• Proceedings of the Korean Nuclear Society Conference
• /
• 2005.05a
• /
• pp.974-975
• /
• 2005

• Proceedings of the Korean Radioactive Waste Society Conference
• /
• 2003.11a
• /
• pp.251-255
• /
• 2003

방사성폐기물 관리시설에 관한 신문의 관심은 매우 컸으며, 3개월 동안에 480건의 기사를 8개 신문에서 실었다. 사설도 38건이었으나 상황과 사안에 따라 모든 신문이 정형화된 내용과 비판을 하였다. 기사는 대부분 정부의 보도 자료에 의존한 하거나, 시위소식 등을 전하는 단순사안이었고, 심층보도는 이 사업 추진에 가장 큰 장애요소가 되고 있는 지역주민과 시민단체의 반대논리와 여론을 이해할 수 있도록 전달하지 못하였다. 특히 가장 쟁점이 될 수 있는 방사성폐기물의 위험과 안전에 대해서는 68건의 심층 보도 가운데 17건에서만 언급되고 있었는데, 그 내용도 위험성과 안전에 대한 해설이나 분석기사는 아니었다. 결과적으로 신문은 정부와 지역주민간의 갈등을 해결하는 조화의 장을 이끌어 내거나 제공하지 못하였고, 찬성과 반대 측 전문가들에게 공론의 장을 제공하여 사회적 합의를 도출하는데 기여하지는 못하였다. 오히려 많은 기사 보도의 남발로 방사성폐기물 관리시설에 대한 부정적인 이미지를 부각시키는 영향만 남았다고 판단된다.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.22 no.1
• /
• pp.81-89
• /
• 2024

Highly radioactive waste is solidified to restrict leaching, retain its shape, and maintain its structural stability to prevent it from affecting humans and the environment as much as possible. This operation should be performed consistently regardless of whether the waste is homogeneous or heterogeneous. However, currently, there are no specific performance requirements for heterogeneous waste in Korea. This study reviewed domestic research results and the status of overseas applications, and proposed immobilization requirements for heterogeneous waste to be applied in Korea. IAEA safety standards, domestic laws, and waste acceptance criteria were reviewed. The status of heterogeneous waste immobilization in countries such as the United States, France, and Spain was reviewed. Most countries treat heterogeneous waste by encasing it in concrete, and impose immobilization requirements on this concrete. Based on these data, safety standards for the thickness, compressive strength, and diffusion limit of this concrete material were proposed as immobilization requirements for heterogeneous waste disposal in Korea. Quantitative values for the above requirements need to be derived through quantitative assessments based on the characteristics of domestic heterogeneous waste and disposal facilities.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.7 no.1
• /
• pp.9-16
• /
• 2009

Transport package for radioactive material should be structurally safe under puncture drop condition and its safety should be verified by test and numerical analysis. Most finite element analyses for puncture drop have been performed without modeling the impact limiter since failure is occurred in the materials of the impact limiter. This paper presents a new modeling methodology, where an element is eroded in case that the material's failure criteria are reached at the element's integration point, to investigate the effect of the impact limiter in the puncture process. The effectiveness of the proposed scheme is shown through the puncture drop analysis of hotcell transport cask, which is under design in KAERI. The results show that about 80 percent of the total impact energy is absorbed due to the deformation of impact limiter. Using the present method the puncture drop can be analyzed more accurately, but it would give conservative results compared to the actual test condition.

• Proceedings of the Korean Radioactive Waste Society Conference
• /
• 2003.11a
• /
• pp.276-282
• /
• 2003

The geoscientific study on geological disposal for radioactive wastes has established the stepwise site characterization program, methods and investigation technology. However the intrinsic properties of geological material such as heterogeneity and scale dependent properties make difficulty on satisfactory understanding of geological conditions. To avoid unnecessary time delay and unexpected extra-cost for site investigation, the accurate and complete site investigation program should be established in a stepwise manner and the QC programs for investigation methods and procedures. Moreover, the technical requirements and preferences for a repository should be distinguished and be assessed at the end of each investigation step.

• Journal of Plant Biology
• /
• v.11 no.1
• /
• pp.1-6
• /
• 1968

The effects of the different temperatures on the amylase activity and growth rate of the rye seedling grown in the solutions containing radioactive sulfur- 35 were studied. The amylase activity of the coleoptiles obtained from the seedlings grown in the solutions of S-35, at 14$^{\circ}C$, appeared to be strongly stimulated in comparison to the control, but the culture temperatures of 22$^{\circ}C$ and 3$0^{\circ}C$ showed the decrease in the amylase activity. The amylase activity of the grains treated with the low intensity of the ratioactive material didn't show clear changes, at any culture temperatures, but the amylase activity of the grains treated with the high intensity of S-35, 50$\mu$c, showed definite decline at the elevated culture temperature, 3$0^{\circ}C$. Similar effects was also found in the growth of the seedlings. However, we would consider the effects of the radioactive materials on the acticity of the amylase and the growth of the seedlings are resulted from the accumulation of the much amount of the radioactive materials, and this accumulation rate depends upon actually the elevation of the culture temperature.

• Nuclear Engineering and Technology
• /
• v.51 no.7
• /
• pp.1805-1815
• /
• 2019

While nickel-based alloys have been widely used for power plants due to corrosion resistance and good mechanical properties, during the last couple of decades, failures of nuclear components increased gradually. One of main degradation mechanisms was primary water stress corrosion cracking at dissimilar metal welds of piping and reactor head penetrations. In this context, precise estimation of welding effects became an important issue for ensuring reliability of them. The present study deals with a series of finite element analyses and crack growth rate evaluation of Alloys 690/152. Firstly, variation of residual stresses and equivalent plastic strains was simulated taking into account welding of a cylindrical block. Subsequently, extraction and pre-cracking of compact tension (CT) specimens were considered from different locations of the block. Finally, crack growth curves of the alloys and heat affected zone were developed based on analyses results combined with experimental data in references. Characteristics of crack growth behaviors were also discussed in relation to mechanical and fracture parameters.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.19 no.1
• /
• pp.9-27
• /
• 2021

As an example of research activities in decontamination for decommissioning, new data are presented on the options for corrosion layer dissolution during the decommissioning decontamination, or persulfate regeneration for decontamination solutions re-use. For the management of spent decontamination solutions, new method based on solvent extraction of radionuclides into ionic liquid followed by electrodeposition of the radionuclides has been developed. Fields of applications of composite inorganic-organic absorbers or solid extractants with polyacrylonitrile (PAN) binding matrix for the treatment of liquid radioactive waste are reviewed; a method for americium separation from the boric acid containing NPP evaporator concentrates based on the TODGA-PAN material is discussed in more detail. Performance of a model of radionuclide transport, developed and implemented within the GoldSim programming environment, for the safety studies of the LLW/ILW repository is demonstrated on the specific case of the Richard repository (Czech Republic). Continuation and even broadening of these activities are expected in connection with the approaching end of the lifespan of the first blocks of the Czech NPPs.

• Journal of Sensor Science and Technology
• /
• v.27 no.4
• /
• pp.232-236
• /
• 2018

A radiation detection sensor was developed and characterized by combining three types of CsI(Tl) scintillators and an array-type SiPM to detect the radioactive contamination of discharged water in real time. The characterization results showed that type 3 exhibited the most desirable characteristics in response linearity (R-square: 0.97889) according to detection sensitivity and incident radiation dose. Furthermore, in terms of spectral characteristics, type 3 exhibited 16.54% at 0.356 MeV (the emission gamma ray energy of $^{133}Ba$), 10.28% at 0.511 MeV (the emission gamma ray energy of $^{22}Na$), 9.68% at 0.356 MeV (the emission gamma ray energy of $^{137}Cs$), and 2.55% and 4.80% at 1.173 MeV and 1.332 MeV (the emission gamma ray energies of $^{60}Co$), respectively. These measurements confirmed the good energy characteristics. The results were used to evaluate the spectral characteristics and energy linearity in a mixed source using type 3 with the best detection characteristics. It was confirmed that the gamma ray peaks of $^{133}Ba$, $^{22}Na$, $^{137}Cs$, and $^{60}Co$ were well resolved. Moreover, it was confirmed that R-square, which is an indicator of energy linearity, was 0.99986. This indicates a good linearity characteristic. Based on this study, further commercialization studies will contribute to measurements in real time and to the management of the contamination caused by radioactive wastewater or radioactive material leakage, which originate from facilities that use radioactive isotopes or care facilities.

• Journal of Radiation Protection and Research
• /
• v.23 no.3
• /
• pp.197-210
• /
• 1998

Regulations for the safe transport of radioactive material published by IAEA Safety Standard Series ST-l is reviewed and summarized. Safety Series No.115(International standard of radiation protection and safety for ionizing radiation and radiation sources), which reflected the new recommendation of ICRP60 published in 1991, has been a important encouragement for IAEA to revise their safety series related to the transportation of radioactive materials. IAEA Safety, Standard Series No. ST-l is summarized by comparing IAEA Safety Series No.6 regarding radiation protection system and its implementation, technical standards of packages, concept of Q system and exemption of regulation. The IAEA regulations of transportation of radioactive materials is summarized from the viewpoint of radiation protection and safety assessment. Research on transportation system of radioactive waste is suggested as a further study.