• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.09a
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• pp.406-409
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• 2004

최근 Lee et al.$^{l-2)}$ 은 화강암질 편마암내 균열면의 방해석이 Eu의 변화에 큰 영향을 주며, 아울러 Eu 은 Am의 유사체로서 매우 적합한 원소라고 제안하였다. 이 논문에서는 1)희토류원소와 액티나이드 원소의 이온반경, 배위수 등의 상호비교와 2) 응집력(cohesive energy)의 유사성과 물리적/화학적 특성 그리고 3) 희토류원소 지구화학의 최근 연구결과를 토대로 하여, 고준위 방사성 핵종원소인 Am의 지질매체내 거동을 예측하기 위한 유사체(analog)로서 Eu이 매우 유용한 역할을 해준다는 가설2)을 검증한 결과를 보고하고자 한다. 연구방법으로서, 핵종원소의 지질매체별 흡착특성을 밝혀내기 위해 금번 실험에서는 희토류원소 암상별 분포의 특성을 고려하여 4종류(화강암질 편마암류 2종, meta-basalts, 응회암)의 시료를 선별하였다. 방사화학적 흡탈착 실험의 핵종동위원소로서는 152Eu와 241Am을 선택하였다. 이는 본 연구팀의 연구결과, Eu과 Am의 밀접한 물리적/화학적 상관관계 그리고 지질환경내에서의 거동특성을 고려한 것이다. 실험결과 양 동위원소의 지질매체와의 흡착 반응 특성을 비교해 볼 때, 시간의 경과에 따라 서로간에 매우 유사한 양상의 증감을 보여주면서 변화함을 알 수가 있었다. 이 결과는 희토류원소가 액티나이드 원소의 지질환경내 거동예측을 위한 유사체로서 매우 훌륭한 도구라는 것을 입증해 주는 것이라 할 수 있다.

• Economic and Environmental Geology
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• v.51 no.2
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• pp.99-111
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• 2018

In this study three target radionuclides ($^{60}Co$, $^{137}Cs$, and $^{125}Sb$) were reacted with solid samples collected from the nuclear facility sites to investigate their sorption and mobility behaviors for preparing unexpected nuclear accidents. The highest sorption distribution coefficients ($K_{ds}$) of target radionuclides ($^{60}Co=947mL/g$, $^{137}Cs=2105mL/g$, $^{125}Sb=81.3mL/g$) were found in topsoil layer under groundwater condition, and the $K_d$ values of three radionuclides decreased in the order of fractured rock and bedrock samples under the same groundwater condition. High $K_d$ values of $^{60}Co$ in topsoil layer and fracture rock resulted from the clay minerals present, and the $K_d$ values decreased 58-69 % under seawater condition due to high ionic strength. $^{137}Cs$ sorption was controlled by the ion exchange reaction with $K^+$ on flayed edge sites (FES) of mica. The $^{137}Cs$ sorption was the most affected by seawater (89-97 % decrease), while $^{125}Sb$ sorption was not much affected by seawater. As the results of column and batch experiments, the retardation factors (R) of $^{137}Cs$, $^{60}Co$, and $^{125}Sb$ were determined about 5400-7400, 2000-2500, and 250-415, respectively, indicating no significant transport for these radionuclides even in fractured zone with groundwater. These results suggest that even in the case of severe nuclear accident at the nuclear facilities the mobility of released radionuclides ($^{60}Co$, $^{137}Cs$, and $^{125}Sb$) can be significantly retarded by the topsoil layer and fractured rock. In addition, the results of this study will be used for the safety and environmental performance assessment of nuclear facilities.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.11b
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• pp.565-570
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• 1996

$^{32}$P는 순수한 $\beta$$^{-}$ 방출핵종(방출에너지 ＝ 1.71 MeV, 반감기 ＝ 14.3일)이며 의료용, 표지화합물 합성용, 유전공학 실험용 등으로 널리 사용되므로 고품질의 $^{32}$P의 수요에 부응하기 위해 감압증류법을 개발하였는 바 그 방법과 결과는 다음과 같다. 연구로 2호에서 중성자 조사된 황 표적을 감압 증류용기내에서 5~10 mmHg의 감압하에 200~30$0^{\circ}C$로 가열하여 황을 증류해 낸 다음 묽은 염산을 역류시켜 넣고 $^{32}$P 를 울궈냈다. 이 용액을 이온교환 수지로 정제하여 약 60 mCi/batch의 정제 $^{32}$P를 얻었다. 이온교환수지에 흡착되는 $^{32}$P의 방사능은 전체의 3% 미만이었고 여기에 흡착되는 불순 핵종은 $^{131}$ Ba, $^{85}$ Sr, $^{59}$ Fe, $^{65}$ Zn, $^{60}$Co이었다. 이 방법으로 얻은 $^{32}$P 최종제품은 핵종순도 >99%, 방사화학적 순도 >98%, 고형성분 함량 <1.2 mg/mL 이어서 그 품질이 우수함을 알 수 있었다.

• Nuclear Engineering and Technology
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• v.27 no.1
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• pp.1-7
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• 1995

The mechanism of radionuclide colloid transport in porous media was studied through modeling and experiment. A nondestructive column scanning system was developed to improve the traditional destructive core slicing method. With an aid of this system we could get much more results from one experiment. Neutron activated clay soaked with soluble isotopes was used as colloid suspension. Filtration coefficients obtained through the experiments show two families of colloids despite their size distribution. New modeling of polydispersed colloid transport was made with two lumped parameters. This new model simulates well. Among the soluble isotopes $^{l37}$Cs mowed mainly as a form of colloid, but $^{85}$ Sr did not.t.

• Nuclear Engineering and Technology
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• v.16 no.2
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• pp.64-69
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• 1984

With regard to the radioactive waste disposal, adsorption properties and migration rates have been evaluated for Cs-137 and Sr-90 with the domestic clay sampled from Cnyang, Sanchong and Mooan. Sorption coefficients (Ksorp) were determined by batch experiments. The measured values of Ksorp were ranged from 8000 to 17,000 ml/gr for Cs-137 of 0.1$\mu$Ci/ml, and from 10,000 to 15,000m1/gr for Sr-90 of 0.l$\mu$Ci/ml. Remarkably, Mooan clay showed lower values of Ksorp than those of the others. This could be explained by the poor soprtion capacity of the quartz found only in the Mooan clay. For the quantitative analysis, sorption isotherm equations of Freundlich type were made with the obtained values of Ksorp. $C_{R}$=18.0 $C_{A}$$^{0.74}$ : Cs-137, $C_{R}$=0.84 $C_{A}$$^{0.45}$ : Sr-90. By introducing the BOX model combined with the above relationships, simulation of underground nuclide movement was carried out. The results showed that the domestic clays could be the effective backfill material for repositories.itories.ies.

• Journal of the Korea Institute of Building Construction
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• v.17 no.1
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• pp.15-21
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• 2017

WHO reported that millions of people die every year because of diseases induced from environmental pollution. In 2012, approximately 7 million people were killed due to air pollution. Major cause of such pollution includes toxin, chemical waste, radiation and air pollution. Therefore, the significance and interest to indoor air quality has been continuously increased. Especially, the interest in radon, the ARC group 1 carcinogen, is rapidly increasing, and banning the use of construction materials that release radon, repairing aged buildings, and developing ventilators. To reduce the level of radon gas was inflowed to indoors and outdoors, this study is to research and develop a radon gas absorption board using absorbents. The absorbents utilized to absorb the radon gas were porous diatomite, natural zeolite, 4A zeolite and 13X zeolite and employed bentonite and illite, montmorillonites with the property of exchanging anions. As the main binder, magnesium oxide was used, with a content of 25% magnesium chloride.

• Tunnel and Underground Space
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• v.13 no.1
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• pp.20-32
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• 2003

To understand the behavior of migration of contaminants in a fractured porous medium is a key to assure the overall safety of a potential radwaste repository. The feasible retention mechanism of contaminant transport in a tinctured medium are sorption of contaminants on solid surface and matrix diffusion of contaminants from a fracture into an adjacent porous medium. The acceleration mechanisms are the migration of contaminants in the form of pseudo-colloids and the limit of a volume f3r matrix diffusion. In this paper, the effects of these two acceleration mechanisms are studied mathematically, then semi-analytically computed by the application of the Talbot theorem and verified. Results indicate that the acceleration processes cannot be neglected in the modeling of contaminant transport in a fractured porous medium.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.4 no.4
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• pp.373-384
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• 2006

Spent ion-exchanged resin generated from various purification systems in CANDU reactor was contaminated with high activity of $^{14}C$ radionuclide. This paper describes the results of fundamental study to develop the applicable technology for the treatment of this spent resin. Based on the adsorption capacity of inactive $HCO_3$ ion and other anions on IRN-150 mixed resin, the removal characteristics of $HCO_3$ ion adsorbed on to IRN-150 by various stripping solutions were evaluated. Maximum adsorption amount of the $HCO_3$ ion onto IRN-150 raw resin was about 11 mg-C/g-resin which agrees with the theoretical adsorption amount of this resin. Adsorption affinity of various anions such as $CS,\;CO,\;Na\;NH_4$ was analyzed in single and multi-component systems. From the results of removal characteristics of the $HCO_3$ ion adsorbed on IRN-150 by various stripping solutions, $NH_4H_2PO_4$ stripping solution is more effective than $NaNO_3,\;Na_3PO_3$ solutions for the complete removal of $^{14}C$ radionuclide from the IRN-150 spent resin.

• Journal of Radiation Protection and Research
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• v.10 no.1
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• pp.3-13
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• 1985

The sorption behavior of some typical fission products such as Cs-137, long-lived radionuclide; Ce-144, rare-earth element; and Co-60, corrosion product on zeolite A, zeolite F-9 (faujasite) and amorphous zeolite was determined with the salt concentrations, 0.01 M- to 2.0 M- nitric acid and ammonium nitrate, and the shaking time, 15 minutes interval from 15 minute to 90 minute. Kd values were obtained through the batch experiment. In conclusion, the optimal conditions for isolation and removal of the typical radionuclides are as following: zeolite, amorphous zeolite; concentration, $0.01\;M-HNO_3\;and\;0.1\;M-NH_4NO_3$; pH4; shaking time, one hour; the most effective species, Cs-137.

• Proceedings of the Korean Nuclear Society Conference
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• 1997.10a
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• pp.375-380
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• 1997

모의 방사성 세탁폐액을 제조하여 오존에 의한 세제 파괴를 확인하고 활성탄 및 이온교환수지를 이용하여 세제 및 Co, Cs 제거율을 조사하였으며 모의 방사성 세탁폐액을 오존으로 부분적으로 산화ㆍ파괴시킨후 활성탄 및 이온교환수지에 의한 흡착 및 이온교환 실험을 수행하여 오존의 세제 파괴가 방사성 물질 제거에 미치는 영향을 조사하였다. 오존에 의해 세제는 75% 정도 제거될 수 있었고 활성탄으로 방사성 모의세탁폐액을 처리할 때 세제농도가 증가하면 방사성 핵종 제거율이 감소하였다. 이온교환수지로 세제를 제거할 때 성취가능 제거율은 Co의 경우 99% 이상이었으며, 세제 존재시 방사성 Co 및 Cs 제거율은 감소하며, 방사성 모의세탁폐액을 오존으로 조사후 활성탄과 이온교환수지로 방사성 핵종을 제거할 때 그 제거율은 거의 변화가 없었다. 이상과 같은 실험 결과로부터 오존으로 부분적으로 산화시켜 활성탄의 세제 제거효율을 최대화하고, 역삼투막에 의한 방사성 핵종을 제거하며 이온교환수지로 잔류 방사성 핵종을 완전히 처리할 수 있는 복합 공정을 도출하였다.