METHOD FOR MOLDING BUFFER AGENT FOR GEOLOGIC DISPOSAL OF RADIOACTIVE POLLUTANT AND MOLDING MANDREL

• Main Authors: NINOMIYA NOBUO, YAMAGATA JUNJI, AKASAKA HIDENARI, SHIMURA SATOSHI, ASANO HIDEKAZU, KAWAKAMI SUSUMU
• Format: Patent
• Language: English
• Published: 19.09.1995
• Edition: 6
• Subjects: DECONTAMINATION ARRANGEMENTS THEREFOR; NUCLEAR ENGINEERING; NUCLEAR PHYSICS; PHYSICS; PROTECTION AGAINST X-RADIATION, GAMMA RADIATION, CORPUSCULARRADIATION OR PARTICLE BOMBARDMENT; TREATING RADIOACTIVELY CONTAMINATED MATERIAL

PURPOSE:To secure a housing hole in the process of molding and reduce the weight of a mold by pressure-molding a powdery molded buffer agent with a pressurizing fluid after placing it around a hollow mandrel shaped a little larger than a pollutant containment and blocking it up with an elastic mold. CONSTITUTION:A powdery molded buffer agent such as bentonite is placed around a hollow mandrel 22 blocked up with an elastic mold 23 in its periphery and loaded into a pressure vessel 21. Then, the internal pressure is heightened in the pressure vessel 21 and by supplying the vessel 21a with pressurizing fluid R generated in a pressure fluid source 24 to elastically transform the elastic mold 23, and the buffer agent X is compressively molded by applying isotropic pressure of it. At this stage, the pressurizing fluid R flows into a hollow part 22a of the hollow mandrel 22 and pressurizes the inner and outer wall of the mandrel at the same time. Therefore, the thickness of the mandrel wall can be thinned and the weight of a mold can be reduced. After pressure- molding, a control valve 28 is switched to relieve pressure, and the hollow mandrel 22 and the elastic mold 23 are torn down to obtain a compact of the buffer agent with a housing hole in the center of it.