• 제목/요약/키워드: Cross-enrichment

검색결과 30건 처리시간 0.024초

심지층 처분시스템 설계를 위한 사용후핵연료 현황 분석 및 예측 (Current Status and Projection of Spent Nuclear Fuel for Geological Disposal System Design)

  • 조동건;최종원;한필수
    • 방사성폐기물학회지
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    • 제4권1호
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    • pp.87-93
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    • 2006
  • 제2차 전력수급기본계획에 의거 2017년까지 계획된 원자로만을 대상으로 심지층 처분시스템 설계 시 필요한 국내 사용후핵연료의 발생량, 제원적 특징, 초기농축도 및 방출연소도 등에 대하여 현재 및 미래 현황을 파악하고 예측하였다. 2057년까지 PWR 및 CANDU 사용후핵연료 발생량은 각각 20,500 및 14,800 MTU로 나타났다. 초기 농축도에 대해서는 4.5 wt.% 이하를 갖는 사용후핵연료가 96.5%를 차지하는 것으로 나타났다. 사용후핵연료의 평균 방출연소도는 90년대 후반에는 36 GWD/MUT 전도, 2000년대 초반에는 40 GWD/MTU를 나타냈으며, 2000년대 중 후반부터는 45 GWD/MTU가 될 것으로 나타났다. 광범위한 분석 및 예측 결과, 총 처분물량을 대표할 수 있는 가상적인 기준 사용후핵 연료는 16 6 한국표준형연료, 단면적 $21.4cm\times21.4cm$, 길이 453cm, 무게 672 kg, 초기 농축도 4.5 wt.%, 방출연소도 55 GWD/MTU로 나타났다.

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파이로공정 시설 개념설계를 위한 기준 사용후핵연료 선정 (Reference Spent Nuclear Fuel for Pyroprocessing Facility Design)

  • 조동건;윤석균;최희주;최종원;고원일
    • 방사성폐기물학회지
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    • 제6권3호
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    • pp.225-232
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    • 2008
  • 제3차 전력수급기본계획에 근거하여 현재 운영중이거나 계획중인 원자력발전소에서 발생할 사용후핵연료의 양과 특성을 추정하였다. 본 연구에서 고려된 대상 특성은 핵연료집합체에 대한 제원, 핵연료봉 배열, 무게, $^{235}U$ 초기 농축도 및 방출연소도이다. 이들은 파이로공정 시설을 설계하는데 필수적인 것이다. 2077년말까지 가압경수로 사용후핵연료의 예상발생량은 약 23,000 tU이 될 것으로 보인다. $^{235}U$ 초기 농축도 4.5 wt.% 이하를 갖는 사용후핵연료의 비율은 전체 발생량의 약 95%를 차지할 것이며, 16$\times$16 배열을 갖는 핵연료집합체는 74%를 차지할 것 같다. 현재 사용후핵연료의 평균연소도는 45 GWd/tU인데 반해, 2010년대 중 후반 이후 발생할 사용후 핵연료의 평균연소도는 55 GWd/tU이 될 것 같다. 이상의 결과에 따라 파이로공정 시설의 설계를 위한 기준 사용후핵연료를 도출하였다. 예상 사용후핵연료는 21.4 cm $\times$ 21.4 cm의 단면적, 453 cm의 길이, 672 kg의 질량, 4.5 wt.%의 $^{235}U$ 초기 농축도 및 55 GWd/tU의 방출연소도를 갖는 16$\times$16 한국표준형연료가 타당할 것으로 판단된다.

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Prediction of Genes Related to Positive Selection Using Whole-Genome Resequencing in Three Commercial Pig Breeds

  • Kim, HyoYoung;Caetano-Anolles, Kelsey;Seo, Minseok;Kwon, Young-jun;Cho, Seoae;Seo, Kangseok;Kim, Heebal
    • Genomics & Informatics
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    • 제13권4호
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    • pp.137-145
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    • 2015
  • Selective sweep can cause genetic differentiation across populations, which allows for the identification of possible causative regions/genes underlying important traits. The pig has experienced a long history of allele frequency changes through artificial selection in the domestication process. We obtained an average of 329,482,871 sequence reads for 24 pigs from three pig breeds: Yorkshire (n = 5), Landrace (n = 13), and Duroc (n = 6). An average read depth of 11.7 was obtained using whole-genome resequencing on an Illumina HiSeq2000 platform. In this study, cross-population extended haplotype homozygosity and cross-population composite likelihood ratio tests were implemented to detect genes experiencing positive selection for the genome-wide resequencing data generated from three commercial pig breeds. In our results, 26, 7, and 14 genes from Yorkshire, Landrace, and Duroc, respectively were detected by two kinds of statistical tests. Significant evidence for positive selection was identified on genes ST6GALNAC2 and EPHX1 in Yorkshire, PARK2 in Landrace, and BMP6, SLA-DQA1, and PRKG1 in Duroc. These genes are reportedly relevant to lactation, reproduction, meat quality, and growth traits. To understand how these single nucleotide polymorphisms (SNPs) related positive selection affect protein function, we analyzed the effect of non-synonymous SNPs. Three SNPs (rs324509622, rs80931851, and rs80937718) in the SLA-DQA1 gene were significant in the enrichment tests, indicating strong evidence for positive selection in Duroc. Our analyses identified genes under positive selection for lactation, reproduction, and meat-quality and growth traits in Yorkshire, Landrace, and Duroc, respectively.

Neutronic simulation of the CEFR experiments with the nodal diffusion code system RAST-F

  • Tran, Tuan Quoc;Lee, Deokjung
    • Nuclear Engineering and Technology
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    • 제54권7호
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    • pp.2635-2649
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    • 2022
  • CEFR is a small core-size sodium-cooled fast reactor (SFR) using high enrichment fuel with stainless-steel reflectors, which brings a significant challenge to the deterministic methodologies due to the strong spectral effect. The neutronic simulation of the start-up experiments conducted at the CEFR have been performed with a deterministic code system RAST-F, which is based on the two-step approach that couples a multi-group cross-section generation Monte-Carlo (MC) code and a multi-group nodal diffusion solver. The RAST-F results were compared against the measurement data. Moreover, the characteristic of neutron spectrum in the fuel rings, and adjacent reflectors was evaluated using different models for generation of accurate nuclear libraries. The numerical solution of RAST-F system was verified against the full core MC solution MCS at all control rods fully inserted and withdrawn states. A good agreement between RAST-F and MCS solutions was observed with less than 120 pcm discrepancies and 1.2% root-mean-square error in terms of keff and power distribution, respectively. Meanwhile, the RAST-F result agreed well with the experimental values within two-sigma of experimental uncertainty. The good agreement of these results indicating that RAST-F can be used to neutronic steady-state simulations for small core-size SFR, which was challenged to deterministic code system.

The impact of fuel depletion scheme within SCALE code on the criticality of spent fuel pool with RBMK fuel assemblies

  • Andrius Slavickas;Tadas Kaliatka;Raimondas Pabarcius;Sigitas Rimkevicius
    • Nuclear Engineering and Technology
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    • 제54권12호
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    • pp.4731-4742
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    • 2022
  • RBMK fuel assemblies differ from other LWR FA due to a specific arrangement of the fuel rods, the low enrichment, and the used burnable absorber - erbium. Therefore, there is a challenge to adapt modeling tools, developed for other LWR types, to solve RBMK problems. A set of 10 different depletion simulation schemes were tested to estimate the impact on reactivity and spent fuel composition of possible SCALE code options for the neutron transport modelling and the use of different nuclear data libraries. The simulations were performed using cross-section libraries based on both, VII.0 and VII.1, versions of ENDF/B nuclear data, and assuming continuous energy and multigroup simulation modes, standard and user-defined Dancoff factor values, and employing deterministic and Monte Carlo methods. The criticality analysis with burn-up credit was performed for the SFP loaded with RBMK-1500 FA. Spent fuel compositions were taken from each of 10 performed depletion simulations. The criticality of SFP is found to be overestimated by up to 0.08% in simulation cases using user-defined Dancoff factors comparing the results obtained using the continuous energy library (VII.1 version of ENDF/B nuclear data). It was shown that such discrepancy is determined by the higher U-235 and Pu-239 isotopes concentrations calculated.

Listeria monocytogenes 신속 검출을 위한 면역크로마토그래피법의 개발 (Development of Immunochromatography for the Rapid Detection of Listeria monocytogenes)

  • 최진길;심원보;제정현;김지영;이규호;김민곤;하상도;김근성;김광엽;김철호;정덕화
    • 한국식품과학회지
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    • 제39권3호
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    • pp.299-303
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    • 2007
  • 본 연구에서는 L. monocytogenes를 신속하게 분석할 수 있는 면역크로마토그래피법을 개발하고자 하였다. 먼저 L. monocytogenes에 대한 단크론성 항체(FKLM-3B12-37)를 개발하여 직경 40nm로 제작된 colloidal gold와 합성한 후 conjugate pad에 처리하였고 nitrocellulose membrane 상의 test line과 control line에 단크론성 항체와 anti-mouse IgG를 각각 처리하여 면역크로마토그래피법을 개발하였다. 개발된 면역크로마토그래피법의 검출한계는 $10^{5}$ cell/mL 수준까지 검출이 가능했으며 다른 식중독 세균과는 교차 반응이 없는 것으로 나타났다. 임으로 오염시킨 식품시료의 경우 증균과정 없이 $10^{4}$ cell/25g까지 바로 분석하는데 어려움이 있으며 24시간의 증균과정을 거친 후에는 $10^{4}$ cell/25g까지 검출할 수 있었다. 본 연구에서 개발된 면역크로마토그래피법은 24시간의 증균 만으로 식품에 오염되어있는 L. monocytogenes를 검출할 수 있는 것으로 사료되었고, 기존의 식중독균 진단방법에 비해 신속하고 간편하게 그 결과를 확인할 수 있었다.

Comparative analysis of two methods of laser induced boron isotopes separation

  • K.A., Lyakhov;Lee, H.J.
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2011년도 제40회 동계학술대회 초록집
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    • pp.407-408
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    • 2011
  • Natural boron consists of two stable isotopes 10B and 11B with natural abundance of 18.8 atom percent of 10B and 81.2 atom percent of 11B. The thermal neutron absorption cross-section for 10B and 11B are 3837 barn and 0.005 barn respectively. 10B enriched specific compounds are used for control rods and as a reactor coolant additives. In this work 2 methods for boron enrichment were analysed: 1) Gas irradiation in static conditions. Dissociation occurs due to multiphoton absorption by specific isotopes in appropriately tuned laser field. IR shifted laser pulses are usually used in combination with increasing the laser intensity also improves selectivity up to some degree. In order to prevent recombination of dissociated molecules BCl3 is mixed with H2S 2) SILARC method. Advantages of this method: a) Gas cooling is helpful to split and shrink boron isotopes absorption bands. In order to achieve better selectivity BCl3 gas has to be substantially rarefied (~0.01%-5%) in mixture with carrier gas. b) Laser intensity is lower than in the first method. Some preliminary calculations of dissociation and recombination with carrier gas molecules energetics for both methods will be demonstrated Boron separation in SILARC method can be represented as multistage process: 1) Mixture of BCl3 with carrier gas is putted in reservoir 2) Gas overcooling due to expansion through Laval nozzle 3) IR multiphoton absorption by gas irradiated by specifically tuned laser field with subsequent gradual gas condensation in outlet chamber It is planned to develop software which includes these stages. This software will rely on the following available software based on quantum molecular dynamics in external quantized field: 1) WavePacket: Each particle is treated semiclassicaly based on Wigner transform method 2) Turbomole: It is based on local density methods like density of functional methods (DFT) and its improvement- coupled clusters approach (CC) to take into account quantum correlation. These models will be used to extract information concerning kinetic coefficients, and their dependence on applied external field. Information on radiative corrections to equation of state induced by laser field which take into account possible phase transition (or crossover?) can be also revealed. This mixed phase equation of state with quantum corrections will be further used in hydrodynamical simulations. Moreover results of these hydrodynamical simulations can be compared with results of CFD calculations. The first reasonable question to ask before starting the CFD simulations is whether turbulent effects are significant or not, and how to model turbulence? The questions of laser beam parameters and outlet chamber geometry which are most optimal to make all gas volume irradiated is also discussed. Relationship between enrichment factor and stagnation pressure and temperature based on experimental data is also reported.

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Escherichia coli O157:H7의 단크론성 항체 생산과 효소면역분석법의 개발 (Production of Monoclonal Antibody against Escherichia coli O157:H7 and Development of Enzyme Linked Immunosorbent Assay)

  • 류희정;김정숙;김경열;남보람;남민지;심원보;김남수;조용진;정덕화
    • 한국식품과학회지
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    • 제42권3호
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    • pp.329-334
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    • 2010
  • 본 연구에서는 최근 식품이나 농축산물 등에서 빈번하게 검출되고 있는 장관출혈성 대장균인 E. coli O157:H7에 대한 단크론성 항체를 생산하고, 신속 정확하게 검색할 수 있는 간접효소면역분석법을 개발한 후 시료적용가능성을 확인하였다. 먼저 LPS, HKEC 및 FKEC를 E. coli O157:H7의 면역원으로 준비하여 mouse 면역에 사용하였고, 세포융합과 cloning을 실시하여 단클론성 항체를 생산하였으며, 생산된 항체 중 높은 역가를 나타낸 HKEC 4G8-5 항체로 ID-ELISA법을 개발하였다. 개발된 IDELISA법의 최저검출한계는 $10^5\;cell/mL$이었고, S. aureus와 Sal. Typhimurium에 대해서 약간의 반응성을 나타내었지만 E. coli O157:H7에 대해 보다 강한 반응성을 나타내었기 때문에 E. coli O157:H7에 매우 특이적인 분석법인 것으로 확인되었다. 개발된 ID-ELISA법을 이용하여 돼지고기, 소고기, 닭고기 및 새싹채소에 대한 검출률 향상을 위해 각 시료를 증균한 결과, 3종의 육류와 새싹채소는 각각 증균 6시간과 2시간부터 검출이 가능한 것으로 나타나 기존의 증균법보다 신속하게 시료 속 E. coli O157:H7을 분석할 수 있을 것으로 판단된다. 따라서 본 연구에서 개발된 IDELISA법을 적용하여 농축산물 중에 존재하는 E. coli O157:H7을 분석한다면 보다 신속하고 간편하게 분석할 수 있을 것으로 판단된다.

Oral Insulin-like Growth Factor-I Combined Alters Intestinal Protein Synthesis in Parenterally-fed Piglets

  • Park, Yoo-Kyoung;Sharon M. Donovan
    • Nutritional Sciences
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    • 제3권2호
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    • pp.57-65
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    • 2000
  • Partial enteral nutrition (PEN) supplemented with insulin-like growth factor-I (IGF-I) to neonatal piglets receiving parenteral nutrition increases lactase-phlorizin hydrolase (LPH) activity, but not LPH mRNA. The goal of the current study was to investigate the mechanism by which IGF-I up-regulates LPH activity. We hypothesized that IGF-I regulates LPH synthesis post-transcriptionally. Methods: Newborn piglets (n=15) received 100% parenteral nutrition (TPN), 80% parenteral nutrition + 20% PEN (PEN), or PEN + IGF-I (1.0mg/kg/d). On day 7, two stable isotopes of leucine, [$^2 H_3$]-leucine and [$^{13}C_1$]-L-leucine were intravenously administered to measure mucosal protein and brush LPH (BB LPH) synthesis. Results: Weight gain, nutrient intake and jejunal weight and length were similar among the treatment groups. PEN increased mucosal weight, villus width and cross-sectional area, LPH activity, mRNA expression and the abundance of proLPHh compared to 100% TPN (p<0.05). IGF-I further increased mucosal weight, LPH activity and LPH activity per unit BB LPH ~2-fold over PEN alone (p<0.05), but did not affect LPH mRNA or the abundance of proLPHh or mature LPH. Isotopic enrichment of [$^2 H_3$]-leucine and [$^{13}C_1$]-L-leucine in plasma, mucosal protein and LPH precursors, and the fractional and absolute synthesis rates of mucosal protein and LPH were similar among the treatment groups. Total mucosal protein synthesis was increased 60% (p<0.05) and LPH synthesis tended (p=0.14) to be greater in the IGF-I treated animals compared to the other two groups. Conclusions: The primary mechanism by which IGF-I up-regulates LPH may be post-translational, either via reducing LPH turnover, or by specifically altering LPH activity.

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애착과 자아존중감이 청소년의 건강효능감에 미치는 영향 (A Childhood Attachment and Adolescent's Self Esteem as Predictors of Health Efficacy in Adolescents)

  • 탁영란;이은영
    • Child Health Nursing Research
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    • 제10권1호
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    • pp.89-97
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    • 2004
  • Purpose: Adolescence is viewed as a critical period in the formation of health behavior and many health behaviors developed during this era persist into adulthood. Social-cognitive theory, self-efficacy as a central construct, has been used to predict and intervene the health behavioral patterns in adolescent. Previous research demonstrated that the attachment in childhood and self-esteem as psychosocial factors are predictors of the health efficacy in adolescent and it is viewed as solely an antecedent for the lifelong health behavior. Method: To investigate the path pattern of attachment in childhood, self-esteem and health efficacy in adolescents, 381 adolescents in high school from two urban cities in Korea were recruited for cross-sectional sample. Attachment in childhood was measured using Mother-Father-Peer Scale. Self esteem was measured with Hare self esteem. Perceived self efficacy in Health was measured by the School Health Efficacy Questionnaire. The path analysis revealed a significant relationship between attachment in childhood and self-esteem, self-esteem and health efficacy in adolescents. Self esteem was the strongest contributing factor for health efficacy in adolescent. The results suggest that attachment in childhood may aid in formulating positive self -esteem in adolescents and self-esteem played a major role in predicting health efficacy in adolescents. Conclusion: Therefore, self-esteem enrichment should be incorporated with adolescent health promotion and certainly should be a component in any health education program in school health program and interventions. These results have implications of psychosocial and family related factors on health promotion and health education for the health care provider with regard to primary and secondary prevention in adolescent population.

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