Device for Cleaning and/or Securing a Safe Containment Defined in a Device for Transporting and/or Storing Radioactive Materials

Abstract

The invention relates to a device (1) for cleaning and / or securing a safe containment defined in a device for transporting and / or storing radioactive materials, which device includes active means capable of cleaning and / or securing said safe containment, and further comprising means forming a casing (2) with an opening (8) and defining a cavity (9) as well as means for closing (10) said opening, which device is designed so that said closure means are capable of being maintained in said closed position by a pressure difference between the inside and the outside of said cavity.

Description

TECHNICAL FIELD [0001] This invention generally relates to the field of cleaning and / or securing a safe containment defined in a device for transporting and / or storing radioactive materials, such as, for example, nuclear fuel assemblies. PRIOR ART [0002] In such safe containments holding nuclear fuel assemblies, the high temperature promotes the conversion of oxides stable under ambient conditions into water, and the radiation emitted by the fuel assemblies cause some of this water to be converted by radiolysis into hydrogen and oxygen. [0003] Thus, because the presence of hydrogen in the containment clearly jeopardizes the safety of the transportation and / or storage device assembly due to significant risks of flammability, explosiveness and pressure build-up that it creates, it is routinely attempted to remove this hydrogen. [0004] To do this, the safe confinements can be equipped with a catalyst for recombining oxygen and hydrogen into water (or catalytic hydrogen recombiner), in ...

AI Technical Summary

Benefits of technology

[0015] More specifically, the objective of the invention is to propose a device for cleaning and / or securing a safe containment which has satisfactory effectiveness, a simple design, and is capable of ensuring protection of the active means from the borated water in the safe containment during the loading of fuel assemblies.

[0040] Also preferably, the active means are arranged in one or more cartridges, and can include a catalyst for recombining oxygen and hydrogen into water, as well as a drying agent. By way of illustration, these two elements can be combined and take the form of palladium deposited on alumina, enabling the catalysis as well as the required drying to be achieved simultaneously.

Problems solved by technology

Thus, because the presence of hydrogen in the containment clearly jeopardizes the safety of the transportation and / or storage device assembly due to significant risks of flammability, explosiveness and pressure build-up that it creates, it is routinely attempted to remove this hydrogen.

Naturally, the presence of water inside this containment also creates significant risks of corrosion, so that it may be necessary to clean the containment, in particular to remove the water, for example using a drying agent.

Of course, it is noted that damaging elements other than those cited above may be present in the containment, which may lead to the use of additional active means suitable for cleaning and / or securing this same safe containment.

Thus, significant convection currents cannot be produced around the active means, so that the overall efficacy of the latter remains relatively low.

In addition, when nuclear fuel assemblies are packaged, it is of course necessary to perform an additional pressurisation operation so as to generate a burst of the membrane, which is susceptible at this time of being broken and scattered in the safe containment.

Although this other solution also enables the risks associated with the incompatibility between the active means and the borated water of the pool inside the safe containment to be avoided when filling fuel assemblies, it is not entirely satisfactory, in particular doe to the fact that it is implemented after the final packaging of the cavity and necessitates an additional operation.

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