주요연구

주요연구

: 8
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  • 8
    • The radioactive waste includes…   
      The radioactive waste includes radioisotope such as 129I and 131I whose half-lives are t1/2 = 1.57x107 years and t1/2 = 8.02 days, respectively. These iodine has harmful effects to humans through external and internal exposure which can bring burns to the skin and affect the thyroid gland. Therefore iodine needs to be removed safely.   "Objectives are capturing iodine species such as iodide, iodate, elemental iodine, and methyl iodide. For this study, we use various adsorbents like zeolite, activated carbon, a…
  • 7
    • Most of nuclear power plants (…   
      Most of nuclear power plants (NPP) and their yard storage facilities are located on or close to the shoreline, because the nuclear power plants need for cooling water.  As a fission product (90Sr, 137Cs, or 99Tc), radionuclides are often stored in a large water-filled tank of NPP facility at or near ground surface level.  In a case of severe accident, the radionuclides may leave the storage sites and transport in the subsurface environment in which nearby seawater can introduce through shattered fractures and cause…
  • 6
    • Efficient and rapid removal of…   
      Efficient and rapid removal of radioactive contaminants is crucial when they are released into the environment as a result of severe nuclear accidents. In addition, various methods have been developed for harvesting uranium (U) from seawater.   Objectives are to develop sorbent for the removal of uranium using tributyl phosphate (TBP) on the surface of Hydroxyapatite (HA). TBP is an organophosphorus extractant, and it is among the most favored extractants in the nuclear industry, which is due in part to the hi…
  • 5
    • Radioactive iodine   
      Radioactive iodine is one of the major constituents among fission products released into the environment from damaged containment at nuclear power plant (NPP) during severe core melt accidents such as Chernobyl and Fukushima as well asnuclear fuel reprocessing. Released radioactive iodine from nuclear reactor and nuclear severe accidents is one of the most hazardous radioactive contaminants and can create significant effect to human health. Several radioactive iodines such as I-131,I-135, I-125, a…
  • 4
    • Glass waste forms for Cs, Sr   
      Cs+ captured fly ash filter waste from pyro-processing was immobilized by alumino-borosilicate glass waste form. Produced glass specimens were irradiated by electrons in order to simulate the beta irradiation during the storage and disposal. Density, glass transition temperature, Vickers hardness and linear thermal expansion coefficient of pristine and irradiated glasses were measured. All of measured glass properties were similar to that of commercial HLW glass waste forms.&n…
  • 3
    • Glass waste form for Tc   
       A new alkali-alumino tellurite glass composition was developed to immobilize highly-volatile technetium (Tc) wastes generated from the pyrochemical processing technology. Tellurite glass can incorporate up to 7 mass% of rhenium (Re, used as a surrogate for Tc) with an average retention of 86%. Normalized elemental releases evaluated by seven-day product consistency test (PCT) satisfied the immobilized low activity waste requirements of United States when concentration of Ca(ReO4)2 in the glass was < 12 m…
  • 2
    • Glass waste form for I   
      Silver tellurite glasses with melting temperatures < 700 °C were prepared to immobilize the 129I that normally volatilizes during high-temperature melting. Glasses have densities of 6.31 ± 0.1 g/cm3 and transition temperatures of 165 ± 3 °C that provide thermal stability at the disposal site. Iodine waste loading in glasses was as high as 12.64 wt.% of all metallic elements and 11.21 wt.% including oxygen. Normalized elemental releases obtained from the product consistency test were well below US regulation of 2 g/…
  • 1
    • Glass-ceramic wasteforms for r…   
      Glass-ceramic wasteforms containing calcium neodymium(cerium) oxide silicate [Ca2Nd8 - xCex(SiO4)6O2] were synthesized to immobilize lanthanide oxide wastes generated from pyro-processing. 1. These Caesilicate crystals (~100 mm in size) were formed from alkali borosilicate glasses by heat-treating at 750 C for 3 h. Ce and Nd ions were partitioned inside the Caesilicate crystalline phases, constituting ~44 wt.% of the crystals. 2. Maximum leaching of these ions in the glasses was >26.8 wt.%. The normalize…