• Analytical Science and Technology
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• v.16 no.6
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• pp.443-449
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• 2003

Thermal neutron irradiation experiment of boric acid solution was carried out using HANARO in following three conditions: (A) $^{10}B$ concentration = $203.0{\mu}g/mL$, irradiation time = 1 hr; (B) $^{10}B$ concentration = $381.4{\mu}g/mL$, irradiation time = 1 hr; (C) $^{10}B$ concentration = $381.4{\mu}g/mL$, irradiation time = 0.5 hr. The amount of lithium produced from $^{10}B(n{\cdot}{\alpha})^7Li$ reaction which was generated on neutron irradiation, was measured by flameless atomic absorption spectroscopy. The concentration of $^7Li$ measured in the three experiments was $0.18{\mu}g/mL$ (78.3% of theoretical value, $0.23{\mu}g/mL$) in (A), $0.31{\mu}g/mL$ (70.5% of theoretical value, $0.44{\mu}g/mL$) in (B) and $0.16{\mu}g/mL$ (71.6% of theoretical value, $0.22{\mu}g/mL$) in (C). The pH value of irradiated boric acid was shifted to considerably low. It is estimated that boric acid would be transformed into the polyborate fonn, by radiolysis products of water, which has high dissociation constant.

• Journal of the Korean Society of Radiology
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• v.16 no.7
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• pp.953-960
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• 2022

The measurement of branching ratio of ¹⁶⁷Yb radioactive isotopes from gamma-ray spectrum of ¹⁶⁹Tm(p,3n)¹⁶⁷Yb reaction were performed by using a 100-MeV proton linear accelerator of the Korea Multi-purpose Accelerator Complex (KOMAC). The ¹⁶⁷Yb isotope has a half-life of 17.5 minutes and decays to ¹⁶⁹Tm. The gamma rays generated from the ¹⁶⁷Yb isotope were measured using an HPGe detector gamma ray spectroscopy system. The energy calibration of the detector and the efficiency measurement of the detector were determined using a standard source. The gamma rays of known main energy (62.9, 106.2, 113.3, 143.5 and 176.3 keV) were measured. On the other hand, information about the intensity of the generated gamma rays is very inaccurate. Therefore, in this study, the decay strength of the main gamma rays was accurately measured. Overall, it was different from the previously known results, and in particular, it was found that the intensity of the main decay gamma ray, such as the 113.3 and 106.2 keV gamma ray, was overestimated, and it was found that the gamma ray, such as 62.9, 116.7 and 143.5 keV was underestimated. The present results are considered to be important information in the fields of nuclear fusion, astrophysics and nuclear physics in the future.

• Journal of the Korean Vacuum Society
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• v.2 no.4
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• pp.416-423
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• 1993

Hydrogen depth profiling was performed by H(19F, $\alpha$${\gamma}$) nuclear resonance reactin . A cesium sputtering ion sorce and 1.7MV Tandem Van de Graaff accelerator was used for the production of 6.5MeV 19F ion. The ${\gamma}$ rays produced by the reaction were measure dby 3" $\times$3" and 6" $\times$8" Nal detectors . A test measurement was done for hydrogen contaminatin layer of a bare silicon wafer, Si3N4(H) and Zr(O)a-Si/Si for the purpose of verifying the applicability , detection limit and the reliability of the method.ility of the method.

• Progress in Medical Physics
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• v.15 no.3
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• pp.140-148
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• 2004

The absorbed dose for proton beam in water was calculated using the PTRAN code system. The proton interactions with water and the description on absorbed dose calculations are discussed, and the file structure and an execution example of the PTRAN codes are described. For 60, 100, 150, 200, and 250 MeV proton beams it is demonstrated that the absorbed dose is determined from the sum of Coulomb interactions and nuclear reactions, and that the Bragg peak feature depends On the energy straggling and multiple scattering. The PTRAN code was useful for studying the fundamental mechanism of the absorbed dose to water for clinical proton beams.

• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.5
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• pp.1472-1478
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• 1991

본 연구에서는 Rectangular Computer Tension(CT) 시편을 수정하여 만든 표준 시편인 MRL-CLWL시편(material research laboratorycrack line wedge loaded specimen )으로 균열정지 인성치를 결정하였다. 그리고 CT시편과 같은 효과를 갖는 Newman등 이 제안한 round compact tension(RCT)시편을 수정한 Round-CLWL 시편으로 균열정지인 성치를 결정하여 상호 비교평가하였다. Round-CLWL 시편은 시편제작시 round-bar를 절단하여 시편으로 가공할 수 있으므로 가공성이 좋으며 따라서 가공비가 적게 든다. 특히 균열 위치 및 방향을 임의로 선택하여 가공하기가 용이하므로 방향성이 있는 소 재의 균열정지 인성치를 결정하는 데 매우 편리한 시편이라 생각된다. 본 논문에서 는 Round-CLWL 시편으로 $K_{1a}$ 값을 계산하는데 필요한 형상계수를 결정하였으며, Polymethylmethacrylate(PMMA)를 사용하여 Round-CLWL 시편 채택의 타당성 확인을 위 한 MRL-CLWL과 Round-CLWL 시편 채택의 타당성 확인을 위한 MRL-CLWL과 Round-CLWL시 편의 $K_{1a}$결정 실험을 하였다.하였다.

• Analytical Science and Technology
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• v.18 no.4
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• pp.292-297
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• 2005

The effect of neutron irradiation on the chemical properties was measured in boric acid solution. The pH of the solution decreased in proportion to the irradiation time and the concentration of boric acid. The concentration of hydrogen peroxide, which is one of the radiolysis products of water, is in proportion to the concentration of boric acid, while in inverse proportion to the irradiation time. The oxygen and hydrogen gases had same chemically equivalent ratio in water radiolysis. The lithiun, which comes from $^{10}B(n,{\alpha})^7Li$, had poor relationship with neutron irradiation time at low concentration, $233{\sim}699{\mu}g/mL$, of boric acid, but the relationship was improved at higher concentration.

• Analytical Science and Technology
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• v.18 no.4
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• pp.263-270
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• 2005

Nuclear track is an useful tool for elemental analysis of radionuclides, such as uranium, plutonium and thorium, etc., and for elements undergoing nuclear reactions with thermal neutrons such as lithium and boron. This method has various application fields such as detecting fissionable radionuelides, measuring the fission rate in nuclear technology, analyzing cosmic radiation from meteorite, calculating the age of minerals as well as their history, etc. Track registration method has been applied to the microscopic analysis of boron and fissionable element such as uranium in KAERI. This report reviews the theoretical background of the nuclear track formation, practical procedures to obtain etched tracks and a perspective of the future.

• The Journal of the Korea Contents Association
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• v.4 no.2
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• pp.76-82
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• 2004

The thermal neutron capture cross-section (at 2,200 m/s value) of the $^{141}$Pr(n,$\gamma$)$^{142}$Pr reaction was measured by an activation method by using the heavy water ($D_2$O) thermal neutron facility at the KUR(Kyoto University Reactor). The thermal neutron fiux used in this experiment was monitored with the$^{197}$Au(n,$\gamma$)$^{198}$Au standard cross-section. The previous results and the evaluated data of JENDL-3.2, ENDF/B-VI, and JEF-2.2 were in good agreement with the current result.

• Nuclear Engineering and Technology
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• v.22 no.4
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• pp.410-415
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• 1990

Prompt fission neutron energy spectrum as a function of energies of neutron inducing fission has been calculated en the basis of the Madland-Nix(MN) model. The resultant spectra have been weighted to excitation functions of $^{27}$ Al(n, $\alpha$), $^{32}$ S(n, p) and $^{115}$ In(n, n') threshold reactions in order to get the average cross sections and then spectral indices which are defined as the average cross section ratio for two selective threshold reactions among the above three. It is appeared that spectral indices together with the neutron spectra are varying with energies of neutron inducing fission. This may indicate that the prompt fission neutron energy spectrum can be determined by measuring experimentally the spectral index.

• Proceedings of the Korean Nuclear Society Conference
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• 1998.05a
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• pp.392-397
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• 1998

PWR 원전의 냉각재 화학 및 체적제어 계통(CVCS) 정화 탈염기는 핵연료에서 방출된 핵분열 생성물질과 방사성 부식생성물을 제거하여 계통 내 방사능 준위를 낮추고, 부식을 유발하는 불순물을 제거하여 계통의 건전성을 유지하며, pH 조절제인 리튬($^{7}$ Li$_3$)의 농도조절을 통해 냉각계 수화학 환경을 최적으로 유지시킨다. 이를 위해 CVCS에는 정화용 혼상 탈염기와 $^{7}$ Li$_3$ 조절용 양이온 탈염기가 설치되었으며, 각각의 탈염기는 독립적인 기능을 수행한다. 이는 원전 운전 중 중성자와 붕소($^{10}$ B$_{5}$ )의 핵반응으로 생성된 $^{7}$ Li$_3$3 의 회수가 불가능하기 때문에 정화 탈염기에는 값비싼 $^{7}$ Li$_3$ 포화형 수지를 충전하여야 한다. Pn 원전은 연료교체를 위해 주기적으로 연료계장전 기간을 갖으며 이에 따라 원자로 기동 수화학, 운전중 B/Li 농도조절에 의한 pH 화학, 원자로 정지화학 등의 주기적인 냉각재 수화학 관리를 해오고 있다. 본 연구에서는 효율적인 정화탈염기의 운영방안을 제시함으로 운전중 붕소의 핵분열로 생성되는 $^{7}$ Li$_3$ 의 회수가 가능하고 수지의 사용량 절감으로 수지폐기물 발생량 저감화를 이를 수 있을 것으로 기대된다.