector counterpart 185 is in connection with the main electrical connector 184, the electric cables 183 provide electric power to the connector grid plate 182 from the power source.
When the coolant is a liquid, the electric connectors and electric connector counter parts are “wet-mated”, meaning that the connection can be established while submerged in the coolant.
When the grid plates 181, 182 are attached to the nuclear reactor 170 and are therefore electrically connected and in operation, the grid plates 181, 182 prevent the drive assembly, the frame 130, and the fuel unit 150 from being transported. In other words, the grid plates 181, 182 and the fuel and control system 100 are arranged where the fuel and control system 100 cannot be removed from the pressure vessel 171 unless the grid plates 181, 182 are removed first. Therefore the grid plates 181, 182 hold the drive assembly 110, the frame 130, and the fuel unit 150 in place. The drive assembly 110 may cause the control rod assembly 140 to be at least partially withdrawn from the fuel unit 150, however the grid plates 181, 182 hold the drive assembly 110 in place, and the control rod assembly 140 is unable to travel through the drive assembly 110 due to the electromagnet 119 and supports 143 not fitting through the linear translator opening 113. Further, the control rod assembly 140 can move the distance of the active height within the fuel unit 150.
When the fuel units 150 are ready to be replaced, the refueling operation commences. The nuclear reactor 170 is first manually shut down, by driving the control rods 144 to the lowered position. The lid 173 of the pressure vessel 171 can be opened to access the reactor core 172 and the fuel and control system 100. Subsequently, the grid plates 181, 182 are removed and thereafter the grid plates 181, 182 are in a disconnected state. The disconnection of the connector grid plate 182 causes the plurality of drive motor and instrumentation electrical connector counterparts 187 to disconnect from the drive motor electrical connector 114 and the instrumentation electrical connector 133 of each fuel and control system 100 in the reactor core 172 in one instance. Further, the main electrical connector 184 and the main electrical connector counterpart 185 are no longer connected and therefore no power is being supplied by the electric cables 183. This ensures that there is no electric power in the fuel and control system 100 and in the reactor core 172 when the connector grid plate 182 is removed. To summarize, the disconnected state of the grid plate 182 causes no power to be provided to the drive motor, the electromagnet 119 and the instrumentation, and prevents the instrumentation to transmit or receive signals.
As there is no power provided to the drive motor 111 and the electromagnet 119 is no longer energized, the control rods 144 cannot be withdrawn from the lowered position, inadvertently or otherwise. This is crucial because this ensures that all control rods 144 are fully inserted, and the reactor remains in a safe shutdown state. It is also crucial that the control rods 144 are in a lowered position while the core is being disassembled, and the fuel and control system 100 is being transported, or more specifically unloaded and loaded.
A reloading machine, not shown in the figures, can make contact with the frame 130 in order to remove the fuel and control system 100 out of the reactor core 172. The removal of the fuel and control system 100 out of the reactor core 172 is called a first transportation state. In other words, when the reloading machine is lifting the frame 130, the following components are being lifted also: the drive assembly, the control rod assembly 140 and the fuel unit 150. Therefore the drive assembly, the frame 130, the control rod assembly 140 and the fuel unit 150 move as one single unit during the first transportation state. This is accomplished by the attachment the frame 130 makes between the drive assembly 110 and the fuel unit 150. According to at least some embodiments, the reloading machine moves the fuel and control system 100 in the direction indicated as Z in
As mentioned previously, the frame 130 has a frame height. The frame 130 creates a space which is open or preferably at least partially enclosed. The frame height is a certain length to allow the control rod assembly 140 to travel at least partially within the space of the frame 130 while the fuel and control system 100 is in operation in the pressure vessel 171. The frame height therefore affects the range of movement of the control rod assembly 140 and the control rods 144. The movement of the control rod assembly 140 and the control rods 144 while in operation is for changing the neutron absorption rate in the reactor core 172. This movement may be referred to as control movement.
According to at least some embodiments, the reloading machine is designed in such way that it cannot make contact with and lift the drive assembly, thereby disconnecting it from the frame 130. Also, the reloading machine is designed to make contact with and lift the frame 130. According to
The arrangement of the fuel and control system 100 is designed to ensure criticality safety because the fuel and control system 100 is lifted as the frame 130 is lifted by the reloading machine. The reloading machine comes into contact with the frame 130 at a contact point, not shown in the figures. The contact point may be at the frame upper section 134. Since the frame 130 is attached to the drive assembly, the drive assembly 110 moves with it. According to the illustrated embodiments
The fuel unit 150 has a plurality of control rod guide tubes for the control rods 144 to travel into, and where the control rods 144 can travel at least most of the height of the fuel unit 150. Located at the bottom of each control rod guide tube, is a dashpot or stopping surface that defines an end of the control rod guide tube. The stopping surface prevents each control rod 144 from travelling further downward. The control rod assembly 140 may move downward until a bottom end of the control rod comes into contact with the stopping surface. When the control rods 144 come into contact with the stopping surface, the control rods 144 are in a lowered state and thus rest at the stopping surface. As a result, the stopping surface allows each control rod 144 to stay in place by gravity. Therefore, when the fuel unit 150 is transported, the control rods 144 and the control rod assembly 140 is transported with the fuel unit 150. The active height of the fuel unit 150 may determine the frame height since the control movement range within the fuel unit 150 may be the same or substantially the same as the control movement range within the space of the frame 130.
To summarize the attachments within the fuel and control system 100 during the first transportation state, the frame 130 is attached to both the drive assembly 110 and the fuel unit 150. Further, the control rod assembly 140 is in connection with the fuel unit 150 when the control rods 144 are in the lowered state. As a result, when the frame 130 is transported, the transporting of the frame 130 causes the drive assembly, the fuel unit 150, and the control rod assembly 140 to be transported also. The structural integrity of the frame 130 or the profile 131 enables the fuel and control system 100 to transport as a one unit.
Once the reloading machine has a secured attachment with a fuel and control system 100, an unloading stage commences and therefore the reloading machine transports the fuel and control system 100, during the first transportation state, out of the reactor core 172 and out of the pressure vessel 171. According to at least some embodiments, the reloading machine lifts the fuel and control system 100 upwards while exiting the reactor core 172 and the pressure vessel 171. Then, the reloading machine may transport the fuel and control system 100 in a direction necessary to place the fuel and control system 100 onto a support rack, not shown in the figures, to hold the fuel and control system 100 in place. Once the support rack holds the fuel and control system 100 in place, the attachment between the reloading machine and the fuel and control system 100 may be detached and thus defines the end of the process of the first transportation state, according to at least some embodiments.
The reloading machine can repeat this process and cause other fuel and control systems 100 to be in a first transportation state and thus be unloaded from the pressure vessel 171 to the support rack.
The support rack may hold many fuel and control systems 100 in place. The support rack is designed in such way, that criticality safety is ensured by geometry. This means that there is enough distance between the fuel units 150 to prevent the neutron chain reaction from being started even when the control rod assemblies 140 are removed from the fuel units 150. Alternatively, criticality safety can be ensured by placing neutron absorbing materials in the structures of the support rack.
During the refueling process, the fuel units 150 of the fuel and control system 100 that are removed from the reactor core 172 are fuel units that may be used again for the loading process or spent fuel units 150, which become waste. This depends on the amount of cycles of usage the fuel unit 150 has been subject to, until the fuel unit 150 becomes waste, which may be, for example, 3 times. The fuel unit 150 that has been used for at least one cycle or is subject to become waste as a spent fuel unit, is referred to as a first fuel unit 151.
During the second transportation state the drive assembly 110 and the control rod assembly 140 are transported by a replacing machine. The replacing machine comes into contact at a second contact point located on the drive assembly. The replacing machine transports the drive assembly 110 and the control rod assembly 140. As the drive assembly 110 and the control rod assembly 140 are transported during the second transportation state, the drive assembly 110 and the frame 130 are detaching. As a result, the first frame attachment 116 and the first frame attachment counterpart 135 detach. According to at least some embodiments, the first frame attachment 116 and the first frame attachment counterpart 135 are in the form of a hole and a pin, respectively. Therefore, as the drive assembly 110 is transported during the second transportation state, the hole 116 moves out of the pin 135 and therefore the drive assembly 110 detaches from the frame 130. Therefore, the first frame attachment 116 and the first frame attachment counterpart 135 achieve an attachment during the first transportation state, and they are able to detach during the second transportation state.
The drive assembly 110 and the control rod assembly 140 are designed to be transported as one unit during the second transportation state. Thus, there is an attachment made between the drive assembly 110 and the control rod assembly 140 during the second transportation state. According to at least some embodiments, the replacing machine provides power to the drive assembly 110 and causes the electromagnet 119 to attach to the plate 142 of the control rod assembly 140. This way, as the replacing machine transports the drive assembly, the control rod assembly 140 is transported also. In addition, the replacing machine may mechanically attach, even if electric power is lost, to the control rod assembly 140 or shaft 141, where the shaft 141 protrudes through the shaft opening 118, in order to avoid the control rod assembly 140 from falling down in case electric power is lost during the second transport state.
According to the illustrated embodiment
During the second transportation state, the replacing machine guides the drive assembly 110 and the control rod assembly 140 into the other frame 130 and the corresponding second fuel unit 152. According to at least some embodiments, the replacing machine lowers the drive assembly 110 and the control rod assembly 140 where the control rods 144 are guided into the control rod guides and then further lowered and guided into the second fuel unit 152. As the control rods 144 are guided into the second fuel unit 152, the first frame attachment 116 and first frame attachment counterpart 135 will be attached. According to at least some embodiments, the first frame attachment 116 and the first frame attachment counterpart 135 are in the form of a hole and a pin, respectively, and the hole is guided to surround the pin. The function of the first frame attachment 116 and the first frame attachment counterpart 135 is to provide an attachment, or a mating of surfaces, where the drive assembly 110 can be moved with the frame 130 and moved without falling to one side or shifting to one side when the frame 130 is moved. After the control rods 144 are in the second fuel unit 152 and the first frame attachment 116 and the first frame attachment counterpart 135 are attached, the replacing machine is detached from the drive assembly, causing the end of the second transportation state. If the replacing machine provides power to the drive assembly, detaching the replacing machine will ensure that there is no power provided which could cause the control rods 144 to move out of the fuel unit 150.
The replacing machine can repeat this process and cause other drive assemblies 110 and control rod assemblies 140 to be in the second transportation state and thus be moved from other first fuel units 151 to other second fuel units 152.
The new fuel and control system 100, which has the second fuel unit 152, the drive assembly, the control rod assembly 140, and the frame 130, is ready to be transported in a third transportation state to be loaded into the pressure vessel 171. This is the loading stage. The reloading machine comes into contact with the new fuel and control system 100 in the same or similar manner as in the unloading stage. The reloading machine transports the new fuel and control system 100 from the support rack to a location above the pressure vessel 171 and lowers the new fuel and control system 100 into the pressure vessel 171 and into the reactor core 172. Once the new fuel and control system 100 is accurately placed into the correct position inside the reactor core 172, the reloading machine detaches from the new fuel and control system 100. The reloading machine can transport more new fuel and control systems 100 into the pressure vessel 171. The grid plates 181, 182 are out of the way, and do not interfere, while the fuel and control systems 100 are loaded and unloaded.
After the reloading operation has been completed, the grid plates 181, 182 are placed above the fuel and control systems 100. The grid plates 181, 182 are installed and are thereafter in a connected state. Now the control rod assembly 140 is able to translate within the fuel unit 150 to regulate the neutron absorption rate. As mentioned before, the installment of the connector grid plate 182 enables power and electrical connections to be provided to the drive motor 111 and the instrumentation, enables the electromagnet 119 to be energized and allows the instrumentation to transmit and receive signals.
A person skilled in the art may foresee several variants of the above described embodiment.
For example, another embodiment comprises the reloading machine having prongs that reach into the reloading machine openings 121. The reloading machine may make the attachment to the frame 130 via a known mechanism for grasping frames. According to an embodiment, the reloading may have prongs that reach into the reloading machine openings 121 and subsequently each prong will translate outward to grasp onto the frame 130. The prongs may reach under a lip located on the frame 130 that when the loading machine is lifted the prongs are lifting the frame 130 via the lip. According to an embodiment, the drive assembly 110 may not have a reloading machine opening 121, and the reloading machine may reach around to an outer side surface of the frame 130 in order to attach to and lift the frame 130. According to another embodiment, the reloading machine may make an attachment with the frame 130 via a snap fit.
The operations performed during the third transportation state may be similar or the same as the reverse order of operations performed during the first transportations state.
The drive motor frame may have the first frame attachment 116 and thus a drive flange 120 may not be necessary to make an attachment between the drive assembly 110 and the frame 130.
The linear translator 117 may be a lead screw, the drive motor 111 joined with the linear translator 117 may make up a linear actuator or another device for translating linearly known per se. The linear translator 117 may have a threaded section. The drive motor 111 may be a brushless DC motor, such as a step motor. The drive unit may include a reduction gear to increase the torque.
The first frame attachment 116 may be a hole and the first frame attachment counterpart 135 may be a pin so that the frame 130 and the drive assembly 110 may be attached to one another, but also allow them to separate. The attachment between the first frame attachment 116 and the first frame attachment counterpart 135 may also be in the form of a temporary attachment known for attaching two parts. This attachment may be rigidly attached temporarily or may be where a surface of the drive flange 120 rests on a surface of the frame 130. This attachment may be made by a fastener which is unfastened before the second transportation state to allow the drive assembly 110 to be transported when the frame 130 is transported and to allow the drive assembly 110 to detach from the frame 130 during the second transportation state.
The instrumentation electrical connector 133 connects to the instrumentation electrical connector counterpart, in which the instrumentation electrical connector counterpart is located in the drive motor and instrumentation electrical connector counterpart 187. The drive assembly 110 may have the instrumentation opening 115 to allow these connections to meet, or may have more connectors and connector counterparts to provide electrical connections without the use of an opening. The instrumentation may comprise a plurality of sensors.
The cross section of the fuel unit 150 may have four sides or may be hexagonal or other known shapes for fuel units. Thus, the frame 130 and other components, for example the drive flange 120, may have an outer surface shape, such as a hexagonal shape, which may conform to the shape of the fuel unit 150.
The frame 130 lower section may be at a bottommost surface of the frame 130 or above the bottommost surface of the frame 130.
The subcomponents of the frame 130 may be manufactured as one solid component. The profile 131 may have a profile as illustrated in
The fuel and control system 100 may be powered by the connector grid plate 182, wires, or by other known methods.
The fuel unit upper section and the frame lower section 136 may be attached by a weld, fasteners, or other attachments known per se for attaching metal parts. The attachment between the fuel unit upper section and frame lower section 136 may be temporary where the attachment is secured during the normal operation of the nuclear reactor 170, the first transportation state, and the second transportation state and where the attachment can be detached and thus the frame can be reused and the fuel unit 150 taken to waste management.
It is to be understood that the embodiments of the invention disclosed are not limited to the particular structures, process steps, or materials disclosed herein, but are extended to equivalents thereof as would be recognized by those ordinarily skilled in the relevant arts. It should also be understood that terminology employed herein is used for the purpose of describing particular embodiments only and is not intended to be limiting.
Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment.
As used herein, a plurality of items, structural elements, compositional elements, and/or materials may be presented in a common list for convenience. However, these lists should be construed as though each member of the list is individually identified as a separate and unique member. Thus, no individual member of such list should be construed as a de facto equivalent of any other member of the same list solely based on their presentation in a common group without indications to the contrary. In addition, various embodiments and examples of the present invention may be referred to herein along with alternatives for the various components thereof. It is understood that such embodiments, examples, and alternatives are not to be construed as de facto equivalents of one another, but are to be considered as separate and autonomous representations of the present invention.
Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided, such as examples of lengths, widths, shapes, etc., to provide a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that the invention can be practiced without one or more of the specific details, or with other methods, components, materials, etc. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the invention.
While the forgoing examples are illustrative of the principles of the present invention in one or more particular applications, it will be apparent to those of ordinary skill in the art that numerous modifications in form, usage and details of implementation can be made without the exercise of inventive faculty, and without departing from the principles and concepts of the invention. Accordingly, it is not intended that the invention be limited, except as by the claims set forth below.
The verbs “to comprise” and “to include” are used in this document as open limitations that neither exclude nor require the existence of also un-recited features. The features recited in depending claims are mutually freely combinable unless otherwise explicitly stated. Furthermore, it is to be understood that the use of “a” or “an”, i.e. a singular form, throughout this document does not exclude a plurality.
| Number | Date | Country | Kind |
|---|---|---|---|
| 20225158 | Feb 2022 | FI | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/FI2023/050099 | 2/17/2023 | WO |
