DE1764459C - Atomic nuclear reactor with a support arrangement for the fuel elements of the core - Google Patents

Description

45

The invention relates to an atomic nuclear reactor with a support arrangement, a number of exchangeably arranged in the support assembly and carried by this fuel elements, the with the support arrangement together form part of the reactor core and with the help of a circumferential Coolant are cooled, each fuel element a number of fuel rods each of which is provided with a jacket having a narrow gas discharge passage containing surrounded nuclear fuel, the gas evacuation passages leading to a fuel element belonging fuel rods are connected to one another by a pipeline system.

In nuclear reactors using solid nuclear fuel, there is often a desire to have the Nuclear fuel with a suitable material, such as a metal, to clad that of the subject Allowing nuclear fuel to be carried out from a liquid cooling stream passing through the reactor core circulates for heat dissipation. With the help of such a coating it should be achieved that impurities of the coolant can be avoided by the nuclear fuel. As a nuclear fuel element during its lifetime in the reactor core of an atomic nuclear reactor for long Periods of exposure to strong radiation and high temperatures should be the case Coating will maintain its cohesion throughout the life of the nuclear fuel element concerned, with a view to the fact that an increase or change in the volume of the solid nuclear fuel material can occur and that fission product gases through this nuclear fuel material be generated.

In so-called fast nuclear reactors, in which it is generally for economic reasons it is desirable to achieve a strong burn-up in the case of enriched nuclear fuel during the currently expected service life of such a nuclear fuel element a considerable Amount of fission product gases generated. Accordingly, when designing an atomic nuclear reactor, this must be done and particularly, take precautions when designing a high temperature, gas-cooled nuclear reactor to discharge these fission product gases.

It is already known (US Pat. No. 3,291,698) to use nuclear fuel elements in a gas-cooled, high-temperature, high-temperature atomic nuclear reactor which are provided with a sealed fuel cladding serving as a coating. In these known nuclear fuel elements, a material such as sodium, which is liquid at the operating temperature, is used to fill the fuel cladding and also as a ? To facilitate heat transfer from the fissile nuclear fuel to the wall of the nuclear fuel cladding. With the aid of a flexible part of the nuclear fuel cladding, which can expand or contract to the pressure difference existing between the inner and the outer part of the nuclear fuel cladding, the mentioned pressure difference is equalized. In these known nuclear fuel elements, the fission products formed are stored within the nuclear fuel cladding in the area which is variable in volume and which is formed by the said flexible part. Although such a nuclear fuel element has various advantages in its application and works satisfactorily in certain nuclear reactor applications, it may be desirable from a hazard point of view not to use a material such as liquid sodium in certain types of nuclear reactors.

Instead of storing gaseous fission products within a sealed nuclear fuel element enclosure In some cases it can be advantageous to extract the relevant cleavage products from the immediate Close to the reactor core and remove them either outside of the nuclear reactor or in to store any other atomic nuclear reactor part, in which it is a much smaller one Have an effect on the neutron balance. In this context there is already a device became known (USA.-Patent 3 201 320), which is used for the removal of fission products from nuclear fuel

5 6

Material elements are used in a reactor core. It contains aisle that is in one in the respective second if a cleaning gas flow ends through an outlet opening located on a porous contact surface, Graphite section of each of the fixing points provided in this and that in a likewise known manner Gas-cooled atomic nuclear reactor facilities are provided that the fuel-nuclear fuel elements submitted. 5 elements can be detachably attached to the support structure,

This cleaning gas flow is through a passage and that the fastening devices the plant access network to a separate area of the atomic surface with the exit reactor not aligned with one another directed there. In addition to a certain opening of the first and second passage Increase in the neutron yield in the reactor - hold together in a liquid-tight manner. The invention The core is as a result of the removal of the fission products from io compared to the known ones considered above the otherwise sealed nuclear fuel elements atomic nuclear reactors have the advantage that they on the transport of the spent nuclear fuel - relatively easy way, d. H. with the help of a relative Fabric element to a distant reprocessing using little construction effort make it possible without the need for an individual gaseous gap pressure equalization facility in the case of the respective nuclear fuel- 15 products to be discharged from fuel elements encased must be made or without the equips.

Danger of transporting pressurized Further advantages and appropriate configurations

Nuclear fuel cladding. Services of the invention emerge from the following

Furthermore, a gas-cooled atomic nucleus description of the reactor shown in the drawings has become known (Swiss patent ao presented exemplary embodiments.
416 858), a support arrangement and a number Fig. 1 shows schematic parts of a different

of atomic nuclei containing interchangeable features of the invention in the support arrangement and fuel reactor system supported by this;

contains elements, which with the support arrangement Fig. 2 shows in exploded perspective

together form part of the reactor core and represent a fuel element of the in FIG. 1 with it With the help of a circulating coolant, the atomic nuclear reactor is cooled together with a will. Each fuel element has a number of these fuel elements carried in the reactor core Fuel rods, each one with a support assembly;

FIG. 1 having a narrow gas discharge passage. 3 shows a top view of a section of the FIG

Containing coated nuclear fuel, wherein 30 F i g. 2 nuclear reactor support assembly shown Gas discharge passages to a combustion;

Fuel rods belonging to the material element by a fig. 4 shows a fuel element along the line in FIG

Piping system are interconnected. From F i g. 5 registered line 4-4 in an enlarged disadvantage in this known gas-cooled Kernre- Berten horizontal section;

The actuator, however, is the relatively complex structure of FIG. 35 FIG. 5 shows an enlarged vertical section individual nuclear fuel elements, to which the during along the in F i g. 4 registered line 5-5, where Fission products formed during operation are shown with the aid of a how the fuel element is in the combined purification stream to be able to dissipate. worn state in a nuclear reactor core

After all, it is already known (being British;

Patent specification 966 978), in gas-cooled atomic nucleus 40 F i g. 6 shows in a view similar to FIG. 5 reactors to provide fuel elements, each of which has a vertical partial section through another Ausein first contact surface, which in each case to guide form according to the invention;
a second, provided on a Traganordnuqg F i g. 7 shows a top view of the embodiment

Contact surface. Fastening form according to FIG. 6;

supply devices provided, which the fuel 45 F i g. 8 shows a sectional view along the lines of fabric elements on the support arrangement that can be detached. 6 registered lines 8-8.
consolidate. This known arrangement is also liable in the case of the FIG. 1 to 5 shown execution

the disadvantage of a relatively high structural shape according to the invention is a fuel wall to from the respective fuel element element 11 used, which consists of a bundle or Remove fission product gases. 50 consists of a plurality of individual fuel rods 13.

The invention is based on the object. Each of these fuel rods 13 contains an elongated one a way to show how with an atomic nucleus thin-walled fuel cladding 15, which at their Reactor of the type mentioned is to proceed, the underside is suitably closed and at its around in a relatively simple and yet safe way top with a pin 17 in the reactor gas-shaped Fission products from the narrow gas discharge 55 is hung. One through the top of the tenon to be able to discharge passages. 17 extending therethrough, defining an interior space

The above-mentioned problem "Bore 19 serves as a ventilation passage; an am in the case of an atomic nuclear reactor, the upper end of each fuel element mentioned at the outset is provided Art according to the invention in that the fuel piping system 21 connects the in each of the elements in a manner known per se in each case a 60 fuel rods 13 of the fuel element present Have contact surface, each at one of which ventilation passages with each other. The pipe second, instruction system 21 provided on the support arrangement 'has in the upper region of the bearing surface is applied so that each fuel element has a fuel element 11 above the fuel rods 13 first, fairly large, cylinder-bound, centrally arranged, with the respective pipeline system Contains passage, which is in a 65-shaped chamber 23. This chamber 23 is with a first contact surface located outlet opening suitable material 25, such as ended with activated charcoal, that the support arrangement fills a second, which by absorption heavy metal Faltproeincr The throughputs leading to the gas intake device, which would otherwise be in the passages of the

Deposits the pipeline system · or spreads a rich lying value of about 0.7 at the pressure

could. of the coolant flow exceeds. With the opening of the

As can be seen particularly clearly from FIG. 5, the line 61 is connected to the valve 41 with the line 49 leading to the beconnects a passage 27 leading to the upper part of the chamber holders. The mer 23 with a point on the outside of a part 5 valve 51 on the container 43 is open, and the the fuel element support device. These support valves S3 and 55 on the remaining containers 45 and device is used, the fuel shown 47 are closed. When the valve 41 opens, element II in the assembled state are thus those in the fuel elements 11 Hang in the reactor core. The carrying device puts resulting gases into the container 43, introduced into here the only detachable connection between the m which initially almost atmospheric pressure There are vent passages in the fuel rods 13. However, as soon as the one in the fuel rods of a fuel element 11 and a passage pressure 13 to a value lying below the wetted 29 in a horizontally extending grid-specific pressure difference, which is lower than the fuel elements 11, the valve 41 closes. the nuclear reactor hanging support arrangement is used. 15 that the valve 41 is switched off during the reactor operation - The passage network 29, which is subsequently opened and closed alternately and is discussed in greater detail in the following, by means of the horizontally speaking manner the fission product gases from the extending grid plate 31 runs, causes a re fuel rods 13 dissipates, while on the other hand Dundant fluid connection of the pipeline - the gas pressure prevailing in the fuel rods systems 21 each fuel element with the tube 30 is regulated in such a way that it is on a slightly systems of adjacent fuel elements. below the pressure of the pressure coolant flow

As shown in FIG. 1 also shows, leads a pipe lying value is held. That way is line 35 from one or more along which a sufficient internal support for the thin-edge of the grid plate 31 is provided to the walled fuel material coating, a gas control system 37. The gas control system 37 as The gas pressure is increased by the gas control system 37 contains in the following also as control valves or in the fuel rods 13 and in the other BeVentile 39 and 41 designated valve devices extend the entire gas evacuation system always and containers representing receptacles a value below the coolant flow pressure 43, 45 and 47, which are held in parallel via shut-off valves 51, so that any gas loss that may occur in the system is locked into the system. The control valves 39 and 41 are directed to open and not to the outside into the coolant and close depending on one over one current. If the radioactive fission product gases in the coolant flow would penetrate the membrane present in the respective valve, this would prevailing pressure difference. Both valves 39 adversely affect the coolant flow and 41 respond to the pressure difference between 35 cleans. But even when the coolant flow drops, which flows through the line 57. medium pressure, either unintentionally, and that in the fuel rods 13 as in an emergency, or on purpose, as during prevailing pressure. the fuel renewal, the valve 41 opens,

When a nuclear reactor is being charged, it prevails as soon as the coolant pressure drops; the valve bleiot

the reactor and in the fuel rods 13 40 then open until the fission product gas pressure

atmospheric pressure. When a gas-cooled by the certain pressure difference on a

Reactor is pressurized so that the pressure value is lowered below the coolant pressure

of the circulating coolant flow to a point or until a point is reached. on which the capacity

desired working pressure of the reactor is increased, the container 43 a further decrease in pressure

z. B. to about 70 at, then the pressure exceeds the 45 connection system releases.

The coolant flow into the Before the reactor is emptied, the into the Fuel rods prevailing pressure, the approximately still fuel rods 13 prevailing fission product gas

is at atmospheric pressure. The valve 39 is pressure to one at atmospheric pressure or

but designed so that it opens when the pressure drops to a slightly lower pressure,

difference exceeds a certain threshold, 50 This is done with the help of the container 45 and, if

z. B. about 7 at. When the valve 39 opens, this becomes necessary, with the aid of the container 47. The containers

Coolant gas through line 59 into line 35 45 and 47 can originally be evacuated for this purpose,

introduced until the pressure in the fuel rods so that in them a pressure of a few millimeters

a value in the range of about 7 at of the coolant prevails; In contrast to this, a (here

Has reached the current pressure. 55 not shown) vacuum pump with these containers

During the operation of the reactor are connected, which these containers evolve periodically due to the fission of the nuclear fuel material. Before the mentioned emptying of the reactor in the fuel rods 13 fission product gases, the valve 51 of which is closed, whereby the occurrence of the rise in the internal pressure in the holder 43 is sealed with the evacuated individual fuel rods leads. This valve 53 connected to pressure to 60 container 45 is opened. the rose affects the container 45 via the lines 35 and 61 is generally so strong that the in Valve 41 off. The valve 41 has a membrane, the fuel rods of the fuel elements on one side of which the pressure in the fuel rods 13 acts in the area or pressure prevailing in the reactor and on the other side of which these elements are associated with the core the pressure of the subatmospheric pressure supplied through the line 57 can be reduced. Coolant flow acts. The valve will open when the pressure is not below the desired value if the pressure in the fuel rods 13 is to drop below, the container 47 can additionally be operated within a certain threshold value. Thus, a suitable approach

10

turning the gas control system 37 in a considerable position, the relevant pin is held, Extent the risk of contamination by z. B. by a welded connection. In the top gaseous fission products during the fuel- the cross member 69 is in each case an open channel or admission. The system 37 also has an open channel 75 provided, which is almost additional advantage that the lowering of the 5 over the entire length of the respective cross member The pressure of the cleavage products at a pressure which is below and which occurs shortly before the respective carrier atmospheric pressure, ends.

without a vacuum pump with radioactive A small, the cross member 69 vertically through

Comes into contact with fission products. The cause running hole 79 connects each in the

this is due to the fact that the containers 45 and 47 are larger in the underside of the cross member

are evacuated to the desired extent before one of the holes 73 with the channel 75.

Valves 53, 55 is opened. plates 79 seal the top of the channel 75 so far That in the illustrated embodiment of the that close above the middle fuel rod one Fuel element 11 applied special gas outlet remains through which a connection to

The guide system is best shown in FIG. 4 and S. 15 to an overlying collecting container 89

According to FIG. 4 and 5 contains the fuel element being manufactured. It should be noted that the gutter is out

11 an outer jacket or one at the ends is provided for reasons of simpler manufacture

open container 65 with essentially square and that in its place also with a bore

table cross-section. This outer jacket surrounds a circular cross section in the cross member 69

a group of 49 fuel rods 13, which in to could be provided.

seven purees are arranged, in each of which seven the one representing a receiving device Fuel rods. The number of collecting containers 81 selected here runs transversely to the cross members Fuel rods is used only for the purpose of 69; it extends in a corresponding manner between the explanation of the invention; If desired, more or less fuel rods 95 can of course be seen on opposing side walls of the fuel element container 65. In the illustrated embodiment, one fuel element can be used. In management form, the collecting container 81 is through a a developed fast gas-cooled reactor, narrow hollow container formed from four in which fuel elements of these general narrow longitudinal stainless steel plates and two Type to be used includes each focal- small end pieces can be welded together, fabric element 15 rows of 15 fuel 30 in the bottom of the sump are seven rods 13. It should be noted that the cross-sectional shape provides holes 83, one of which is in the liquid of the fuel container from the above-mentioned connection and can deviate directly above the central opening square shape and that the combustion of the provided in the respective cross member Fabric rods any to the fuel tank gutter 75 is arranged. May have overhead bulkhead spacing appropriate. 35 container 81 is on the seven cross members 79 in such a way

Each of the fuel rods 13 contains a thinly attached that prevents the escape of gases at this related sheath 15, which is prevented in the upper region of its binding site. To that end is The collecting container is sealed circumferentially to the pin 17 in a suitable manner on the top surface of the transverse, e.g. B. by welding. The girders are welded on. In this way are through the Hole 19 in this pin serves as a gas discharge 40 collecting container 81 over all fuel rods 13 passage for the relevant fuel rod. The corresponding openings in the cross members 69 upper pins 17 have a circular cross-connected to each other.

cut like the fuel cladding 15. The fuel element container 65 has a own. The upper end of the upper pin 17 is offset by a cylindrical longest formed in diameter, so that a shoulder 67 45 container-like extension part 87 with slightly smaller The fuel rods 13 depend on the dimensions. This approach part extends from The underside of seven cross members 69 down and the upper end of the container in question run into the fuel element container 65. The above; it is open at the top. The horizontal one Cross members 69 span the interior of the grid plate 31 consists of a plurality of im Fuel element container, between 50 substantially vertically arranged metal plates 89 stops formed by plates 71, which are on and 91, which run at right angles to each other and opposite sides of the inner wall of the focal point, which are at right angles Fabric element container 65 are attached to each of the cut that a lattice structure with a plurality The cross member 69 shown has on its lower open, vertically oriented compartments 93 with im page seven, circular holes73 arranged at equal distances from one another. As shown in Figure 4, each of these vertically extending compartments is shown, have the cross members 69 in the areas 93 is se designed that there is the extension part 87 of a a smaller width between the holes 73 so that the fuel element container can be accommodated, that the axially downward through the at their ends to the fuel element 11 in a desired Open container-directed coolant flow is to be carried in a 60 position in a grid plate compartment 93 less resistance is opposed. over the top of the fuel element loading

The upper pin 17 and the cross member 69 of the container extension 87 projecting central hanger 95

are made of a suitable material, such as rust-provided. The hanger 95 is m its position

free steel. As can be seen from FIG. 5, it is held by four arms 99 from the four corners The portions 65 of the container-like projection 87, which are offset in diameter, stretch diagonally

* sets of the upper pins 17 in each case in the one in the inside and the one on the container and on the

Underside of the cross member located hole 73, and hangers are attached in a suitable manner, e.g. B.

as far as the shoulder € 7 allows. In this by a welded connection. The lower end of the

11 "12

Hanger is discontinued; it has one, one welded joint, so that a resistant

smaller diameter having part 101, which a and gas-tight connection is achieved. The entire

Tube 103 receives, which is at this part in a suitable weight of the fuel element 11 of the Way is attached, e.g. B. gebagsn by a welding connection approach 119.

manure. By a pin 105 is the bottom of the 5 The upper end of the projection 119 is with a

Tube 103 closed. In this way, a conical support surface 125 is provided in which

middle chamber 23 is formed, which with the material is the existing bore opening at this point

25 is filled as with activated carbon, the heavy metal is located. To the weight of the fuel element 111

Catches fission products and from the fuel from the pull rod 113 to the conical upper

to transfer material rods during reactor operation- io area 125 of the approach "is the tensile

separates the fission product exhaust gases. Surrounded by the pin rod by a pressure sleeve 127; furthermore, is

and through the top surface of the collecting container 81, a nut 129 (FIG. 2) is provided which, with its

run through three holes 107, which have an internal thread (not shown) on a

Flow passage from the sump to rich of the Zagstabes provided external thread

represent the chamber 23 out. 15 (not shown) is screwed on. The lower end of the

The upper end of the chamber 23 extends to the pressure sleeve 127 with a tapered top to the open lower region of the hanger 95; surface 131 provided which has the same cone angle In this area, the relevant upper end of the has like the conical chamber 23 provided on the extension via the passage 27 with the through-shaped surface 125 output network 29 connected. The passage 27 may have one or more slots with surface 130 Shut-off valves should be provided, which the fuel 133 (see Fig. 5), which seal the lower end of the pressure element during the fuel supply. sleeve 127 give the appearance of a chuck. Before the gas forwarding in the pipeline is examined in more detail, the inner diameter of the lower part of the pressure system should first be that the sleeve 127 for as is approximately equal to the outer diameter one in one of the cylindrical part of the hanger 95 provided in the grid plate 31 Compartment 93 is inserted into the fuel element container, against which the said sleeve rests. set state, the weight of the fuel -

The upper end of the hanger 95 has an element from the pull rod through the nut and the Central opening 109, which is provided with suitable attachments 30, the upper end of the pressure sleeve on the attachments over-111, which wear as a J-shaped connection. The radial slots 133 run to the sub-element of the relevant hanger through one side of the pressure sleeve 127. This gives the Bayonet lock on the underside of a long underside of the pressure sleeve which is necessary in itself Allow pull rod 113 to be attached. The pull rod elasticity, in order not only to achieve an excellent seal, but also extends upwards through a (not shown) 35 device between the matching conical standpipe to the top of the reactor pressure vessel-shaped surfaces there. The standpipe just mentioned also provides an excellent seal between the part a cylindrical outer surface of the hanger 95 and extending through the pressure vessel The through-opening of the cylindrical inner surface of the pressure sleeve 127

The lower end 40 cut off between d * m, in areas where the of the tension rod 113 and the gas discharge passage connections from the side walls. Around the opening 109 provided in the hanger 95 has a certain, defined rotational position between the to reach the protruding Ansätee 111 formed bayonet-locking pull rod 113 and the pressure sleeve 127, circuit is designed so that it is provided by a corresponding in the upper region of the pressure sleeve an Innenarmchende rotation with respect to the fuel element 45 cross 135 (Fig. 2), which is on the connected to the hanger or directly from this pull rod next to its upper end can be solved. The threaded part receiving the nut 129 from the mentioned opening under dsm protruding parts 111 are shaped and so provided wedges 137 cooperate sized so that they are J-shaped connectors by being different that represent the fuel elements. These J-shaped connecting elements 50 elements-supporting device forming elements in one hold the pull rod 113 in a defined, specific relative rotational position coordinated with respect to one another rotational position, based on the hanger, a gas-tight connection is achieved which 95 when the latter removes the fuel element container after removing the fuel element 11 carries, namely after the bayonet lock ver- the reactor core can be easily detached. the binding made and the tension rod under tension 55 relative rotational position between the Ansät 119 and is brought. the hanger 95 of the fuel element

When the fuel element in question is received by the through the relatively tight fit between the outer nuclear reactor, the pull rod surface of the upper extension 87 of the fuel element 113 and the hanger 95 are attached by a container and the inner side walls of the sate 119 provided central bore upwards out- 60 relevant fuel element receiving grid. The attachment 119 represents a part of a plate compartment 93. In this combined spider 121, which has four arms 123, the slope can be seen from Fig. 5, that the height of the four corners at the top each at or depth of panels 89 and 91 that make up the Grid plate 31 formed square compartment 93 grid plate structure is slightly larger than that (Hollow part) diagonally inwards to the mentioned 65 route, which of the sowing 87 upwards over the Seeds run out. The arms in question are on fuel element container 65 protrudes at a the reactor arrangement 119 and at the corners of the grid plate-practically executed reactor arrangement subjects attached in a suitable manner, e.g. B. by a sowing 87 a height of about 0.9 m at a

13th

Fuel element 11 with an overall height that is partially blocked by deposits,

own about 3 m. In this case, the fuel element would result in a diffusion of the gas through it

Container attachment 87 in the close-fitting compartments - the respective partially blocked passage or

Walls held in such a way that it is cantilevered as a result of a flow of gas through a

Approach can be called. As above, there is another area of the redundant transit network

thinks that the J-type bayonet catch will not cause any problems.

a certain relative threatening position between the fuel elements 11 in the pull rod 113 and the hanger 95 is reached. To introduce the reactor, a fuel will cause the wedges 137 and w 93 provided in the reactor lattice structure near the upper end of the tension rod element below the respective desired compartment and the pressure sleeve and inserted into the reactor lattice structure and connected with keyway 135 that a relative rotational position of a tie rod 113 is connected by the on between the pressure sleeve and the pull rod results. The upper end of the selected compartment can then pass through the underside of the chuck, the support cross 121, to the pressure sleeve 127 and through the lower part of the tube located above the reactor pressure vessel in each of the four quadrants, through the standpipe actuatable hanger 95 a short hole will be drilled 139, the train then raises the pull rod 113 together with the part of the fuel element passageway the hanger passing through ^v located in the correct position is 27, and with the passageway network container neck 87 to bring in the desired him 29 the grid plate is connected. To be able to use subject.

In the grid structure there is a strongly redundant as shown in FIG. 5 are the bottom edges dantes pass-through network for the routing of the panels 89 and 91, which form the side walls of the Fission product gases provided. How particularly clear the respective subject form beveled, so that a from Fig. 3 and S, each arm 123 is the inwardly sloping peripheral surface 143 yields. Spider 121 with a bore passage 141 The fuel element container is with a for this purpose provided, which is provided over the respective diagonal length as matching peripheral surface 145, which the extends and in the conical surface 125 guidance of the fuel element container attachment 87 of the approach ends. How particularly clear from in the respective subject as well as the centering in this F i g. 3 shows, the individual passages are made easier. With the focal point 141 in place in the arms of the spider at the corners of the fabric element 111, the pressure sleeve 127 and the respective grid compartment 93 by a cross connector 30 nut 129 above the tension rod 113 in position with the passages 141 of three each. Thereby are the wedges 137 and the Keihiute other grid compartments connected, which are arranged together with 135 in such a way that they have the desired Secure the first mentioned grid compartment four at the corners relative rotation position. When the mother 129 colliding grid compartments of the grid plate then down on the threaded part of the tension rod to represent the image. Accordingly, each one is screwed by a 35 113, the fuel element-specific fuel element support lug 119 is put away in the grid compartment in which it is inserted, render passage 141 at one corner with the through-clamped. The lower end of the chuck of the pressure passages 141 of three adjacent arm sleeves 127 is in particular in the area cross 121 connected. A connection between the flow rate contained between the conical surface 125 of the Anvier arm of each spider and the concentric inner cylinder surface Ganges takes place through four double passages 27, wedged in the hanger, so that the whole of each of the fuel element halves located in the area of the releasable connection of the fuel element on the approach will carry out when the upper inclined edge of the down into the upper region of the chamber 23 fuel element container 65 at the beveled runs. If a lower redundancy is required, the edge of the grid plate compartment comes to rest, Of course, the number of passages can be reduced by tightening the nut 129, which reduces the fuel 141, e.g. 123 of each spider 121 only one passage of the chuck part of the pressure sleeve between the is provided. The number of conical surface of the neck and the Adjacent spider crosses formed intersection points 50 cylindrical surface of the hanger fixed. can be correspondingly lower. stuck so that an extremely tight connection

The passages 141 in the arms of the arms - the only detachable connection point in the for Longitudinal holes defining crosses 121 may be of any of a variety of sizes suitable in a fuel element and seen in stainless steel in front of the fuel rods 13 of which the support grid structure is made. 55 pipeline system is achieved. In this case, passages with a diameter can be used in a system of the type just considered 3.2 mm, the entire reactor core in eight different zones is considered to be extremely sufficient are to be divided to accommodate the fission product gas stream. Each of the eight zones can be able. In a fast gas-cooled high temperature with a separate gas control system 37 and with temperature reactor with a nominal outlet 60 separate gas collecting vessels of the above capacity of 1000 MW (e) will be provided with about 45,000 of the types described. One of those with a Fuel rods 13 used. Each such division has associated advantages Fuel rod 13 is about 100 cm long and in the fact that in the unlikely case have a diameter of about 7.6 mm that a leak occurs, as a result of which coolant-nuclear fuel-containing area only enters the gas passage working pressure of about 70 atm every two minutes during normal operating conditions with a gas from the coolant stream, about 1 ecm of splitting product gas is generated. Even where such a leak is detected by monitoring the Case that the small passages in the network 29 into the container 43 is determined gas flowing

can be. In addition, the above-mentioned division of the reactor keraes into a multitude of zo- JJ »* ™ · j £ iKKtaS? The tie rods exclude the leakage to a part of the entire stop here, too, the J ^ ro ™ B Rotation position, limit the reactor core. The breakdown; of the MS m «nerdJjgJJ. This can be carried out in a suitable manner, such as by omitting or disabling the interconnections and shutting off interconnections at the ports of the locks . ^ ^ ^ _b corners of the compartments present in the lattice structure ^ g ^^% ^ S3JL 207 surround, and the transitions. It turns out that even if 203 Bt of a ^ ™ ^c ^ j _wng ^ by one of the reactor core are divided into individual zones, almost t. "e B ^^^" the same degree of redundancy in the fission product in. " * «« Jg Jaflrit sleeve transfer The through network 29 of a certain zone is present gSCSStf at the upper end of the pressure sleeve. Another associated with this redundancy ^? R 208 »^^ _ibe J ₀₉ ^ ₁ . Advantage can, if necessary, nor by ER 207 via "^^ JJ ^ _Tr aggebüde be aufgenomzielt that of the gas control system 37 for 15 Be, ^ J ^ Ä ^ ii wTrden the pull rod, a zone connected line 35 mene a Viekahl « ^Β « ^ ™ Χ _ώ is connected below through one of points on the circumference of the grid plate structure «JJriÄ ^ f ¹ approach 211 led through. ί ^ α c ^ dedicates a part of an ann cross 212 It should be noted that the throughput redundancy achieved in the fuel element- The approach büdetemen Ie ^ ^ _{shock control} n verti also in "™? J ¹ " * ™ ₂ " _after inside in 90 "ranges 2U the gas control system can be achieved by changing the kaler« * £ * ^ Ef _6n . _The plates 214 are in

5, ggrebtj

In addition to increasing the neutron yield, form. The ^ arms, _{attentächer m} more suitable

of the reactor core by deriving the _{gap pro ^ e} ^ S ζ B through a welded connection. products in boilers which are either rearranged against loads outside the core or which are shielded by a suitable new connection eroe L the electron reflecting material, the fuel elements 201 is supported by the gas control system if possible, a reduction in the ££ 1 * iSSl.

required strength of the coating 15. Large *% £ "££££££ * from the fuel element pressure differences between the inside and the""JÄETitt ta the hanger 206 on the outside of the fuel rods are avoided, and 2OJ« bzufuh en JSt » _included cut drilling

this also applies to the commissioning of the reactor. The 35 gang 216 ^ vorgesene ^ _passage

The pressure differences that exist in each case are so large, section up ^ t ^ _{6 217 des Au} f.

that the cylindrical metal sheaths under ^^^^ are at this point a connection pressure and are therefore more resistant to swelling hangers ZlO una _Ame ^ ₃ ^^ _h than this would be the case if J ^ SwIukljSNiidiiMi 219, who appoint them be under tension. Accordingly allows 4 _"d a spa» produ "g _{Inne" area 2M?} ^ dnd the present invention to use in nuclear reactors fuel- °! ^ ^y "° M _a " _sa tees 211 contained Ausnttsoffstoffstätze ^B , in which the thickness of the ^^ SJTJ. Cylinder surfaces 222 and 1 respective metal cladding, e.g. B. Hastelloy X, only nung ^ Zl ena ^ ^ fuel element 201 is about 5 · /. of the radius of the fuel ^{rod 13 aus- 'e} _d ^{en a} ^ S _de ^ _{02 M} arranged that the Ausmachi. In addition, the invention enables 45 J ^^ SS and 218 aligned in this way, also fuel rods 13 for gas-cooled high-temperature ^ ™ ^ ² ^ passages 216 and 219 to produce a temperature reactors and fuel envelopes ^^ 7 ^^. _B ei this compound besitet lungs of stainless steel with a Innendurch- VeAmdungöe. "" _Aat ^ ^^ ^ ₂₂ l _Buu diameter of about 8.6 mm and a Wandungsd.cke ^ ^{_Γ εη Χ} ^ _ίβηβ1β processing method hergezwischen about 0.25 and 0.38 mm to be used. 50 αηβηι aurcn g B _Pieter hmesser. Since the through-In the following the JjJjK ^ J, shown in Fig. 6 to 8, outlet opening 221 downward m embodiment of the invention is considered in more detail. S "* X_; _a £ _{211 ver} runs and from there further Be this embodiment of the invention is only the f * ^ ² £ _is ^ _a fuel element only one detachable connection for each fuel element J ^^ v ^ ndung required, namely to the required, in contrast, _{221 and} 218. F i g in in 55 ^, ^ _s 1 to 5 embodiment shown, two releasable ^Α ^ ^ι _ ^ΰ0 ™ ^g _{densities of} i _age contact between the compounds provided in the... Execution * - UjJ1 emen m ^^^ _{un (J} ^ form according to Fig. 6 to 8 provided fuel- ^! Tight protection at the outlet openings element 201 is in a similar way as »be. The to jjg ⁶ ™ ^, _k ⁸ _ege L-shape formed Anlageerst described embodiment of a one and to _hd f _{e in Wese} New Testament the «« jdgta. ^fl ^ ⁿ jX _{bene 'n} in the horizontally extending mesh plate 203 embodiment of existing support assembly supported. Here, m is the middle off- Aivo ■ correspond The zyhnderformige opening 204 of a cylindrical hollow hanger rs 206 em Anjjeuaaien ν ^ _{sejnem upper E d} tension rod 203 dJdi a suitable bayon ^ tver - HoJ ^? ^% ^ _{6η (1εη} area of greater thickness closure or J-shaped structure attached. The 65 ^^ _{area is} attached with a r outer kegelfdrmi -ZtabHÖ runs through a standpipe (not auK ue _ven . _marry essentially the

schluu oacr J-H) IiIMg ^ K. ».Y -.-"

Tension rod 203 runs through a standpipe (not up. This uereicii in the um ■. ·· ». - "-

shows) towards the top of the Rcaktordruckkesscls. The gene area 224 is provided which is essentially the

. ·. - "- ι - u: iii..i ..!" Ο, "TimI uiner is opposite through the contact surface 212, in which the output

_Z cigt) to the upper part of the reactor pressure kess ^
mentioned standpipe forms a 1 part one through the

Iaßöffung221 is provided. The area of the contact surface 222 and the conical surface 224 is according to the use of four to the scope of the approach around distributed slots 226 can be defined in the radial direction. The lower end of the Pressure sleeve 2P7 is provided with a conical surface 227 which forms part of the inner surface of the Sleeve forms. At the lower end of the sleeve abuts a region 228 which has a larger inner diameter possesses, on the conical surface 227. When the pressure sleeve 207 with the nut 208 in is guided in the axial direction against the shoulder 211, the effect of the abutting one another leads conical surfaces 224 and 227 to a loading of the deformable area of the approach. on towards this load, the two surfaces 222 and 217 are pressed against each other radially inwards, with which a seal of the. Outlet openings 218 and 221 is effected. Since in the pressure sleeve 207 no gap product gas passage is required, it is unnecessary to provide this sleeve with internal grooves in order to to maintain a certain position to the pull rod 203, as is the case in the embodiment described above.

The fuel rod element 201 corresponds to the fuel rod element explained in the above-described embodiment; it contains one Fuel tank that has four vertical walls of the same size. The upper edges of the walls are bevelled; you can at an appropriate, at abut the lower edges of the bevel provided in the support structure 202 included plates 214. The fuel element container contains a upper area of reduced size; this "area consists of four equal vertical panels 236, which are welded to the walls. The walls 236 abut the inner hexagonal compartment formed by the plates 214. Four horizontal arms 237 extend inwardly from the top of wall 236 and support hanger 206. Arms 237 are attached to walls 236 and hanger 206 in any suitable manner, e.g. B. by a Welded joint. The remainder of the fuel element (not shown) can be described in the manner as described in connection with the first embodiment has already happened

Thus, the present invention has provided an improved nuclear reactor that has a improved device for diverting gaseous fission products from otherwise closed fuel cladding to one of the immediate vicinity the reactor core remote location, with only a minimal number of detachable connections are provided. The one between the interior the pressure difference between the fuel envelopes and a pressurized coolant system is kept within desired limits.

Finally, it should be pointed out that the invention is not restricted to the exemplary embodiments described above, but rather without Deviation from the inventive concept can still be modified in various ways.

1 sheet of drawings

Claims (15)

Patent claims: ■ ψ, 1. Atomic nuclear reactor with a support structure, a number of replaceably arranged in the support structure and carried by this fuel elements, which with the Support arrangement together form part of the reactor core and with the help of a circumferential Coolant are cooled, each fuel element being a number of fuel rods each of which has one of a casing having a narrow gas discharge passage contains surrounded nuclear fuel, the gas evacuation passages of the fuel rods belonging to a fuel element through a pipeline system are interconnected, characterized in that the Fuel elements (11) each have a first contact surface (125) in a manner known per se each on a second contact surface provided on the support arrangement (31) apply that each fuel element (11) a first with the respective pipeline system (21) connected passage (27) contains, which is located in a in the first contact surface The outlet opening ends in that the support arrangement (31) contains a second passage (141) leading to a gas intake device (81), which ends in an outlet opening located in the respective second contact surface, and that fastening devices (127,129) are also provided in a known manner, which the Fasten the fuel elements (11) releasably to the support arrangement (31), and that the fastening devices (127, 129) support the contact surface Hold together aligned outlet openings of the first and second passages (27, 141) in a liquid-tight manner. 2. Nuclear reactor according to claim 1, characterized in that each fuel element (11) contains a container (65) with a non-circular cross-section that the intended containers (65) are each in a receiving compartment (93) the support arrangement (31) are arranged that a beveled contact surface is provided at the end of the receiving compartment (93) and that the Container (65) with a correspondingly beveled one, beveled on the first-mentioned one Contact surface adjacent contact surface (125) is provided. 3. Nuclear reactor according to claim 2, characterized in that the fuel elements (11) associated container (65) each have a plurality of cross members (69) that Fastening means (117, 127, 131, 133) for fastening the ends of the fuel rods (13) are provided on the cross members (69) and that these fastening devices (117, 127, 131, 133) have bores (117), which with the interior spaces (19) of the fuel rods (13) are each connected and serve to evacuate gas. 4 nuclear reactor according to claim 3, characterized in that the pipeline system (81) in each cross member (69) contains a passage (75) which the gas discharge passages (19) all from the respective cross member (69) supported fuel rods (13) connects together, pnd that the piping system (21) further comprising an upper sump (81) interconnecting the cross member passages (75) connects. 5. Nuclear reactor according to one of claims 1 to 4, characterized in that the first and second contact surface is essentially cylindrical in each case, so that the support arrangement (31) has a cylindrical hollow part (89, 93) for each fuel element (11) contains that this hollow part (89, 93) has a conical surface comprises that the support arrangement (31) further contains a plurality of pressure sleeves (127) whose ' each has a conical surface at one end, the conical surface FJfläche of a cylindrical hollow part rests, and that the fastening device (117, 127, 129) the pressure sleeves (127) are loaded in the axial direction so that the conical surfaces rest against one another. 6. Nuclear reactor according to claim 5, characterized in that each fuel element (11) 'Contains a cylindrical longitudinal part (87) and that the printing sleeves (127) in this longitudinal part (87) are releasably clamped. 7. Nuclear reactor according to claim 6, characterized in that the respective first contact surface at least a portion of the outer surface of the longitudinal portion (87) comprises the conical surface of the pressure sleeve (127) forms at least part of the outer surface of the pressure sleeve, so that the respective second contact surface forms at least a part the inner surface of the pressure sleeve (127) at the relevant end of the conical surface contains that the conical surface on the cylindrical hollow part at least a part the associated inner surface and that the respective pressure sleeve (12) in the region of the second Contact surface is slotted and radially deformable. 8. Nuclear reactor according to claim 7, characterized ^ characterized in that the first contact surface at least part of the outer surface of a The longitudinal part includes that the second contact surface contains at least part of the inner surface of a cylindrical hollow part, that the conical surface of the cylindrical hollow part forms at least part of the outer surface in the region of the second contact surface and that the first cylindrical part is slotted in the region of the second contact surface and radially deformable. 9. Nuclear reactor according to one of claims 1 to 8, characterized in that a first Valve device (41) is present, which is used to discharge a fission product gas stream from the Inner spaces of the fuel rods (13) to the gas receiving device (81) is only open when the pressure in the fuel rods (13) is within a certain The pressure value of the circulating coolant flow exceeds the threshold range, and that a second valve device (39) is provided for introducing gas into the interiors the fuel rods (13) is opened through the gas discharge passages when the pressure of the circulating coolant reduces the pressure prevailing in the fuel rods (13) by one pressure value exceeding a certain threshold range, the latter being the latter The swelling range is greater than the first-mentioned swelling range. 10. Nuclear reactor according to claim 9, characterized in that the pipeline system has a Contains fission product collecting device (23). 11. Nuclear reactor according to claim 9 or 10, characterized characterized in that the coolant consists of a gas and that the gas that is through to the second valve device (39) is introduced into the interior of the fuel rods (13), originates from the pressurized coolant flow. 12. Nuclear reactor according to claim 10, characterized is characterized in that an additional evacuated receiving device (43) is provided and that means (51) for separating and connecting this receiving device (43) from or with the first valve device (41) can be seen and that the receiving device (43) has a sufficient volume and a substantial part of the gaseous fission product from the fuel rods (13) Ability to dissipate connection with these. 13. Nuclear reactor according to one of claims 1 to 12, characterized in that the fuel rods (13) each a cylindrical solid nuclear fuel material having a circular cross section included, which is surrounded by a thin-walled envelope (15), the inner diameter of which corresponds approximately to the outer diameter of the fuel material. 14. Nuclear reactor according to one of claims 1 to 13, characterized in that the casing (15) a wall thickness no more than about 1/2 the radius of the cross-sectional area of the Has casing (15). 15. Nuclear reactor according to one of claims 1 to 14, characterized in that the cladding material consists of stainless steel and has a maximum wall thickness of 0.38 mm.