DE7830884U1 - SHIELDING CONTAINER WITH NEUTRON SHIELDING FOR THE TRANSPORT AND / OR STORAGE OF BURNED FUEL ELEMENTS - Google Patents

Description

TRANSNTJKLEAR GmbH
6450 Hanau 11
10

Shielded container with neutron shielding for transport
and / or the storage of spent fuel

Ί5 The invention relates to a shielded container for the transfer f

port and / or the storage of spent fuel, with ^'4 a neutron shield on the outer container surface. \

Containers that are removed for transport and / or storage.

burned fuel elements are used, the radio |

Safely enclose the activity of the brought in goods and in |

strict tests prove that this is guaranteed even in extreme accident f-situations. But at the same time they have to
"also the deji radioactive decay reactions are released

shield the gamma and neutron beams and the destruction |

dissipate any heat to the outside. jf

Known shielding containers usually consist of a metallic | Basic container, with the required mechanical strength | ^ou and the wall thickness required to shield the gamma rays, usually steel or a combination of lead
and steel, and an outer shell made of neutron shielding material, mostly polyethylene beads cast in synthetic resin.

On the metallic body there are normally heat |

Redirecting webs or ribs that penetrate the resin layer |

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welded or soldered on. They are required for enlargement the metallic surface of containers that are designed for high heat output and to dissipate the Heat through the neutron shielding layer, which is generally poorly thermally conductive.

The disadvantage of these constructions is that even slight collisions of the container, as occurs with routine Operation can occur, can lead to damage to the heat conduction fins and the resin layer and then an expensive one Require repairs to the entire container.

Furthermore, cleaning or, in the event of contamination, is a Decontamination of the outer surface of the container formed by the ribs or webs is possible. This must therefore be at Handling work where there is a risk of surface contamination, for example during loading and unloading, be protected by putting on a protective shirt.

Another disadvantage of this known shielding container is that the number of heat conduction ribs and the Thickness of the neutron shielding must be used for the maximum design case intended for transport. At a "Most of the transports and when used as storage casks, however, contain spent fuel elements that are in the fuel element storage pool of the! nuclear power plant have already subsided to such an extent that in these cases both the neutron shielding as well as the rib surface of the container is oversized

are.
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It was therefore an object of the present invention to provide a shielded container for the transport and / or storage of spent fuel elements with a neutron shield on the outer To create a container surface in which a repair on the neutron shielding without repair work on the entire container

* barely

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is possible in which handling work with a risk of contamination is also possible without wearing a protective shirt and . the possibly changing requirements of the individual case can be adjusted with respect to radiation intensity.

According to the invention, this object was achieved in that the neutron shielding consists of a series of neutron shielding materials filled hollow bodies made of highly thermally conductive material, which are provided with heat conduction ribs and with each other connected are attached to the container surface. This neutron shielding can be achieved with special fastening Clamping devices can be easily removed from the shielded container and reattached. The number and thickness of the hollow bodies is adapted to the respective requirements. In Figs. I to IV the structure is shown schematically in an exemplary embodiment a removable neutron shield according to the invention is shown. In Fig. I the shielded container is partially open Neutron shielding jacket shown in cross section. The hollow bodies forming the neutron shielding jacket (7) (2) with the attached heat conduction ribs (3) Bind on elastic steel straps (4). The steel bands (4) are preformed so that they have a slightly wider curvature than the curvature of the basic container (1). The elastic Steel strips (4) are connected on one side, for example with a hinge (5), and can be used on the opposite side Side can be clamped in the closed state with a clamping lock (6) around the surface (9) of the basic container (1).

The shielding jacket (?) Can also be divided into several parts

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be, which are then each connected to a hinge or other element.

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The hollow bodies (2) can be placed on the elastic steel strips (4) in any way, in particular by means of rivets, screws, or welded connections.

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Figure II shows a particularly advantageous embodiment of the one filled with a neutron shielding material (8) Hollow bodies (2), in which, due to the partial overlap, direct passage of the neutron radiation at the joints the hollow body (2) is prevented. Through the closure device (6) these are attached to a steel band (4) Hollow profiles (2) attached to the container surface (9).

In Fig. III and IY, a single hollow body (2) is preferably with molded heat conducting ribs (3) schematically in the transverse and longitudinal section. The cavity of the hollow body (2) is made of a neutron shielding material (8) fills.

Instead of the elastic steel belts (4) there are also link belts or chains can be used, as well as these belts can be omitted entirely if the individual hollow profiles are directly connected elastic or hinge-like connections are connected to one another.

Likewise, the elastic steel strips (4) do not have to be below the hollow bodies (2), but can also be above the hollow bodies (2) be appropriate. In this embodiment, a permanent attachment of the hollow body (2) to the elastic Steel bands (4) can be dispensed with.

The neutron shield according to the invention has opposite the previously known constructions of 'heat conduction fins and neutron shields for transport and / or storage containers a number of advantages.

In the event of damage to the heat-conducting ribs and / or the neutron shielding, there is no costly repair of the whole Container required. Since a container that has already been used, this would inevitably have to carry residual radioactivity

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is, in a "hot workshop", i.e. in one for the order a workshop that has been set up and approved for use with radioactive substances. A damaged according to the invention Neutron shielding or heat conduction rib can usually be attached

5 Can be repaired on the spot by replacing the damaged elements. In the event of major damage, the whole Neutron shielding jacket can be exchanged and the container can be used again immediately.

The neutron shielding jacket can be used to load and unload the container can be removed, so it is not necessary to wear a special protective shirt.

Several removable neutron shielding jackets with different designs can be used for a transport and / or storage container with regard to heat dissipation and neutron shielding. This allows for a transport and / or "Storage insert of a container with the appropriate jacket provided will. When transporting spent fuel elements with a longer decay time, this reduces the transport weight and the external dimensions of the containers.

Claims (2)

ro TRANSNUKLEAR GmbH 6450 Hanau 11 10 shielding containers with neutron shielding for the transport and / or storage of spent fuel elements 2ASStTAlISPRiJCHE 1. Shielded container for transport and / or storage spent fuel assemblies with a neutron shield on the outer container surface, characterized. that the neutron shield from a series of with Neutron shielding material (8) filled hollow bodies (2) made of a material that conducts heat well and is provided with heat conduction ribs (3) are provided and attached to one another connected to the container surface (9). 25th 2. shielding container according to claim 1, characterized in that the hollow bodies (2) are designed so that they overlap at the edges. J. shielding container according to claim 1 and 2, characterized in that the heat conduction ribs (3) are formed on the hollow O bodies (2). - 2- -2- 1-4 shielding container according to claim 1 to 3t characterized / characterized. dasB the hollow bodies (2) adapted to the container circumference and curvature, provided with one or more hinges (5) and clamping devices (6) * 5 steel straps (4) are attached.