FR2560709A1 - CONTAINER FOR TRANSPORTING RADIOACTIVE SUBSTANCES - Google Patents

Abstract

THE INVENTION RELATES TO A CONTAINER FOR TRANSPORTING RADIOACTIVE SUBSTANCES. IN THIS CONTAINER SERVING FOR THE TRANSPORT OF RADIOACTIVE SUBSTANCES AND WHICH CONSISTS OF AN ENCLOSURE WHICH IS CLOSED FROM ALL SIDES AND WHICH IS FORMED BY AN INTERIOR SHEET AND BY AN EXTERIOR SHEET REMOTE FROM THE PREVIOUS ONE, IT IS PROVIDED BETWEEN THE INTERIOR SHEET 5 AND THE EXTERIOR SHEET 6 AN INTERLAY LAYER MADE IN THE FORM OF A MIXTURE OF A SYNTHETIC RESIN AND A HARD GRANULAR FILLING MASS AND CAST IN THE PLASTIC STATE. APPLICATION IN PARTICULAR TO THE TRANSPORT OF RADIOACTIVE WASTE.

Description

The invention relates to a container for transporting substances

  radioactive material and which is realized in the form of a closed enclosure on all sides and is

  consisting of an outer plate and an inner plate

  ri.eure, the plates being separated from each other in space. The container according to the invention can be

  particularly used in the transport of industrial wastes

  atomic energy, spent fuel elements and other similar substances, within the framework of the

  high security requirements.

  In the case of the use of radioactive substances in technological processes and in view of

  recovering residual emitters or radioactive waste

  existing assets, it is necessary to use

  to transport them. These containers have

  many embodiments, depending on the state, the composition of nuclides, the quantity and the other quantities characteristic of the substances

and radiation.

  In addition, as part of the classification required in increased security categories, re:

  Containers are subject to high requirements, which. oiJ-

  may be evaluated in particular by tests, in

guarantee security.

  The great diversity of conditions has led to many forms of construction, without it being necessary

  possible to classify them clearly in groups. Pre-

  We use the type of massive construction,

  in which case it is possible to provide additional layers

  made of different materials, on the inside

  or on the outer face of the massive wall of the container, for example to improve the trarnsfext

  hermetic, protection against corrosion, l.a pro.ec-

  against radiation and in order to obtain

effects.

  For example, in British Patent Specification 1,311,069 there is described a transport container of which

  the solid wall is made of a density material

  high barrier for protecting against gamma rays, and a thin layer of

  containing hydrogen and used to

against neutrons.

  The German patent application published under

  No. 3,012,256 discloses a transport container comprising

  as a massive shielding wall against radiation

  which is enveloped both internally and externally

  by layers of absorbent material

  neutrons as well as corrosion-resistant materials

  erosion. British Patent No. 1,220,027, US Patent No. 3,731,102 and the Published German Patent Application

  under No. 2,817,193 respectively indicate reci-

  transport containers for radioactive material and in

  which the massive radiation shielding layer

  is inserted, for technological reasons, before

  an inner envelope and in front of an outer envelope

  made of another material, in which case

  there is no connection between the different layers.

  German Patent Application Publication No. 30 04758 discloses a transport container

  whose wall consists of several massive layers

  They are formed of different materials, and in which the materials of the layers are more and more noble from the outside to the inside, in the chain of electromotive forces. In the case of this container, there is no

  no connection between the different layers.

  Mostly the type of construction

  massive is already provided by the necessary shielding of

  against the radiation of intense emitters. These containers then have most of the time a good

  resistance to drilling, but have poor

  in the event of an accident and are

  partly sensitive to the action of fire.

  Other conditions are present in containers for radioactive residues present in a large volume and having a mean level of radiation. These containers could be constructed lighter for protective shielding purposes, i.e. the walls could be dimensioned thinner. The small wall thicknesses of such containers, however, are damaged by drilling, to a high degree, by a single point load of the type detected by means of the drop test on a spindle, so that the possibility of reduction of the shielding can not be achieved. not

  be used and that a type of construction

massively.

  The manufacture of bulk transport containers implies a consequent use of

  materials and requires processes and equipment.

expensive manufacturing processes.

  The object of the invention is to create a container for the transport of radioactive substances and which, in addition to having a type of construction which makes it possible to save material and which is simple from the point of view of the manufacturing technique, satisfies high standards.

of security.

  The teaching on which the invention is based lies

  in the fact that in the case of the use of the material

  synthetic, one can obtain a type of construction in which the materials are joined together and therefore

  security parameters can be significantly improved

  res in all embodiments.

  That's why the goal is to make a container that combines high drilling resistance,

  good energy absorption behavior, good

  resistance to the action of fire and sufficient protection

vis-à-vis the radiation.

  This problem is solved according to the invention

  with a container for the transport of radioactive substances, which consists of an enclosure which is closed on all

  inside and by an outer sheet remote from the

  cedeente, characterized in that there is provided between the inner sheet and the outer sheet an intermediate layer

  made in the form of a mixture of a synthetic resin

  that and a granular filling mass lasts and

  in the plastic state. The synthetic resin used

  is for example a synthetic resin based on phenol-

  formaldehyde, vinyl chloride or an epoxy resin and its percentage is advantageously chosen between 10 and 30% by volume, the remaining part being constituted by the filling material which is formed for example by siliceous sand having a granulation between 0.1 and 0.4 mm and in which the fraction of a size of 0.3 mm is the most common. The composition of the interlayer and the type and quantity also

  synthetic resin rather than the

  pleating are selected according to the purpose of use.

  containerization. The substance is introduced at

  plastic sheet by means of openings made appropriately in the space between the outer sheet and the inner sheet and is hardened there. After

  hardening, the openings must be closed.

  It is appropriate to deposit on the surfaces adjoining the intermediate layer, both of the outer sheet and the inner sheet, a film of

  synthetic resin whose basic substance is identi-

  than or compatible with the synthetic resin used in

  the interlayer. This ensures better adherence

  In the case of thin sheets, the advantage is that their permeability is reduced relative to other substances. It may also be advantageous to provide elements for fixing the distance between the sheets.

  This is desirable especially in the case of plates available

  horizontally, in which case first

  the mixture of the interlayer on the lower plate

  re, which is then covered with the upper sheet.

  It is also advantageous to use vertical elements in the form of plates for the parts

  vertical lines of the enclosure, which allows for

  smaller volume and facilitates the insertion of the plastic mass of the interlayer as well as

its distribution.

  The essential advantages of the invention

  can be seen in the fact that as a result of the combination

  different synthetic resins and different

  fillers. hard, such as quartz, boron carbide or metal balls, there is an extensive possibility of variation, allowing to take into account and bring to meet requirements

  very different from the point of view of the physics of

  mechanics and manufacturing technology

  tion. The advantages of construction also lie in the fact that thanks to the resin layer of a resin

  synthetic and glued or can be glued inside-

  against the sheets, a resistance envelope is obtained.

  high quality, which has much better properties than

  an equivalent steel layer of the same mass. In

  Besides, it is advantageous that the container conforms to the

  vention is better able to resist deformation than

  massive bodies in the case of extremely high loads

  as determined by the free fall test over a height of 9 m, and therefore guarantees better

  sealing and the absence of damage to the

  ge, without the need for additional costly shock absorbers. The expense of manufacturing containers can be greatly reduced compared to other types of construction. Overall we get

  a favorable combination of economic benefits and

  advantages from the point of view of safety technology.

  Other features and benefits of the

  present invention will emerge from the description given

  hereinafter an embodiment of the invention taken in reference to the accompanying drawing, which shows the cross-sectional view of the container according to the invention,

  on which part of the structure of the wall is

presented in enlarged view.

  The container according to the invention represents

  In the figure is constituted by a closed enclosure on all sides and which is formed by a casing 1, a cover 2 and a bottom 11, the cover 2 and the bottom 11 being joined by screws to the casing 1. The elements

  mentioned in the enclosure consist of an internal plate

  5 and an outer sheet 6 which determine

  a free internal space as they are available

  at a certain distance from each other. The casing 1 comprises a lower flange 3 and an upper flange 4. The free space between the inner sheet 5 and the outer sheet 6 is filled by means of an intermediate layer

  7 which is constituted by a mixture of a synthetic resin

  and a filling substance which is cast in the plastic state. The composition of the mixture varies in

  purpose of use of the container in accordance with the

  vention. The lid 2 consists of two sheet metal plates 8 and a ring formed of the intermediate layer 7, which is inserted between the two sheet metal plates 8. One

  sheet metal plates 8 constitutes, as an inferior plate,

  the inner plate 5 and the other plate serving as the upper plate constitutes the outer plate 6.

  bottom 11 is made in a similar manner.

  The intermediate layer 7 is adhesively bonded directly or via a film

  synthetic resin to internal and external

  5, 6. The synthetic resin film is advan-

  tagged by the same synthetic resin as

  which is used for mixing synthetic resin and filler and is deposited so

  known for example by painting or spraying

  authorization. The choice of layer thickness and

  components of the substance constituting the mixture of

  synthetic material and filling material for

  Insert 7 is determined by calculations from the data indicated for the substances as well as by

  from the necessary parameters of the speaker of the

  neur and is conveniently controlled by model testing. The substance used to form the intermediate layer 7 of the container is formed in a known manner according to specific formulations, is mixed and is

  inserted in the plastic state in the predefined free spaces

  completed the envelope 1, the cover 2 and the bottom. In the case of the envelope, the insertion can also be facilitated by the use of vertical plates. In the case of the lid 2 and the bottom 11, the material is molded

  plastic of the intermediate layer 7 on the lower plate

  and then the upper plate can be removed. To

  avoid ejection of the plastic mixture, you can use

  be plates forming spacers. The vertica plates--

  the as well as the plates forming spacers play a

  secondary role as regards the guarantee of obtaining

  the mechanical strength of the container, and it is absolutely not necessary for them to be able to withstand

  stresses greater than the weight of the sheet.

  The intermediate layer 7 is glued directly

  or by means of the synthetic resin film

  thetic on the inner walls and hardens at a rate dependent on temperature and composition. If necessary, curing can be accelerated by means of a heat treatment and / or an increase in temperature. For the insertion of the substance of the intermediate layer 7, it is possible to provide filling orifices which are closed, after hardening, with

  an additional ring or using a covering element

  vrement. The choice of the synthetic resin and the hard granular filling substance still depends on the problem to be solved. In the case of the use of a

  interlayer 7 in accordance with a definite formulation

  born and having a determined thickness as well as thanks to the presence of inner and outer sheets 5, 6

  having the necessary thickness, it is possible to satisfy simul-

  at the same time to several requirements imposed on the

  coach. It is particularly advantageous that one can

  relatively thin steel sheets and the additional strengths necessary to prevent damage by drilling

  of the inner wall, by means of the intermediate layer

  re 7 constituted by a mixture of a synthetic resin

  and a filler and that is particular-

  advantage of the fact that not only is it put in place by filling, but also

  also adheres to the inner surfaces of the walls

  Tourant. Similarly, partial deteriorations of the enve-

  outer steel liner do not pose any particular problem

  because of stickiness and hardening.

  the mixture, no loss can occur

  from the intermediate layer 7 to the locations of the

  riorations. Thanks to the choice of different synthetic resins

  of different types of radiation, for example neutrons, it is possible to absorb, knowingly, particular types of radiation, for example neutrons, and to obtain insulation against

the action of fire.

  It is also necessary to highlight the best energy absorption behavior, for example in the case of the drop test over a height of 9 m, which

  leads to a reduction in shock forces and consequently

  more careful management of the burden of

  content. We can act positively on the manufacturing cycle when we can perform the filling

  plastic mixture also in complex shapes.

  It is also advantageous to reduce the cost of

  material for steel. This implies a reduction of

  mass, which also affects the cost of transport.

Claims (6)

  1. Container used for the transport of substances   these radioactive and that consists of an enclosure that is   closed on all sides and which is formed by an internal plate   (5) and by an outer plate (6) spaced from the previous one, characterized in that between the inner panel (5) and the outer panel (6) is provided an intermediate layer (7) made in the form of a mixture of   synthetic resin and a granular filling   Hard luster and casting in the plastic state.   Container according to claim 1,   characterized in that a film of synthetic resin (10) is deposited on the surfaces of the inner sheet (5) and the outer sheet (6), which delimit the layer insert (7).   Container according to claim 2, characterized   characterized in that the synthetic resin film (10) is constituted by an identical synthetic resin or   compatible with the synthetic resin used in the interlayer (7).   4. Container according to any one of the   1 to 3, characterized in that spacer plates are provided between the inner plate (5) and the outer sheet (6).   5. Container according to any one of the   1 to 4, characterized in that the enclosure has plates in its vertical parts located between the   inner plate (5) and the outer plate (6).   6. Container according to any one of the   1 to 5, characterized in that the inner layer   calaire (7) contains 10 to 30% of synthetic resin.