• Title/Summary/Keyword: Radioactive material

Search Result 450, Processing Time 0.032 seconds

Electrochemical oxidation of sodium dodecylbenzenesulfonate in Pt anodes with Y2O3 particles

  • Jung-Hoon Choi;Byeonggwan Lee;Ki-Rak Lee;Hyun Woo Kang;Hyeon Jin Eom;Seong-Sik Shin;Ga-Yeong Kim;Geun-Il Park;Hwan-Seo Park
    • Nuclear Engineering and Technology
    • /
    • v.54 no.12
    • /
    • pp.4441-4448
    • /
    • 2022
  • The electrochemical oxidation process has been widely studied in the field of wastewater treatment for the decomposition of organic materials through oxidation using ·OH generated on the anode. Pt anode electrodes with high durability and long-term operability have a low oxygen evolution potential, making them unsuitable for electrochemical oxidation processes. Therefore, to apply Pt electrodes that are suitable for long-term operation and large-scale processes, it is necessary to develop a new method for improving the decomposition rate of organic materials. This study introduces a method to improve the decomposition rate of organic materials when using a Pt anode electrode in the electrochemical oxidation process for the treatment of organic decontamination liquid waste. Electrochemical decomposition tests were performed using sodium dodecylbenzenesulfonate (SDBS) as a representative organic material and a Pt mesh as the anode electrode. Y2O3 particles were introduced into the electrolytic cell to improve the decomposition rate. The decomposition rate significantly improved from 21% to 99%, and the current efficiency also improved. These results can be applied to the electrochemical oxidation process without additional system modification to enhance the decomposition rate and current efficiency.

PROPERTIES OF LOW-PH CEMENT GROUT AS A SEALING MATERIAL FOR THE GEOLOGICAL DISPOSAL OF RADIOACTIVE WASTE

  • Kim, Jin-Seop;Kwon, S.;Choi, Jong-Won;Cho, Gye-Chun
    • Nuclear Engineering and Technology
    • /
    • v.43 no.5
    • /
    • pp.459-468
    • /
    • 2011
  • The current solution to the problem of using cementitious material for sealing purposes in a final radioactive waste repository is to develop a low-pH cement grout. In this study, the material properties of a low-pH cement grout based on a recipe used at ONKALO are investigated by considering such factors as pH variation, compressive strength, dynamic modulus, and hydraulic conductivity by using silica fume and micro-cement. From the pH measurements of the hardened cement grout, the required pH (< pH 11) is obtained after 130 days of curing. Although the engineering properties of the low-pH cement grout used in this study are inferior to those of conventional high-pH cement grout, the utilization of silica fume and micro-cement effectively meets the long-term environmental and durability requirements for cement grout in a radioactive waste repository.

Practical Radiation Safety Control: (I) Application of Annual Limit on Intake and Derived Air Concentration (방사선안전관리 실무: (I) 연간섭취한도와 유도공기중농도의 적용)

  • Kim, Hyun Kee
    • Journal of Radiation Protection and Research
    • /
    • v.38 no.4
    • /
    • pp.234-236
    • /
    • 2013
  • Some of radioactive contamination is unavoidable in the facilities using the unsealed radioactive material. The primary purpose of radioactive contamination control in the workplace with contamination concern is the effects from the potential intake of radioactive material into the body. This paper provides procedures to estimate the level of internal exposure for the worker based on the conservative assumptions and simple calculations. They consist of two processes; to calculate air concentration of radioactive material and annual intake by inhalation with contaminated air and to compare each of them to Derived Air Concentration and Annual Limit on Intake mentioned in the related notification. The procedures are applicable to make a decision on practical requirements for monitoring air contamination and internal exposure of worker as follows; needs for measurement of air contamination and internal exposure and acquisition of information on the design of the ventilation system.