다양한 함수비를 가진 화강암의 열전도도 추정을 위한 실험적 모델

조원진,권상기,이재완,Cho, Won-Jin,Kwon, Sang-Ki,Lee, Jae-Owan 한국방사성폐기물학회 2010 방사성폐기물학회지 Vol.8 No.2

To obtain the input data for the design and long-term performance assessment of a high-level waste repository, the thermal conductivities of several granite rocks which were taken from the rock cores from the declined borehole were measured. The thermal conductivities of granite were measured under the different conditions of water content to investigate the effects of the water content on the thermal conductivity. A simple empirical correlation was proposed to predict the thermal conductivity of granite as a function of effective porosity and water content which can be measured with relative ease while neglecting the possible effects of mineralogy, structure and anisotropy. The correlation could predict the thermal conductivity of granite with the effective porosity below 2.7% from the KURT site with an estimated error below 10%.

압축 벤토나이트 및 벤토나이트-모래 혼합물의 열전도도

조원진,이재완,권상기,Cho, Won-Jin,Lee, Jae-Owan,Kwon, Sang-Ki 한국방사성폐기물학회 2008 방사성폐기물학회지 Vol.6 No.2

For the Kyungju bentonite which is considered as a candidate material for the buffer and backfill in the high-level waste repository, the thermal conductivities of compacted bentonite and a bentonite-sand mixture were measured. The thermal conductivities of the compacted bentonites with a dry density of 1.2 to $1.8\;Mg/m^3$ and the bentonite-sand mixture with a dry density of 1.6 and $1.8\;Mg/m^3$ were measured within the gravimetric water content range of 10wt% to 20wt% and the sand fraction range of 10 to 30wt%. The thermal conductivity of compacted bentonite and a bentonite-sand mixture increases with increasing dry density and sand weight fraction in the case of constant water weight fraction, and increases with increasing water weight fraction and sand weight fraction in the case of constant dry density. The empirical correlations to describe the thermal conductivity of compacted bentonite and a bentonite-sand mixture as a function of water fraction at each dry density were suggested. These correlations can predict the thermal conductivities of bentonite and a bentonite-sand mixture with a difference below 10%.

고준위폐기물 처분연구용 지하터널의 기본설계

조원진,권상기,박정화,한필수,Cho Won-Jin,Kwon Sang-Ki,Park Jung-Hwa,Hahn Pil-Soo 한국방사성폐기물학회 2004 방사성폐기물학회지 Vol.2 No.4

The underground research tunnel is essential to validate the integrity of a reference high-level waste disposal system, and the safety of geological disposal. In this study, a basic design of an underground research tunnel (URT) was tried to be developed. The candidate site for URT was described briefly, and it was intended to suggest the basic concept of the underground research tunnel. In order to develop the design of URT based on the basic concept, design requirements were established. Based on the basic concept and the design requirements, the basic design of URT was performed. Research items to be studied in the URT were also derived in this study.

Influence of Water Salinity on the Hydraulic Conductivity of Compacted Bentonite

조원진,김진섭,최종원,Cho, Won-Jin,Kim, Jin-Seop,Choi, Jong-Won Korean Radioactive Waste Society 2011 방사성폐기물학회지 Vol.9 No.4

다양한 건조밀도를 가진 압축벤토나이트의 수리전도도에 물의 염도가 미치는 영향이 조사되었다. 압축벤토나이트의 수리전도도는 벤토나이트의 건조밀도가 상대적으로 낮은 경우에만, 염도가 증가함에 따라 증가하였으며, 염도의 증가에 따른 수리전도도의 증가 정도는 벤토나이트의 건조밀도가 낮을수록 더 현저하였다. 건조밀도가 1.0 $Mg/m^3$ 및 1.2 $Mg/m^3$ 인 압축벤토나이트의 경우, 0.4 M NaCl 용액의 수리전도도는 탈염수의 경우에 비해 각각 7배 및 3배가 증가하였다. 그러나 1.4 $Mg/m^3$ 보다 큰 건조밀도를 가진 압축벤토나이트의 경우에는, 수리전도도에 미치는 염도의 영향이 크지 않았으며, NaCl의 농도가 0.04 M에서 0.4 M 인 범위에서는 거의 일정한 값을 유지하였다. 벤토나이트 시편을 탈염수로 미리 포화시키는 것은 수리전도도에 큰 영향을 미치지 않았다. The influence of water salinity on the hydraulic conductivities of compacted bentonites with several dry densities were studied. The hydraulic conductivity increases with increasing salinity only when the dry density of bentonite is relatively low. The degree of increase becomes more remarkable at a lower dry density of bentonite. For bentonite with the density of 1.0 $Mg/m^3$ and 1.2 $Mg/m^3$, the hydraulic conductivity of the 0.4 M NaCl solution increases up to about 7 times and 3 times, respectively higher than that of freshwater. However, for the bentonite with a dry density higher than 1.4 $Mg/m^3$, the salinity has an insignificant effect on the hydraulic conductivity, and the hydraulic conductivity is nearly constant within the salinity range of 0.04 to 0.4 M NaCl. The pre-saturation of the bentonite specimen with freshwater has no significant influence on the hydraulic conductivity.

한국원자력연구원 지하처분연구시설

조원진,권상기,박정화,최종원,Cho, Won-Jin,Kwon, Sang-Ki,Park, Jeong-Hwa,Choi, Jong-Won 한국방사성폐기물학회 2007 방사성폐기물학회지 Vol.5 No.3

고준위폐기물 기준처분시스템의 건전성과 처분안전성의 실험적 검증에 필수적 시설인 지하처분연구시설이 한국원자력연구원 부지 내에 건설되었다. 지하처분연구시설의 부지조사 결과에 대해 기술하고, 이 부지에 건설될 지하처분연구시설의 설계, 인허가, 건설 과정과 건설된 시설의 개요에 대해 하였다. 또 지하처분연구시설에서 수행 중인 현장실험에 대해 소개하였다.

고준위폐기물처분장 공학적방벽시스템의 열-수리-역학적 복합거동 해석 모델 개발 현황

조원진,김진섭,이창수,최희주,Cho, Won-Jin,Kim, Jin Seop,Lee, Changsoo,Choi, Heui-Joo 한국방사성폐기물학회 2012 방사성폐기물학회지 Vol.10 No.4

현재까지 개발된 고준위폐기물 심지층처분장의 열-수리-역학적 복합거동 해석을 위한 전산 코드의 현황을 조사하고, 문헌에 보고된 각 코드에 의한 계산치와 현장실험 측정치의 비교 결과를 이용하여, 기존 전산 코드들의 신뢰도를 분석하였다. 개발된 전산코드들은 완충재가 없는 처분장에서는 붕괴열에 따른 암반의 열-수리-역학적 거동을 비교적 잘 모사하였으나, 포화 경암층에 위치한 완충재가 존재하는 처분장의 공학적방벽시스템 내에서 일어나는 열-수리-역학적 복합거동의 예측은 만족스럽지 못하였다. 현재 제안된 열-수리-역학적 복합거동 해석모델을 고준위폐기물 처분장 공학적방벽시스템의 거동 해석에 적용하기 위해서는 완충재 내의 수분함량 및 전 압력 분포를 보다 정교하게 모사할 수 있도록 수학적 모델의 개선이 필요하다. The current status of the computer codes for the analysis of coupled thermal-hydrological-mechanical behavior occurred in a high-level waste repository was investigated. Based on the reported results on the comparison between the predictions using the computer codes and the experimental data from the in-situ tests, the reliability of the existing computer codes was analyzed. The presented codes simulated considerably well the coupled thermal-hydrological-mechanical behavior in the near-field rock of the repository without buffer, but the predictions for the engineered barrier system of the repository located at saturated hard rock were not satisfactory. To apply the current thermal-hydrological-mechanical models to the assessment of the performance of engineered barrier system, a major improvement on the mathematical models which analyze the distribution of water content and total pressure in the buffer is required.

A novel viscosity measurement using a falling ball viscometer with a high-speed camera

Won Jin Jo(조원진),Bock Choon Pak(박복춘),Young I Cho(조영일) 대한기계학회 2006 대한기계학회 춘추학술대회 Vol.2006 No.11

This study introduces a new approach to a falling ball viscometer by using a high speed motion camera to measure the viscosity of both Newtonian and non-Newtonian fluids from the velocity-time data. This method involves capturing continuous photographs of the entire falling motion of the ball as the ball accelerates from the rest to the terminal velocity state. Ball’s velocity was determined from the distance traversed by the ball by examining video tape frame by frame using the marked graduations on the surface of the falling ball cylinder. Each frame was pre-set at 0.01. Glycerin 74% was used for Newtonian solution, while aqueous solutions of Polyacrylamide and Carboxymethyl Cellulose were for non-Newtonian solutions. The experimental viscosity data were in good agreements with the results obtained from a rotating Brookfield viscometer.

임상 : 방사선에 예민한 구조물 인근에 위치한 뇌종양에 대한 분할 조사 감마나이프 시술의 임상적 경험

조원진 ( Won Jin Cho ),정신 ( Shin Jung ),문경섭 ( Kyung Sub Moon ),김인영 ( In Young Kim ),정태영 ( Tae Young Jung ),박승진 ( Seung Jin Park ) 대한뇌종양학회 2009 대한뇌종양학회지 Vol.8 No.1

Objective:This study was performed to investigate the radiological and functional outcomes after fractionated gamma knife radiosurgery in the patients with intracranial tumors located near radiosensitive structures. Material & Methods:A total of 19 patients performed fractionated GKRS from 2006 to 2008. Among these patients, 12 patients followed at least 6 month were retrospectively reviewed. Fractionated GKS was performed because of old age, higher surgical risk, large size and adjacent to critical structures. There were 4 male & 8 female patients(mean age 59.3, range 37-80). GKRS performed as a primary technique in 8 patients and adjuvant treatment following open surgery and chemotherapy in 4 patients. The mean tumor volume was 12.4(range 1.2-30.9). The dose delivered at the tumor margin ranged 5 to 12 Gy(mean dose 6.9 Gy) and fraction time was 2.5(range 2-3). Results:The locations were maxilla in one case, suprasellar in one case, hypothalamus & suprasella in one case, clinoid in two cases, frontal lobe in one case, tuberculum sellae in one case, sphenopetoclival in one case, multiple in two cases and petroclivocavernous in two cases. The presumptive diagnosis of the lesion were maxillary cancer in one case, craniopharyngioma in two cases, multiple metastatic cancer in two cases, meningioma in seven cases. The critical structures, should be spared from high dose radiation were optic apparatus and brain stem in our patients. Among the 12 cases, 2 (16.7%) cases showed a tumor response as shrunken, static in 8(66.7%) of the cases and none of the case showed enlarged. Pre-operative neurological deficits were found in 6 cases, 4 cases(66.7%) showed a clinical improvement and 2 cases showed no changes. There were no specific complications & no delayed worsening or new cranial nerve deficits after fractionated GKRS. Conclusion:The fractionated GKRS were usefully used in near critical structure, large volume, surgically high risk patients and provided good tumor controls in some cases without any adverse effects.

다짐 토양-벤토나이트 혼합물의 투수성

조원진 ( Won-jin Cho ),이재완 ( Jae-owan Lee ),강철형 ( Chul-hyung Kang ) 한국폐기물자원순환학회 2002 APLAS Vol.2002 No.2

여러 가지 밀도를 가지는 벤토나이트 함유량이 토양-벤토나이트 혼합물의 투수능에 미치는 영향에 대한 연구를 수행하였다. 벤토나이트의 함량이 증가할수록, 혼합물의 최적 함수량이 증가하였고, 최대 건조밀도가 감소하였다. 중량비로 20%나 벤토나이트를 증가시켰지만 건조밀도 1.4 Mg/m³ 와 1.5 Mg/m³ 인 토양-벤토나이트 혼합물의 투수성은 눈에 띄게 감소하지 않았다. 그러나, 1.6 Mg/m³ 과 1.8 Mg/m³의 건조 밀도를 갖는 혼합물에서는 벤토나이트의 함량이 증가할수록 투수성이 빠르게 감소하였고, 벤토나이트가 중량비로 10%이상 높아질 때, 10^-9m/s 보다 줄어든다. The effects of bentonite content on hydraulic conductivity of the soil-bentonite mixtures with several densities were studied. With increasing bentonite content, the optimum water content of the mixture increased, and the maximum dry density decreased. The hydraulic conductivities of the soil-bentonite mixtures with dry densities of 1.4 Mg/m³ and 1.5 Mg/m³ were not significantly decreased with increasing bentonite content up to 20% by weight However, for the mixtures with dry densities of 1.6 Mg/m³ and 1.8 Mg/m³, the hydraulic conductivities decreased rapidly with increasing bentonite content, and were less than 10^-9 m/s when the bentonite content is higher than 10 % by weight.

고준위폐기물처분장 완충재 및 뒷채움재의 열전도도 예측을 위한 관계식

조원진(Won-Jin Cho),이재완(Jae-Owan Lee),권상기(Sangki Kwon) 한국암반공학회 2010 터널과지하공간 Vol.20 No.4

현재 제안되고 있는 고준위폐기물 심지층처분장의 설계에 따르면, 완충재와 뒷채움재의 재료로 벤토나이트 및 벤토나이트-모래 혼합물이 고려되고 있다. 후보물질인 경주벤토나이트를 대상으로, 압축 벤토나이트와 벤토나이트-모래 혼합물의 열전도도를 측정하였다. 경주벤토나이트와 벤토나이트-모래 혼합물의 열전도도를 건조밀도, 함수비 및 모래 함량의 함수로서 예측할 수 있는 관계식을 제안하였다. 제안된 관계식은 실험 조건하에서 열전도도를 10% 이내의 오차로 예측할 수 있다. In the present design concept of a high-level waste repository, the bentonite and bentonite-sand mixture are considered as the buffer and backfill material. For the Kyungju bentonite which is a candidate material, the thermal conductivities of compacted bentonite and bentonite-sand mixture were measured. A correlation has been proposed to predict the thermal conductivity of the Kyungju bentonite and the bentonite-sand mixture as a function of the dry density, the water content and the sand fraction. The proposed correlation can predict the thermal conductivity with a difference less than 10% under the experimental conditions.