JPH0269700A - Transport and/or storage vessel made of metal for biological obstruction - Google Patents

Abstract

PURPOSE: To easily manufacture a container with no strain and improved in corrosion resistance and contamination resistance and in which an excellent heat transfer is established, by forming a corrosion-resistant film firmly sticking onto the internal surface of the container including a shielding lid and protective lid by applying the melt of the metal and similarly forming a film on the surface of the first film so that the second film can be compression-homogenized with the first film. CONSTITUTION: A corrosion-resistant firmly sticking film 4 of a nickel-chromium alloy is formed on the internal surface of a container main body 1 including parts of a shielding lid 2 and a corrosion-resistanceprotective lid 3 by applying the melt of the alloy to the internal surface to a thickness of 0.1-0.4mm by thermal melt- spraying. The a similar film 5 is formed on the surface of the film 4 by applying the melt of the alloy so that the total thickness of the films 4 and 5 can become 0.5-1.2mm and the film 5 is compression-homogenized with ball blast, etc. Accordingly, a metallic transporting and preserving container for biohazardous substance which is improved in thermostability and radiation, corrosion, and contamination resistances and has no shearing and in which an excellent heat transfer is established can be manufactured readily.

Description

[Detailed Description of the Invention] [Industrial Application Field] ■ The present invention consists of a container body and shielding and protective lid equipment, and the interior of the container body is provided with metal corrosion protection. Concerning metal transportation and/or storage containers for radioactive materials.

[Conventional technology]

Metal containers are used to transport and/or store biohazardous substances;
The corresponding safety regulations regarding tightness and possible accidents must be met. For storage in corrosive containers, at least the interior of the container must have a protective layer, and the protective layer must also be well cleanable in the case of reusable containers. This is especially true for the transport of radioactive materials and/or
Or applicable to storage containers. Such containers for irradiation nuclear fuel elements are loaded into boron-treated water in nuclear power plants.

These containers must therefore be corrosion resistant on the container surface, ie also on the internal surface, and have good stain resistance. This is because the water in the cargo cover can contaminate the vessel with contaminated surface debris from irradiated nuclear fuel elements. Contamination occurs particularly inside the container, since the outer surface of the container is generally protected by a so-called shell during submerged loading.

Accordingly, the inside of the container is often lined with a special steel plate, also called a liner. These liners nevertheless require further sealing to the actual container body. A further disadvantage is the poor heat transfer due to the unavoidable gaps between the liner and the container body in the case of exothermic radioactive stores. In order to minimize this gap, West German patent application No. 302,497
No. 4 proposes the use of a slitted metal cladding as an inner lining. The coating is lined as closely as possible to the internal surface of the container body, with the slits subsequently being welded. However, optimum heat transfer is again not achieved with this manufacturing method.

Furthermore, the West German utility model registration number 7 for cast iron containers.
No. 819,282 proposed the use of lost metal molds as liners. Due to the influence of the casting on this type of mold, the liner must be expensive to post-process.

Nickel coatings (German Utility Model No. 77 28 331) have a cost disadvantage and do not protect against corrosive solutions, for example.

Producing an internal surface that is compact, highly smooth, and has good stain resistance is a special problem. Synthetic resin coatings on rough surfaces are often unsuitable because they have neither radiation resistance nor thermal stability and therefore, in combination with unacceptable pressure configurations, result in gas leakage.

[Problem to be solved by the invention]

The object of the present invention is therefore to provide a metal transport and/or storage container for biohazardous substances, in particular radioactive substances, consisting of a container body in which metal corrosion protection is arranged, and shielding and protective lid equipment. It is an object of the present invention to provide such a container which establishes satisfactory heat transfer, prevents corrosion, is strain-free, has good stain resistance, and is relatively easy to manufacture.

[Means to solve the problem]

The problem is solved according to the present invention by providing a corrosion-proofing adhesive film made of a nickel-chromium alloy on which the corrosion-protective material is melt-coated, and a uniform compressed film similarly melt-coated on the corrosion-resistant adhesive film.
The problem is solved by the fact that the anti-corrosion adhesion film and the coating film cover the inside of the container body and also cover the shielding lid and the protective lid. be done.

The invention will be explained in more detail with reference to the schematic diagram of FIG. 1, in which the coating is preferably applied in a protective gas.

The inner surface of the container body 1 has an anti-corrosion adhesion film (4). It is made of a nickel-chromium alloy and is melt applied, for example by thermal spraying. From the viewpoint of adhesion, the coating is preferably carried out in the presence of oxygen. The thickness of the anticorrosive adhesive film 4 is, for example, 0.1
~0.4mm.

On the anti-corrosion bonding film 4, a coating film 5 made of the same material is melted in a single layer or in multiple layers, for example, again by thermal spraying.

In order to avoid oxygen inclusions and to obtain a uniform coating, it is particularly advantageous to carry out the thermal spraying in a protective gas. The desired thickness of the coating, including a certain excess, is adjusted according to the requirements of the individual container parts (lid part, seal part, bottom and girth part). The anti-corrosion adhesion film 4 and the coating film 5 are attached to the container body l.
, and also covers the periphery of the shielding lid 2 and the protective lid 3.

After the coating 5 has been applied, its surface is post-treated by mechanical compression. The common final thickness of the anticorrosion bonding coating 4+covering coating 5 is achieved by a predetermined excess thickness reduction. Usually the final thickness will be between 0.5 and 1.2 mm.

The compression can be carried out, for example, by pole blasting using steel balls or by hammering with a needle-like tool driven by compressed air. This mechanical compaction can optionally be followed by a final surface finish.

This mechanical compression eliminates stress or converts tensile stress into compressive stress (improvement of film properties). Any pre-existing or existing porosity is reduced or eliminated. Overall, a decisive improvement in the corrosion resistance results.

〔Example〕

Internal dimensions length - 2980mm, diameter 720/960/1
First, an anti-corrosion adhesion film made of NiCr80/20 alloy was thermally sprayed and automatically applied to the internal surface of a graphite/cast iron container with a diameter of 240 mm and an outlet wall thickness of approximately 360 mm (thickness of 0 and 3 m).
m). Subsequently, the same alloy is applied in the same manner but in an argon atmosphere as a coating in 2 to 7 layers depending on the location of the coating.
It was applied to the inner wall of the container.

This coating thickness is 0.7-1.5 m, including consideration of an average excess of approximately 0.2 mm, depending on the requirements of the individual container parts.
It was m.

Subsequent hammer compression reduced the predetermined excess of coating thickness. In other words, the thickness of the previously applied film was 20~
It decreased by 30%.

The film had a porous surface similar to sandpaper before hammer compression, but after the compression process the surface roughness was only about 5μ on average (Ra). The anticorrosion coating was uniform, showed no pores or bubbles, and had no bonding defects at the transition to the container body. Adhesion strength is approximately 3ON/mm
2, and the hardness was approximately 250 (Vickers hardness grade 0.1). No corrosion damage was observed after storage in dilute boric acid for 11 days.

[Brief explanation of the drawing]

FIG. 1 shows the metal transport and/or transport for biohazardous substances according to the present invention.
Or a schematic cross-sectional view of a storage container l...container body,
2... Shielding lid, 3... Protective lid, 4... Anti-corrosion adhesion film, 5... Coating film

Claims (1)

[Claims] In a metal transport and/or storage container for product-obstructing substances, which consists of a container body with a metal anti-corrosion installed inside, and a shielding and protective lid, the anti-corrosion fixing is made of a nickel-chromium alloy to which the metal anti-corrosion is applied by melting. It is composed of a coating (4) and a uniform, compressed, smooth coating (5) of the same material that is similarly melt-coated on the anticorrosive adhesive coating (4), and the anticorrosive adhesive coating (4) and the coating film (5)
metal transport and/or for biohazardous substances, characterized in that the material extends inside the container body (1) and further covers parts of the shielding lid (2) and the protective lid (3). storage container.