Classifications

• • G—PHYSICS
  • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
  • G21F—PROTECTION AGAINST X-RADIATION, GAMMA RADIATION, CORPUSCULAR RADIATION OR PARTICLE BOMBARDMENT; TREATING RADIOACTIVELY CONTAMINATED MATERIAL; DECONTAMINATION ARRANGEMENTS THEREFOR
  • G21F5/00—Transportable or portable shielded containers
  • G21F5/005—Containers for solid radioactive wastes, e.g. for ultimate disposal
• • G—PHYSICS
  • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
  • G21F—PROTECTION AGAINST X-RADIATION, GAMMA RADIATION, CORPUSCULAR RADIATION OR PARTICLE BOMBARDMENT; TREATING RADIOACTIVELY CONTAMINATED MATERIAL; DECONTAMINATION ARRANGEMENTS THEREFOR
  • G21F5/00—Transportable or portable shielded containers
  • G21F5/06—Details of, or accessories to, the containers

Definitions

• the present invention relates to a package for transporting and / or storing radioactive material. It relates more specifically fluidic communication systems between the interior of the containment and the outside thereof, particularly when these systems are not closed.
• the main function of transport and / or storage packages for radioactive materials is to isolate their contents from the external environment.
• the packaging has a containment chamber in which are housed the radioactive materials.
• This sealed enclosure is made using several packaging elements, usually a lateral body, a lid, and a bottom.
• These packaging elements are conventionally equipped with fluidic communication systems between the inside and the outside of the enclosure. It may for example be a vent system for venting the enclosure. It can also be a drainage system for extracting the residual water from the enclosure, when the package is loaded under water. Finally, it may be a gaseous sampling system in the containment.
• each fluid communication system can be associated with two plugs each provided with at least one seal, so as to form a double sealing barrier when the containment requires it.
• the level of radiological protection may then be insufficient in the fluid communication systems.
• the dose equivalent rate level may then be higher than the required criterion under operating conditions.
• the invention therefore aims to at least partially overcome the problem mentioned above, relating to the achievements of the prior art.
• the subject of the invention is a packaging for transporting and / or storing radioactive materials, comprising a plurality of packaging elements internally defining a confinement chamber for the radioactive materials, at least one of the elements of wherein the package is traversed by at least one fluid communication system having, at an inner surface of the enclosure, at least one fluid inlet opening and, at a fluid outlet area of the surface external of the packaging element concerned, at least one fluid outlet opening, said fluid communication system being associated with a closure plug covering said fluid outlet zone so as to close said at least one outlet opening of fluid.
• the fluid communication system defines at least two distinct fluid flow paths between the at least one fluid inlet opening and the at least one fluid outlet opening.
• the invention thus provides, in an original manner, a duplication of traffic paths which makes it possible to offer a satisfactory compromise between the simplicity of shape of the paths concerned, and the radiological protection conferred in the event of withdrawal of the plug. Indeed, providing no longer a single path but several paths of smaller sections, increases the capacity of the packaging element equipped with the fluidic communication system to absorb gamma radiation occurring in all directions. It is nevertheless noted that the different traffic routes can share common areas, without departing from the scope of the invention.
• the invention also makes it possible to limit the dose rate when the stopper is in place.
• the invention preferably has at least one of the following optional features, taken alone or in combination.
• the fluidic communication system comprises a number greater than or equal to a NI of fluid inlet openings, and a number greater than or equal to one N2 of fluid outlet openings, the number N1 being greater, equal to or equal to less than the number N2.
• Said closure cap is at least partially housed in a housing provided on the associated packaging element, said housing being defined by said fluid outlet zone of the outer surface of the same packaging element.
• the plug which is then entirely projecting at the outer surface of the packaging element.
• the cap in the assembled position, covers each fluid outlet opening, or penetrates into at least one of them.
• the distinct paths of fluid circulation are made from several elementary channels which communicate with at least one main channel of larger section and provided in a number less than that of the elementary channels, each main channel defining a part of several of said paths. traffic of fluid.
• each main channel opens at the level of the fluid outlet zone, and the elementary channels open into the confinement enclosure, or vice versa.
• the package preferably comprises two elementary channels opening into the containment chamber, and a single main channel opening at the fluid outlet zone.
• the distinct paths of fluid circulation are made from several elementary channels which each open on the one hand in the confinement enclosure and on the other hand at the fluid outlet zone, and each elementary channel defines one of said fluid flow paths.
• Yet another possibility lies for example in having a single main inlet channel opening into the confinement enclosure and a main outlet channel opening at the fluid outlet zone, and providing a secondary channel network connecting the two main channels.
• the elementary channels and / or the main channel (s) are straight, or non-right, preferably having at least one elbow and / or baffle.
• the elementary channels and / or the main channel (s) of the same fluid communication system are part of the same fictitious plane.
• the fluid communication system is preferably a drainage system, a vent system or a gas sampling system.
• a tungsten plate may be attached to the packaging element in the vicinity of the fluid communication system. Any other high density material may also be considered to form this additional barrier to gamma radiation.
• FIG. 1 shows a schematic longitudinal sectional view of a package for the storage and / or transport of radioactive material according to the invention
• FIG. 2 is a cross-sectional view taken along the line of FIG. 1 showing a fluid communication system fitted to one of the packaging elements shown in FIG. 1;
• FIG. 2a is a view similar to that of FIG. 2, with the fluidic communication system equipped with its plug. ;
• FIG. 3 is a cross-sectional view taken along the line M INI of FIG. 2;
• Fig. 4 is a cross-sectional view taken along the line IV-IV of Fig. 2;
• FIG. 5 is a view similar to that of Figure 2, according to an alternative embodiment.
• FIGS. 6a to 6d are views similar to that of FIG. 5, showing still other preferred embodiments. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
• FIG. 1 there is shown a schematic longitudinal sectional view of a package for the transport and / or storage of radioactive materials, such as irradiated fuel assemblies or radioactive waste 3.
• L 1 is shown in a vertical storage position, in which its longitudinal axis 2 is oriented vertically.
• the package 1 comprises a containment chamber 4 delimited internally by a plurality of packaging elements, among which a bottom 6, a lateral body 8 and a closure system comprising one or more lids 10.
• the bottom 6 and the cover 10 are spaced from each other along the longitudinal axis 2, on which is centered the lateral body 8 of circular cross section or polygonal shape.
• the package 1 also comprises a head damping hood 12 and possibly a bottom damping hood (not shown).
• the head damping hood 12 is provided with a hollow zone 16 centered on the axis 2, this hollow zone housing at least a portion of the lid 10 and a head end 8a of the lateral body 8.
• the lid 10 is removably attached to the lateral body 8, preferably by means of screws 22, one of which is schematically shown by its center line.
• the lateral body 8 has at its head end 8a a fluid communication system 30 specific to the invention, which will now be described with reference to Figures 2 to 4.
• the system 30 may be a drainage system, a vent system, or a gas sampling system. It is associated with a closure plug 32 helping to define the containment chamber 4 when it closes the system 30. This plug also forms a radiological shield to limit radiological leakage to the system 30.
• the system 30 is provided to cooperate with a shielded draining or venting tool, which comprises a sealing system ensuring that the confinement of the radioactive materials is guaranteed during the operations performed.
• the communication system 30 passes through here the head end 8a of the lateral body 8, which is generally formed by a metal shell 34 radially covered by a neutron protection layer 36.
• This system 30, which takes the general shape of a network of channels, has two fluid inlet openings 38a, 38b at an inner surface 40 of the containment chamber 4.
• This system 30 comprises at a fluid outlet zone 42 of the outer surface 44 of the lateral body, a single fluid outlet opening 39.
• the plug 32 associated with this system 30 covers this exit zone of fluid 42, as can be seen in FIG. 2a.
• This is also the portion of the outer surface 44 covered by the cap 32 which defines said fluid outlet zone 42 within the meaning of the invention. Still in this mounted position, the plug 32 closes the fluid outlet opening 39, covering or penetrating therein as well.
• the fluid outlet zone 42 defines a housing 48 provided for housing at least a portion of the closure cap 32, when it occupies its mounted position.
• the plug 32 is thus at least partially integrated into the lateral body 8, as can be seen in FIG. 2a.
• the fluidic communication system 30 defines two distinct fluid circulation paths 46a, 46b between the inside and the outside of the containment enclosure 4. More precisely, the first path 46a begins at the first fluid inlet opening 38a from which extends a first elementary channel 48a having a bend 50, for example 90 °. Similarly, the second path 46b begins at the second fluid inlet opening 38b from which extends a second elementary channel 48b having a bend 50, also of the order of example at 90 °.
• the two elementary channels 48a, 48b each have an upstream part and a downstream part separated by the bend 50. The two upstream parts are substantially parallel, while the two downstream parts are of coinciding axes and meet at the same level. a junction with a main channel 52 defining a downstream portion common to the two fluid flow paths 46a, 46b.
• the main channel 52 is preferably straight, and has an axis parallel to the two axes of the upstream portions of the two elementary channels 48a, 48b.
• the axis of the main channel 52 is arranged between the two aforementioned axes, which are distributed symmetrically with respect to this axis of the main channel.
• the channels 48a, 48b, 52 are preferably inscribed in the same plane 54 schematized on the 4, corresponding to a transverse plane of the package, that is to say orthogonal to its axis 2. It is noted that in the case where the system 30 is implanted on the cover, the fictitious plane in which s' integrate the channels is preferably a longitudinal plane of the package, passing through its axis 2.
• the single main channel 52 ends with the fluid outlet opening 39 opening into the housing 48 defined by the fluid outlet area 42.
• the elementary channels 48a, 48b each have a section smaller than that of the main channel 52.
• the sum of the sections of the two elementary channels 48a, 48b are identical or similar to the higher section of the main channel 52.
• the channels 48a, 48b, 52 are made directly in the shell 34, or in an insert 60 reported in a housing 62 formed in this shell, at the inner surface 40 of the containment. This latter solution, shown in the figures, makes it easier to make the channels, especially when they include 90 ° bends.
• Figure 5 shows an alternative embodiment in which the plug 32 is no longer in a housing, but is entirely projecting relative to the outer surface 44 of the lateral body.
• the plug 32 here covers the fluid outlet zone 42 of the surface 44, and covers the outlet opening 39.
• FIGS. 6a to 6d show other conceivable embodiments, all sharing the same inventive concept aiming at providing several fluid circulation paths associated with the same closure plug 32.
• two elementary channels 48a, 48b are distinct from each other and respectively define two independent fluid flow paths 46a, 46b.
• the channels are straight and inclined relative to each other, so as to form a V.
• Each elementary channel 48a, 48b therefore extends between the inlet opening 38a, 38b and the fluid outlet opening. 39a, 39b.
• the embodiment differs from the previous embodiment in that each elementary channel 38a, 38b additionally integrates a baffle 64.
• the design differs from that of Figure 5 by the simple fact that the upstream portions of the elementary channels 48a, 48b are no longer parallel, but inclined relative to each other to form a V.
• the design is inverted with respect to that of FIG. 5, by providing a main channel 52 extending from the inlet opening 38, as well as two elementary channels 48a. 48b ending respectively in two outlet openings 39a, 39b.
• the two distinct paths 46a, 46b are merged upstream in the main channel 52, before separating by passing respectively through the two elementary channels 48a, 48b.

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• Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• High Energy & Nuclear Physics (AREA)
• Packages (AREA)
• Packging For Living Organisms, Food Or Medicinal Products That Are Sensitive To Environmental Conditiond (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=58737627

Family Applications (1)

Country Status (6)

Families Citing this family (2)

Family Cites Families (13)

• 2016
  • 2016-12-09 FR FR1662237A patent/FR3060192B1/fr not_active Expired - Fee Related
• 2017
  • 2017-12-07 JP JP2019530124A patent/JP7018445B2/ja active Active
  • 2017-12-07 WO PCT/FR2017/053435 patent/WO2018104670A1/fr not_active Ceased
  • 2017-12-07 CN CN201780075739.0A patent/CN110050309B/zh active Active
  • 2017-12-07 EP EP17821974.7A patent/EP3552215B1/de active Active
  • 2017-12-07 ES ES17821974T patent/ES2853982T3/es active Active

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