Radiochemical Separation of Nb Isotopes in Radioactive Waste Samples From the Nuclear Power Plant Using Anion Exchange Resin

Myung Ho Lee,Byoung Chul Song,Kyung Sik Kim,Young Jae Maeng,Choon Sung Yoo,Byoung Chul Kim 한국방사성폐기물학회 2022 한국방사성폐기물학회 학술논문요약집 Vol.20 No.2

This study presents a rapid and quantitative radiochemical separation method for Nb isotopes in radioactive waste samples from the nuclear power plant with anion exchange resin after Fe coprecipitation. After radionuclides were leached from the radioactive waste samples with concentrated HCl and HNO3, the Nb isotopes were coprecipitated with Fe after filtering the leaching solution with 0.45 micron HA filter, while the Sr, Tc and Ni isotopes were in the solution. The Nb isotopes were separated in HCl medium with anion exchange resin. The purified Nb isotopes were measured using a low level liquid scintillation counter after installing quenching curve with standard Nb-94 isotopes. The separation method for Nb isotopes investigated in this study was applied to neutron dosimeter samples from the nuclear power plant after validating the Nb activity concentration with gamma spectrometry system.

Pd 분리막을 이용한 수소동위원소 회수 실험과 공정 시뮬레이션

정우찬,박종환,한상우,장민호,이현곤 한국수소및신에너지학회 2021 한국수소 및 신에너지학회논문집 Vol.32 No.4

Hydrogen isotopes, which are used as raw materials in fusion reaction, participate in the reaction only in small amount, and most of them are released together with impurities. In order to recover and reuse only hydrogen isotopes from this exhaust gas, a recovery process is required, and most of the hydrogen isotopes can be recovered using a Pd Membrane. In this study, the recovery rate of hydrogen isotopes was measured through the first and second stage Pd membrane experiments. In the case of the experiment using a single stage Pd membrane, about 99.2%, and in the case of the first stage and second stage Pd membrane connection experiments, a recovery rate of 99.9% or more was obtained. Therefore, the recovery rate of Pd membrane process applied to hydrogen can be applied to hydrogen isotopes. In addition, the simulation model was established using aspen custom modeler, a commercial software, and the validity of the simulation was checked by applying the references and experimental data. The simulation results based on the experimental data showed a difference of 2% or less.

강우와 융설의 안정동위원소 변동에 의한 동위원소 수문분리법의 계통오차계산

이정훈,고동찬,추미경 한국지구과학회 2014 한국지구과학회지 Vol.35 No.2

An isotopic hydrograph separation technique has been able to determine the contribution of new water (event water such as rain or snowmelt) and old water (pre-event water like groundwater) to a stream hydrograph for last several decades using stable water isotopes. It is based on the assumption that the isotopic compositions of both new water and old water at a given instant in time are known and the stream water is a mixture of the two waters. In this study, we show that there is a systematic error (standard error in the new water fraction) in the isotopic hydrograph separation if theaverage isotopic compositions of new water were used ignoring the temporal variations of those of new water. The standard error in the new water fraction is caused by: (1) the isotopic difference between the average value and temporal variations of new water; (2) the new water fraction as runoff contributing to the stream during rainfall or spring melt; and (3) the isotopic differences between new and old water (inversely). The standard error is large, in particular, when new water dominates the stream flow, such as runoff during intense rainfall and in areas of low infiltration during spring melt. To reduce the error in the isotopic hydrograph separation, incorporation of fractionation in the isotopic composition of new water observed at a point should be considered with simultaneous sampling of new water, old water and stream water. 물안정동위원소를 이용하여 지하수와 강우 또는 융설이 하천에 미치는 영향을 정량적으로 분리하는 방법을 동위원소 수문분리법이라고 하며 지난 30년 동안 사용되어 왔다. 오래된 물(지하수)과 새로운 물(강우 및 융설)의 두 성분이 하천에 영향을 미치는 것으로 가정하고 새로운 물과 오래된 물의 주어진 시간동안의 동위원소를 측정하여 각각의 성분에 대한 비율을 결정할 수 있다. 본 연구에서는 동위원소 수문분리법을 수계에 적용할 때 새로운 물의 시간적인안정동위원소분화를 고려하지 않고 새로운 물의 평균값을 이용하였을 때 계통오차가 발생함을 보였다. 이러한 표준오차의 크기는 (1) 새로운 물이 하천에 많이 기여할수록, (2) 사용된 평균값과 분화된 새로운 물의 안정동위원소 값과 차이가 클수록, 마지막으로 (3) 오래된 물과 새로운 물의 안정동위원소 값의 차이가 작을수록 커진다. 집중 호우로 유출이 증가하거나 봄철에 지면이 아직 녹지 않아 융설이 유출이 되는 경우 새로운 물이 하천에 미치는 영향이 커지게 되어 상대오차 역시 증가한다. 이러한 오차를 줄이기 위해서 각각의 새로운 물, 오래된 물, 하천의 안정동위원소를 같은 시간 간격으로 측정하여 새로운 물이 분화되는 것을 고려한 수문분리법을 수행하는 것을 고려하여야 한다.

A Study of Simple α Source Preparation Using a Micro-coprecipitation Method

Myungho Lee,Tae-Hong Park,BYUNG CHUL SONG,Jong Ho Park,KYUSEOK SONG 대한화학회 2012 Bulletin of the Korean Chemical Society Vol.33 No.11

This study presents a rapid and simple α source preparation method for a radioactive waste sample. The recovery of 239Pu, 232U and 243Am using a micro-coprecipitation method was over 95%. The α-peak resolution of Pu and Am isotopes through the micro-coprecipitation method is enough to discriminate the Pu and Am isotopes from other Pu and Am isotopes. The determination of the Pu and Am isotopes using the microcoprecipitation method was applied to the radioactive waste sample, so that the activity concentrations of the Pu and Am isotopes using the micro-coprecipitation method in the radioactive waste sample were similar to those using the electrodeposition method.

A Study of Simple α Source Preparation Using a Micro-coprecipitation Method

Lee, Myung Ho,Park, Tae-Hong,Song, Byung Chul,Park, Jong Ho,Song, Kyuseok Korean Chemical Society 2012 Bulletin of the Korean Chemical Society Vol.33 No.11

This study presents a rapid and simple ${\alpha}$ source preparation method for a radioactive waste sample. The recovery of $^{239}Pu$, $^{232}U$ and $^{243}Am$ using a micro-coprecipitation method was over 95%. The ${\alpha}$-peak resolution of Pu and Am isotopes through the micro-coprecipitation method is enough to discriminate the Pu and Am isotopes from other Pu and Am isotopes. The determination of the Pu and Am isotopes using the micro-coprecipitation method was applied to the radioactive waste sample, so that the activity concentrations of the Pu and Am isotopes using the micro-coprecipitation method in the radioactive waste sample were similar to those using the electrodeposition method.

Methodological Study on Measurement of Hydrogen Abundance in Hydrogen Isotopes System by Low Resolution Mass Spectrometry

Lia, Jin-Ying,Shib, Lei,Hub, Shi-Lin Korean Society for Mass Spectrometry 2011 Mass spectrometry letters Vol.2 No.1

China's rapid economic growth has resulted in significant environmental side effects. Therefore, China has been interested in reducing her dependence on foreign oil and gas by developing technologies needed for hydrogen, in addition to her increasing energy mix of nuclear and renewable energy form, such as solar and wind power. There are three isotopes of hydrogen, i.e. protium (P or H), deuterium (D), and tritium (T). Both deuterium and tritium are important materials in nuclear fuel cycle industry. Tritium is one of the critical radioactive nuclides. Planning for and implementing contamination control as a part of normal operation and maintenance activities is an important function in any hydrogen facility, especially tritium facility. The development of hydrogen isotopes analysis is the key issues in this area. Mass spectrometry (MS) with medium (about 600) and high resolution (> 1,400) is commercially available; however, the routine analysis of hydrogen isotopes is done with low-resolution MS (< 200) in China. This paper summarizes the progress of MS measurement technology for hydrogen isotope abundance in China, focusing on our lab's research program and technical status. An analyzing method has been introduced for accurate measurement of tritium abundance in the H.D.T system by low resolution MAT-253 MS. The quotient of compression ratio coefficient is determined by building up equipment for laboratory-scale preparation of secondary standard gases and by considering the difference in sensitivity between hydrogen isotopes. The results show that the measured value is reproducible within the relative error range of 0.8% for gas samples of different tritium abundance.

Methodological Study on Measurement of Hydrogen Abundance in Hydrogen Isotopes System by Low Resolution Mass Spectrometry

Jin-ying Li,Lei Shi,Shi-lin Hu 사단법인 한국질량분석학회 2011 Mass spectrometry letters Vol.2 No.1

China’s rapid economic growth has resulted in significant environmental side-effects. Therefore, China has beeninterested in reducing her dependence on foreign oil and gas by developing technologies needed for hydrogen, in addition to herincreasing energy mix of nuclear and renewable energy form such as solar and wind power. There are three isotopes of hydrogen,i.e. protium (P or H), deuterium (D), and tritium (T). Both deuterium and tritium are important materials in nuclear fuel cycleindustry. Tritium is one of the critical radioactive nuclides. Planning for and implementing contamination control as a part ofnormal operation and maintenance activities is an important function in any hydrogen facility, especially tritium facility. Thedevelopment of hydrogen isotopes analysis is the key issues in this area. Mass spectrometry (MS) with medium (about 600) andhigh resolution (>1400) is commercially available; however, the routine analysis of hydrogen isotopes is done with low-resolutionMS (<200) in China. This paper summarizes the progress of MS measurement technology for hydrogen isotope abundance inChina, focusing on our lab’s research program and technical status. An analyzing method has been introduced for accurate measurementof tritium abundance in the H-D-T system by low resolution MAT-253 MS. The quotient of compression ratio coefficient isdetermined based on building up equipment for laboratory-scale preparation of secondary standard gases and considering thedifference in sensitivity between hydrogen isotopes. The results show that the measured value is believable in the relative errorrange of 0.8% for gas samples of different tritium abundance.

수증기안정동위원소의 물순환 해석에의 적용에 대한 고찰

이정훈,한영철,고동찬,김송이,나운성,Lee, Jeonghoon,Han, Yeongcheol,Koh, Dong-Chan,Kim, Songyi,Na, Un-Sung 한국지하수토양환경학회 2015 지하수토양환경 Vol.20 No.3

Studies using stable water vapor isotopes have been recently conducted over the past two decades because of difficulties in analysis and sample collection in the past. Stable water vapor isotope data provide information of the moisture transport from ocean to continent, which are also used to validate an isotope enabled general circulation model for paleoclimate reconstructions. The isotopic compositions of groundwater and water vapor also provide a clue to how moisture moves from soil to atmosphere by evapotranspiration. International Atomic Energy Agency designates the stations over the world to observe the water vapor isotopes. To analyze the water vapor isotopes, a cryogenic sampling method has been used over the past two decades. Recently, two types of laser-based spectroscopy have been developed and remotely sensed data from satellites have the global coverage. In this review, measurements of isotopic compositions of water vapor will be introduced and some studies using the water vapor isotopes will also be introduced. Finally, we will suggest the future study in Korea.

Estimation of thermodynamic properties of hydrogen isotopes and modeling of hydrogen isotope systems using Aspen Plus simulator

노재현,Alyssa Marie Fulgueras,Leah Jessica Sebastian,이현곤,김동선,조정호 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.46 No.-

Physical properties of hydrogen isotopes, hydrogen (H2), hydrogen-deuterium (HD), hydrogen-tritium(HT), deuterium (D2), deuterium-tritium (DT), and tritium (T2) were estimated through vapor pressureprediction, and validated by steady-state simulation of ITER isotope separation system (ISS). Peng–Robinson (PR) equation of state with Twu alpha function was selected for modelling which showedfavorable prediction from the experimental vapor pressures of each hydrogen isotopes. The steady-statesimulation of ITER ISS using Aspen Plus consists of four distillation columns and seven equilibriumreactors with four purified products: D2, T2, HD, and DT. Converged solution from simulation producedpotential scenario for actual ITER ISS process.

Anthropogenic influences on benthic food web dynamics by interrupted freshwater discharge in a closed Geum River estuary, Korea

Noh, Junsung,Yoon, Seo Joon,Kim, Hosang,Lee, Changkeun,Kwon, Bong-Oh,Lee, Yeonjung,Hong, Seongjin,Kim, Jaeseong,Ryu, Jongseong,Khim, Jong Seong Elsevier 2019 Environment international Vol.131 No.-

<P><B>Abstract</B></P> <P>Stable isotope analysis was used to investigate the benthic food web dynamics in the Geum River estuary where continuous river flow has been blocked by a sea dike over the past 25 years. In order to address the dike effect(s) on distribution of food sources (i.e., organic matters and microphytobenthos) and their utilization by marine predators, a three years monitoring survey (total of 30 surveys) was seasonally conducted at four fixed locations at both inside of dike and outer tidal flats. All the collected biota (total of 19 species; >1100 individuals and microphytobenthos) and abiotic (<I>n</I> = 118) samples were analyzed for carbon (δ<SUP>13</SUP>C) and nitrogen (δ<SUP>15</SUP>N) stable isotopes. In particular, two dominant marine bivalves inhabiting outer reach of tidal flats, <I>Mactra veneriformis</I> and <I>Cyclina sinensis</I>, were targeted to identify their feeding strategies that being related to a year-round population growth. In general, the stable isotopic signatures of samples indicated dissimilarity in distribution of organic matters between inside and outside of dike, supporting geographical and/or trophic isolation. The taxa-dependent trophic levels are also evidenced in consistent manner, with two to three levels being positioned over the years. Meantime, their dietary contributions varied in time, i.e., seasonal chances in compositions of major food sources (microphytobenthos and particulate organic matters) were observed for two target bivalves. Such temporal variations could be further linked to selective feedings that evidenced by age(size)-dependent and/or tissue specific distributions. Altogether, the present study suggested seasonality, diet preference, and growth dependent food web dynamics in the Geum River estuary. Overall, the present study suggested that the stable isotopic technique could be a powerful tool for characterizing the long-term anthropogenic influences of a sea dike on marine food-web dynamics.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Isotopic compositions of marine organisms and food sources identified in a closed estuary </LI> <LI> Terrestrial organic matters in discharged water lesser contributed to benthic food web. </LI> <LI> Microphytobenthos contributed as key diet for macrobenthos in growth dependent manner. </LI> <LI> Benthic bivalves showed organ-specific allocation of organic matter for nutrient storage. </LI> <LI> A closed estuary preventing a natural river flow altered typical marine trophic pathways. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>