Abstract: The present invention is directed to an apparatus for decontaminating radioactive items such as parts and machinery including means for shotblasting or sandblasting to remove the radioactivity, means for cleaning the substance with a cleaning solution, means for washing the grit used to shotblast or sandblast with a washing solution, means for filtering the washing solution, and means for decontaminating the filtered washing solution by purifying it. The apparatus includes means for decontaminating washing solution to allow reuse thereof.

Abstract: Applying shotblast or sandblast to a substance contaminated with radioactivity, cleaning the substance with a liquid, washing the grit of shotblast or sandblast with an organic solvent, filtering the resulting organic solvent, decontaminating the organic solvent itself by distilling the organic solvent filtered, and using this decontaminated solvent for washing said grit.

Abstract: A radioactive decontamination method for decontaminating a radioactive-contaminated object by using methylene chloride in place of conventionally used hydrocarbon fluoride or perchloroethylene. The radioactive-contaminated object is impacted by methylene chloride solution. Before the impacting, a preparatory step is executed as required in which radioactive contaminant, which is usually radioactive-contaminated epoxy-resin paint layer on a part used in a nuclear facility, is impregnated with methylene chloride solution so as to swell, thus facilitating exfoliation of the contaminant from the object. The methylene chloride solution is filtered and distilled so as to be decontaminated and subjected to a repeated use for impacting the radioactive-contaminated object.

Abstract: A method and an apparatus for bonding parts of a disappearing model used for casting. This method comprises placing portions of parts of a disappearing model to be bonded so as to oppose each other to form portions to be adhered, surrounding the portions to be adhered by an injection mold frame which is previously formed, has an internal shape that accords with the external shape of the portions to be adhered and comprises a receiving mold and an injection mold that has an injection hole formed therein to allow an adhesive to be injected, and injecting the adhesive into the portions to be adhered from the injection hole.

Abstract: A flask is filled with a heat resistant filling material, such as sand, to embed therein a pattern of the type which melts down and generates combustible gas when it is heated, a runner connected to the pattern and provided with a sprue and a hollow venting device having an open upper end and a sidewall provided with at least one vent opening. A molten metal is poured into the sprue. The molten metal reaching the pattern through the runner heats the pattern and causes it to melt down and generate gas. The molten metal occupies a cavity formed by the meltdown of the pattern and drives out the gas into the venting device through the filling material and the vent opening. The gas is burned at the upper end of the venting device. Disclosed also is an apparatus which can be used for carrying out the method as hereinabove summarized. The apparatus is useful for either a batch or a continuous type of casting operation.