DE2745408A1 - Demolishing large radioactively contaminated vessels or shielding - by internal blasting explosion after walls have been weakened by local cutting charges - Google Patents

Abstract

Thick-walled vessels esp. reactor vessels, heat exchangers and shielding structures of cast iron or concrete, which have become radio actively contaminated, are broken by first notching or weakening the vessel wall by cutting charges and then producing an internal pressure by an internal charge to force the notched structure apart. This internal bursting pressure may be produced by a flexible explosive, a liq. explosive or damped explosive in the latter case, a liq. such as water or plastics foam may be used for tamping. The min. access to radioactive zones is required for demolition. The arrangement of the initial, external charges can be varied to suit the thickness and strength of the structure.

Description

Method for dismantling thick-walled containers, in particular

those that are radioactive.

The invention relates to a method for dismantling thick-walled containers, especially those that, like demolished reactor vessels, heat exchangers and these shielding, cast iron or concrete protective housings of nuclear power plants, are radioactively contaminated.

It is known that large components that have been used up are radioactively contaminated of nuclear power plants, such as reactor boilers, heat exchangers and protective housings protecting them made of cast iron or concrete, for transport in protective containers on mechanical Way to shred. It is considered a disadvantage that this - conditional due to the large dimensions of an object of the aforementioned type to be dismantled, the the accessibility to this aggravating structural structure of the nuclear power plant, the need for remote control of the comminution process for radiation reasons and the radioactive contamination of the tools used - an immense effort must be operated.

The present invention is therefore based on the object of a far to develop less complex process of the type mentioned at the beginning.

This object is achieved in that initially the Container wall by means of hollow cutting charges, cutting cords or Detonation cords pre-notched and then inside the container by means of at least an explosive charge such a pressure is generated that the pre-notched wall points burst.

With the method according to the invention, for example, obsolete Reactor boilers, heat exchangers and protective housings of nuclear power plants that protect them Controlled in parts with effortless compliance with the radiation protection regulations disassemble, remotely controlled without the need for complex control measures. It is easy to achieve dismantling parts of any desired size. Namely, the number and local distribution of the pre-notches only need to be appropriate to be varied. In addition, there is the especially for particularly thick walls interesting possibility, said pre-notches by repeatedly using hollow cutting charges To broaden and deepen cutting cords or detonation cords as desired. It remains to be mentioned as advantageous that due to the notch it is comparative low pressures are sufficient to prevent the container in question from bursting at the pre-scored Establish to bring about. This has two positive effects. Once is the need for preferably flexible or liquid explosives for the cargo accordingly low for generating burst pressure. On the other hand, the environment remains Preserved from excessive pressure surge loads.

What about explosives requirements and pressure surge loading above has been carried out, applies to an even greater extent if according to the design features of the invention the explosive charge or

Explosive charges for generating the bursting pressure inside the container be dammed, for example by filling it with water or foamable Plastic.

Finally, the following also turns out to be worth mentioning: For example a disused reactor boiler of a nuclear power plant in the conventional way by means of disassembled mechanical cutting tools or cutting torches, a multitude arrives radioactive particles from the cutting zones into the environment and contributes to an additional Radiation exposure of the same.

This radiation exposure does not occur in the method according to the invention more evident, since here the bursting process without any noteworthy formation of such radioactive particles going on.

(Shear fracture)

Claims (6)

Process for dismantling thick-walled containers, in particular those that are radioactively contaminated. Claims 1. A method for dismantling thick-walled containers, in particular those such as demolished reactor vessels, heat exchangers and these shielding, cast iron or concrete protective housings of nuclear power plants, are radioactively contaminated, as a result of the fact that initially the Container wall by means of hollow cutting charges, cutting cords or detonation cords pre-notched and then inside the container by means of at least one explosive charge such a pressure is generated that the pre-notched wall points burst. 2. The method according to claim 1, characterized in that g e k e n n -z e i c h n e t that for the explosive charge or explosive charges to generate the bursting pressure in Flexible explosives inside the container is used. 3. The method according to claim 1, characterized in that g e k e n n -z e i c h n e t that for the explosive charge or explosive charges to generate the bursting pressure in Inside the container liquid explosive is used. 4. The method according to any one of claims 1 to 3, characterized g e k e n n S e i n e t that the explosive charge resp. Explosive charges for generating the bursting pressure inside the container be damned. 5. The method according to claim 4, characterized in that g e k e n n -z e i c h n e t that for damming the inside of the container is filled with a liquid such as water will. 6. The method according to claim 4, characterized in that g e k e n n -z e i c h n e t that for damming the inside of the container is filled with foamable plastic.