염화칼리와 석회의 동시살포가 주요 작물의 생육중에 침적한 $^{54}Mn,\;^{60}Co,\;^{85}Sr\;and\;^{137}Cs$의 뿌리흡수에 미치는 영향

최용호,조재성,이명호,최근식,이정호,Choi, Yong-Ho,Jo, Jae-Seong,Lee, Myung-Ho,Choi, Geun-Sik,Lee, Jeong-Ho 대한방사선방어학회 1995 방사선방어학회지 Vol.20 No.4

2년 간의 온실실험을 통하여 벼, 콩, 배추, 무의 생육초기에 $^{54}Mn,\;^{60}Co,\;^{85}Sr\;and\;^{137}Cs$의 혼합용액을 산성 양질사토로 상층부를 채운 재배강자내 담수 또는 토양의 표면에 가한 후 비료용 염화칼리와 소석회를 각각 $m^2$당 200g 및 83g 수준으로 동시에 처리하고 흡수억제 효과를 조사하였다. 칼리와 석회 처리시 각 핵종의 작물체 부위간 농도분포 및 작물에 따른 흡수양상의 변화는 대체로 무처리시와 비슷한 경향이었다. 토양-작물체간 핵종의 전이계수는 칼리와 석회 처리에 의해 벼에서는 $^{85}Sr$와 $^{137}Cs$, 배추에서는 네 핵종 모두, 무에서는 $^{54}Mn,\;^{60}Co,\;and\;^{137}Cs$의 경우 생육장해 없이 왜 크게 감소하였으나 이밖의 경우에는 감소효과를 인정할 수 없었다. 벼에서 전이계수의 감소 정도는 $^{85}Sr$가 60% 정도로 가장 컸고 배추와 무에서는 $^{54}Mn$가 80% 정도로 가장 컸다. 본 연구결과는 작물 생육중 농경지의 방사능 오염시 대책 수립을 위한 기초정보로 이용될 수 있다. The effects of a simultaneous application of KCl and lime on the root uptake of $^{54}Mn,\;^{60}Co,\;^{85}Sr\;and\;^{137}Cs$ by rice, soybean, Chinese cabbage and radish were investigated through 2 years' greenhouse experiments. At their early growth stages, a mixed solution of the radionuclides was applied to the water or soil surfaces of the culture boxes filled with an acidic loamy-sandy soil for the upper 20cm and $83g/m^2$ of fertilizer KCl and $200g/m^2$ of slake lime were applied to the surfaces. Distribution of radioactivities among plant parts and change in uptake pattern with plant species were not, on the whole, significantly affected by the application. It reduced effectively soil-to-plant transfer factors of $^{85}Sr\;and\;^{137}Cs$ for rice, of all for Chinese cabbage and of $^{54}Mn,\;^{60}Co,\;and\;^{137}Cs$ for radish without their growth inhibition. In rice, $^{85}Sr$ showed the highest decrease $({\sim}60%)$ while, in Chinese cabbage and radish, $^{54}Mn$ did $({\sim}80%)$. The exprimental results can become valuable reference data to establish countermeasures against a radioactive contamination of farm-land during plant growth.

용담호 진안천 유역의 비점오염유출특성1

최용호 ( Yong-ho Choi ),정용훈 ( Yong-hoon Jeong ),곽동희 ( Dong-heui Kwak ) 한국물환경학회 2021 한국물환경학회·대한상하수도학회 공동 춘계학술발표회 Vol.2021 No.-

오이의 재배기간중 처리한 방사성 핵종의 토양-작물체간 전이계수 및 지하이동

최용호,박효국,김상복,최근식,이정호 ( Yong Ho Choi,Hyo Kook Park,Sang Bog Kim,Geun Sik Choi,Jeong Ho Lee ) 한국환경농학회 1997 한국환경농학회지 Vol.16 No.4

In greenhouse, a mixed solution of Mn-54, Co-60, Sr-85 and Cs-137 was applied to the soil of culture boxes 2 days before sowing cucumber and at 4 different times during its growth for measuring their transfer factors (TFs) for fruit and migration in soil. TFs varied with radionuclide, application time and harvest time by factor of up to about 60. Variations in TFs with application time showed different patterns among radionuclides. TFs decreased on the whole in the order of Sr-85$gt;Mn-54$gt;Co-60$gt;Cs-137. TFs of Mn-54, Co-60 and Cs-137 mixed with topsoil before sowing were a little higher than those for the soil-surface application made at an early growth stage while no difference in Sr-85 TF was found. After harvest, soil concentrations of the radionuclides applied at an early growth stage were examined. They decreased with increasing soil depth and 80∼99% of the radioactivity remained in top 3㎝. Soil pemeation of the radionuclides migration decreased in the order of Sr-85$gt;Mn-54$gt;Co-60$gt;Cs-137. The present data can be utilized in estimating radionuclide concentration in cucumber fruit, taking proper measures for its harvest and consumption and designing the best way of soil decontamination following an radioactive deposition during the cucummber growing season.

용담호 진안천 유역의 비점오염유출특성

최용호 ( Yong-ho Choi ),정용훈 ( Yong-hoon Jeong ),곽동희 ( Dong-heui Kwak ) 한국물환경학회 2021 한국물환경학회·대한상하수도학회 공동 춘계학술발표회 Vol.2021 No.-

InGaAs/InAlAs 다중 양자우물을 이용한 표면 반사형 전광 스위치의 해석

최용호,김경환,최우영,Choi, Yong-Ho,Kim, Kyung-Whan,Choi, Woo-Young 대한전자공학회 2000 電子工學會論文誌-SD (Semiconductor and devices) Vol.37 No.9

본 논문에서는 InGaAs/InAlAs 다중 양자우물을 이용한 두가지 타입의 비대칭 Fabry-Perot 전광 스위치에 대한 해석을 시도하였다. 전광 스위치의 동작을 해석하기 위해서 먼저 양자우물의 광 흡수계수와 굴절율의 변화 특성을 계산하였다. 양자우물의 비선형성 해석 결과를 토대로 전광 수위치의 ON/OFF 비와 스위칭 속도를 비교하였다. 시뮬레이션 결과로부터, DBR을 이용한 구조의 전광 수위치는 DBR이 없는 형태의 전광 수위치보다 ON/OFF 비를 향상시킬 수 있을 뿐만 아니라 스위칭 시간도 단축시킬 수 있음을 알 수 있었다. The performance of two types of surface reflecting all-optical switches with InGaAs/InAlAs multiple quantum wells are investigated. The absorption spectra and the refractive index changes of the quantum well are calculated for various pump and probe beam intensities and device conditions. From theses results, on ON/OFF ratio and switching speed of the two switches are compared. It is shown that the switch using DBR has higher ON/OFF ratio and higher switching speed than the switch without DBR.

⁹⁹Tc의 토양-쌀알 전이 감소를 위한 소석회와 유기질 비료의 토양첨가

최용호,임광묵,전인,김병호,금동권,Choi, Yong-Ho,Lim, Kwang-Muk,Jun, In,Kim, Byung-Ho,Keum, Dong-Kwon 한국방사성폐기물학회 2013 방사성폐기물학회지 Vol.11 No.1

논의 $^{99}Tc$ 오염 시 소석회와 유기질 비료의 토양 첨가가 쌀알 내 $^{99}Tc$ 농도 저감 대책으로서 유용한지 알아보기 위하여 온실 내에서 두 가지 논토양에 대해 포트실험을 수행하였다. 모내기 15 일 전에 약 20 cm 깊이에 해당하는 상부 토양을 상기 농용 물질과 $^{99}Tc$로 처리하였다. 처리 효과는 토양 중 농도에 대한 작물체 내 농도의 비로 정의되는 전이계수(TF)로 비교하였다. 대조 작물체의 경우 두 토양에서 현미 TF 값은 $4.1{\times}10^{-4}$ 및 $4.3{\times}10^{-4}$였다. 각종 유형의 첨가 중에서 한 토양에 대해 60%정도의 TF 값 감소를 나타낸 소석회 저수준 첨가(약 0.6 kg $m^{-2}$)만이 대책으로서 이용 가능성이 있을 것으로 판단되었다. 다른 한 토양에서는 동 첨가의 효과가 거의 없었으므로 다수의 토양에 대한 평균적인 효과를 알아내는 것이 중요하다. 두 가지 다른 수준의 유기질 비료의 첨가는 모두 TF 값을 증가시켰다. 위보다 더 낮은 수준의 소석회 첨가에 대해 실험을 수행할 필요가 있을 것으로 사료되었다. To see if slaked lime and organic fertilizer applications to soil are useful as countermeasures for reducing $^{99}Tc$ concentrations in rice seeds after $^{99}Tc$ contamination of paddy fields, pot experiments were performed for two different paddy soils in a greenhouse. The upper soils for a depth of about 20 cm were treated with the agricultural materials and $^{99}Tc$ 15 d before transplanting. The effects were compared using the transfer factor (TF) defined as the ratio of the plant concentration to the soil concentration. In the case of control plants, TF values for brown rice in the two soils were $4.1{\times}10^{-4}$ and $4.3{\times}10^{-4}$. Of various types of the application, only the application of slaked lime at a lower dose (about 0.6 kg $m^{-2}$), which led to a 60% reduction in the TF value for one soil, seemed to be worth using as a countermeasure. Little effect of the same application was found in the other soil so it is important to determine the effect averaged for a number of soils. Organic fertilizer applications at both of two different doses increased the TF value. It is considered necessary to perform experiments for slake lime applications at doses lower than the above.

요오드 증기($I_2$)의 무 작물체에 대한 침적속도 및 뿌리 전류계수 : 피폭실험 결과

최용호,임광묵,전인,박두원,금동권,Choi, Yong-Ho,Lim, Kwang-Muk,Jun, In,Park, Doo-Won,Keum, Dong-Kwon 한국방사성폐기물학회 2010 방사성폐기물학회지 Vol.8 No.2

In order to measure the deposition velocity of $I_2$ vapor for radish plants and its translocation factor for their roots, radish plants were exposed to $I_2$ vapor for 80 min. at different growth stages between 29 and 53 d after sowing. The exposure was performed in a transparent chamber during the morning time. Deposition velocities ($ms^{-1}$) were on the whole in the range of $1.0{\times}10^{-4}{\sim}2.0{\times}10^{-4}$ showing an increasing tendency with an increase in the biomass density. The results showed some agreement with existing reports that a higher relative humidity would lead to a higher deposition velocity. The acquired deposition velocities were lower than by factors of several tens than some field measurements probably due to a very low wind speed (about $0.2\;ms^{-1}$) in the chamber. Translocation factors (ratio of the total iodine in the roots at harvest to the total plant deposition), estimated in a more or less conservative way, were $1.3{\times}10^{-3}$ for an exposure at 29 d after sowing and $5.0{\times}10^{-3}$ for an exposure at 53 d after sowing. In using the present experimental data, meteorological conditions and chemical and physical forms of iodine need to be carefully considered.

경주 방사성 폐기물 처분장 주변 논에 대한 방사성 요오드와 테크네튬의 토양-쌀알 전이계수

최용호,임광묵,전인,박두원,금동권,한문희,Choi, Yong-Ho,Lim, Kwang-Muk,Jun, In,Park, Doo-Won,Keum, Dong-Kwon,Han, Moon-Hee 한국방사성폐기물학회 2010 방사성폐기물학회지 Vol.8 No.4

Radiotracer experiments were performed over two years using pot cultures in a greenhouse to investigate soil-torice seeds transfer factors of radioiodine and technetium for paddy fields around the radioactive-waste disposal site in Gyeongju. Before transplanting rice seedlings, the top about 20 cm soils were thoroughly mixed with $^{125}I$ (2007) and $^{99}Tc$ (2008), and the pots were irrigated to simulate flooded rice fields. Transfer factors were determined as the ratios of the radionuclide concentrations in dry rice seeds (brown rice) to those in dry soils. Transfer factors of radioiodine and technetium were in the ranges of $1.1{\times}10^{-3}{\sim}6.4{\times}10^{-3}$ (three soils) and $5.4{\times}10^{-4}{\sim}2.5{\times}10^{-3}$ (four soils), respectively, for different soils. It seems that the differences in the clay content among soils played a more important role for such variations than those in the organic matter content and pH. As the representative values of radioiodine and technetium transfer factors for rice seeds, $2.9{\times}10^{-3}$ and $1.1{\times}10^{-3}$, respectively, were proposed. In order to obtain more highly representative values in the future, investigations for the sites of interest need to be carried out continuously.

토양 strontium - 90 의 땅콩과 참깨에 의한 흡수 및 축적

최용호,조재성 ( Yong Ho Choi,Jae Seong Jo ) 한국환경농학회 1996 한국환경농학회지 Vol.15 No.1

A greenhouse experiment on the Sr-90 uptake by peanut and sesame was conducted through pot cultures on a sandy loam soil of pH 6.35 treated with Sr-90 in 5.2 and 31.2Bq per gram. The rate of Sr-90 transfer from soil to each plant part, the ratio of Sr-90 concentration in the part to the concentration in soil, and the patterns of their temporal changes were not, on the whole, significantly different between the two treatments. About 0.7 and 0.5 % of Sr-90 in soil transferred to all the mature plants of peanut and sesame, respectively, with the radioactivities in their roots not counted. Only 4% and less than 15% of Sr-90 absorbed by peanut and sesame, respectively, translocated to their seeds. Both crops showed the highest Sr-90 concentration in the leaf and the lowest in the seed. At maturities, the concentration ratio in dry seed was 0.4 in peanut and 3.3 in sesame and that in dry leaf was 12.5 and 10.7, respectively. Sr-90 concentrations in the top 15 cm soil after harvests averaged about 80 % of the concentrations at starting. Sr-90 uptake resulted in neither growth inhibition nor yield decrease.

Experimental Studies for Analyzing Direct Contamination Pathway $^{54}Mn,\;^{57}Co,\;^{85}Sr,\;^{103}Ru$ and $^{134}Cs$ in Rice

최용호,임광묵,박효국,이원윤,이창민,Choi, Yong-Ho,Lim, Kwang-Muk,Park, Hyo-Guk,Lee, Won-Yun,Lee, Chang-Mi Korean Association for Radiation Protection 2000 방사선방어학회지 Vol.25 No.1

For analyzing the direct contamination pathway of radionudides in rice plants, a Solution containing $^{54}Mn,\;^{57}Co,\;^{85}Sr,\;^{103}Ru$ and $^{134}Cs$ was applied to the aboveground Parts of the between RI application and harvest. Its highest observed value was 0.94. The fractions of the initial plant deposition that remained in rice plants at harvest were in the range of $19{\sim}47%,\;17{\sim}43%,\;19{\sim}42%,\;23{\sim}61%$ and $11{\sim}69%$ for $^{54}Mn,\;^{57}Co,\;^{85}Sr,\;^{103}Ru$ and $^{134}Cs$, respectively, when no decay was assumed. The translocation factors of those radionuclides in hulled seeds were in the range of $6.9{\times}10^{-4}3.8{\times}10^{-2},\;3.6{\times}10^{-3}{\sim}1.6{\times}10^{-1},\;5.8{\times}10^{-4}{\sim}3.2{\sim}10^{-2},\;1.6{\times}10^{-4}{\sim}7.6{\times}10^{-3}$ and $3.2{\times}10^{-2}{\sim}2.0{\times}10^{-1}$, respertively, and were highest when they were applied at the stage of active seed development. It was indicated that the remaining percentage and translocation factor would not be greatly affected by the difference in the rain frequency if it is within a factor of 2. These results can be utilzed for predicting the radionuclide concentrations in rice seeds when an accidental deposition of those radionuclides occurs during the rice-growing season. 벼의 방사성 핵종 직접오염 경로를 분석하기 위하여 동위원소 실험온실내에서 $^{54}Mn,\;^{57}Co,\;^{85}Sr,\;^{134}Cs$의 혼합용액을 벼의 생육중 여섯 차례에 걸쳐 작물체 지상부에 처리하였다. 작물체 차단계수는 핵종 간에 차이가 없었고 처리시기가 수확기에 가까울수록 증가하여 최고 약 0.94에 달리하였다. 작물계에 침적한 각 핵종의 수확시 잔류율은 방사능 붕괴가 없다고 가정할 예 처리시기에 따라 각각 $19{\sim}47%,\;17{\sim}43%,\;19{\sim}42%,\;23{\sim}61%,\;11{\sim}69%$였다. 종실 전류계수는 처리시기에 따라 각각 $6.9{\times}10^{-4}{\sim}3.8{\times}10^{-2},\;3.6{\times}10^{-3},\;1.6{\times}10^{-1}{\sim}5.8{\times}10^{-4}{\sim}3.2{\times}10^{-2},\;1.6{\times}10^{-4}{\sim}7.6{\times}10^{-5},\;3.2{\sim}10^{-2}{\sim}2.0{\times}10^{-1}$의 범위였고 모두 종실의 발육성기 처리시 가장 높았다. 강우 빈도의 차이가 2배 이내일 때는 강우빈도가 잔류율과 전류계수에 큰 영향을 미치지 않는 것으로 나타났다. 본 연구결과는 벼의 생육중 사고침적시 쌀알 내 핵종농도 예측에 활용될 수 있다.