WO2011128575A1

WO2011128575A1 - Underwater electrical energy generation facility provided with protection means

Info

Publication number: WO2011128575A1
Application number: PCT/FR2011/050832
Authority: WO
Inventors: André Kolmayer
Original assignee: Dcns
Priority date: 2010-04-13
Filing date: 2011-04-12
Publication date: 2011-10-20
Also published as: FR2958782B1; FR2958782A1

Abstract

Underwater electrical energy generation facility provided with protection means. This underwater electrical energy generation facility of the type comprising at least one underwater electrical energy generation module (110) and having means in the form of a caisson, in which there are integrated means forming an electrical energy generation unit that includes means forming a nuclear boiler, these being associated with electrical energy generation means connected to an external electrical energy distribution station via electrical cables (111) is characterized in that perimeter protection means (112) are placed around said at least one module, at a certain distance therefrom.

Description

Underwater installation for the production of electrical energy provided with means of protection

The present invention relates to an underwater installation for producing electrical energy provided with protection means and comprising at least one submarine module for producing electrical energy.

More particularly, the invention relates to an installation comprising at least one submarine module for producing electrical energy which comprises means in the form of an elongated cylindrical box in which are integrated means forming an electrical energy production unit comprising means forming a nuclear boiler, associated with means for producing electrical energy connected to an external electrical power distribution station by electric cables.

Such modules are already known in the state of the art.

For example, reference may be made to US Pat. No. 5,247,553, JP 50,018,891 and US Pat. No. 4,302,291.

These various documents actually describe submarine modules for producing electrical energy in which energy production means associated with means forming a nuclear boiler can be integrated for example.

Such structures are known to have a number of advantages because nuclear-based energy is an effective and cost-effective response to energy problems.

Such structures also make it possible to solve a certain number of problems, in particular as regards risks that are of natural origin, for example earthquakes or other, or human, such as, for example, terrorist attacks or acts of malicious intent. .

It is also known that these different projects have not resulted in industrial operations because they have not been fully finalized.

The object of the invention is therefore to solve these problems by proposing various improvements to this type of modules and installations.

To this end, the subject of the invention is an underwater installation for producing electrical energy of the type comprising at least one submarine module for the production of electrical energy comprising box-shaped means in which are integrated means forming an electric power generation unit comprising nuclear boiler means, associated with electrical energy production means connected to an external electrical power distribution station by electric cables, characterized in that means of protection perimetric are placed around said at least one module, at a distance from it. In other aspects, the installation may have one or both of the following features taken in combination or in isolation:

the protection means comprise means in the form of a protective net,

the means in the form of a protective net comprise means forming a door for access to the module,

the net-shaped means are placed on support means around said at least one module,

the support means comprise support columns,

the support means comprise means in the form of a lattice forming a support cage for the net,

it comprises several modules arranged under common protection means.

The invention will be better understood with the aid of the description which follows, given solely by way of example and with reference to the appended drawings, in which:

FIG. 1 represents a general view of an electrical energy production site comprising submarine modules for producing electrical energy according to the invention,

FIG. 2 represents a general view of a module for producing electrical energy according to the invention, at sea,

FIG. 3 represents a general side view of an electric power generation module according to the invention,

FIG. 4 represents a perspective view of the module illustrated in FIG. 3,

FIG. 5 represents such a module for producing electrical energy with torn off and transparent portions illustrating the internal structure thereof,

FIGS. 6, 7 and 8 represent different perspective views of a module according to the invention,

FIG. 9 illustrates a module according to the invention placed on the deck of a support carrying vessel,

FIG. 10 illustrates a detail of an underwater module for producing electrical energy according to the invention, showing an exemplary embodiment of means for securing nuclear boiler means forming part of the constitution thereof;

FIG. 11 represents a sectional view of a part of such a module illustrating an alternative embodiment of these securing means, FIG. 12 schematically represents the connection of electric cables associated with such an electrical energy production module,

FIG. 13 represents a side perspective view of an airlock forming part of an electrical energy production module according to the invention,

FIG. 14 represents a schematic sectional view illustrating the structure of such an airlock,

FIG. 15 represents a schematic sectional view of an embodiment of a nuclear boiler compartment forming part of a module according to the invention, and

FIG. 16 illustrates an exemplary embodiment of protection means for at least one module according to the invention forming part of an installation for producing electrical energy.

As indicated above, the invention relates to an underwater module for producing electrical energy.

Such modules are for example illustrated in this Figure 1 and are designated for example by the general references 1, 2 and 3 in this figure.

These modules are for example immersed off a coast designated by the general reference 4, and they are placed on the bottom or kept some distance from the bottom in an electrical energy production site designated by the general reference 5.

These different modules are then connected by electrical cables designated by the general reference 6, to an external electrical power distribution station, also acting as control center / remote control modules, this center being for example based on land and being designated by the general reference 7 in this figure.

This external electrical power distribution station is then connected in a conventional manner via electrical distribution lines designated by the general reference 8, for example to an electrical power distribution network supplying, for example, a nearby city. and designated by the general reference 9.

It will also be noted that terrestrial infrastructures such as, for example, a port designated by the general reference 10, may be envisaged to house support means such as, for example, support vessels, one of which is designated by the general reference 1 1 on this figure, to intervene on the production site. These support means allow for example to place the modules, to ensure their maintenance in condition or even to recover for heavy interventions to be performed on land. In fact and as illustrated in FIG. 2, each submarine module for producing electrical energy such as that designated by the general reference 1 in this FIG. 2, comprises means in the form of an elongate cylindrical box, the ends of which are for example rounded. These means are designated by the general reference 12 in this figure, and are placed on the bottom or kept at a distance from the bottom for example 13 of the sea and comprise, as will be described in more detail later, means of base designated by the general reference 14 and anchoring means designated by the general reference 15, for positioning and maintain this module at the bottom.

As will be described in more detail below, this module can be associated with a submersible electrical connection unit designated by the general reference 16, for connecting the module to the electrical energy distribution station via cables. electric.

A support vessel such as for example a carrier ship is also illustrated near the module in this figure 2, this vessel being designated for example by the general reference January 1.

These various elements are also illustrated in FIGS. 3 and 4 on which the module designated by the general reference 1 is recognized, the means in the form of a cylindrical box designated by the general reference 12, the base means 14 thereof, the anchoring means 15 on the bottom and the submersible electrical connection unit 16.

This unit will be described in more detail later and it will be noted simply for the moment that this unit is connected by means of carrying cables or support for example 18 and 19 to the submarine module 1, these cables or carriers of support being adapted to receive and support electrical cables designated by the general references 20 and 21, extending between the module and the submersible connection unit 16.

It will also be noted that this unit 16 is associated with anchoring means on the bottom designated by the general reference 22 in these figures and is also associated with one end of a hoisting rope designated by the general reference 23, of which another end comprises a signal buoy designated by the general reference 24, adapted to float on the surface of the water and thus allowing the support means, such as for example the vessel 1 1, to locate and recover this connection unit to allow an intervention on it.

As illustrated in these figures, anchoring means of the module on the bottom can be regularly distributed around it. Referring now to FIG. 5, in which the interior of an electric power generation module according to the invention is seen in greater detail, it can be seen that in the means of an elongated cylindrical box 12, are integrated power generating unit means comprising nuclear boiler means, associated with means for producing electrical energy.

In fact, two electric power production units are arranged symmetrically on either side of a central transverse plane of the box-shaped means 12, along the longitudinal axis thereof.

These units are designated by the general references 25a and 25b in FIG. 5 and may for example be identical production units arranged symmetrically.

These can then be placed on either side of a servitude compartment common to the two electrical energy production units, itself placed at the center of the box-shaped means 12.

This service compartment is designated by the general reference 26 in this figure 5.

It will also be noted that at least one service passage extending from one end to the other of the box-shaped means 12, passing through this service compartment 26 and serving the different means of each production unit of electrical energy 25a and 25b, to allow one or more operators to intervene in them, may also be envisaged, this servitude passage being designated by the general reference 27 in this figure 5 and being conventionally protected in this type applications to ensure operator safety.

In fact, it is generally possible to distinguish in this FIG. 5 the nuclear boiler means designated by the general references 28 and 29 of the electric power generation units 25a and 25b and the electrical energy production means 30 and 31, respectively. of these units.

In the electric power generation module according to the invention, one of the ends of the nuclear boiler means 28 and 29 is contiguous to the service compartment 26. As is indeed illustrated, one of the ends of the means forming nuclear boiler 28 and 29, is contiguous to the service compartment 26, on each side thereof, while the electric power generation means 30 and 31 respectively, are contiguous at the other end of these boiler means, symmetrically.

The different elements involved in the constitution of these different means not being the subject of the invention, they will not be described in more detail later. It will simply be noted that in a conventional manner, these various means then comprise a nuclear boiler, exchangers, turbine generators, auxiliary components of the secondary loop, electric batteries and high-voltage power plants, etc. ...

The service compartment 26 can meanwhile include various conventional equipment in this type of applications and also adjusters for adjusting the apparent weight of the module, these adjusters being designated by the general reference 32 in Figure 5.

It will also be noted that the ends of the box-shaped means 12 comprise ballasting means 33 and 34, respectively, making it possible to maneuver the module in particular during its diving and ascent phases or the like.

This maneuver can also be assisted by means of pod-shaped propulsion placed on the sides of the box-shaped means 12 and being for example in the form of electrically powered pods in a conventional manner.

These different elements can be remotely controlled from the control / control station based for example on the ground.

As also illustrated, the box-shaped means 12 may have a double shell, namely an inner shell designated by the general reference 35 in this figure 5, in which are delimited receiving compartments of the nuclear boiler means and means for producing electrical energy, and an outer protective shell designated by the general reference 36.

The compartments intended to receive the means forming a nuclear boiler are designated by the general references 37 and 38 respectively, while the compartments intended to receive the means for producing electrical energy are designated by the general references 39 and 40 respectively.

Note also that these different compartments can be separated by cofferdams such as for example the cofferdams designated by the general references respectively 41, 42, 43 and 44, to ensure isolation of the compartments 37 and 38 respectively, intended to receive the means forming a nuclear boiler, on the one hand the service compartment 26 and on the other hand compartments 39 and 40 for receiving the means for producing electrical energy. As previously described, each production unit is then connected to the external electrical power distribution station by its own electrical cables. This allows each production unit to be independent.

As already indicated above, the lower part of the box-shaped means 12 of the electric power generation module 1 is equipped with the base means 14, illustrated in greater detail in FIGS. 6, 7 and 8, allowing it to rest on the bottom or, as shown in Figure 9, on the deck of a support carrier such as ship 1 1.

An embodiment of these base means is illustrated in greater detail in FIGS. 6, 7 and 8 and these have the general shape of a sled extending from one end to the other of the shaped means. of box 12 and whose ends are curved in the form of spatula at each end of the box-shaped means.

Indeed, each end respectively 50 and 51 of these sled-shaped means, is shaped in the form of a spatula at each end of the box-shaped means 12, which makes it possible to solve in particular various problems of laying the module on the bottom.

In fact, these sled means comprise a frame-based structure including a central spar designated by the general reference 52 in these figures, and two side rails designated by the general references 53 and 54.

These longitudinal members are interconnected by reinforcing and connecting arms, one of which is for example designated by the general reference 55 in these figures, and their ends are bent and bent to be fixed to each other at the end. spatula shape at each end of the box-shaped means of the module.

In addition, the side rails are connected to the electric power generation module by support columns, one of which is for example designated by the general reference 56 in FIG.

As can be seen more clearly in this FIG. 8, the central spar 52 can also comprise means in the form of support flanges of the electric power generation module, one of which is for example designated by the general reference 57 on this Fig.

This central spar 52 may also include ballast-shaped means placed for example in the lower part of this spar, these ball-shaped means being designated by the general reference 58 and having any conventional structure in this field. It should also be noted that the sled-shaped base means 14 may comprise zones for absorbing length variations of the box-shaped means 12, related to the pressure variation applied to them when they are submerged. or reassembled.

It is known in fact that the length of such modules, which may be several tens of meters, may vary depending on the depth of immersion and therefore the pressure that applies to this module.

These areas of absorption of the module length variations, may for example be formed by telescopic portions of the longitudinal members or by elastically deformable bellows portions thereof.

Of course other embodiments can be envisaged.

The module according to the invention can also be equipped with passive securing means in the event of a problem in the nuclear boiler means.

Indeed, it may be indispensable at one time or another, especially in case of serious damage, to ensure the evacuation of residual heat thereof, while preserving the environment of the module.

For this purpose, in the module according to the invention, the box-shaped means comprise in their upper part and in their lower part and in the zone in which are placed the means in the form of a nuclear boiler, orifices of circulation of cooling water of these.

Two exemplary embodiments of these securing means are given respectively in FIGS. 10 and 11.

Note that these orifices may for example be associated with grids or movable flaps between opening and closing positions thereof.

In fact, the nuclear boiler means can also be connected to heat exchanger means placed in the cooling water circulation path between the water circulation holes in the box-shaped means, the upper part and the lower part of the nuclear boiler means being then connected to the upper part and the lower part of the exchanger means.

FIG. 10 illustrates a first exemplary embodiment of these securing means, on which a portion of an underwater power generation module, designated by the general reference 60 in this figure, is recognized. also comprising box-shaped means designated by the general reference 61 in which is defined a compartment 62 for receiving nuclear boiler means designated by the general reference 63. This compartment 62 is separated from the other compartments of the box-shaped means respectively by cofferdams 64 and 65 provided on each side of this compartment 62.

As is conventional, these cofferdams 64 and 65 are in fact free spaces.

Orifices 66, 67, 68 and 69 are then formed in the upper and lower portions of the box-shaped means 61 facing these cofferdams and in fluid communication with them to allow a circulation of water therebetween. lower orifices and the upper openings of the box-shaped means.

It should be noted that heat exchangers 70a and 70b respectively can be placed in these cofferdams and are connected to the upper and lower portions respectively of the nuclear boiler means 63 to remove residual heat from them in the water.

In the example shown, these exchanger means comprise at least two exchangers placed on either side of the means in the form of a nuclear boiler in the cofferdams.

Such a structure then allows long-term heat removal and does not require external energy due to the natural circulation of water.

According to the exemplary embodiment illustrated in FIG. 11, an underwater module 71 always comprises box-shaped means designated by the general reference 72 in which the nuclear boiler means 63 are arranged. However, in this exemplary embodiment , the box-shaped means 72 comprise a double shell, namely an inner shell designated by the general reference 73 and an outer shell designated by the general reference 74, spaced from the inner shell.

Water circulation orifices 75 and 76 are then formed in the outer shell respectively above and below the zone in which the nuclear boiler means 63 are placed. This then allows water to circulate. around these means forming a nuclear boiler and in particular around means forming a heat exchanger designated by the general references respectively 77 and 78, placed on either side of the means in the form of a nuclear boiler between the two shells means in the form of caisson.

These exchanger means are then always connected to the nuclear boiler means.

As indicated above, each power generation unit is connected by electrical cables to an external distribution station placed for example on the ground, through an easily accessible submersible connection unit.

Indeed, such a unit can be used to avoid having to access the module whenever it is desired to intervene on the connection means.

Such a structure is illustrated generally in FIG. 12, on which the electric power generation module 1 is shown schematically in this figure, the connection unit 16, the hoisting cable 23, the signaling buoy 24, one of the carrying cables, for example the cable 18 and the corresponding electric cable, such as, for example, the corresponding cable 20.

In fact, this cable 20 is a first electrical cable providing the electrical connection of the module and more particularly of the or each electrical power generation unit of this module to the submersible connection unit 16, in which this first electric cable is connected to a second electrical cable designated by the general reference 80 in this figure 12, for connecting the assembly to the external electrical power distribution station.

It will also be noted that cables or optical fibers constituting information transmission means can be used between the control / remote control center of the module based for example on the ground and the electrical energy production module itself for control / control the operation of it.

In fact and as illustrated, one of the ends of the carrying cable 18 is connected to the electric power generation module and the carrier cable passes over means of return constituted for example by pulleys for example 81 of the unit submersible connection 16, to extend under this unit towards the bottom. The other end of this carrier cable 18 then comprises stabilizing counterweight means in position of this connection unit.

These counterweight means are for example designated by the general reference 82 in this figure and are mounted slidably movable in a protective sheath designated by the general reference 83, extending under the unit.

This then makes it possible to stabilize this position in position while preventing the cables from becoming entangled.

Note also that the submersible connection unit 16 may comprise adjusting means for adjusting its apparent weight, these means being designated by the general reference 84 in this figure 12, to enable it for example to be immersed between two waters. Finally, it will be noted that a submersible connection unit such as that just described can be associated with each production unit of an electric power generation module or that a common submersible connection unit can be associated. to the two production units of each power generation module.

Each unit also comprises, for example, means for supplying electrical energy. This energy can be provided by the external environment in nominal operation. Redundantly backup power means can also be provided such as batteries or other storage means, for example fuel cells activated by seawater when necessary, ... to ensure a the minimum safety functioning of this unit, such as emergence assistance.

Note also that the operation of this unit can be controlled / controlled from the outside, the latter then being connected to the environment by wire connection means, controlled by acoustic signals or the like.

It has also been illustrated in the preceding figures and in particular in FIG. 5, that the module according to the invention can be equipped with different evacuation chambers of the operators, distributed in different places of the box-shaped means.

Thus for example, such locks designated by the general references 90 and 91 are illustrated in Figure 5 and are placed for example at the ends of the box-shaped means to open into the receiving compartments of the electric power generation means.

Similarly, the service compartment 26 is provided with an access lock for operators and also for introducing / extracting material box-shaped means.

This lock is designated by the general reference 92 in Figure 5 and is illustrated in more detail in Figures 13 and 14.

In fact, we recognize in these figures the box-shaped means 12 of the electric power generation module 1 and these box-shaped means comprise at least one horizontal log access port opening into the service compartment 26 of the module electrical energy production, this airlock always being designated by the general reference 92.

This airlock is equipped with various access panels for example from outside or inside the module and is also equipped with a decompression chamber for operators, this decompression chamber being designated for example by the reference General 93. As is illustrated in more detail in FIG. 14, the ceiling of the chamber 92 may also be equipped with a rail such as the rail 94 for suspending load handling means, which can then be placed on a horizontal floor such as for example the floor 95, provided at the bottom of this lock.

The bottom of the airlock may also present a gap such as for example the gap 96 illustrated in this figure 14, opening into the service compartment 26 and closed by a retractable flap such as the shutter designated by the general reference 97.

This shutter can be a bolted shutter on the rest of this airlock.

Of course, other embodiments may be envisaged.

The airlock is also equipped with other panels or doors opening allowing exchanges between its different zones.

Several special points can be noted about the decompression chamber. Indeed it can be accessible from inside the airlock or from outside. In immersion, it can be accessible under atmosphere.

The decompression chamber is designed to withstand immersion pressure and can be accessed by immersion by divers.

The emptying of the decompression chamber can be done by a pumping whose work is reduced by the pressurization of the water of the water to be evacuated by a gas (which may be air) under pressure which comes to replace the water hunted. This allows the diver, among other things, to start the decompression procedure (desaturation of the nitrogen in the organic tissues) while preventing the barotraumatic risks by a fine control of the atmospheric pressure in situ.

It is then conceivable that such a structure of electric power generation module has a number of advantages, particularly in terms of its insensitivity to human-caused attacks such as sabotage or malice or natural and related for example to the environment such as storms, earthquakes and lightning. In addition, the water is inert, it provides natural protection in case of problems.

Moreover, such an electric power production module can be relatively easily manufactured in series for example in a shipyard and moved to be implemented in a required location, such as for example a place that has just been damaged. and who needs an independent power supply.

The power generation units can be manufactured for example simultaneously in parallel and then coupled to the ends of the service compartment, which reduces the manufacturing time of such a module. Such a module also has a relatively small size while giving the possibility of having a reasonable power and requires a relatively low investment, particularly compared to a conventional nuclear power plant based on ground.

It can be built relatively quickly and benefit from the effects of series.

It also does not require a crew to the extent that it can be controlled / controlled remotely.

Operators can however intervene inside the module thanks to the airlock, this one also allowing to introduce or to extract from this module loads of relatively large size.

The particular structure of the sled-shaped base means also allows the module to land independently on the bottom or to be transported by a balastable carrier vessel or a pool.

This particular sled shaped structure whose ends are curved in the form of spatulas, allows the module to land everywhere, including a plate and a cottage of several degrees and ensuring the stability of the module while it conferring good mechanical strength.

This then makes it possible to avoid having recourse to external assistance for placing these modules as with the modules of the state of the art.

The particular structure of these base means also makes it possible to ensure a sufficient resistance of the module to prevent any deformation or even breakage.

Passive securing means make it possible to optimize the safety of nuclear boiler means by removing residual heat from the nuclear core in the long term while ensuring the protection of the environment.

It is also a system that operates without external energy supply by simple natural circulation of water heating in contact with the exchanger means or the wall of the corresponding compartment.

The electrical connection unit allows for it to connect or disconnect or generally to intervene on an electric cable connected to the submarine module, without the need to intervene on the latter which can for example be submerged to a relatively large depth.

The support means such as, for example, a support vessel can then, on the one hand, locate the signaling buoy of the connection unit and, on the other hand, hoist it out of the water so as to allow such intervention. as a connection, disconnection or other cables and put this unit back into the water after this intervention. Finally, the large airlock to access the service compartment of the power generation module allows to introduce or extract from it of relatively large size equipment.

FIG. 15 shows a schematic sectional view of an embodiment of a nuclear boiler compartment equipped with safety means.

In this figure 15, the nuclear boiler compartment is designated by the general reference 100 and it then comprises nuclear boiler means, designated by the general reference 101, equipped for example with a tank designated by the general reference 102.

As described above, these nuclear boiler means are part of power generation unit means and are therefore associated with electrical power generation means connected to an external electrical power distribution station by means of the electric cables.

In addition, the compartment 100 is equipped with means for flooding it with seawater in the event of an incident.

These means are designated by the general reference 103 in this figure 15 and comprise for example controlled valve means passing through the partition of the compartment 100 to drown it in case of incident.

These valve means can be remotely controlled and / or be equipped with means for triggering their opening sensitive to pressure, temperature, etc. ... in the compartment.

In addition, the tank 102 of the nuclear boiler means may also be equipped with depressurization means and means for gravity injection of seawater therein in the event of an incident, these means being designated by the general reference

104 in this figure and thus crossing the wall of the tank.

These means also have any conventional structure with a suitable valve.

It should be noted that at least one heat exchanger designated by the general reference

105 can also be provided in this compartment.

The inner face of the compartment, under the means forming a nuclear boiler, may also be equipped with ashtray means for receiving the molten nuclear core in the event of an incident.

These ashtray means are designated by the general reference 106 in this figure 15 and may for example be in the form of an ashtray made based on elementary plates fixed on a support mesh provided with suspension means in the compartment. Such means are intended to receive the corium in case of fusion of the heart.

It is understood that this has a number of advantages in terms of module security in the event of an incident.

Indeed, the means that have just been described are passive safety systems that do not require any external power source and make it possible to attenuate or even retain naturally by sea water, radiotoxic substances leading in all situations, to a reduction of the radiological consequences of all accidents, including the most serious accidents.

In particular, the depressurization means 104 make it possible to ensure an automatic and passive depressurization as fast as possible of the tank, while allowing a rapid and permanent equalization of the pressures between the boiler means and the compartment, and therefore a thermo-thermal coupling. strong hydraulics guaranteeing the possibility of a passive gravity supply in water of the heart.

The flooding of the compartment receiving the means forming a nuclear boiler with seawater, which is in this case an inexhaustible cold source, makes it possible to improve the general safety of the assembly, while at the same time ensuring passively and in the long term, extracting the residual power of the core by cooling the vessel from the outside and all of the boiler means through the compartment and the exchanger.

In addition, such a structure provides a passive means of retention in dissolved form, in the seawater of the box, many radioactive products or substances such as iodine or cesium, because of the naturally basic nature of the water of sea (pH between 7.5 and 8.4 with an average pH of 8.2).

In the structure as described, this effect is obtained naturally and passively using seawater.

It should also be noted that the flooding of this compartment allows a redeposition in the box of the other radioactive particles.

Thus, this structure has the advantage of a powerful protection of populations in case of accident, by preventing or reducing the atmospheric dissemination of radioactive substances.

Indeed the flooding of the caisson by sea water and the surrounding sea constitutes a device of protection of the populations against all the accidents with radiological consequences, while retaining in dissolved form in the seawater naturally basic the products of fission- key like Iodines, Cesiums, Strontiums, Bariums, Telluriums, Rutheniums, Rubidiums, Bromes, ... in addition to fuel particles and actinides. With such a structure, the melting of the core and the eventual piercing of the tank, are therefore considered highly improbable.

However, and in such a situation, assuming that the core melts, passes through the tank, and has not immediately undergone solidification quenching in contact with the flooding seawater, the corium then spreads over the shaped means. ashtrays that are also cooled from above, that is to say by the seawater contained in the compartment and from below, that is to say by the seawater outside the module.

It goes without saying of course that such a compartment can be integrated into a module as described above, which then comprises for example two electrical energy production units arranged symmetrically on either side of a central transverse plane of box-shaped means, along the longitudinal axis thereof, the two production units being for example identical.

Of course, other embodiments may be envisaged and the box-shaped means may have different shapes from that described.

In addition to these security means, protection means against external attacks of modules of this type can also be envisaged.

An exemplary embodiment of such protection means is illustrated in FIG.

In Figure 16, it has in fact illustrated an underwater installation for producing electrical energy which comprises at least one submarine module as described above, for producing electrical energy.

In this figure 16, a single module is shown and designated by the general reference 1 10 and it then comprises box-shaped means in which are integrated power generating unit means comprising nuclear boiler means , associated with electrical energy production means, connected to an external electrical power distribution station by electrical cables designated by the general reference January 1 in this figure 16.

This module then enters into the constitution of an underwater installation for producing electrical energy, which also includes perimeter protection means placed around this module, at a distance from it.

In the embodiment illustrated in this figure 16, these perimeter protection means are designated by the general reference 1 12 and in fact comprise net-shaped means designated by the general reference 1 13, placed on designated support means by the general reference 1 14, to extend around the module.

Several possible embodiments of these support means may be envisaged, and these may for example be in the form of support columns or means in the form of mesh forming support cage of the net. It will also be noted that the net-shaped means may comprise module access door means designated by the general reference 1 and that several modules may be arranged under common protection means of this type.

These means of perimeter protection then provide an anti-aggression function of the module and are for example intended to protect the modules against aggression type torpedoes, mines, divers, etc ...

Of course, other embodiments may be envisaged.

It is then conceivable that these various provisions make it possible to improve the operational safety of installations of this type, as well as their safety and in particular their safety in the event of accidents such as, for example, a major nuclear accident.

Claims

1. - Underwater power generation plant of the type comprising at least one submarine module (1 10) for producing electrical energy having box-shaped means, in which are incorporated means forming a production unit. electric energy comprising nuclear boiler means, associated with electrical energy production means connected to an external electrical power distribution station by electric cables (1 1 1), characterized in that perimeter protection means (1 12) are placed around said at least one module, remote from it.

2. - Subsea installation for producing electrical energy according to claim 1, characterized in that the protection means (1 12) comprise means in the form of protective net (1 13).

3. - Subsea installation for producing electrical energy according to claim 2, characterized in that the means in the form of protective net (1 13) comprise means (1 15) forming access door to the module.

4. - subsea installation for producing electrical energy according to claims 2 or 3, characterized in that the net-shaped means (1 13) are placed on support means (1 14) around said at least one module.

5. - Subsea installation for producing electrical energy according to claim 4, characterized in that the support means (1 14) comprise support columns.

6. - Subsea installation for producing electrical energy according to claim 4, characterized in that the support means (1 14) comprise means in the form of mesh forming a support cage of the net.

7. - Underwater installation for producing electrical energy according to any one of the preceding claims, characterized in that it comprises a plurality of modules (1 10) arranged under common protection means.