Patent Number: 054810612
Section: claims

1. A method for solidifying a radioactive waste with cement as a main solidifying material to produce a solidified radioactive waste, comprising: mixing water, a hydrophilic polymer emulsion and cement to form a first mixture, said cement having a coefficient of linear expansion of 0.1 to 0.5% with respect to volume change upon hardening and containing an expanding agent selected from the group consisting of calcium sulfate, calcium sulfoaluminate and calcium oxide;  adding radioactive waste to said first mixture and kneading the radioactive waste and first mixture to form a kneaded mixture, said radioactive waste being a water-absorptive; and  packing the kneaded mixture into a solidifying container. 2. A method for solidifying a radioactive waste according to claim 1, wherein the step of mixing said water, said hydrophilic polymer emulsion and said cement to form said first mixture is accomplished in a first mixer and wherein the steps of adding the radioactive waste to said first mixture and kneading the radioactive waste and first mixture to form said kneaded mixture is accomplished in a second mixer. 3. A method for solidifying a radioactive waste according to claim 1, wherein a mixing ratio of water to cement is 0.15 to 0.45. 4. A method for solidifying a radioactive waste according to claim 1, wherein said hydrophilic polymer emulsion is latex emulsion. 5. A method for solidifying a radioactive waste according to claim 1, wherein said radioactive waste is a concentrated liquid radioactive waste containing sodium sulfate and i wherein said method further comprises drying the concentrated liquid radioactive waste to obtain dried sodium sulfate powder and remaining concentrated radioactive liquid waste, and wherein the dried sodium sulfate and the remaining concentrated liquid radioactive waste are separately added to said first mixture.