WO2015097304A1

WO2015097304A1 - Method for the management of nuclear reactors, and corresponding management assembly

Info

Publication number: WO2015097304A1
Application number: PCT/EP2014/079348
Authority: WO
Inventors: Jean-Claude DELLINGER; Xavier Augustin
Original assignee: Societe Technique Pour L'energie Atomique
Priority date: 2013-12-27
Filing date: 2014-12-26
Publication date: 2015-07-02
Also published as: FR3016073A1

Abstract

The invention relates to a method comprising at least the following steps: production of said nuclear reactor (30, 99); transport of the nuclear reactor (30, 99), with the core (46) thereof, to the operations centre (64); transport of the nuclear reactor (30, 99), with the core thereof, from the operations centre (64) to a maintenance centre (84); and implementation, in the maintenance centre (84), of at least one operation out of a maintenance operation on the nuclear reactor (30, 99) or a core-refuelling operation (46).

Description

Nuclear reactor management method, and corresponding management set

The present invention generally relates to the management of nuclear reactors. More precisely, the invention relates, according to a first aspect, to a method for managing at least one nuclear reactor, the method comprising at least the following steps:

-Manufacturing said nuclear reactor in a manufacturing facility, the nuclear reactor comprising a vessel, a core disposed in the vessel, and at least one heat exchanger with a secondary side having a secondary fluid outlet;

transport of the nuclear reactor to an operating workshop having at least one receiving structure intended to keep the nuclear reactor in position and a secondary circuit;

attaching the nuclear reactor to the receiving structure and connecting the secondary fluid outlet of the nuclear reactor to the secondary circuit;

separation of the nuclear reactor and the receiving structure, separation of the secondary fluid outlet and the secondary circuit.

Such a method of operation is known from US Pat. No. 6,259,760. This method provides that the nuclear reactor at the end of its life is transferred to a final storage site with its fuel. The life of the reactor corresponds to that of the nuclear fuel. When the nuclear fuel is exhausted, the entire reactor is replaced and sent to a final storage site. This eliminates reactor outages for core refilling. The nuclear fuel of this reactor is enriched up to 20%, and the life of the reactor can be up to 20 years.

Such an operating method makes it possible to drastically reduce the interventions on the nuclear reactor in the operating workshop. However, it requires the use of highly enriched nuclear fuel.

In this context, the invention aims to provide an operating method that allows the use of enrichment nuclear fuel less than 5%, without increasing the interventions on the nuclear reactor in the operating room. .

To this end, the invention relates to an operating method of the aforementioned type, characterized in that it comprises the following steps:

- transport of the nuclear reactor from the production workshop to a maintenance workshop;

- Realization in the maintenance workshop of at least one of a maintenance operation of the nuclear reactor or a core reloading operation. Typically, the method further comprises a step of operating the nuclear reactor, between the fixing step and the separation step. During this step, the nuclear reactor supplies the secondary circuit with hot secondary fluid, for example to produce a useful energy such as steam, heat, electricity, etc.

In US 6,259,760, the use of a highly enriched fuel allows an increase in the life of the fuel, the latter becoming substantially equivalent to the service life of the reactor components.

In the invention, the maintenance of the nuclear reactor and the recharging of the core are carried out in a specialized workshop, far from the operating workshop. There is therefore no maintenance / reloading operation in the operating room.

In addition, providing a maintenance / reloading workshop makes it possible to use nuclear fuel whose enrichment is within the limit allowed for civil applications, namely 5%. The lifetime of this nuclear fuel is indeed lower than in US 6,259,760. The components of the nuclear reactor are subjected to less severe operating conditions than in US 6,259,760. life of these components is much longer than that of nuclear fuel. The provision of a core maintenance and reloading workshop makes it possible to reuse the main components of the nuclear reactor, well beyond the lifetime of a nuclear fuel refill. These components are for example the tank, the heat exchangers and all the internal equipment of the tank.

Because the maintenance and recharging operations of the core are performed in a dedicated maintenance workshop, and not in the operating room, the latter is not equipped with means to load and unload the fuel or to intervene on the nuclear reactor itself. Only limited means are provided for interventions on the secondary circuit. This secondary circuit is normally not contaminated. Thus, it is not necessary to intervene on active equipment in operation. There is therefore no need in the host country for personnel trained in the maintenance of nuclear materials.

In addition, because the maintenance of the nuclear reactor is carried out in the maintenance workshop, the production of radioactive waste in the operating room is almost nil. Similarly, the radioactive contamination of the operating facility is almost zero.

Thus, it is possible to produce nuclear energy in countries that do not have technical and regulatory infrastructures specially adapted for this purpose. Indeed, maintenance, fuel renewal, Waste treatment and conditioning are all performed in a centralized maintenance facility that can be located outside of this country. It is therefore not necessary for the host country to have, for example, radioactive waste disposal sites or associated regulations for waste treatment and / or maintenance and / or decommissioning. 'a nuclear central

The method of the invention may also have one or more of the following characteristics, considered individually or in any technically possible combination:

the method further comprises a step of operating the nuclear reactor, between the fixing step and the separation step.

- The nuclear reactor, at least during the operating step, is in permanent contact with a control facility that is not in the operating room, for example over the air.

at least some operating parameters of the nuclear reactor are remotely controlled by the control installation during the operating step, these operating parameters including, for example, the speed of rotation of the primary pumps, or the radiological activity primary fluid.

during the transport step of the nuclear reactor to an operating workshop and / or during the transport step of the nuclear reactor from the operating workshop to a maintenance workshop, the thermal power released by the heart is evacuated to a cold source.

- The nuclear reactor is automatically immersed in a cold source, in case of accident and / or aggression and / or natural disaster.

a plurality of reactors are manufactured at the manufacturing stage, the method comprising the following steps:

- Fixing a nuclear reactor of the plurality of nuclear reactors to the receiving structure and connecting the secondary fluid outlet of the nuclear reactor to the secondary circuit;

- operation of the nuclear reactor;

separation of the nuclear reactor and the reception structure, separation of the secondary fluid outlet of the nuclear reactor and the secondary circuit;

- Attaching another nuclear reactor of the plurality of nuclear reactors to the receiving structure and connecting the secondary fluid outlet of the other nuclear reactor to the secondary circuit;

- operation of the other nuclear reactor. a plurality of reactors are manufactured at the manufacturing stage, the operating workshop having at least first and second reception structures provided for holding the nuclear reactor in position, the secondary circuit having at least first and second interfaces secondary cells capable of being connected respectively to the nuclear reactor fixed to the first reception structure and to the nuclear reactor fixed to the second reception structure, the method comprising the following steps:

- Fixing a first nuclear reactor of the plurality of nuclear reactors to the first receiving structure and connecting the secondary fluid outlet of the nuclear reactor to the first secondary interface of the secondary circuit;

- operation of the first nuclear reactor;

separating the first nuclear reactor and the first receiving structure, separating the secondary fluid outlet from the first nuclear reactor and the first secondary interface of the secondary circuit;

- Attaching a second nuclear reactor of the plurality of nuclear reactors to the second receiving structure and connecting the secondary fluid outlet of the second nuclear reactor to the second interface of the secondary circuit;

- operation of the second nuclear reactor.

the step of attaching a second nuclear reactor to the second structure for receiving and connecting the secondary fluid outlet of the second nuclear reactor to the second interface of the secondary circuit takes place in masked time during the operating step of the first nuclear reactor.

the method comprises the following steps:

- manufacturing a plurality of nuclear reactors in a manufacturing facility, each nuclear reactor comprising a vessel, a core disposed in the vessel, and at least one heat exchanger with a secondary side having a secondary fluid outlet;

transporting the nuclear reactors each to one of a plurality of operating workshops, each operating workshop having at least one receiving structure designed to hold the nuclear reactor in position and a secondary circuit;

in each operating workshop, attaching the nuclear reactor to the receiving structure and connecting the secondary fluid outlet of the nuclear reactor to the secondary circuit;

- in each operating workshop, operation of the nuclear reactor; in each operating workshop, separation of the nuclear reactor and the receiving structure, separation of the secondary fluid outlet and the secondary circuit;

- transportation of the nuclear reactor from each operating site to a single maintenance shop;

- Realization on each of the nuclear reactors in the single maintenance workshop of at least one of a maintenance operation or a reloading operation of the heart.

the maintenance operation of the nuclear reactor comprises the deconstruction of the nuclear reactors into a plurality of main components, and the reuse of at least two of the main components in at least two other nuclear reactors, the main components comprising the vessel, the heat exchanger, clusters of controls, a control mechanism clusters of controls.

According to a second aspect, the invention relates to a management assembly of at least one nuclear reactor, the assembly comprising at least:

- At least one nuclear reactor comprising a vessel, a core disposed in the vessel, and a heat exchanger with a secondary side having a secondary fluid outlet;

a workshop for manufacturing said nuclear reactor;

- At least one operating workshop having at least one receiving structure provided to maintain in position the nuclear reactor and a secondary circuit;

a device for transporting the nuclear reactor from the manufacturing workshop to the operating workshop;

a device for fixing the nuclear reactor to the reception structure and a device and for connecting the secondary fluid outlet of the nuclear reactor to the secondary circuit;

- a device for operating the nuclear reactor;

a device for separating the nuclear reactor and the receiving structure, and a device for separating the secondary fluid outlet and the secondary circuit;

a maintenance workshop arranged for carrying out at least one of a maintenance operation of the nuclear reactor or a recharging operation of the core;

a device for transporting the nuclear reactor from the operating workshop to a maintenance workshop.

This operating set is intended to implement the method described above. The management set of the invention may also have one or more of the following characteristics, considered individually or in any technically possible combination:

- The nuclear reactor comprises a containment chamber, wherein is disposed at least the vessel.

- A heat exchange fluid is disposed between the containment chamber and the vessel.

the nuclear reactor comprises a device for cooling the core independent of the secondary circuit, designed to evacuate to a cold source the residual heat released by the core when the nuclear reactor is stopped, for example when the nuclear reactor is at edge of the nuclear reactor transport device from the operating workshop to a maintenance workshop and / or when the nuclear reactor is on board the nuclear reactor transport device from the manufacturing plant to the operating workshop.

the receiving structure comprises a shape that can be filled with water.

- the nuclear reactor transport device from the operating workshop to a maintenance workshop and / or the nuclear reactor transport device from the production workshop to the operating workshop are boats arranged to cause immersion of the nuclear reactor in case of accident and / or aggression and / or natural disaster.

the management unit comprises a plurality of identical nuclear reactors.

the operating workshop has at least first and second reception structures designed to maintain the nuclear reactor in position, the secondary circuit having at least first and second secondary interfaces that can be connected respectively to the nuclear reactor maintained in the reactor; first receiving structure and the nuclear reactor maintained in the second receiving structure.

the management assembly comprises a plurality of operating workshops, each operating workshop having at least one receiving structure designed to hold the nuclear reactor in position and a secondary circuit, the assembly comprising a single maintenance workshop arranged for the realization on each of the nuclear reactors of at least one of a maintenance operation or a reloading operation of the core.

- The management set includes a control facility, which is not in the operating room, adapted to remotely control the nuclear reactor connected to the steam circuit in the operating room. Other advantageous features of the invention will be accompanied by the detailed description which is given below, by way of indication and in no way limiting, with reference to the appended figures, among which:

- Figure 1 is a simplified schematic representation of the means for operating the method of the invention;

- Figure 2 is a simplified schematic representation of a nuclear reactor of the type used in the method of the invention.

- Figure 3 is a simplified schematic representation of the nuclear reactor located in the operating room;

- Figure 4 is a schematic representation of the various steps of the method of the invention;

- Figure 5 is a view similar to that of Figure 3, illustrating an operating room to implement the method of Figure 6; and

- Figure 6 is a view similar to that of Figure 4, for a variant of the method of the invention.

The method of the invention is implemented by a set of means shown in Figures 1 to 3. This set comprises the following elements:

- A plurality of nuclear reactors 30, each nuclear reactor comprising a tank 31, a core 46 disposed in the tank 31 and at least one heat exchanger 48 with a secondary side having a secondary fluid outlet 52 (Figure 2);

a manufacturing workshop 62 of said nuclear reactors 30;

a plurality of operating workshops 64, each operating workshop 64 having at least one receiving structure 68 provided for holding in position one of the nuclear reactors 30, and a secondary circuit 70 (FIG. 3);

a device 66 for transporting the nuclear reactors 30 each from the manufacturing workshop 62 to one of the operating workshops 64,

- A single maintenance workshop 84, arranged for the realization on each of the nuclear reactors 30 of at least one of a maintenance operation or a reloading operation of the core 46;

a device 86 for transporting the nuclear reactors 30 from each operating workshop 64 to the single maintenance workshop 84.

Nuclear reactors are generally referred to as NSSS in English

(Nuclear Steam Supply System). They can be of any type: PWR, BWR, or any other type. Each reactor has a thermal power typically between 50 and 1000 megawatts thermal, for example between 100 and 600 megawatts thermal. For example, the nuclear reactor has a power of 450 megawatts thermal about. The power of the nuclear reactor is limited by its transportability, which itself depends on its mass, its size and the means of transport and handling available for transport to the workshop or maintenance.

In the following description, the nuclear reactors are of the PWR type, the secondary fluid being water exiting in the form of steam from the outlet 52.

The nuclear reactors are all identical. They are manufactured in series. Each nuclear reactor 30 is of the type shown in FIG.

Each nuclear reactor 30 comprises a frame 128 on which the tank 31 is rigidly fixed, and a containment enclosure 130, in which is disposed at least the tank 31. This enclosure forms a sealed barrier around the tank 31. The enclosure 130 comprises a removable upper base 132. The enclosure is rigidly fixed to the frame 128. It is for example metallic.

The frame 128 constitutes the lower part of the nuclear reactor. It supports the nuclear reactor. The nuclear reactor rests on its support surface via the frame 128.

The tank 31 comprises a lower portion 32 and a lid 34. The lower portion 32 itself comprises a shell 36 closed at a lower end by a lower convex bottom 38. The shell 36 delimits opposite the bottom 38 an opening 39 closed by the lid 34. The opening 39 allows the introduction and exit of the internal equipment and nuclear fuel assemblies of the tank.

The lower part 32 comprises around the opening a flange 40, the cover having a counter flange 42. The lower part and the cover are secured to one another inviolably, via the flange 40 and The cover 34 and the lower part 32 can be separated from each other only in the dedicated service shop 84, in a suitable environment and with the aid of specially designed tools. for this reason. Such an operation requires the use of specific means controlled remotely. Conventional means - such as screwdrivers - can not be used for this purpose. This ensures that new or used fuel can not be diverted during transport (non-proliferation).

The core 46 comprises a plurality of nuclear fuel assemblies, arranged vertically, and held in position by equipment provided for this purpose. This equipment is known and will not be detailed here.

In the example shown, the heat exchanger 48 is annular. It is placed for example in the tank. Alternatively, the heat exchanger is placed outside the vessel, for example in the containment enclosure 130. In this case, the The primary side of the heat exchanger is connected by conduits (loops) to the tank, so as to allow the circulation of the primary fluid between the tank and the primary side of the heat exchanger.

The heat exchanger 48 is here a steam generator. It comprises a primary side in which circulates the primary fluid of the nuclear reactor. The primary side is in thermal contact with the secondary side, in which circulates the secondary fluid of the reactor. The heat exchanger 48 is placed inside the tank. It adjoins the ferrule 36.

The secondary side of the heat exchanger is connected to a secondary fluid inlet 50 opening out of the confinement enclosure 130, and to a vapor outlet 52 also opening out of the enclosure of containment 130.

The primary fluid is water, with appropriate chemical additives. It circulates inside the tank 31. It heats up through the core 46, then flows through the primary side of the heat exchanger 48 by yielding its heat to the secondary fluid. It then returns to the heart 46. The circulation of the primary fluid inside the tank is channeled by partitions arranged appropriately.

The secondary fluid is also water, with appropriate chemical additives.

The reactor also comprises clusters 54 for controlling the reactivity of the core 46. These clusters are typically arranged in the volume 56 delimited internally by the annular heat exchanger 48. These clusters are of known type and will not be described in more detail here. The reactor 30 also comprises a control cluster control mechanism 54. This mechanism is arranged to control the displacement of the clusters 54 in the vertical direction so as to make them penetrate inside the core 46. command is of known type and will not be detailed here.

The reactor 30 also comprises a control device 60, connected inter alia to the mechanism 58 for controlling the control clusters. The device 60 is connected to the ends of the lines for electrically powering the actuators of the control mechanism 58. It is connected to the ends of the lines for controlling the mechanism 58. It is also connected to the ends of the instrumentation lines of the tank. 30. This instrumentation comprises, for example, temperature probes, pressure probes, neutron flux measurement probes, probes for determining the respective positions of the different clusters 54, etc.

A heat exchange fluid is disposed between the confinement enclosure 130 and the tank 31. This fluid is for example water. The reactor 30 is designed such that the main components are interchangeable standard modules. In other words, it is designed so that it is easy, once removed the upper bottom 132 of the containment and the cover 34 of the tank, to introduce or leave the enclosure 130 the different components of the nuclear reactor.

The reactor thus consists of a set of components and subcomponents designed as simple geometry objects. Components and subcomponents are remotely assembled and unassemblable. Each component and subcomponent is equipped with its own means of protection and support. Interface points between components and subcomponents are standardized and further designed to guide and position process interfaces.

These components are for example the lower part 32 of the tank, the heat exchanger 48, the control rod control mechanism 58 54, the clusters 54 themselves, the nuclear fuel assemblies of the core 45, the primary pumps etc.

The fact that these components are interchangeable standard modules makes it possible to speed up and simplify the production at the nuclear reactor line. It also facilitates maintenance operations. In particular, it is possible to easily replace a module that has reached the end of its life, this making it possible to reduce the production of ultimate waste during maintenance operations, as well as during deconstruction at the end of its life. You can also easily replace an old design module with a more powerful module. This facilitates the upgrading of installations and optimally deals with obsolescence and improved performance, particularly through technological advances in components.

This contributes to reducing the cost and time of construction and commissioning of nuclear reactors. This reduction is achieved because of the modular design of the nuclear reactor, the standardization of components, and the mass production of these components. Similarly, the cost of reactor maintenance and management of nuclear fuel assemblies is also reduced.

The transport device 66 is of any type suitable for transporting the nuclear reactor. Depending on the location of the operating facility 64, the transport is carried out by sea and / or fluvial and / or terrestrial.

The nuclear reactor 30 is transported in the form of a subset already assembled, ready to be installed and connected in the operating workshop. In particular, the nuclear fuel assemblies are already in the tank at the time of transport. No maintenance or deconstruction of the reactor takes place in the operating room, and more particularly outside the maintenance and deconstruction workshop and the manufacturing workshop.

The transport device preferably comprises at least one boat. The boat is typically a barge, motorized or not. As shown in Figure 1, it comprises a shim 142 in which is disposed the nuclear reactor.

This is locked in position by means not shown. For example, the frame 128 of the nuclear reactor is rigidly fixed to the floor of the hold.

The boat comprises means for filling the wedge 142 with water, so as to facilitate the cooling of the reactor.

The transport device 66 is arranged to cause the immersion of the nuclear reactor automatically in case of accident, and / or aggression, and / or natural disaster.

It should be noted that transport by land is possible only if a cold source is available for the cooling of the core, in a continuous manner.

Advantageously, the transport device 66 is equipped with means for recovering and recovering the residual heat released by the core.

The exploitation workshop 64 is represented very schematically in FIG.

3.

The receiving structure 68, in the example shown, has a shape 144 filled with water.

The 144 form is a basin. Alternatively, the form 144 is a barge, floating on a volume of water. This volume of water is a sea, a river, a basin, etc.

The frame 128 of the nuclear reactor is placed on the bottom 146 of the form 144, and is rigidly fixed thereto in a reversible manner. It is possible to provide other structures to secure the upper parts of the nuclear reactor to shape.

The nuclear reactor is thus immersed permanently in the water filling the form 144.

This water ensures the cooling of the containment enclosure, by natural convection, especially in case of loss of the primary or secondary circuit.

In a variant, the nuclear reactor is not immersed permanently in the form. Immersion is automatically caused in case of accident and / or aggression and / or natural disaster.

The secondary circuit 70 is connected to an alternator turbine assembly 72. It comprises a condenser 74 and a circulation pump 76. Upstream, the alternator turbine assembly 72 is connected via a steam interface 78 to the outlet of secondary fluid 52 of the reactor. Downstream, the pump 76 is connected through a feedwater interface 80 to the secondary fluid inlet 50 of the reactor.

The interfaces 78 and 80 are, for example, flanges designed to be connected in a sealed manner to the outlet 52 and to the inlet 50.

All connections to power supplies on the surrounding infrastructure are fast, safe and remote, whether for connections of water, steam, electricity, compressed air, etc.

Alternatively, the secondary fluid produced by the nuclear reactor is not used to produce electricity, but is used for heating, to produce hydrogen, or for any other suitable use.

The workshop 64 is equipped in particular:

- Tooling 80a for fixing the nuclear reactor 30 to the receiving structure 68;

tooling 80b making it possible to connect the input 50 and the output 52 to the interfaces 80 and 78;

- Tooling 80c for separating the nuclear reactor 30 of the receiving structure 68;

of tools 80d making it possible to separate the inlet 50 and the outlet 52 from the interfaces 80 and 78.

These tools are of known type, and are represented symbolically in FIG.

The operating workshop 64 is still equipped with all the equipment 80e necessary to operate the nuclear reactor, in particular a building around the reactor 30, a tertiary circuit for discharging into the atmosphere the heat recovered at least at the level of the condenser 74 etc.

The operating workshop 64 comprises in particular a control system 82 and a power supply 83, designed to be connected to the control device 60 of the tank.

Once the connection is made, the electrical power necessary for the operation of the actuators and the instrumentation of the nuclear reactor 30 is supplied by the power supply 83.

However, the nuclear reactor 30 includes an energy storage device, designed to supply backup to the control device 60 of the tank in case of loss of the power supply 83. This storage device is for example a battery . Furthermore, information can then be exchanged between the control system 82 of the workshop and the control device 60 of the nuclear reactor. More specifically, the control device 60 transmits to the control system 82 all the information necessary for the effective efficiency of the evacuation and recovery of the energy produced by the nuclear reactor. The command control device 60 receives from the control system 82 of the workshop the information necessary to trigger the safety of the nuclear reactor, in the event of an incident, aggression or natural disaster, in particular with a view to triggering automatic disconnection of the nuclear reactor.

The device 86 for transporting the nuclear reactor from the operating workshop 64 to the maintenance workshop is typically one that provides transportation between the production workshop and the operating workshops. Thus, the same device provides transport from the operating room 64 to the maintenance workshop, and from the manufacturing workshop and operating workshops. Alternatively, there are two different devices that provide transport from the operating room 64 to the maintenance shop, and from the manufacturing workshop and operating workshops.

Each nuclear reactor 30 comprises a device 140 for cooling the core independent of the secondary circuit 70, provided for discharging to a cold source the residual heat released by the core 54 when the secondary circuit can not evacuate the residual heat. This is the case when the reactor is at a standstill or is not connected to the secondary circuit.

This cold source is a volume of water.

When the nuclear reactor is on board the transport devices 66, 86, the volume of water is the sea or the river on which the transport device is navigating.

When the nuclear reactor is in the operating room, the volume of water corresponds to the 144 form.

The device 140 is arranged between the confinement enclosure 130 and the tank 31. The device 140 comprises a heat exchange means between the primary fluid of the nuclear reactor and a stream of water taken from the volume of water. The flow of water circulates inside the confinement enclosure 130. The primary fluid transfers its heat to the flow of water, directly or indirectly through a loop through which a heat transfer fluid circulates. The stream of warmed water is released into the water volume.

The maintenance workshop 84 is equipped with all the means necessary to carry out maintenance of the main equipment of the nuclear reactor, and the operation of recharging the core with fresh nuclear fuel assemblies. He is equipped in addition, to carry out the first commissioning of the new nuclear reactors, before transport to the workshop.

Preferably, the dismantling of the end-of-life nuclear reactors and their components is carried out in the maintenance workshop 84. The operating workshop 64 therefore does not include any means for carrying out this dismantling.

Preferably, the nuclear waste resulting from the maintenance of the nuclear reactors 30 is packaged in the maintenance workshop 84. The operating workshop 64 does not include means for packaging waste.

More specifically, the maintenance workshop 84 comprises:

a first zone 150 dedicated to receiving and commissioning the new nuclear reactors;

a second zone 152 dedicated to the maintenance of the main equipment of the reactor, and to the recharging of the core in assemblies of fresh fuels;

a third zone 154 dedicated to the dismantling of end-of-life nuclear reactors and their components.

The first zone 150 is equipped with all the means to carry out the first loading of nuclear fuel, to check and qualify the nuclear reactor before transport to the operating workshop. It comprises in particular a secondary circuit test, a complete set of control and monitoring of the reactor, and test means, for example for testing the pressure resistance of the containment. Thus, the first zone is equipped to test the operation of the hot nuclear reactor, when it is connected to the secondary circuit test.

The second zone 152 is equipped with means for removing the upper bottom 132 of the enclosure 130, and for separating the cover 34 from the lower part 32 of the tank. It is also equipped to extract and insert the internal equipment inside the tank 31, through the opening 39 and to unload and recharge the nuclear fuel assemblies in the tank.

The second zone 152 is equipped to replace defective or end-of-life internal equipment and to replace depleted nuclear fuel assemblies with fresh nuclear fuel assemblies.

The second and third zones 152 and 154 are equipped with means for conditioning the radioactive waste generated by these maintenance or reloading operations. This waste may be the internal equipment of the reactor, or consumables used during maintenance operations.

After conditioning according to the standards in force, the packaged waste is sent to a storage site 90 (Figure 1). The third zone 154 is still equipped to dismantle, that is to say deconstruct, the reactors 30 at the end of their life. For example, the tank and other internal equipment are cut, packaged and sent to the storage site 90.

The maintenance workshop 84 thus comprises means of containment and remote operations, making it possible to intervene on the reactor vessels containing the spent fuel assemblies. Preferably, the special tools, the means of maintenance and protection, the means of control, inspection, tests (including the steam circuit), control command, the treatment of nuclear waste, storage, security and guarding are shared for the three zones.

It is possible, in the second and third zones 152 and 154, to completely deconstruct a nuclear reactor 30 and to recover its main components. All or part of these components can be reused in several other nuclear reactors 30. Thus, new reactors can be formed by reusing components from one or more other nuclear reactors 30, possibly adding new components.

Typically, the maintenance workshop 84 is in the immediate vicinity of the production workshop 62.

As can be seen in FIG. 1, the reactors installed in the various operating workshops 64 can be piloted from a single piloting installation 92, common for all the reactors 30. The control installation 92 is not in operation. General is located in an operating workshop 64. It is located for example remote workshops 64. It can be installed in another country or even on another continent. For example, the control installation is installed at the same place as the production workshop 62 or the maintenance workshop 84.

The control installation 92 is equipped with means 94 for communication with each of the nuclear reactors 30. Similarly, each nuclear reactor 30 is equipped with means 96 for communicating with the control installation 92. Typically, the control installation 92 communicates with the control device 60 of the nuclear reactor via the means 96. The communication is wireless, with redundancy wired.

The nuclear reactor 30 receives commands from the control installation 92 and sends information relating to the operating parameters of the nuclear reactor 30 to the control installation 92.

This is particularly convenient, especially for countries that do not have trained personnel for the operation of nuclear reactors. Thus, at least some operating parameters of the nuclear reactor 30 are controlled remotely by the control facility 92 during the operation of the nuclear reactor. More precisely, the thermal power delivered by the nuclear reactor is controlled from the operating workshop. All other operating parameters are controlled from the pilot workshop. Among these operating parameters controlled from the pilot shop, we find, in particular, the speed of the primary pumps, the level of radiological activity in the primary fluid, the level of the safety covers of the primary circuit, etc.

The nuclear reactor 30 sends to the piloting workshop 92 information:

- on the radiological state of the nuclear fuel, of the primary fluid,

on the state of different organs of the nuclear reactor, for example the primary pumps, the pressurizer, etc.,

- relating to the monitoring of the state of the various components of the nuclear reactor, in particular the wear of the various moving elements.

In another embodiment, the nuclear reactor 30 is controlled by the control unit 92 permanently and remotely for the duration of its operation, including during its transport phases. Alternatively, the nuclear reactor 30 is continuously piloted for the duration of its operation by various piloting installations 92.

The control installation 92 ensures continuous control of the safety level of the reactor 30 and makes it possible to keep the operating personnel of the reactor 30 at a distance.

The operating method of the invention is shown in FIG. 4. It comprises the following steps:

step 10: manufacture of nuclear reactors 30 in the production workshop 62; step 12: transportation of the nuclear reactors 30 each to one of the operating workshops 64;

step 14: in each operating workshop 64, fixing the nuclear reactor 30 to the structure of the reception 68 and connecting the secondary fluid outlet 52 of the nuclear reactor 30 to the secondary circuit 70;

step 16: in each operating workshop 64, operating the nuclear reactor 30, typically to produce steam;

step 18: in each operating workshop 64, separation of the nuclear reactor 30 and the receiving structure 68, separation of the secondary fluid outlet 52 and the secondary circuit 70;

step 20: transport of the nuclear reactor 30 from each operating workshop

64 to the single maintenance shop 84; step 22: production on each of the nuclear reactors 30 in the single maintenance workshop 84 of at least one of a maintenance operation or a recharging operation of the core 46.

The method may further comprise a step 24 of dismantling the nuclear reactors 30 in the maintenance workshop 84.

The nuclear reactor 30 operates continuously and safely from its start-up in its manufacturing workshop until its upgrade or dismantling in the maintenance workshop 84, including the stage of operation in the workshop operating conditions, including during the transport phases. This ensures that part of the nuclear reactor can not be diverted during these stages and transport (non-proliferation).

In step 10, the nuclear reactor is assembled in the manufacturing workshop 62, visible in FIG. The tank 31 is introduced into the containment enclosure 130. The tank and the containment chamber are fixed to the frame 128. The internal equipment of the tank is put in place.

The nuclear reactor is then transferred to the first zone 150 of the maintenance workshop 84. The core 46 is placed inside the tank 31, and the nuclear reactor 30 is connected to the secondary circuit of the test. The nuclear reactor 30 then undergoes its first commissioning, as well as qualification tests.

In step 12, the various nuclear reactors 30 are transported in the assembled state to the various operating workshops 64. Typically, the nuclear reactors 30 are produced one after the other, and are therefore transported one after the other. others until the operating workshops that are to receive them. Each nuclear reactor 30 is cooled by the cooling device 140 during transport.

It should be noted that the receiving structure of each operating workshop can be built in masked time during the reactor manufacturing, since the complete manufacture of the reactor is carried out far from the operating workshop. This reduces the time and cost of construction and commissioning.

In step 16, the nuclear reactors 30 are remotely controlled, from the control installation 92, by one or more teams trained in the control of the reactor 30. The steam produced is sent into the secondary circuit 70, and allows useful energy production.

In stages 14 and 18, the nuclear reactor is respectively mounted in the operating workshop and disassembled, by teams of operators, using tools 80a / b / c / d.

In step 20, the reactor 30 is transported in one piece. The heart 46 remains inside the tank 31 during transport, as well as the various equipment such as the heat exchanger 48 or the cluster control mechanism 58. The nuclear reactor 30 is cooled by the cooling device 140 during transport.

In step 22, the maintenance and reloading operations for the reactors installed in the various operating workshops 64 are all carried out in the same maintenance workshop 84. This therefore serves a large number of operating workshops. 64.

In particular, a nuclear reactor can be completely deconstructed and its components used to constitute other nuclear reactors.

As illustrated in Figure 4, after the completion of the maintenance and reloading operation, the nuclear reactor 30 is returned to an operating workshop 64. This workshop may be the one where it was previously installed, or another.

The process can be implemented with a single nuclear reactor serving a single operating room. However, it is particularly well suited for operating a plurality of nuclear reactors, installed in a plurality of operating workshops distributed in different locations.

Thus, it is possible to limit the interruptions of supply of hot secondary fluid in each operating workshop by standard exchange of the nuclear reactor.

On the other hand, when a large number of nuclear reactors are produced at the chain, it is possible to reduce production costs.

In addition, it is possible to provide a fleet of nuclear reactors, located in various workshops, and whose maintenance is provided in a single central workshop. The farm workshops can be located in different parts of the same country and / or in different countries. A nuclear reactor, after use in a given operating room, is returned to the maintenance shop for maintenance and / or reloading of the core. It is then returned either in the same maintenance workshop or in another.

This significantly reduces maintenance costs, and the costs associated with the core reloading operation, since only one set of maintenance / refueling equipment for nuclear fuel assemblies is used for a whole fleet of nuclear reactors. Similarly, it is the same teams of operators who carry out core maintenance / reloading operations for the entire fleet of nuclear reactors.

Figures 5 and 6 illustrate a variant of the operating method of the invention, and an operating room particularly suitable for the implementation of this method. Only the points by which this process and this operating workshop differ from those of Figures 1 to 4 will be detailed below. Identical elements or the same function will be designated with the same references.

As shown in FIG. 5, the operating workshop comprises, in addition to the first receiving structure 68, a second receiving structure 98, designed to hold a second nuclear reactor 99 in position. The structure 98 comprises a shape, identical to form 144 of structure 68.

In addition to the interfaces 78 and 80, the steam circuit 70 includes a second steam interface 100 and a second food water interface 102. The interface 100 is shunted parallel to the interface 78. Similarly, the interface 102 is shunted relative to the interface 80, parallel thereto. When the second nuclear reactor 99 is in place in the second receiving structure 98, the second steam interface 100 is connectable to the secondary fluid outlet 104 of the second nuclear reactor. The interface 102 may be connected to the secondary fluid inlet 106 of the second nuclear reactor. The steam circuit 70 further comprises a set of valves 108, 1 10, 1 12, 1 14. The valves 108 and 1 12 make it possible to connect the alternator turbine assembly 72 selectively, upstream, or at the fluid outlet secondary of the first reactor is at the secondary fluid outlet of the second reactor. The valves 1 10 and 1 14 make it possible to selectively connect the discharge of the pump 76 either to the secondary fluid inlet of the first reactor or to the secondary fluid inlet of the second reactor.

To limit the interruptions of supply of secondary fluid when it is desired to return the first reactor 30 to the maintenance and recharging workshop 84, the following steps are performed in masked time, during step 16 of operation of the first nuclear reactor ( see Figure 6):

step 1 16: transport of the second nuclear reactor 99, for example from the maintenance workshop 84 to the operating workshop 64;

step 1 18: securing the second nuclear reactor 99 to the second receiving structure 98, and connecting the secondary fluid outlet 104 and the secondary fluid inlet 106 respectively to the interfaces 100 and 102.

Once these steps have been performed, it is possible to interrupt the operation of the first nuclear reactor 30. The valves 108 and 1 10 are closed and the valves 1 12 and 1 14 are open, so as to connect the turbine-generator assembly 72 to the second nuclear reactor 99. Switching from one reactor to another is extremely fast, so that the production losses are minimal. This ensures the continuity of energy supply on the operating room. After the end of the operation step of the second reactor 99 (step 120), the second reactor 99 is separated from the second receiving structure 98, the secondary fluid outlet 104 is separated from the interface 100, and the second secondary fluid inlet 106 is separated from the interface 102 (step 122). The second nuclear reactor is then returned to the maintenance workshop 84 for maintenance or reloading of the core. Another nuclear reactor is set up on the first receiving structure 68 during the operating step 120. It is put into service immediately after stopping the second nuclear reactor.

Due to the duplication of the receiving structure and the interfaces with the secondary circuit, it is thus possible to shorten as much as possible the interruption of supply of hot secondary fluid in the operating workshop. The second nuclear reactor takes over the first virtually as soon as it is stopped.

Claims

1. - Method for managing at least one nuclear reactor, the method comprising at least the following steps:

- Manufacture of said nuclear reactor (30, 99) in a manufacturing facility (62), the nuclear reactor (30, 99) comprising a vessel (31), a core (46) disposed in the vessel (31), and at least one a heat exchanger (48) with a secondary side having a secondary fluid outlet (52, 104);

- transporting the nuclear reactor (30, 99) to an operating workshop (64) having at least one receiving structure (68, 98) arranged to hold the nuclear reactor (30, 99) in position and a secondary circuit (70);

- fixing the nuclear reactor (30, 99) to the receiving structure (68, 98) and connecting the secondary fluid outlet (52, 104) of the nuclear reactor to the secondary circuit (70);

- separating the nuclear reactor (30, 99) and the receiving structure (68, 98), separating the secondary fluid outlet (52, 104) and the secondary circuit (70);

characterized in that the method further comprises the following steps:

- transporting the nuclear reactor (30, 99) from the operating workshop (64) to a maintenance workshop (84);

- Realization in the maintenance workshop (84) of at least one of a maintenance operation of the nuclear reactor (30, 99) or a recharging operation of the core (46).

2. - Method according to claim 1, characterized in that it further comprises a step of operating the nuclear reactor (30, 99) between the fixing step and the separation step.

3. - Method according to claim 2, characterized in that the nuclear reactor (30, 99), at least during the operating step, is in permanent connection with a control installation (92) which is not in the operating room (64), for example over the air.

4. A method according to claim 3, characterized in that at least some operating parameters of the nuclear reactor (30, 99) are remotely controlled by the control installation (92) during the operating step, these operating parameters including, for example, the speed of rotation of the primary pumps or the radiological activity of the primary fluid.

5.- Method according to any one of the preceding claims, characterized in that during the step of transporting the nuclear reactor (30, 99) to a workshop (64) and / or during the transport step of the nuclear reactor (30, 99) from the operating workshop (64) to a maintenance workshop (84), the thermal power generated by the heart is evacuated to a cold source.

6. - Method according to any one of the preceding claims, characterized in that the nuclear reactor (30, 99) is automatically immersed in a cold source, in case of accident and / or aggression and / or natural disaster .

7. - Process according to any one of the preceding claims, characterized in that a plurality of reactors (99) are manufactured in the manufacturing step, the method comprising the following steps:

- attaching a nuclear reactor (30) of the plurality of nuclear reactors to the receiving structure (68) and connecting the secondary fluid outlet (52) of the nuclear reactor (30) to the secondary circuit (70);

- operation of the nuclear reactor (30);

separating the nuclear reactor (30) and the receiving structure (68), separating the secondary fluid outlet (52) from the nuclear reactor (30) and the secondary circuit (70);

- Attaching another nuclear reactor (30) of the plurality of nuclear reactors to the receiving structure (68) and connecting the secondary fluid outlet (52) of the other nuclear reactor (30) to the secondary circuit (70). );

- operation of the other nuclear reactor (30).

8. - Method according to any one of the preceding claims, characterized in that a plurality of reactors (30, 99) are manufactured at the manufacturing step, the operating workshop (64) having at least first and second receiving structures (68, 98) arranged to hold the nuclear reactor (30, 99) in position, the secondary circuit (70) having at least first and second secondary interfaces (78, 100) connectable respectively at the nuclear reactor (30) attached to the first receiving structure (68) and the nuclear reactor (99) attached to the second receiving structure (98), the method comprising the steps of:

- Attaching a first nuclear reactor (30) of the plurality of nuclear reactors to the first receiving structure (68) and connecting the secondary fluid outlet (52) of the nuclear reactor (30) to the first secondary interface (78). ) of the secondary circuit (70);

- operation of the first nuclear reactor (30);

- separating the first nuclear reactor (30) and the first receiving structure (68), separating the secondary fluid outlet (52) from the first nuclear reactor (30) and the first secondary interface (78) of the secondary circuit ( 70); - attaching a second nuclear reactor (99) of the plurality of nuclear reactors to the second receiving structure (98) and connecting the secondary fluid outlet (104) of the second nuclear reactor (99) to the second interface (100) ) of the secondary circuit (70);

- operation of the second nuclear reactor (99).

9. - Method according to claim 8, characterized in that the step of attaching a second nuclear reactor (99) to the second receiving structure (98) and connecting the secondary fluid outlet (104) of the second nuclear reactor (99) at the second interface (100) of the secondary circuit (70) takes place in masked time during the operating step of the first nuclear reactor (30).

10. - Method according to any one of the preceding claims, characterized in that it comprises the following steps:

- manufacture of a plurality of nuclear reactors (30, 99) in a manufacturing facility (62), each nuclear reactor (30, 99) comprising a tank (31), a core (46) disposed in the tank (31) and at least one heat exchanger (48) with a secondary side having a secondary fluid outlet (52, 104);

transporting the nuclear reactors (30, 99) each to one of a plurality of operating workshops (64), each operating workshop (64) having at least one receiving structure (68, 98); ) provided to maintain in position the nuclear reactor (30, 99) and a secondary circuit (70);

- in each operating workshop (64), fixing the nuclear reactor (30, 99) to the receiving structure (68, 98) and connecting the secondary fluid outlet (52, 104) of the nuclear reactor (30, 99 ) to the secondary circuit (70);

- in each operating workshop (64), operation of the nuclear reactor (30, 99);

in each operating workshop (64), separating the nuclear reactor (30, 99) and the receiving structure (68, 99), separating the secondary fluid outlet (52, 104) and the secondary circuit (70); );

- transporting the nuclear reactor (30, 99) from each operating shop (64) to a single maintenance shop (84);

- performing on each of the nuclear reactors (30, 99) in the single maintenance shop (84) at least one of a maintenance operation or a reloading operation of the heart (46).

1 1. - Process according to any one of the preceding claims, characterized in that the maintenance operation of the nuclear reactor (30, 99) comprises the deconstruction of the nuclear reactors into a plurality of main components, and the reuse of at least two of the main components in at least two other nuclear reactors, the main components including the vessel (31), the heat exchanger (48), control clusters (54), a mechanism (58) of controlling clusters of controls (54).

12.- Management set of at least one nuclear reactor, the assembly comprising at least:

at least one nuclear reactor (30, 99) comprising a tank (31), a core (46) disposed in the tank (31), and a heat exchanger (48) with a secondary side having a secondary fluid outlet ( 52, 104);

a workshop (62) for manufacturing said nuclear reactor;

- At least one operating workshop (64) having at least one receiving structure (68, 98) provided to maintain in position the nuclear reactor (30, 99) and a secondary circuit (70);

- a device (66) for transporting the nuclear reactor (30, 99) from the manufacturing facility (62) to the operating workshop (64);

a device (80a) for fixing the nuclear reactor (99) to the receiving structure (68, 98) and a device (80b) for connecting the secondary fluid outlet (52, 104) of the nuclear reactor (30); , 99) to the secondary circuit (70);

a device (80) for operating the nuclear reactor (30, 99);

a device (80c) for separating the nuclear reactor (30, 99) and the receiving structure (68, 98), and a device (80d) for separating the secondary fluid outlet (52, 104) and the circuit secondary (70);

a maintenance workshop (84) arranged for carrying out at least one of a maintenance operation of the nuclear reactor (30, 99) or a recharging operation of the core (46);

- A device (86) for transporting the nuclear reactor (30, 99) from the operating workshop (64) to a maintenance workshop (84).

13. - assembly according to claim 12, characterized in that the nuclear reactor (30, 99) comprises a containment enclosure (130), wherein is disposed at least the vessel (31).

14. - assembly according to claim 13, characterized in that a heat exchange fluid is disposed between the containment enclosure (130) and the vessel (31).

15. - assembly according to any one of claims 12 to 14, characterized in that the nuclear reactor (30, 99) comprises a device (140) for cooling the core (46) independent of the secondary circuit (70), provided for evacuating to a cold source the residual heat released by the core (46) when the nuclear reactor (30, 99) is at a standstill, for example when the nuclear reactor (30, 99) is on board the nuclear reactor transport device (86) (30, 99) from the operating workshop (64) to a workshop (84) and / or when the nuclear reactor is on board the nuclear reactor transport device (66) (30, 99) from the manufacturing facility (62) to the operating facility (64). ).

16. - assembly according to any one of claims 12 to 15, characterized in that the receiving structure (68) comprises a form (144) may be filled with water.

17. - assembly according to any one of claims 12 to 16, characterized in that the device (86) for transporting the nuclear reactor (30, 99) from the operating workshop (64) to a workshop of maintenance (84) and / or the device (66) for transporting the nuclear reactor (30, 99) from the production workshop (62) to the operating workshop (64) are boats arranged to provoke the immersion of the nuclear reactor (30, 99) in the event of accident and / or aggression and / or natural disaster.

18.- assembly according to any one of claims 12 to 17, characterized in that it comprises a plurality of nuclear reactors (30, 99) identical.

19. - assembly according to any one of claims 12 to 18, characterized in that the operating workshop (64) has at least first and second receiving structures (68, 98) provided for holding in position the reactor nuclear reactor (30, 99), the secondary circuit (70) having at least first and second secondary interfaces (78, 100) connectable respectively to the nuclear reactor (30) maintained in the first receiving structure (68) and at the nuclear reactor (99) maintained in the second receiving structure (68).

20. - assembly according to any one of claims 12 to 19, characterized in that it comprises a plurality of operating workshops (64), each operating workshop (64) having at least one receiving structure ( 68, 98) provided for maintaining in position the nuclear reactor (30, 99) and a secondary circuit (70), the assembly comprising a single maintenance workshop (84) arranged for the realization on each of the nuclear reactors (30, 99 ) at least one of a maintenance operation or a core reloading operation (46).

21. - An assembly according to any one of claims 12 to 20, characterized in that it comprises a control installation (92), which is not in the operating room (64), adapted to remote control the nuclear reactor (30, 99) connected to the steam circuit (70) in the operating workshop (64).