• Journal of Radiation Protection and Research
• /
• v.40 no.4
• /
• pp.267-276
• /
• 2015

Several analyses on tritium that is the largest release of gas or liquid radioactive waste from domestic PWR and PHWR NPPs were carried out, such as release comparison, directional frequency of wind and tritium behavior changes in environmental samples. First of all, analysis result showed that tritium released from PHWR was more than ten times as gas and double to three times as liquid in comparison to PWR in 2013. Independent release management in NPP units is needed to precisely control and analyze tritium, since there were 2 units of some NPPs having the same amount of release during analysis. In analysis on frequency of wind direction, average range showed 1.7 to 11.5% by 16-point compass. In case of analysis on sampling points by wind direction, Result showed most of the sampling points are right in places. However, There are some areas needed to examine. In analysis on tritium concentration changes in environmental samples, tritium concentration near NPPs was higher than one far away from NPPs. In case of environmental samples far from PWR, a trace of tritium occur. While, tritium concentration near NPPs was more than or equal to one further from PHWR. In conclusion, tritium occurs considerably in PHWR and is lower than standard in samples. but, it is still detected. Therefore, it is needed to strengthen control in system in NPPs and to consistently monitor tritium in environment.

• Journal of Adhesion and Interface
• /
• v.6 no.2
• /
• pp.6-12
• /
• 2005

The plasma generally, ionized gas state, is the 4th material state composed the universe. Generating the plasma artificially has been studied by spending energy and it has a lot of applications in human's life. There are several merits to modify the surface of polymer using plasma. Above all, plasma maintains the property of polymer because of it changes the property of surface only. Also, it doesn't use a organic solvent and it is the environment friendship because of there are no waste under processing. Furthemore, in case of high-pressure plasma, it is possible that automated-processing continuously. In this study, we tried the reforming of surface to rise the adhesive strength between the material of polymer, experimented the rising of adhesive strength through a experiment of peel strength by virtue of processing time and using gas, confirmed the change of polymer's surface through measuring the surface contact angle analyzer and scanning electron microscopy (SEM).

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.13 no.3
• /
• pp.211-218
• /
• 2015

The reaction rates of ZIRLO cladding hulls with cross-section openings were investigated using a thermo-gravimetric analysis system in order to identify whether selective recovery of Zr from oxidized cladding hulls is possible. The experimental results showed that an oxidized ZIRLO cladding hull was not reactive with chlorine gas at 400℃. However, providing fresh cross-sections on one or both ends of the ZIRLO hulls enabled a chlorination reaction. This reaction was completed after 8 hours; a 14% increase on the 7 hours seen with a bare ZIRLO cladding hull. The Sharp-Hancock plot analysis results revealed that the contracting volume model is the best for describing the reaction between the cross-section opened ZIRLO hulls and chlorine gas under the condition of this work. It was concluded that the chlorination process can be employed for oxidized ZIRLO cladding hulls by providing cross-section openings.

• Proceedings of the Korean Radioactive Waste Society Conference
• /
• 2005.06a
• /
• pp.121-128
• /
• 2005

A study on the selective separation of $^{99}Tc,\;^{94}Nb,\;^{55}Fe,\;^{90}Sr$ and $^{59}Ni(^{63}Ni)$ from various radioactive wastes discharged from the nuclear power plants in Korea is being performed for use in their quantifications which are indispensible for the evaluation of the radionuclide inventory. Separation behaviour of Ce, Ca, Mg, Al, Cr, Ti, Mn and Cu recovered along with Ni during the separation of Re (as a surrogate of $^{99}Tc$), Nb, Fe and Sr by anion exchange and Sr-Spec extraction chromatography was investigated by cation exchange and Ni-Spec extraction chromatography using synthetic radioactive waste dissolved solutions containing matrix elements such as Re, Nb, Fe, Sr, Ni, B, Na, K, Ce, Co, Ca, Mg, Al, Zn, Cr, Pb, Cd, Mo, Mn, Cu, Zr, Ti and U. To purify the Ni fraction recovered and prepare a radionuclide source available for gas proportional counting, an application of the Ni precipitation procedure with dimethylglyoxime in the medium of ammonium citrate and tartaric acid solutions as a masking agent for co-existing metal ions was described in detail.

• Proceedings of the KAIS Fall Conference
• /
• 2009.12a
• /
• pp.1030-1033
• /
• 2009

고형연료(RDF)는 가연성 폐기물을 성형된 형태로 만드는 것으로 화석연료의 대체 에너지로 이용되어질 수 있을 뿐만 아니라 일반 소각설비에 비해 수송성, 저장성이 뛰어나며 발열량이 거의 일정하여 연소 안정성이 우수하고 액체연료나 기체연료의 비해 경제성과 안정성이 높다는 장점이 있다. 하지만 고형연료의 미량 포함되어 있는 중금속 물질에 의해 연소장치의 부식이나 시설 노후 촉진화와 같은 원인을 제공하며, 심각한 환경오염원의 전구물질이 생성될 수 있어 실용화에는 큰 장해 요인이 되고 있다. 따라서 본 연구에는 고형연료의 재료가 되는 폐기물을 분석하여, 중금속성분이 미치는 영향을 조사하고 부존자원의 최적 이용 방안을 도출하며, 이를 바탕으로 부존자원 액상/고상 연료화 기술, 부존자원 복합이용시스템, 폐열활용 시스템과 같은 기술에 적용하여 부존자원 재활용 및 에너지를 최적 활용할 수 있는 D/B 구축을 하는 것이 최종 목표이다.

• Journal of Korean Society of Water and Wastewater
• /
• v.7 no.2
• /
• pp.9-23
• /
• 1993

Emission of hazardous and volatile organic chemicals from solid waste landfill site was become to important issue because of environmental pollution and health risk by such chemicals. Laboratory batch and continuous experiments were conducted respectively to elucidate isothermal sorption behaviors and transport phenomena(by gas through unsaturated solid waste layer) in wet solid waste-gas system. Source separated and size reduced refuse(bulky waste) and incinerated ash were used after controlling water content, and trichloroethylene(TCE) was chosen among many such chemicals because of it's generality among those man-created pollutants. Isothermal TCE sorption equilibria wet solid waste-gas system can be described in linear equation and partition coefficient in this system can be estimated approximately by the simple equation derived from schematic structure of the system. Transport equation modified by instantaneous equilibrium sorption fraction and kinetic sorption rate(overall mass transfer capacity coefficient) simulated well the column experiment results.

• Proceedings of the Korean Radioactive Waste Society Conference
• /
• 2003.11a
• /
• pp.158-161
• /
• 2003

To develop an effective adsorbent for radio active Carbon Dioxide, $^14CO_2$, which is discharged to nearby atmosphere from nuclear power plants of CANDU type, we made some preliminary adsorbents and tested their abilities of $CO_2$ removal. The chemical agents used was LiOH and we supported or impregnated it on the surface or the internal volume of activated Carbon(GW-H). The physical and chemical properties of various adsorbents were measured using methods such as XRD, BET. SEM images were taken to investigate the change of surface morphology of the adsorbents. Finally, amount of $CO_2$ adsorption of them were verified under specific conditions. We found that mechanical mixing of LiOH and activated Carbon showed the maximum $CO_2$ removal ability, while surface activation of activated Carbon by Nitric Acid-treatment enhanced its $CO_2$ removal efficiency to some degree.

• Proceedings of the Korean Radioactive Waste Society Conference
• /
• 2003.11a
• /
• pp.463-469
• /
• 2003

PWR-GALE Code is a computerized mathematical model for calculating the releases of radioactive material in gaseous and liquid effluents from PWRs. In PWR-GALE Code, Auxiliary building iodine removal efficiency, one of the code input data, did not reflect adequately the new design of KSNP which has two auxiliary buildings(PAB and SAB). In this study, we developed a revised method how to correct iodine removal efficiency in KSNP. And newly proposed methodology through case study using Ul-Jin 5, 6 design data was verified.

• Proceedings of the Korean Radioactive Waste Society Conference
• /
• 2003.11a
• /
• pp.509-513
• /
• 2003

The radioactive Carbon, C-14, although present in small amount, emits a high energy(up to 0.156MeV) $\beta$ ray and has extremely long half-life(5730years). So special monitoring and management on its generation and discharge is inevitable. A PHWR, due to its own specific designs generates about six times as much C-14 as a PWR does and over 90% of the discharged C-14 comes from the Moderator system and discharged in to the environment through the process of periodic purging of the moderator cover gas system. The present study focussed on the development of effective C-14 scrubber and after production of a test facility and experiments using it, we found that our test facility is very efficient in $CO_2$ removal.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.3 no.4
• /
• pp.309-317
• /
• 2005

A study on the separation of $^{99}Tc,\;^{94}Nb,\;^{55}Fe,\;^{90}Sr\;and\;^{59/63}Ni$ in various radioactive wastes discharged from nuclear power plants has been performed for a use in their quantification which is indispensible for the evaluation of the radionuclide inventory Ni was recovered along with Ca, Mg, Al, Cr, Ti, Mn, Ce, Na, K, and Cu through the sequential separation procedure of Re(as a surrogate of $^{99}Tc$), Nb, Fe and Sr by anion exchange and Sr-Spec extraction chromatography. In this research, chemical separation of Ni from the co-existing elements was investigated by cation exchange and Ni-Spec extraction chromatography. Precipitation behaviour of Ni and the co-existing elements with dimethylglyoxime(DMG) was investigated in ammonium $citrate/ethanol-H_2O$ and tartaric $acid/acetone-H_2O$ in order to purify separated Ni fractions and to prepare $^{59/63}Ni$ source for the radioactivity measurement using a gas proportional counter. Recovery of Ni separated through ion exchange chromatographic separation procedure was $92.1\%$ with relative standard deviation of $0.9\%$. In addition, recovery of Ni with DMG in the tartaric $acid/acetone-H_2O$ was $85.6\%$ with relative standard deviation of $1.9\%$.