FR2630250A1 - RADIOACTIVE WASTE STORAGE CONTAINER - Google Patents

Abstract

The container consists of a receptacle (2) and a plug (3), the receptacle comprising a concrete outer enclosure (4) and a composite inner wall (5) both together constituting a vessel intended to contain the waste while making it possible to absorb the dimensional changes of the enclosure with time and to insulate the enclosure thermally from the interior of the vessel. The plug (3) is a prefabricated concrete plug comprising a metal cladding (20). The receptacle (2) is provided with an annular member (15) integrally attached to the vessel and resting on the enclosure (4) to form a seat for the plug (3). Lateral parts (21) of the cladding (20) and (17) of the annular member (15) are adjacent and project into a groove (23) arranged on the upper face of the container. The edges of these lateral parts are joined, for example by welding. The container is suitable for the transport and storage of weakly or moderately radioactive solidified waste.

Description

t

  The invention relates to storage containers

  ckage of radioactive waste, more particularly adapted to the storage of weakly solidified waste

  and moderately radioactive nuclear sites.

  The containers concerned are concrete containers and the waste consists in particular of so-called process waste such as filters, evaporator concentrates and spent ion exchange resins. Concrete containers are de rigueur

  for the transport and storage of such radioactive waste

  dioactives as soon as the measured radioactivity exceeds

mrem / h.

  Liquid waste is poured into the

  containers and then packaged for their

lidification.

  Storage containers should be designed to provide optimal usable volume while ensuring biological protection over time. Known containers consist of a container closed by a plug. The container comprises a concrete shell or casing and a metal inner tub whose wall includes, if necessary, a layer of lead constituting a shield. The cap is a plug, most often made of concrete, poured on

  square. The cast-in-place concrete plugs

  sometimes cracking due to

  dimensional dimensions of concrete over time and they

  are of variable quality and difficult to control.

  Other known plugs consist of lead pellets embedded in a mixture of pitch and

  epoxy resin. This solution offers a better

  protection against radiation, but it is difficult

and expensive to achieve.

  The object of the invention is to obviate these

  by proposing a container allowing a

  faster and safer chage with a stopper

  whose quality can be controlled beforehand.

  The subject of the invention is a radioactive waste storage container, more particularly adapted to a storage of low or medium radioactive solidified waste, consisting of a container and a stopper. The container has an envelope

  outer concrete and a composite inner wall

  both mantle tank intended to contain the waste

  while allowing for the absorption of variations in

  In time, the envelope is thermally insulated from the inside of the vessel and, in cooperation with the envelope, confines the radiation inside the container. The container is characterized in that the plug is a prefabricated concrete plug having connecting means

  with said container, and in that the container

  carries a seat for the cork and means of connection

  its intended to cooperate with the connecting means of the cap to allow sealing of the container. The use of the invention makes it possible

  Moreover, a lower requirement for qualification of per-

  operator, which is of interest, particularly

  in the exported facilities (South Africa,

  South Korea, People's China, ...).

  According to other features of the invention,

tion:

  - the cap has a metal coating

  that the edge constitutes said connecting means

  of the cap and whose face turned towards the tank deli-

  moth with it the interior volume of the container;

  the container is provided with a solid annular element

  the vessel and resting on the envelope to form

  sea the seat for the cap; the outer edge of the annular element constitutes the connecting means of the container; the edges of the covering of the cap and the annular element are, after the installation of the cap on the seat, juxtaposed and project towards

the outside of the container.

  - the edges are connected together so

  sealed by a continuous weld seam or a crimped

continuous sage.

  - The metal coating is cup-shaped; the annular element comprises a radial core

  and a skirt directed upwards: the edges of the cu-

  vette and skirt protrude up the container.

  - the stopper is provided with a recess

  tending to the entire periphery of its upper surface

  re; the container shell is provided with an

  dement corresponding to the end of its inner wall facing the cap; the recesses form, when

  the cap is placed on the container,

  ge in which open the edges of the bowl and

of the skirt.

  the side wall of the cap liner and the skirt of the annular element of the container are flared to ensure centering and to contribute to

  the sealing by contact of the side wall of the coating

the cap on the skirt.

  The invention will now be described more in

  details with reference to the accompanying drawings on

what:

  FIG. 1 is a schematic side view of

  the, partially in section, of a container following a

  first embodiment of the invention.

  FIG. 2 is a view from above of the

neur of Figure 1.

  Figure 3 is a partial sectional view of a container according to a variant of the first embodiment. Figure 4 is a partial sectional view of a container according to a second embodiment of the invention; and FIG. 5 is a partial sectional view

  container according to a third method of

of the invention.

  Figures 1 and 2 show a first embodiment of the invention. The container 1 consists of a container 2 hermetically closed to

  using a prefabricated concrete plug 3.

  The container comprises an outer casing 4 of concrete and a composite inner wall 5 forming a vessel. The inner wall is of cylindrical shape and composed of different elements arranged in the order

  following from the inside to the outside of the

  Figure 1: first a first steel element 6 forming the inner face of the container, followed by a heavy material element such as lead 7 forming radiation shielding. This shield is covered by a second steel element 8 followed by a flexible element 9.

  The flexible element 9 has the function of absorbing

  ber the dimensional changes in time of the casing 2, which is essential to avoid cracks in the concrete caused by tensions in it during its withdrawal. The flexible element 9 must also serve as thermal insulation during the

  filling of container 2, since the

  Chets can be poured into the container in the hot state and undergo a rise in temperature during solidification, which causes thermal stresses in the concrete. It is therefore desirable to mitigate these stresses by providing a thermo-insulating element between the tank and the concrete shell.

  The flexible element 9 is preferably constructed

filled with expanded polystyrene.

  The element must be protected against moisture

  contained in the concrete and this protection may

  be provided by a layer 10 of a suitable material

  required, for example polyane, applied on the outer face of the flexible element 9 to prevent it from being in direct contact with the envelope 4 of concrete. An agitator 13 may be used for the

  conditioning of waste with a view to solidifying

  cation and then remains with the waste in the container. In this case, a shoe 11 forming a support for the axis 12 of the stirrer 13 with blades 14 is fixed to

center of the bottom of the tank 5.

  The container 2 is provided with an annular element

  laire 15 integral with the open end of the tank 5

  and intended to form a seat for the plug 3.

  The annular element 15 has an ime ra-

  16, a skirt 17 facing upwards and a collar

  reentrant axial lerette 18 which forms an anti-

  overflow during agitation of the waste for packaging and which delimits the useful volume

of the container.

  The container 2 is, all around its periphery, provided with a groove 19 intended to receive a belt

  handling of the empty container or container filled

fold and closed.

  The concrete plug 3 is provided with a

  metal body 20 whose side facing the tank defines with it the interior volume of the container. In the first embodiment illustrated in FIG. 1, the metal coating 20 is shaped

Bowl.

  The side wall 21 of the bowl 20 cooperates with

  re, when the cap 3 is in place on the container

  2, with the skirt 17 of the annular element 15 of the recess

  2 so that their respective edges form

  connecting means of the cap with the container.

  The edges are juxtaposed and assembled on all sides.

  length by a continuous weld seam.

  Welding is advantageously applied using a welding robot, which automates the entire sealing process. This assembly process

  also has the advantage of ensuring an absolutely

between the elements.

  Instead of applying a weld bead

  to assemble the cap and the container, it is pos-

  sible to carry out a continuous crimping

waterproof appearance of the elements.

  The side wall 21 of the bowl 20 and the skirt 17 of the annular element 15 preferably have a flared shape. The flared shape ensures the centering of the cap 3 during the introduction thereof on the container 2. The skirt 17 of flared shape forms a

  bearing surface against which the side wall rests

  21 of the coating 20 also flared, which also contributes to the seal between the cap 3 and

the container 2.

  The side wall 21 of the bowl 20 and the skirt 17 of the annular element 15 can also be

  cylindrical shape, which then requires a

  tain the game between these elements to make it easier to

place of the cap.

  The outer casing 4 of concrete exceeds in height the skirt 17 of the annular element. The open face of the plug 3 is preferably flush with or protrudes

  slightly the upper end face of the enve-

  loppe 4, when the cap is put in place on its seat, so as to present such a homogeneous surface

  as possible to facilitate the stacking of

during storage.

  The envelope 4 of the container 2 is, at the end

  mity of its inner wall which is opposite the plug 3, provided with a continuous recess 23a. The plug is provided with a corresponding recess 23b extending over

  the entire periphery of its upper face. The evidenced

  23a, 23b form, when the cap is put into

  placed on the container, a groove 23 in which

  close the edges of the bowl 20 and the skirt 17.

  The groove 23 is filled with a mortar 24 for

protect the weld bead 22.

  - The groove 23 communicates with the side wall

  the outer of the casing 4 by radial grooves

  26 forming weirs regularly arranged to the ex-

open end of it.

  The container is preferably provided with a ring 25 of heavy material of the same kind as the shield 7 forming a shield for compensating for the reduction in thickness of the wall of the container and the plug of the presence of said groove 23. L Ring 25 is disposed inside the container 2 and connected to the annular member 15 thereof. The ring 25 may be an insert as shown in Figure 1

  or be part of the shielding 7 of the inner wall 5.

  The plug 3 is provided with two sockets

  raudées 27 arranged in opposite recesses 28 on its upper face. Sockets are intended for

  cooperate with screws 29 secured to hoisting rings

  age 30 set up only during handling

of the cap.

  Figure 3 is a partial sectional view

  a variant of the first embodiment of the invention.

  vention. The container 31 consists of an envelope

  32 concrete and a composite inner wall 33 form-

  mantle tank. The inner wall 33 has the same structure as the inner wall already described with reference to FIG.

  The concrete plug 34 has a coating

  metallic metal 35 in the form of a plate. The container 31 has a flat annular element 36 which forms a

seat for the cap.

  The edge of the coating 35 and the outer edge

  The annular element 36 protrudes towards the outer lateral surface of the container. The plug 34 is provided with a recess 37a extending over its entire periphery and the envelope 32 of the container is provided

  of a corresponding element 37b at the upper end

  re of its outer side wall. The recesses 37a, 37b form, when the cap is placed on the container, a groove 37 in which open the edges of the metal coating 35 of the cap and the annular element 36 of the container. Said edges 30

  constitute the respective means of connection of the

  35 and the annular element 36. They are

  bound by a continuous weld seam 38.

  The plug 34 is provided with at least two channels 39 which connect the groove 37 to the upper face

  34. The channels 39 are intended to fill

  wise of the groove 3 by a mortar (not shown) and the evacuation of the air thereof. The groove 37 must be closed using a formwork (not shown) after the application of the weld bead 38, which allows the filling of the groove and the protection of the

weld seam.

  The plug 34 is preferably provided with a centering flange 40 disposed on its face facing the container 31. The centering flange 40 cooperates with the inner edge of the annular element 36 of the container

  31 for placing the plug 34 on the recess

  tainer. The annular element 36 is, as in the embodiment already described, preferably provided with

  a reentrant axial collar 41 delimiting the

  opening of the container 31 and forming an anti-

  overflow cooperating with the centering flange 40.

  The container 31 comprises a ring 42 made of

  heavy material forming a shield for compensating for the reduction in thickness of the wall of the container 31 and

  plug 34 due to the presence of the throat 37. The

  Water 42 constitutes an extension of the shielding of the composite inner wall 33 forming a flange

  turned towards the inside of the container.

  Figure 4 is a partial sectional view

  showing a second embodiment of the invention.

  The container consists of a container 43 closed by a plug 44. The container comprises a casing 45 and a composite inner wall 46 forming a vessel. The inner wall 46 has the same structure as that described with reference to Figure 1. The cap is provided with a metal coating 47 forming connecting means

  intended to cooperate with liaison

  container constituted by a ring element 48 which is

  of the tank 46 and which furthermore forms a seat for

cap.

  The metal coating 47 is shaped

  bowl and provided with a peripheral flange 49. The

  lateral king 47a of the bowl 47 forms a centering member during the introduction of the cap on the container. The plug 44 and the envelope 45 delimit,

  when the plug is put in place, an annular groove

  50 leading to the top of the container. The connecting means between the stopper 44 and the container

  43 are arranged at the bottom of the groove 50.

  The flange 49 is provided at its periphery d-e

  51 regularly spaced holes arranged opposite.

  corresponding holes 52 in the annular element

  48. Assembling means are constituted by bolts 53 arranged to cooperate with

  nuts 54 through said holes 51, 52 for

sealing of the container.

  A seal 55 is preferably

  mounted between the faces opposite the metal coating

  47 of the plug 44 and the annular element 48 of the

container 43.

  A metal ring 56 identical to that

  already described with reference to Figure 3 extends radially

  inside the container 43. In this case

  the ring 56 is connected to a central axial flange

  57 defining the opening of the container and forming

an anti-overflow member.

  The groove 50 communicates with the lateral wall

  the outer of the casing 45 by radial grooves

  58 forming weirs regularly arranged to the ex-

open end of it.

  Figure 5 is a partial sectional view

  showing a third embodiment of the invention

  tion. The container consists of a container 59 closed by a cap 60. The container 59 comprises a casing 61 and a composite internal wall 62 forming

  tank. The inner wall 62 has the same structure as that

  The cap 60 is provided with a metal coating 63 forming connecting means for cooperating with means for connecting the container 59 constituted by an element.

  ring 64 secured to the tank 62. The annular element

  In this case, the wire 64 is advantageously constituted by a radial extension of the composite inner wall 62. This annular element also forms a seat for

cap.

  The metal coating 63 of the cap 60 is cup-shaped. The side wall 63a of said bowl is cylindrical and forms a centering member during the introduction of the cap 60 on the

container 59.

  The peripheral part of the metal coating

  63 forms a flange 65. The container 59 is

  seen of retaining members 66 regularly arranged on

  the envelope 61 and extending radially towards the interior

  container. The retainers 66 are

  intended to cooperate with the upper face of the

  65. The flange 65 of the metal coating 63 is provided with complementary cutouts 67 of the retaining members 66 so as to allow the cap 60 to abut against the seat. Stop members 68

  are arranged on the upper face of the flange 65.

  The stop members 68 are intended to come into operation

  against the retaining members 66 of the container 59 by angular displacement of the cap 60 relative thereto. The flange 65 and the retaining members 66

  thus form a bayonet interlock which

  kills the means of connection between the stopper and the recess

  tainer. As in the second embodiment, a seal 69 is preferably mounted between the facing faces of the metallic coating 64 of the cap 60 and of the annular element 64 of the container 59.

  A groove 70 is formed between the inner wall

  of the envelope 61 and the lateral wall of the

  60. The groove 70 is filled with a mortar (not re-

  presented) after closing the cap. The throat 70

  communicates with the outer sidewall of the enve--

  loppe 61 by radial grooves 71 forming an opening

  nights regularly arranged at the open end of

it.

  The annular element 64 further comprises a reentrant axial flange 72 delimiting the opening

  of the container and forming an anti-overflow member.

  The flange 65 of the cap 60 according to this mode of

  realization can advantageously include on its sur-

  upper side of the corner portions (not shown

*) co-operating with the relevant restraining devices

  66 to block the plug in its position

closure.

  The present invention thus makes it possible

  fast and on containers. It also ensures a good quality of tightness in time between

the cap and the container.

Claims (15)

  1.- Radio waste storage container   assets, more particularly suited to the storage of   solidified waste weakly or moderately   active ingredients, consisting of a container (2; 31; 43; 59) and   cap (3; 34; 44; 60), the container comprises   both a shell (4; 32; 45; 61) outer concrete   and a composite inner wall (5; 33; 46; 62) forms   both mantle tank intended to contain the waste   while allowing the variations   in time of the envelope (4; 32; 45;   61) and thermally isolate the envelope of the   of the vessel and, in cooperation therewith, confining the radiation within the container, characterized in that the plug (3; 34: 44; 60) is a prefabricated concrete plug having   connecting means (20; 35; 47; 63) with said recess   and in that the container comprises a seat for the cap and connecting means (15; 36; 48; 66) for cooperating with the connecting means of the cap to allow sealing of the container. 2. Container according to claim 1, characterized in that the plug (3-; 34) comprises a metal coating (20; 35) whose edge constitutes said connecting means of the plug and whose face facing the tank delimits with the latter the interior volume of the container, in that the container (2;   31) is provided with an annular element (15;   from the tank and resting on the casing (4; 32) to form the seat for the plug (3; 34), in that the outer edge of the annular element (15; 36)   constitutes the means of connection of the container, and in this   after insertion of the cap on the seat, said edges of the liner (20; 35) of the cap (3; 34) and the annular member (15; 36) of the container;   (2, 31.) are juxtaposed and protrude outwards. container.   Container according to claim 2, characterized in that the edges are sealingly connected together by a continuous bead (22; soldering or by continuous crimping.   4. Container according to claim 3, characterized in that the metal coating (20) is cup-shaped, in that the annular element (15) comprises a radial core (16) and a skirt (17) directed towards the top, and in that the edges of 1-a bowl (20) and the skirt (17) project towards the top of the container.   5. Container according to claim 4, characterized in that the plug (3) is provided with a recess (23b) extending over the entire periphery of the container.   its upper face, in that the envelope (4) of the recess   pient (2) is provided with a corresponding recess (23a) at the end of its inner wall facing the plug (3), and in that said recesses (23a, 23b) form, when the plug (3) is placed on the container (2), a groove (23) in which open the edges of the bowl (20) and the skirt (17). Container according to claim 4 or, characterized in that the side wall of the   ment. (20) of the cap (3) and the skirt (17) of the   the annular portion (15) of the container (2) are cyan   lindrique. 7. Container according to claim 4 or, characterized in that the side wall of the coating (20) of the cap (3) and the skirt (17) of the element   ring (15) of the container (2) are complementary flared.   8. Container according to claim 2 or 3, characterized in that the metal coating (35)   plug (34) is plate-shaped, in that the   the annular element (36) of the container is flat and in that the edge of the coating (35) and the outer edge of the annular element (36) protrude towards the surface outer side of the container.   9. Container according to claim 8, characterized in that the plug (34) is provided with a recess (37a) extending over its entire periphery, in that the envelope (32) of the container (31) is provided   a corresponding recess (37b) on its side wall   outer portion, and in that said recesses (37a, 37b) form, when the plug (34) is in place t5 on the container (31), a groove (37) in which the edges of the metal coating (35) open out. of   cap (34) and the annular element (36) of the container pient (31).   10. Container according to claim 9, characterized in that the groove (37) is connected to the   upper face of the cap (34) by at least two   nails (39) for filling said groove (37) with a mortar and for exhausting the air out of -this one.   11. Container according to claim 1, characterized in that the plug (44; 60) comprises a metal coating (47; 63) comprising the means   connecting the plug and forming a peripheral flange   that (49; 65). the face of the coating (47: 63)   towards the tank (46; 62) delimiting with it the   lume interior of the container, in that the container (43; 59) is provided with an annular element (48; 64) integral with the bowl (46; 62) and forming a seat for the cap (44; 60), and constituting in addition the connecting means of the container (43; 59), in that the   cap (44; 60) and the envelope (45; 61) of the container   (43; '59) delimit, when the plug (44) is in place, an annular groove (50; 70) opening towards the top of the container, and in that the connecting means between the plug (44; ) and the container (43; 59) are arranged at the bottom of said throat (50; 70).   12. Container according to claim 11, characterized in that the flange (49) is provided at its   periphery of regularly spaced holes (51)   opposite corresponding matching holes (52)   in the annular element (48), and in that means.   are constituted by bolts (53)   arranged to cooperate with nuts (54)   to said holes (51, 52) for sealing of the container.   13.- container according to claim 11, characterized in that the container (59) is provided with retaining members (66) regularly arranged on   the envelope (61) and extending radially towards the   interior of the container, in that the flange (65) is provided with complementary cutouts (67) of the retaining members (66) so as to allow the cap (60) to bear against the seat, and stop members (68) disposed on its upper side, intended to abut against the retaining members (66) of the container (59) by angular displacement of the cap (60) with respect thereto.   14. Container according to claim 13, characterized in that the flange (65) comprises on its   upper surface of the cooperating corner portions   with the corresponding retainers (66)   to lock the plug (60) in its iron position.   meture. 15. Container according to claim 12 or 13, characterized in that the metal coating (47; 63) is plane. 16. Container according to claim 12 or 13, characterized in that the metallic coating (47; 63) is dish-shaped with a peripheral flange (49; 65) and that the side wall   (47a, 63a) of said bowl (47; 63> is cylindrical   and forms a centering element when setting   placing the plug (44; 60) on the container (43; 59) -.   17.- Container according to any of the   claims 8, 9, 10 and 15, characterized in that   the coating (35) is provided on its side facing the container with a centering flange (40) cooperating with the inner edge of the annular element (36) of the container, for the introduction of the cap (34) on the container (31), 18.- container according to any one of   claims 2 to 17, characterized in that the element   ring (15; 36; 48 '; 64) further comprises a   reentrant axial collar (18; 41; 57; 72) delimits   placing the opening of the container (2; 31; 43; 59) and   forming an anti-overflow member.   19.- Container according to any one of   Claims 4 to 18, characterized in that a ring   heavy material (25; 42; 56; 64) forming a shield;   compensating step of reducing the thickness of the container wall (2; 31; 43; 59) and the plug (3; 34; 44; 60) due to the presence of said throat;   (23; 37; 50; 70), is placed inside the recess   (2; 31; 43; 59) and linked to the annulling element   re. 20.- Container according to any one of   Claims 5 to 7 and 9 to 19, characterized in that   said groove (23; 37; 50; 70) is filled with a protective mortar of the assembly of the connecting means of the container (2; 31; 43; 59) and the plug (3; 34; 44; 60).   21.- Container according to any of the   Claims 2 to 20, characterized in that   facing the metal coating (47; 63) of the plug (44; 60) and the annular member (48; 64) of the container (43; 59) is mounted a seal (55; 69).   22.- Container according to any one of   Claims 4 to 7 and 10 to 21, characterized in that   the groove (23; 50; 70) communicates with the side wall   outside the envelope (4; 45; 61) for reasons   radial channels (26; 58; 71) forming weirs,   gularly arranged at the open end of this this.