Patent Number: 
Section: claims

1. A method for storing radiocontaminated waste matter, the method comprising the steps of:mixing paper sludge-derived sintered carbonized porous grains with radiocontaminated waste matter;filling said mixture of the paper sludge-derived sintered carbonized porous grains and the radiocontaminated waste matter into a container provided with a lid and a bottom base plate, the container being made of a same material as the lid and the bottom base plate. 2. The method for storing_radiocontaminated wasted matter according to claim 1, wherein the container is made of concrete, and the thickness and a density of the container are 60 to 65 mm and 2.0 to 2.4 g/cm3, respectively. 3. The method for storing radiocontaminated waste matter according to claim 1, wherein the material of the container includes the paper sludge-derived sintered carbonized porous grains, and a thickness and a density of the container are 60 to 65 mm and 1.8 to 2.4 g/cm3, respectively. 4. The method for storing radiocontaminated waste matter according to claim 2, wherein the material of the container includes the paper sludge-derived sintered carbonized porous grains, and the thickness and the density of the container are 60 to 65 mm and 1.8 to 2.4 g/cm3, respectively. 5. The method for storing radiocontaminated waste matter according to claim 3, wherein the material of the container includes gravel, and the content of the paper sludge-derived sintered carbonized porous grains is 15% to 35% of the gravel. 6. The method for storing radiocontaminated waste matter according to claim 4, wherein the material of the container includes gravel, and the content of the paper sludge-derived sintered carbonized porous grains is 15% to 35% of the gravel. 7. The method for storing radiocontaminated waste matter according to claim 1, wherein the container is made of steel sheet, and a thickness and a density of the container are 10 to 15 mm and 7.0 to 7.8 g/cm3, respectively. 8. The method for storing radiocontaminated waste matter according to claim 1, wherein said mixture is ashed at 750° C. to 950° C. for 30 to 100 minutes before being filled into the container. 9. The method for storing radiocontaminated waste matter according to claim 2, wherein said mixture is ashed at 750° C. to 950° C. for 30 to 100 minutes before being filled into the container. 10. The method for storing radiocontaminated waste matter according to claim 3, wherein the mixture is ashed at 750° C. to 950° C. for 30 to 100 minutes before being filled into the container. 11. The method for storing radiocontaminated waste matter according to claim 4, wherein said mixture is ashed at 750° C. to 950° C. for 30 to 100 minutes before being filled into the container. 12. The method for storing radiocontaminated waste matter according to claim 5, wherein said mixture is ashed at 750° C. to 950° C. for 30 to 100 minutes before being filled into the container. 13. The method for storing radiocontaminated waste matter according to claim 6, wherein said mixture is ashed at 750° C. to 950° C. for 30 to 100 minutes before being filled into the container. 14. The method for storing radiocontaminated waste matter according to claim 7, wherein said mixture is ashed at 750° C. to 950° C. for 30 to 100 minutes before being filled into the container. 15. The method for storing radiocontaminated waste matter according to claim 8, wherein an ash obtained by ashing said mixture is mixed with the paper sludge-derived sintered carbonized porous grains before being filled into the container. 16. The method for storing radiocontaminated waste matter according to claim 1, wherein a shape of the container is polygonal cylindrical with at least four corners or circular cylindrical. 17. A container for the method to shield radiocontaminated waste matter according to claim 1, wherein the paper sludge-derived sintered carbonized porous grains and the radiocontaminated waste matter are mixed together before being filled into the container.