DEW0014831MA - - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

Registration date: September 7, 1954. Advertised on May 9, 1956

GERMAN PATENT OFFICE

The invention relates generally to atomic nuclear reactors in which an easily controllable Chain reaction is generated by nuclear fission, in particular on reactors for stationary systems.

There are reactors known in which by bombardment of buildable materials, such as Uranium 238 and Thor 2S32, matter that can be fissioned with neutrons, such as B. Plutonium 239 or Uranium 233, is produced.

Such reactors generally operate at low temperatures and pressures that require but adequate control of the process and measures for cooling.

Reactors have also already been proposed for generating energy. These works predominantly at much higher temperatures and pressures; many of the control and cooling problems are similar to the first mentioned known reactors. The use of reactors is also have been suggested for a number of other purposes, beginning with purely experimental purposes serving plants up to reactors for special purposes, like ζ. Β. Material investigations and generation of isotopes.

A number of different types of reactors find use for these purposes; all known Systems, however, are subject to strict restrictions on use, in particular with regard to on the adaptability and the ease of control in operation.

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The reactor according to the invention can be used for all of the above-mentioned purposes. It provides a reactor core in which the reaction takes place while generating heat. In the following the invention is explained using the example of a reactor for the production of Energy; there is a closed cooling system that works at high pressure and high temperature Use in conjunction with a

ίο High pressure boiler for the reactor core. The invention However, it is not restricted to energy generation, but can be used in a modified embodiment can be used for other purposes. In the embodiment shown in the drawing According to the invention, part of the heat developed is removed in a heat exchanger located in the core of the reactor containing primary circuit is located; the heat withdrawn in this way is used to generate Steam for turbo generator systems or the like. Used. In other embodiments of the invention Reactor, a high pressure vessel for the reactor core is not required, and one is sufficient simpler form of cooling.

The most popular version so far is the one with. solid fuel working so-called heterogeneous Type in which solid plates or blocks of fissile matter in a well-defined System are arranged in the reactor core and a coolant, e.g. B. Water, in the primary circuit circulated through the reactor core, © this embodiment requires extremely complicated and expensive manufacture of the fuel elements and complex support structures for the fuel elements and flow a coolant. The replacement of the fuel elements in the reactor core is very difficult and requires reactor shutdown for a relatively long period of time; although can unused fissile matter can be recovered, the process required for this - is however, very cumbersome and expensive.

Another genus of reactors, called the homogeneous type, uses the fissile type Matter in solution with a liquid, e.g. B. water. In this embodiment that is Corrosion problem in view of the need to circulate the solution in the entire primary system a significant disadvantage.

Finally there are reactors in which the fissile matter is in a suitable liquid suspended to a relatively viscous mixture in the form of a slurry. These reactors have the same disadvantages as the homogeneous reactors mentioned above; Additionally there is a difficulty in keeping the slurry uniform. Both this embodiment like those of the homogeneous type is subject to restrictions in the use of fissile matter of low enrichment, because of the impossibility to accommodate. Enough of such matter in the required volume. The reactor problems apply to the two last-mentioned genera of reactors into the whole primary circle because the matter circulating in the circle is highly radioactive. After all, the amount of fuel or fuel required is very large because of the part of the primary circuit that is present outside the actual reactor contributes nothing to the cracking process inside the reactor.

In the invention a new form of reactor core is provided, along with means for controlling, cooling, reflecting and moderating. In doing so, the fissile matter is given shape of particles used, for example, tablets, pills, pearls or the like. Shape and are in a container of the reactor core, in which through a layer of this Particles through an upwardly directed stream of a cooling liquid flows, which so can be controlled that the fuel particles are raised and carried by the flow of liquid separated from each other and in a sense suspended in it, to a degree and in a distribution that depends on the intensity of the liquid flow. It stands to reason that such a reactor does not have the disadvantages of the known types; in addition owns it has further advantages, which will be pointed out below.

The use of nuclear fuel particles in tablet, pill, pearl or the like form is at Atomic nuclear reactants are known per se. Furthermore, a reactor is known whose container has a perforated Soil as a support for a layer of solid fuel particles in tablet form, one of which includes at least a portion of fissile matter, has and means for generating one through the perforated bottom and up through the container to an outlet in the top of the container having directed liquid flow. In this known reactor, however, the tablets fill completely out of the reactor core container and cannot move.

In contrast, according to the invention, the fuel particles in tablet, Pills, pearls or the like. Move freely, and) means are provided that allow the To regulate the amount and pressure of the liquid flow so that the fuel particles in the container be raised to a predetermined critical distribution. This allows the splitting process control in the reactor easily and effectively, without the need for complicated To use control devices.

The figures show exemplary embodiments of the invention. It shows

Fig. Ι a reactor according to the invention in longitudinal section,

Fig. 2 shows an embodiment of an inventive Reactor in connection with facilities for the filling of used fuel particles ! and for filling fresh fuel particles into the reactor,

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Fig. 3 is a schematic representation of the ikompletten Plant with a reactor according to FIG. 2.

In the simplified embodiment according to FIG. Ι the reactor consists of a relatively thick-walled pressure vessel 2 made of suitable, highly resistant material, e.g. B. steel. The The inside of the boiler can be coated with a corrosion-resistant material, e.g. B. stainless steel, designed being. However, this is not necessary if corrosion-inhibiting agents are added to the coolant or when using a non-corrosive coolant. The boiler is in one piece in FIG shown; however, it can consist of several interconnected in a suitable manner, e.g.

be assembled welded parts. The boiler has an outlet opening at its upper end 4, an inlet opening 6 at its lower end.

In the interior of the pressure vessel 2 there are a central shielding cylinder 8 and an inner shielding cylinder 10; these screens are adapted in their shape to the inner shape of the pressure vessel 2, but are spaced from its inner surface and from one another. The screens are made of steel or stainless steel, for example. The intermediate ^{screen 8 1} is held by the pressure vessel 2 by means of a number of spacers 12, 16 and 22 which are distributed at intervals over the height of the pressure vessel and fixed between this and the screen 8 in a suitable manner, e.g. B. are welded. The Ab-. Stand holders 12, 16 and 22 are interrupted on the circumference so that liquid can flow through in the longitudinal direction. The inner screen 10 is supported by the intermediate screen 8 in a similar manner by spacers 14, 18 and 20, which are expediently covered on the spacers 12, 16 and 22 and attached to the two screens 10 and 8 in a suitable manner, e.g. B. are welded to them. The spacers 14, 18 and 20 are also not continuous on the circumference, but rather interrupted for the purpose of creating through openings for a flow of liquid.

The upper ends of the screens 8 and 10 are with each other and with the jacketed pressure vessel 2 united by a suitably conical sleeve 24; this sleeve has outlet openings 28 and 26, which open into the annular space between the screens 8 and 10 and into the annular space between the screen 8 and the pressure vessel 2.

In the lower part of the pressure vessel 2 there is a transverse wall 30, preferably in line with the spacers 12 and 14 or in the vicinity of these spacers, where this partition is attached to the inner screen 10 by welding or in some other way. This wall 30 is provided with a large number of perforations 32, the majority of which open into an inner container 13. The latter is essentially cylindrical, stands on the transverse wall 30 and rests with its upper edge on the inner screen 10. The container 13 is held in its position in a suitable manner, for example by welding to the transverse wall 30 at its lower edge and to the inner screen 10 at its upper edge. Between the container 13 and the inner screen OK there is an annular space; the transverse wall 30 has at least one opening which opens into this annular space ·; At its upper end the container 13 also has openings 33 which serve as outlet openings for a flow of liquid rising upwards in the annular space between the container 13 and the inner screen 10.

The fuel or fuel elements in the container 13 are solid, separate particles 34, For example, in tablets, pills, pearls or the like, which contain fissile matter. The special one Concentration of fissile matter in the particles 34 or the exact form in which the Particles are used are not essential to the invention; there can be different arrangements of shapes of the particles 34 are used. Likewise, the particular amount of fissile Matter and other elements involved in the composition of the particles can be varied. So it is if in the container 13 by atomic fission as a result of bombardment of fissile matter by suitable radiation, e.g. B. neutrons, heat is to be generated, only essential, that at least some of the particles 34 contain fissile matter, e.g. uranium 235, plutonium or the like and that additional neutrons are emitted as a result of the fission process. Such matter may be incorporated into particles 34 in relatively pure form or in the form of an alloy or compound, which in turn with a protective substance, z. B. zirconium or aluminum can be. This can be done in various ways within the scope of the invention.

The container 13 is preferably made of a material with a small neutron absorption cross section has, such as aluminum or zirconium. However, steel can also be used as a material can be used for the container 13 because if it also has a larger neutron absorption cross-section has, the neutrons are inelastically scattered by it, so it reflects neutrons Possesses properties. The reflection of neutrons emerging from the container 13 in this container back 'can be completed by the relatively thick circular ring' of coolant, which the container 13 in the annulus between it and the inner screen 10 immediately surrounds. Of course, some of the radiation is absorbed by the screens 8 and 10; these are e.g. B. matched by difference in strength so that the radiation absorption in the wall of the pressure chamber 2 is low enough to contain excessively high temperatures, to exclude. Since, however, some of the radiation in the material of the chamber 2 and the screens 8 and 10 is absorbed, it is necessary to pass these components through a coolant flow in the intermediate To cool annulus.

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If the reactor according to the invention is not in operation, then the fuel particles are 34 due to their heaviness as a layer in the lower part of the container 13 (drawn out in Fig. 1). The fuel particles 34 are in a non-critical state and must be in a critical state State to be moved in 'which the number of emitted in a split and to Causing further fission available neutrons approaches the number one. To the fuel particles Bringing 34 into such a critical state is a suitable liquid flow through the inlet port 6 of the pressure vessel under controlled pressure and controlled Admitted flow conditions.

That to expand the layer of fuel particles 34 from the extended position of Fig. Ι in the dashed position medium used can be of any suitable type; according to the illustrated embodiment According to the invention, a medium is used which acts as a coolant and the heat from the reactor core dissipates for the purpose of energy generation and which also acts as a moderator, d. h that neutrons emitted during the fission process are slowed down. A suitable medium for this Purpose is water. However, the invention is not limited to this particular liquid; other examples are liquid metals such as sodium, bismuth, lithium and various alloys these metals; also various organic liquids or inorganic compounds, such as alkali metal hydroxides can be used.

The medium admitted at 6 is divided into a multiplicity through the perforation 32 of the base plate 30 broken up by upward currents and evenly distributed over the whole area of the Layer of fuel particles 34. The pressure and flow of this medium, which is also called Coolant acts can be adjusted so that the particles are separated from each other and in the Medium up to a certain height and in a certain geometric shape or distribution

+5 are suspended in the container 13 such that the cleavage process enters the critical stage and a chain reaction can be obtained. Besides In this quasi-flowing state of the particles finds a general movement and even touch instead of what. the separation of corrosion products from the fuel particles is promoted.

The flowing medium leaves the pressure vessel through opening 4 and circulates in a primary cooling system, in which the heat is drawn off to do useful work. It can be seen that the heat generated in each particle 34 by the cracking process from the flow of coolant is quickly removed because each particle is carried individually by the rapidly flowing medium and is surrounded by it. In this sense, the ratio of the surface area of a fuel particle to be large in volume. It can also contain fuel particles because it is on their Form does not matter, find use in relatively simple forms, so that their production can be done easily, quickly and cheaply.

Since the critical condition of the reactor is essentially determined by the equilibrium between the neutrons which are absorbed by fission-generating fuel elements, the absorbed but not fission-generating neutrons and the neutrons lost through leakage from the reactor, when using a moderator Cool- . by means of, e.g. B. Water, which slows down the fast neutrons emitted during fission, so that they are more easily detected by fissile matter and additionally cause fission; the degree of the critical state of the reactor can thus be regulated by changing the quantitative ratio between the fuel and the coolant which has a moderating effect. If the latter is a substance such as B. heavy water (D ₂ O), which does not absorb neutrons to a significant extent, then an increase in the amount of cooling liquid causes an increase in the number of neutrons slowed down by the moderator effect in relation to those neutrons that escape or do not participate in the fission process have been lost; in this way the number of neutrons available for the fission process is increased. In the reactor designed according to the invention, this can be achieved simply by increasing the coolant flow in such a way that the fuel layer expands further and thus the ratio of the amount of moderator agent to the amount of fuel is increased. On the other hand, if the moderating coolant z. B. is ordinary water, which has a considerable neutron absorption cross-section, perform control in the same way; However, increased expansion of the fuel layer beyond a predetermined, critical limit results in an increased capture of neutrons by the moderating coolant and thus a weakening of the critical state of the reactor.

This embodiment is automatically secured in the event of failure of the pump that in this If the fuel particles 34 move out of the expanded position indicated by dashed lines in FIG fall back to the position shown in solid lines, d. H. in a position in which the quantitative ratio between moderating coolant and fuel is small and subcritical. On the other hand will the reactor, as stated earlier, even with excessive coolant flow, d. H. so at excessive expansion, subcritical. For a given flow, the critical state can be be regulated by introducing fuel particles 34 of various sizes. Also Such a design offers security in the event that the flow of the coolant decreases or ceases, also in the event that the flow of the cooling medium exceeds an upper limit;

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because in both cases there is a change in the quantitative ratio between the moderator and the fuel. In most known reactors, this ratio is fixed and only a function of temperature and pressure. When the subject of the present invention leaves this ratio can vary slightly.

Part of the flowing medium is in the annular spaces between the pressure vessel 2,. the

Lo screens 8 and io and the container 13 deflected, to exert a certain braking effect on neutrons escaping from the container 13 and a cooling of the pressure vessel itself and the inside thereof by circulating part of the to effect flowing medium through these gaps.

In the modified embodiment of the reactor according to FIG. 2, the pressure vessel is 36 equipped with a container 50 for the reactor core and a cylindrical screen 43; the The container 50 as well as the screen 43 are closed on the top by covers which have a large number of perforations 45 have. In addition, a grid 47 can be provided. The container 50 and the screen 43 are fastened in the boiler 36 while maintaining annular spaces, z. B. welded, using spacers 49, 51, 53, 57 as in the reactor according to Fig. 1. The spacers are not continuous on the circumference, but interrupted, around the passage of the cooling medium in the annular space between container 50 and screen 43 as well as in the space between the latter and to enable the pressure vessel 36. The suitably attached, e.g. B. welded The bottom 38 of the container 50 is provided with a multiplicity of evenly distributed perforations 39. Inside the container 50 there is a fuel support 40, which is also shown in has perforations 41 evenly distributed. This edition 40 is lower than that lying center point to be inclined downwards. In the middle it has an opening for the connection a fuel delivery pipe 37, which the bottom 38 of the container 50 and the wall of the Pressure vessel 36 interspersed.

The pressure vessel 36 is at its lower part below the bottom 38 with an inlet chamber 42 provided, which opens with inlet openings 44 in the pressure vessel .. In a similar way is the Boiler on the top, over the screen 43, provided with an outlet chamber 46, which through . openings 48 opens into the boiler. The operation of the reactor according to FIG. 2 is similar that of the reactor described with reference to FIG. The inlet chamber 42 is pressurized a coolant is supplied which enters the lower part of the boiler 36 and flows upwards, wherein the bottom 38 and the bearing surface 40 an even distribution of the cooling medium into a multiplicity of vertically upwardly directed, penetrating the fuel layer 34 Cause currents. A small part of the current directed upwards enters the room between the boiler and the screen 43 and into the space between the screen 43 and the container 50 branched off. At the top flows through the Mediujn, the grid 47 and the perforations 45 of the container 50 and the screen 43 in order to reach the outlet chamber 46 via the openings 48. Like in In the case of the embodiment according to FIG. 1, the flow strength can be varied in order to achieve a movement bring about the fuel particles 34 upwards in the state of critical distribution. The system offers the same control options and the same automatic ones Fuses like the reactor of FIG. 1. The perforations 45 are kept narrower than that Size of the fuel particles 34, so that discharge of fuel particles 34 into the Cooling system is avoided with certainty.

The inlet chamber 42 and the outlet chamber 46 of the pressure vessel 36 are connected to a closed primary cooling circuit. An embodiment for this is shown in FIG. 3. The inlet chamber 42 is located on a return line 58 which has a throttle valve VT for regulating the flow from the line 58 into the lower part of the pressure vessel 36. Similarly, the outlet chamber is connected to a line 56 in the primary cooling circuit.

An advantage of the invention is that the shape of the fuel elements used, the introduction same in the container of the reactor core and. the application from the latter to special allowed in a simple way. For this purpose, the container 50 is provided with the fuel delivery pipe already mentioned 37 provided; Through this pipe, the fuel particles 34 from the container 50 into a container 60 for used Operating fluid discharged. To manage the transport of the fuel particles, is the container 60 is preferably connected to the primary cooling system, specifically in parallel with the boiler 36 through a conduit 62 which connects the conduit 56 to the top of the container 60. In line 60 there is a control valve 64. Another line 66 connects the Lower part of the container 60 with the return line 58 of the primary cooling system; lie in this line a control valve 70 and a pump 68.

The container 60 is provided in its lower part with an intermediate wall 72 which is above the Connection point of the line 66 is and has perforations 74 evenly distributed. the Partition 72 is similar to the support 40 of the pressure vessel 36 towards the center point inclined down. In the center opens a fuel delivery pipe 76, which down the The bottom of the container 60 is penetrated.

The delivery pipe 37 of the pressure vessel 36 is outside the vessel with a control valve 78 provided, a shunt tube 80 of smaller cross-section is provided, which the Line 58 connects to tube 37 on the side of valve 78 facing the pressure vessel.

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A control valve 81 is located in the line 80. The container 60 includes a number of plates 82 which are neutron absorbing Material, e.g. B. boron, cadmium, hafnium or the like. Contain the formation of a chain reaction to prevent in the container 60 when this is filled with fuel particles 34. The Conveyor pipe 76 has a valve 84 from which a bypass pipe 86 branches off for manufacture

to a connection between the conveyor pipe 76 and the line 66. In the line 86 is a Control valve 87. The lower end of the fuel delivery pipe 76 opens into a discharge line 88, ■ which is on the high pressure side of the pump 68 and has a valve 90.

The container 60, as nicely indicated, serves to store the fuel particles 34 after they have been consumed in the container 50 to a point at which their usefulness decreases, so that replacement of these particles is desired. This is done with the aid of the system according to FIG and 58 flows with the throttle valve VT opened to a certain degree. It is then first necessary either to close the throttle valve VT slightly or to reduce the flow through the primary cooling system in some other way, for example by reducing the speed of the pump in the system. This measure leads to the fact that the fuel layer collapses; In the process, however, it is expedient to maintain a medium flow which is sufficient to keep the fuel particles that have fallen down in slight movement. The consequence of this is that the chain reaction in the reactor ceases, with a coolant flow of reduced extent continuing to circulate in the primary cooling system and removing residual heat from the pressure chamber 36 and the operating material elements 34. Now the pump 68 is put into operation after opening the valves 64 and 70, so that the speed of the medium flow conveyed through the container 60 is slightly above the speed at which the fuel particles 34 would be kept in motion. The valve 78 in the delivery pipe 37 is then fully opened so that the coolant flows through the delivery pipe 37 into the fuel layer of the container 50. This flow is set so that its speed is slightly greater than the speed required to keep the fuel particles in motion and less than the rate of descent of the fuel particles, so that the latter through the coolant column rising up in the pipe 37 can fall down into the container 60. The coolant flow in the delivery pipe 37 can be regulated by the valves 64 ′ and 70. The falling movement of the fuel particles 34 through the conveyor pipe 37 into the container 60 is facilitated by the reduced coolant flow of the primary circuit, which is sufficient, however, to keep the fuel layer in such slight movement that the fuel particles due to their gravity to the opening in the center of the Strive for support 40 and fall into the conveyor pipe 37 here. The upward flow of medium in the conveying pipe 37 regulates the extent of the transfer of fuel particles from the container 50 into the container 60.

It is useful. that before the valve 78 is opened, a stream of the in the container Primary cooling system circulates to preheat this container and that this coolant flow is maintained after all fuel particles have fallen into the container 60, in order to dissipate residual heat from the fuel particles caused by radioactive decay of the Fission products and the release of neutrons retained in the fuel arises. Then the valve 78 of the delivery line 37 is closed, and the medium flow through the container 60 is reduced by setting the valves 64 and 70 accordingly the speed at which the fuel particles 34 are kept in motion. -90

In general, it is desirable to keep the fuel particles 34 in the container 60 long enough to allow a considerable decrease in the gamma-ray activity of the fission products before they are transported away for reprocessing. After a sufficient long storage period in the container 60, the fuel particles are transported away that the upward flow through the container 60 with the appropriate setting the valves 64 and 70 increases again, in order to increase the fuel particles in slight motion offset; the flow, however, allows the falling movement of the fuel particles through the conveying pipe 76 do not inhibit. The valve 90 is then opened to high speed through the drain 88 to be generated after the processing plant. Then the valve 84 of the delivery line 76 open; medium flows through this line into container 60 at a speed which is slightly higher than that at which the fuel particles are kept in motion, but below the free fall speed. This speed is controlled by means of the valves 64 and 70 regulated. The fuel particles now fall through the delivery line 76 into the discharge line 88, in which it detects the flow of liquid exiting at high speed and transported away. After the particles have been discharged from the container 60, this part of the system by stopping the pump 68 and closing all valves 64 ,. 70, 84 and 90 (valve 78 was already before . closed) to be returned to the starting position.

The purpose of the secondary line 80, when the valve 78 is closed, is to provide a black via the valve 81

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chen coolant flow to generate fuel particles. cool what is in this Part of the conveying pipe 37 are located and, since they are in a neutron flux, generate heat be able. Similarly, when the valve 84 is closed, the secondary line 86 enables regulated through its valve 87, a coolant flow through fuel particles in the pipe 76, so that by gamma rays .in in the fuel particles contained fission products is dissipated heat generated.

The system according to FIG. 2 is also for the supply of fresh operating material 34 from a Equipped reservoir 94 in the container 50 by hydraulic means. The reservoir 94 is of essentially the same construction as the container 60 for used fuel. Corresponding parts are therefore provided with the same reference numerals and are no longer used described in detail. One difference in the construction of the container 94 is that it has an opening that can be closed by a plug 96 on the top. The container 94 is also to the primary cooling circuit in parallel with the pressure vessel 36 and in parallel with the container 60 connected. This is done for the upper part of the container 94 through a line 98 with valve 100 and the already mentioned line 62. A second line 102 connects the lower part of the container 94, below the partition 72 with the return line 58 of the primary cooling circuit via a pump 104; A control valve 106 is located between the latter and the container 94.

The fuel transport pipe 76 of the container 94 is connected to a delivery line 108 which leads to the upper part of the pressure vessel 36. The outlet end 110 of this conduit penetrates the side walls the pressure vessel 36, the cylindrical screen 43 and the container 50 next to the upper ends of these parts, but below the upper end walls of the container 50 and the Screen and under the grille 47. Line 108 is under the control of a regulating valve 112, which is between the conveyor pipe 76 of the container 94 and the line 102 and expediently with a secondary line 114 with a narrower cross-section is equipped.

If a charge of operating fluid is introduced into the container 94 with the stopper 96 removed and the stopper has been put back in the closed position, then the container can open The temperature and pressure are brought up by starting the pump 104 and opening the valves 100 and 106. The fuel layer 34 in the container 94 is regulated accordingly the speed of the medium flow brought into motion by means of the valves 100 and 106; however, the speed of the flow must be less than the falling speed of the fuel particles lie. If valve 112 of delivery line 108 is opened, a higher current rises Speed through this line in the upper part of the container 50. When the valve 84 is open Delivery line 76 of the container 94 fall ■ the fresh fuel particles through the pipe 76, in which the ascending flow of the medium is only at a speed that does not impede free fall may have, in the conveying line 108 and are conveyed up into the container 50. When the container 94 is completely emptied, the valves 84, 100, 106 and 112 can be closed and the pump 104 can be stopped. The reactor is then started up by increasing it of the current in the primary cooling circuit for the purpose of expanding the fuel layer in the Container 50 to the critical level.

It is an advantage of reactors of the so-called homogeneous type mentioned at the outset that parts the solution can be replaced and so that the reactivity is maintained despite the burning of the fuel and the formation of poisoning products and the like in the reactor. It is evident, however, that a reactor of the type according to the invention better addresses this problem solves because the fuel particles 34 can be removed hydraulically in a simple manner, without Impairment of cooling and without interruption of operation in the reactor itself. How can be seen by removing used fuel or adding fresh Enable control of fuel in the desired quantity. This reduces reactivity by removing a relatively small portion of the fuel particles 34 from the container 50 in the container 60. Conversely, the reactivity in the container 50 is increased when one a little fresh fuel is transferred from the storage container 94 into the container 50. This Regulation is used in particular to prevent the impoverishment of fissile material and its formation to counteract poisoning products, reducing reactivity in the container 50 would be reduced, as well as to compensate for temperature and pressure effects on the Reactivity.

. It is already known that the critical state of a number of Reasons such as depletion of fuel elements, introduction of impurities and toxins, does not remain constant. The relatively simple measures to introduce fresh fuel and to remove spent fuel from the container of the reactor core allow the To keep the reactor core in a state of equilibrium with regard to the fission process.

It may be desirable to have those existing in the vessel 50 of the reactor core at any one time Check conditions; this can be done in a simple manner with the subject matter of the invention by placing a relatively small amount of fuel 34 in container 60 transferred, this sample examined and then transported away through the line 88.

It is clear that at least some of the fuel elements do not include any fissile substances must, but purposes other than those

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can be used to generate energy or heat. For example, part of the fuel. elements contain a neutron absorbing substance such as boron, cadmium, hafnium or the like, for the purpose of controlling the cleavage processes; other fuel elements can consist of one Substance, the heavier isotopes of which are to be obtained by exposing them to radiation suspends in the vessel 50 of the reactor core.

It is also possible to add fuel elements that have a braking effect on neutrons Contain substances such as hydrogen or carbon. When the reactor produces fissile matter or if it is used partly for this purpose and partly to generate energy are fuel particles that contain corresponding elements, such as uranium 238 or Thorium 232 for the production of fissile plutonium 239 and uranium 233, fed into the reactor.

leads. In summary, it should be said that the invention is not restricted to the use of fuel particles 34 that only contain fissile matter, that rather others Materials in tablets, pills, pearls or the like.

Find form for different purposes use and in the same way in the container 50 of the Introduced reactor core, expanded in it with regard to their stratification and out of it again can be removed, as can the particles 34.

According to FIG. 3, the lines 56 and 58 of the primary cooling circuit are shown in FIG connected in a closed circuit with a boiler 116, which is connected between the line 56 and a line 118; the latter forks in two arms 120, in each of which a pump 122, each with a control valve 124 or 126 on both Sides lies.

The primary cooling circuit thus contains Putnpen- ^N units which can be regulated for the purpose of controlling the speed of the coolant flow in the primary circuit and which convey the coolant under pressure via the throttle valve VT into the lower part of the pressure vessel 36 of the reactor. On the way through the pressure vessel from bottom to top, the temperature of the coolant rises; the coolant flows from the top of the pressure vessel to the boiler 116 and from there to the pump unit.

The boiler 116 includes a heat exchanger tube in, which by lines 113 with a Steam boiler 109 is connected. The steam generated in the pipe in the boiler is in the Boiler 109 collected; from this boiler it is withdrawn through a pipe 115 and the Consumers, e.g. B. a steam turbine supplied. A line 117 serves the purpose of supply of water to the boiler.

The cooling circuit is filled with coolant via a feed line 119 by means of a Pump 121 and a pipe 125 to the line 118 between the boiler and the main pump sets 122. The line 125. is under the control of a valve 123.

If necessary, the primary cooling circuit can be combined with a system that regulates the cooling be the various controls for the purpose of preserving the coolant in one prescribed Condition contains. The embodiment of FIG. 3 includes control pumps 128 which Circulate coolant in the control system. The control pumps 128 are inlet side via a Line 130 connected to line 58 of the primary cooling circuit, so that part of the coolant is branched from the primary circuit into the control system. The outlet sides of the control pumps 128 are each regulated by a valve 132 and connected to a discharge line 134.

Part of the control system includes a pressure equalizer 140 to maintain constant pressure and equipped for degassing the cooling liquid. This part of the control system has a line 136, which on the one hand is connected to the line 56 of the primary cooling circuit and on the other hand to a heat exchanger 138 is connected. The latter is connected by a line 137 with the pressure equalization and degassing vessel 140. Contains in water-filled systems this vessel 140 heating elements, e.g. B. electrical heating resistors 142 to the temperature of the incoming Bring water to the level required to create a volume of steam in the top; to the top of the vessel 140 is connected to a line 144, which forks into two arms; one of the two arms includes a check valve 146, the other includes a liquid seal 148; both arms open into a conduit 150 which in turn empties into the atmosphere. Collect any dissolved gases are in the vapor and are through the liquid seal 148, which is used for this purpose has capillary-shaped outlet, blown out.

Line 134 which controls the output of the control pumps 128 receives is on the one hand connected to the main line 56 via a check valve 152 and is on the other hand via a line 158 passed through the heat exchanger 138 with the pressure equalization and degassing vessel 140 in connection. In the line 158 are a Control valve 156 and a check valve 154.

The described control system according to the invention works in such a way that, depending on the relative pressures, the coolant in one of the flows through line 136 in both directions and that the volume of steam and gas in the Vessel 140 acts as a pressure wave absorbing and reducing cushion. When the control pumps 128 are in operation, then the line 134 is under increased pressure, and, depending again from the pressure in the vessel 140, the main line 58 is withdrawn liquid returned directly to the main line 56 via the check valve 152, or it flows through the Heat exchanger 138 and vessel 140 when valve 156 is open and then through Line 137, heat exchanger 138 and line 136 to main line 56. Any excess pressure

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in the vessel 140 escapes through line 150 in the atmosphere.

The coolant control system can also be combined with devices for cleaning the liquid being; for example, ion exchanger 160 may be any suitable ion exchange medium contains, for example synthetic resin materials or the like., As well as filters 162 may be provided. Coolant withdrawn from the primary cooling circuit and the main line 58 by the pumps 128 when valve 166 is open, via line 164 through heat exchanger 167 and over a connecting line 168, if necessary conveyed through a second heat exchanger 170. The second heat exchanger 170 is via lines 172, 174 from the outside with a independent cooling medium charged. After leaving the second heat exchanger 170 If the valve 176 is open, the liquid flows into a chamber 178 and from here through the filter 162 into a line 180, which the liquid through the first heat exchanger 167 via a Check valve 182 of the main line 56 of the primary circuit supplies again.

If the liquid in the cooling circuit is additionally exposed to the action of the ion exchanger 160 is to be subjected, valve 176 is closed and valve 184 in the feed line to the ion exchanger open. Likewise, valve 186 of line 188 is opened from the ion exchanger leads back to chamber 178. ■

The described coolant control system is only one example of the control measures used in an energy-generating reactor according to the invention can be made in the primary cooling circuit be able. Such a control system can operate continuously or intermittently for the purpose the degassing and cleaning of the liquid circulating in the primary cooling circuit. As you can see, the control system is capable of removing all sorts of contaminants from the coolant in the reactor, including gaseous and solid components existing impurities to remove.

If the reactor according to the invention can only produce fissile matter or experimental Is to serve purposes, the boiler 116 by a simple, at low temperatures and low pressure heat exchangers are replaced. In this case the boiler can 116 or the heat exchanger, if a fresh water source is available, completely to be dispensed with; the pure water is then fed directly to the reactor and directly from the same derived again.

Claims (11)

PATENT CLAIMS: i. Atomic nuclear reactor with a container for the reactor core, its perforated bottom as a support for a layer of solid fuel particles in tablets, pills, pearls Od. Like. Form, of which at least a part contains fissile matter, and with Means for generating a flow of cooling liquid through the perforated floor and the Container to an outlet in the upper part of the container, characterized by such Arrangement that the fuel particles are freely movable in the container, and through Means for changing the strength and pressure of the coolant flow, such as that the fuel particles are raised in a predetermined critical distribution will. . . · 2. Reactor according to claim 1, characterized in that the perforations on the bottom of the container are relatively tight and evenly distributed, so that the upward Liquid flow pulls through the container in an even distribution. 3. Reactor according to claim 1 or 2, characterized in that the container is arranged in a closed vessel which has a liquid inlet on the side of the perforated bottom and a liquid outlet on the opposite side, wherein ^! Between the side walls of the container and the side walls of the boiler there is an annular space which forms a neutron reflection screen. 4. Reactor according to claim 3, characterized in that the annular space at its upper and lower end narrowed inlet and outlet openings, so that through this A limited stream of coolant flows through the space. 5. Reactor according to claim 1 and 2, characterized by an upright, closed, tubular boiler with cooling liquid inlet at the bottom and cooling liquid outlet on the head side, a plurality of concentrically arranged tubes of different diameters, which has a plurality of outer annular spaces and an inner, cylindrical container for the Reaktorkern'bilden, with narrowed inlet openings in each of the annular spaces in the lower part and narrowed outlet openings are provided in the upper part, so that in the annular spaces Coolant bypasses flow and reflection screens for the vessel of the reactor core are formed. 6. Reactor according to claim 1 to 5, characterized by the use of a cooling liquid, which has the property of slowing down neutrons. 7. Reactor according to claim 1 to 6, characterized by the use of a material for some of the fuel particles that are suitable to be converted into fissile matter to be converted. 8. Reactor according to claim 3 to 7, characterized in that the liquid inlet and the liquid outlet of the boiler (36) in a closed primary cooling circuit (56, 58) 609 514/416 W 14831 VIHc / 21g the pumps (122) for generating the circulation of the liquid under pressure and means (VT) for adjusting the liquid flow through the boiler (36) from a minimum value at which a noticeable agitation of the fuel particle layer does not take place, to a higher value Value at which the fuel particles, with mutual separation in the state of critical distribution maintaining a chain reaction, in which each particle is surrounded on all sides by coolant, are driven up in the container of the reactor core. 9. Reactor according to claim 8, characterized in that the cooling circuit (56, 58) has a Contains heat exchanger (in 16, 116). 10. Reactor according to claim 8 or 9, characterized / that in connection with the Primary cooling circuit and parallel to the boiler (36) an additional flow circuit for treatment of fuel particles is provided, consisting of a fuel particle storage container (60), a device for controlling the flow through the additional circuit, a fuel delivery line (37) between the top of the reservoir, an opening in the perforated partition of the container (50) and means for opening and closing this delivery line, such that when the delivery line is open and with a reduced flow of the cooling liquid through the container of the reactor core, the fuel particles fall into the storage container. 11. Reactor according to claim 10, characterized in that that for refilling fresh A further storage container (94) is provided in the container of the reactor core for operating fluid whose lower part is connected to the upper part of the boiler (36) through a feed line (108) connected "is in such a way that fresh fuel particles are removed from the storage container and can be fed to the boiler (36) via the feed line (108). Referred publications:
Swiss Patent No. 275951;
Journal de Physique et le Radium, Vol. 12, 1951, p. 751. 1 sheet of drawings © 609 514/416 5.56