Japan and IAEA shows a number of similarities and differences. The U.S
onsequently, tough separation and restraint periods (hundreds of years) are necessary for such wastes. LLWs may also contain a blend of radionuclides with short half-lives at higher concentrations and long-lived radionuclides at lower levels of activity (International Atomic Energy Agency 5). ILWs have a higher content of radionuclides with long half-lives and, therefore, require a larger extent of separation and restraint than that provided by near-surface clearance.
However, there is minimal heat dispersion during their storage and discarding. ILWs contain radionuclides that release alpha particles during decay and need to be buried ten to a hundred meters beneath the surface of the earth. HLWs include wastes with radioactivity that produces significant quantities of heat during the decay process. Additionally, these wastes contain large quantities of long-lived radionuclides. Therefore, great caution is required during the disposal of these wastes. As a rule, these wastes are usually buried in stable pits whose depth extends for several hundred meters.
A comparison of the classification system of radioactive wastes in the U.S., Japan and IAEA shows a number of similarities and differences. The U.S. and IAEA systems have six categories of radioactive wastes. Out of these, only two categories share similarities in the two systems. These two categories are low-level wastes and high-level wastes. Conversely, the Japanese system of classification has only two categories of wastes. However, the subclasses of the second category in the Japanese system contain four subclasses that share a number of characteristics with the main groups of the IAEA system.
