Abstract: Method for the final conditioning of radioactive and/or toxic waste by fusing it into thermoplastic matrix material, binding radioactive and/or toxic pollutants contained in the waste from all sides, characterized by the feature that radioactive thermoplastic synthetic material is used as the thermoplastic matrix material.

Abstract: Incinerator furnace for incinerating organic substances, especially compounds which contain radioactive actinides in chemically bound form or are contaminated with chemical compounds, having an incinerating chamber which has a feed opening for oxygen-containing gas, a discharge opening for exhaust gas, and a filter body of the exhaust gas stream. The filter body is cup-shaped, and is arranged with its opening at the feed opening for oxygen-containing gas. The filter body on the side facing the feed opening for oxygen-containing gas forms a receiving space for the organic substances.

Abstract: Method for dissolving hard-to-dissolve thorium and/or plutonium oxides, especially dioxides such as ThO.sub.2, PuO.sub.2 or (U/Pu)O.sub.2 mixed oxides by heating the oxides in a hermetically sealed vessel in fluoride-free nitric acid. The use of a gas atmosphere containing oxygen in the sealed vessel is advantageous.

Abstract: Dissolving hard-to-dissolve nuclear fuels such as ThO.sub.2 and PuO.sub.2 in a nitric acid fission material solution which contains nitric acid and a Pu-fluoride complex to provide free fluorine ions in a small catalytically active amount due to small dissociation of fluoride ions from the Pu-fluoride complex. This permits dissolving hard-to-dissolve nuclear fuels in normal metallic dissolving vessels and also eliminates need for using polytetrafluoroethylene.