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
  • G21F5/08—Shock-absorbers, e.g. impact buffers for containers

Definitions

• Container system for the transport and storage of highly radioactive materials
• the constructive design of the packages of type B (these are the containers with a radioactive inventory above the limit values, the release of which would not pose an inadmissibly high hazard), based on cumulative mechanical, thermal and radiological tests that ensure the safety of the containers even in serious accidents. They are the only category of dangerous goods packaging where safety against serious accidents must be taken into account when designing.
• the mechanical tests for type B packages which are conventionally massive "heavy containers" include the sequence 9 m fall on an unyielding foundation and the fall from 1 m height on a steel mandrel, in each case in the position in which the most serious damage, which means It is important to note that a large number of drop positions must be taken into account for each test sample, since the most severe stress for different container components or areas occurs before each of the different drop positions.
• the thermal test following the drop tests is defined as a 30-minute fire test with a complete flame encapsulation of the container by an openly burning heating oil fire, which applies at least 800 ° C to the container on all sides.
• the type B container must meet the radiological requirements. These requirements are also explicitly laid down in the ST-1.
• the container system can also eliminate this shielding layer against ionizing radiation e.g. be used for other dangerous punishment.
• casks were predominantly turned as monolithic objects out of a monolithic block of spheroidal graphite cast steel, hollowed out, provided with separate drill holes and fitted with turned-on cooling fins, and are used to hold the spent fuel elements in the decay pool (wet loading), in which the fuel elements for intermediate cooling ( at least 5 years).
• the complete, machined, still monolithic thick-walled, between 100 t to 150 heavy container block for receiving the spent fuel is totally immersed in the decay pool water.
• a surface treatment must be carried out.
• the container system consists of an outer container which encloses at least one inner container in which the radioactive material is arranged.
• This embodiment has the advantage that all damaging influences acting on the container system from the outside are completely or almost completely absorbed by the outer container, so that the inner container is in turn no longer reached by these influences or in any case these do not have such a significant effect on the inner container can be exposed to a considerable risk of damage.
• the outer container can be designed so that even if it is damaged or almost destroyed, it serves as a sacrificial vessel for the actual container, which in turn fully meets the requirements of the IAEA ,
• the container system can also be designed in such a way that it contributes to securing the insufficiently proven safety of conventional Castor containers in such a way that they can be safely transported and stored within an outer container according to the invention without the use of head and shock absorbers.
• FIG. 1 shows a longitudinal section through a container system with an outer container, a middle container and an inner container
• FIG. 3 shows a longitudinal section through an outer container in an exploded view
• FIG. 5 shows a longitudinal section through a central container with an inner container
• Inner container in longitudinal section and
• Fig. 7 a longitudinal section through an outer container with a commercial Castor container enclosed by it.
• a container system essentially consists of an outer container 1, in which an inner container 2 is arranged, which is essentially enclosed by a central container 3.
• the outer container 1 consists of a cylinder 4, the jacket 5 of which is made of prestressed steel centrifugal concrete. Furthermore, it is provided with a lid 6 and a base plate 7, which consist of reinforced concrete, preferably also of prestressed steel centrifugal concrete mixed with boron oxide for the additional moderation of neutrons, which originate from radioactive materials arranged in the inner container 2.
• the outer container 1 has in its interior 8 on the inner surface 9 and on the cover 6 and the bottom plate 7 inwardly directed spring elements 10, 11. These spring elements 10, 11 are preferably provided with shock absorbers (not shown), as are used, for example, in railway car buffers.
• the spring elements 10 arranged on the jacket 5 are distributed rotationally symmetrically over the inner surface 9 and a multiplicity of spring elements 10 are arranged next to or above one another in the longitudinal direction of the jacket 5.
• the spring elements 11 arranged on the cover 6 and the base plate 7 are each evenly distributed over the cover 6 and the base plate 7. They have comparatively greater spring travel and greater clamping force than the spring elements 10 provided on the inner surface 9 of the jacket 5.
• Each spring element 10, 11 is provided with a biasing device (not shown), which biases it in the outer direction of the outer container 1.
• the pretensioning devices can consist of threaded bolts which penetrate the casing 5 and the cover 6 and the base plate 7 and are in engagement with an internal thread in a press disk which limits the respective spring element 10, 11 in the direction of the interior 8.
• the inner container 2 is essentially surrounded by the middle container 3, on the jacket 12 and the cover 13 and base plate 14 of the spring elements 9, 10 are resiliently supported.
• the jacket 12 of the middle container 3 consists of prestressed steel centrifugal concrete.
• the lid 13 and the base plate 14 also consist of reinforced concrete, preferably of prestressed steel centrifugal concrete with boron oxide added for additional moderation of neutrons which originate from radioactive materials arranged in the inner container 2.
• the middle container 3 has on its inner circumferential surface 15 and its cover 13 and its bottom plate 14 on their inner surfaces 16, 17 layers of polyethylene 18, 19, 20, which serve to moderate neutrons that come from radioactive materials in the Inner container 2 are arranged.
• the inner container 2 is also a cylinder which is double-walled and made of stainless steel. Between the inner walls 21 and the outer walls 22 of its jacket 23, its cover 24 and its base plate 25, spaces 26, 27, 28 are formed, in which a gamma and neutron radiation shielding absorber 29 is provided. In this case, the absorber 29 encloses the interior 30 essentially so completely that no radiation window that transmits gamma and neutron rays remains.
• the absorber 29 can consist of depleted uranium (uranium oxide) or similarly acting materials.
• the inner container 30 is provided with particularly smooth surfaces both on the inner surfaces 31 of the inner walls 21 and on the outer surfaces 32 of the outer walls 22.
• the inner container 2 has on its upper side 33 facing its lid 24 an annular flange 34 which projects over the inner container 2 and is adapted in its radial outer dimensions to the outer surface 35 of the middle container 3, so that the radial outer surface 36 with the outer surface 35 of the middle Container 3 is aligned.
• the inner container 2 has a fastening ring 37 adjacent to and within the ring flange 34, which closes an annular gap between the inner wall 21 and the outer wall 22 of the inner container 2.
• the mounting ring 37 is with Provided threaded bores 38 for receiving fastening bolts 39 which penetrate the cover 24 of the inner container 2 in a fixed manner.
• An intermediate cover 40 is provided above the cover 24 of the inner container 2, which is fastened to the ring flange 34 with the aid of threaded bolts 41 and which on its underside 42 covers the layer of polyethylene (13) adjacent to it.
• the jacket 5, the lid 6 and the base plate 7 of the outer container 1 and the jacket 12, the lid 13 and the base plate 14 of the middle container 3 are each penetrated by empty tubes 43, 44, in which fastening elements for tightening and sealing the outer container 1 and the middle container 3 are arranged.
• the fasteners 45, 46 consist of tie rods.
• the outer container 1 is provided adjacent to its base plate 7 with air inlet openings 47 and adjacent to its cover 6 with air outlet openings 48, each of which is distributed in a plurality in a plurality in a radially symmetrical manner over its jacket 5.
• the air inlet openings 47 and the air outlet openings 48 can be closed.
• a commercially available castor container 49 can also be arranged in the interior 8 of the outer container 1 and thus form a monolithic inner container 50.
• the radiation window of the CASTOR is covered in the interior 8 of the outer container 1 by layers of polyethylene.
• the stainless steel used for the inner container 2 is made particularly smooth both on its inner walls 21 and on its outer walls 22 in order to keep any contamination as low as possible or to make decontamination as easy as possible.
• the inner walls 21 and the outer walls 22 are preferably a maximum of 40 mm thick.
• the absorbers 29 provided in the spaces 26, 27, 28 essentially consist of enriched uranium (uranium oxide) or similar building materials, which not only the special properties of the gamma and neutron shielding from the mass of Material but preferably also from the material property absorbing.
• the layers 18, 19, 20 made of polyethylene 18, 19, 20 have the sole function of neutron shielding. In contrast to conventional containers, this is also a closed container.
• the inclusion of the inner container 2 in the middle container 3 creates a further all-round shielding container with an all-inclusive corona effect made of prestressed steel centrifugal concrete, as is very clearly described, for example, in DE 199 19 703 C2.
• the use of prestressed steel centrifugal concrete leads to extremely strong, torsionally stiff and at the same time comparatively light structures, which in any case have much better mechanical properties than spheroidal graphite cast steel with a lower weight.
• the shielding performance is also at least equal.
• prestressed steel centrifugal concrete has a highly homogeneous, smooth outer surface, which does not require a color coating and which can also be decontaminated without great effort.
• the inner container 2 and the middle container 3 essentially have all the necessary features in order to be able to fulfill a package by itself according to the IAEA regulations. However, in order to ensure that the mechanical, thermal and radiological requirements are also met in the required test situations (accident test, drop test, fire test), the inner container 2 and the middle container 3 are placed in the outer container, which is also made of prestressed steel centrifugal concrete Dimensioning is designed so large that it can hold the inner container 2 and the middle container 3 floating.
• the energy distortion paths required from the precisely dimensioned preload spaces can be consumed proportionally from the load cases by the spring paths of the spring elements 10, 11 and converted into (damped) movement.
• the spring elements 10, which are arranged rotationally symmetrically about the jacket 5 of the outer container 1 and in the longitudinal direction of the outer container 1, are designed by their pretensioning such that the mass of the inner container 2 with the middle container 3 (approx. 801) is horizontally oriented in its middle position Location only slightly shifted. Even in the vertical position of the outer container 1, the spring elements 11 adapted thereon on the cover 6 and the base plate 7 are designed in such a way that they do not permit any substantial displacement of the inner container 2.
• the respective spring preload is in any case so strong that the weight of the inner container 2 with the middle container 3 does not have a shifting effect.
• the container system according to the invention is used as follows:
• the middle container 3 is lifted out of the decay tank together with the inner container 2 and the connection between the inner container 2 and the middle container 3 is released in such a way that the inner container 2 is lifted out of the middle container 3 and into one another middle container 3 is sunk.
• This has the advantage that the radioactivity remaining on the first related middle container 3 does not have to be removed, but only those areas of the ring flange 34 which have been brought into direct contact with the radioactive water in the decay basin.
• the first related one can be used to load a further inner container 2 middle container 3 in turn connected to the inner container 2 and lowered into the decay tank.
• the lid 6 is closed.
• the spring elements 10, 11 are then each matched to one another and relaxed in such a way that the tensioning elements are unscrewed and the openings remaining in their place are provided with appropriately adapted sealing plugs.
• the outer container which is equipped with radioactive material in this way, is completely radiation-free even without any contamination due to the various shielding measures.
• the outer container 1 is provided adjacent to its base plate 7 with air inlet openings 47, the corresponding air outlet openings 48 being provided near the cover 6.
• thermal effects principle of gravity
• the middle container 3 and the inner container 2 as a result of which the inflowing air heats up and, after exiting the air outlet openings 48, can be used to obtain thermal energy, so that complex cooling and ventilation of the bearing can be used such container systems can be avoided.
• the air inlet openings 47 and air outlet openings 48 are designed to be closable in order to effectively shield the interior 8 of the outer container 1 in the event of a possible fire or for an underwater test.
• the container system is protected against any form of mechanical influences from outside by the use of the high-strength materials and the springy suspension and thus mechanical shielding of the radioactive material in the inner container 2 and the middle container 3.
• An impact or a sequence of impacts acting on the outer container 1 by drop test is absorbed by the latter without major damage, in particular because only its own mass is initially exposed to this effect, while the middle container 3 and the inner container 2 only in damped movements in the interior 8 are offset. This even goes so far that the container system can survive an airplane crash unscathed. It is dimensioned so strongly that it withstands the given load case of 1 1 due to a delay of 300 m / s 2 .
• the container system also withstands the fall of ceiling structures from a warehouse, which comes close to a plane crash. This means that the ceilings, which are not sufficiently sturdily constructed, can continue to be used in the approved interim storage facilities in Gorleben, Ahaus and Rugenow.
• the container system is also adequately protected against an enveloping fire.
• a container must have at least one 800 ° C total enveloping flame exposure over an exposure time of at least 30 min. withstand.
• the system according to the invention withstands at least 3 hours at an ambient temperature of 1000 ° C. (New York requirement).
• the inner container 2 with the middle container 3 already meet all radiological requirements, especially due to the spent nuclear fuel.
• the depleted uranium (uranium oxide) etc. exert a shielding force, so that the activity already measured outside the inner container 2 is significantly lower than prescribed.
• the container system is also optimally protected against the effects of armor-piercing projectiles, as is required against the background of terrorist activities. In the event that an armor-piercing projectile acts on the outer container 1, this already completely intercepts the projectile energy because of its high strength.
• the advantages of the container system described above can also be used in order to be able to continue to use the Castor container 49, which is not or no longer permitted according to the previously applicable regulations. Otherwise, these would have to be retired, which would result in considerable economic damage in view of the comparatively high number of existing containers.
• the dimensions of the outer container 1 are also such that it can accommodate and cushion a corresponding castor and can also continue to use the transport handling and storage facilities previously used for this purpose.

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• Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• High Energy & Nuclear Physics (AREA)
• Filling Or Discharging Of Gas Storage Vessels (AREA)
• Measurement Of Radiation (AREA)
• Buffer Packaging (AREA)
• Packages (AREA)

Applications Claiming Priority (3)

Publications (1)

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• 2002
  • 2002-06-25 DE DE10228387.7A patent/DE10228387B4/de not_active Expired - Lifetime
• 2003
  • 2003-06-21 RU RU2005101770/06A patent/RU2298242C2/ru active
  • 2003-06-21 WO PCT/DE2003/002073 patent/WO2004001766A2/de not_active Application Discontinuation
  • 2003-06-21 EP EP03760568A patent/EP1527460A2/de not_active Withdrawn
  • 2003-06-21 US US10/519,902 patent/US7186993B2/en not_active Expired - Lifetime
  • 2003-06-21 AU AU2003250267A patent/AU2003250267A1/en not_active Abandoned

Non-Patent Citations (1)

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