• 방사선산업학회지
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• 제9권3호
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• pp.111-117
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• 2015

In this paper, production of $^{166}Ho$ by double neutron capture from HANARO research reactor was evaluated. This production approach provides $^{166}Ho$ with high specific activity. $^{164}Dy$ is transmuted into $^{165g+m}Dy$ by (n,${\gamma}$) reaction, then $^{165g+m}Dy$ is transmuted into $^{166}Dy$ by (n,${\gamma}$) reaction. At the end of neutron irradiation, population of $^{166}Dy$ atoms reaches highest point. And $^{164}Dy$ exists as a mixture with $^{165m}Dy$, $^{165}Dy$, $^{166}Ho$ and $^{165}Ho$ at this point. To obtain $^{166}Ho$ with high specific activity, Ho isotopes from irradiated target is separated out. Then $^{166}Ho$ decayed from $^{166}Dy$ is eluted at radioactive equilibrium state. At each step, the number of relevant nuclide is calculated by the state equation. The neutron irradiation time for maximum $^{166}Dy$ is calculated for 283 hour. When 100 mg target of $Dy_2O_3$ (96.8% enriched $^{164}Dy$) is used, possible activity of $^{166}Ho$ is 3.54 Ci($1.31{\times}10^{11}Bq$). For separation efficiency of Dy/Ho is 99.99%, $^{166}Ho/Ho$ is 0.62.

• Nuclear Engineering and Technology
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• 제54권11호
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• pp.4226-4230
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• 2022

The Korea Atomic Energy Research Institute (KAERI) has designed a Hybrid-Low Power Research Reactor (H-LPRR) which can be used for critical assembly and conventional research reactor as well. It is an open tank-in-pool type research reactor (Thermal Power: 50 kW_th) of which the most important applications are Neutron Activation Analysis (NAA), Radioisotope (RI) production, education and training. There are eight irradiation holes on the edge of the reactor core: IR (6 holes for RI production) and NA (2 holes for NAA) holes. In order to quantify the elemental concentration in target samples through the Instrumental Neutron Activation Analysis (INAA), it is necessary to measure neutron spectrum parameters such as thermal neutron flux, the deviation from the ideal 1/E epithermal neutron flux distribution (α), and the thermal-to-epithermal neutron flux ratio (f) for the irradiation holes. In this study, the MCNP6.1 code and FORTRAN 90 language are applied to determine the parameters for the two irradiation holes (NA-SW and NA-NW) in H-LPRR, and in particular its α and f parameters are compared to values of other research reactors. The results confirmed that the neutron irradiation holes in H-LPRR are designed to be sufficiently applied to neutron activation analysis, and its performance is comparable to that of foreign research reactors including the TRIGA MARK II.

• Nuclear Engineering and Technology
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• 제51권1호
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• pp.176-189
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• 2019

This paper presents a feasibility study for producing the medical isotope $^{99m}Tc$ using the hazardous and currently wasted radioisotope $^{99}Tc$. This can be achieved with the nuclear resonance fluorescence (NRF) phenomenon, which has recently been made applicable due to high-intensity laser Compton scattering (LCS) photons. In this work, 21 NRF energy states of $^{99}Tc$ have been identified as potential contributors to the photo-production of $^{99m}Tc$ and their NRF cross-sections are evaluated by using the single particle estimate model and the ENSDF data library. The evaluated cross sections are scaled using known measurement data for improved accuracy. The maximum LCS photon energy is adjusted in a way to cover all the significant excited states that may contribute to $^{99m}Tc$ generation. An energy recovery LINAC system is considered as the LCS photon source and the LCS gamma spectrum is optimized by adjusting the electron energy to maximize $^{99m}Tc$ photo-production. The NRF reaction rate for $^{99m}Tc$ is first optimized without considering the photon attenuations such as photo-atomic interactions and self-shielding due to the NRF resonance itself. The change in energy spectrum and intensity due to the photo-atomic reactions has been quantified using the MCNP6 code and then the NRF self-shielding effect was considered to obtain the spectrums that include all the attenuation factors. Simulations show that when a $^{99}Tc$ target is irradiated at an intensity of the order $10^{17}{\gamma}/s$ for 30 h, 2.01 Ci of $^{99m}Tc$ can be produced.

• Nuclear Engineering and Technology
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• 제38권5호
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• pp.443-448
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• 2006

The OPAL (Open Pool Australian Light-water) reactor is currently being constructed to replace HIFAR (HI-Flux Australian Reactor, commissioned in 1958) in mid-2006. HIFAR will be shutdown for decommissioning after several months of simultaneous operation with OPAL for smooth transition of operating systems and business. OPAL is a 20 MW multipurpose research reactor for radioisotope production, irradiation services and neutron beam research. The OPAL reactor uses low enriched uranium fuel in a compact core, cooled by light water and moderated by heavy water, yielding maximum thermal flux not less than $4{\times}10^{14}ncm^{-2}s^{-1}$. The reactor containment building is constructed of reinforced concrete and has been designed to protect the reactor from all external events such as seismic occurrences and impact from a hypothetical light aircraft crash. This paper describes the main elements of the reactor design and its applications.

• 대한방사선치료학회지
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• 제2권1호
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• pp.23-29
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• 1987

The general features and measured results of the 143cm, variable-energy, three sector-focused MC-50 cyclotron installed at Korea Cancer Center Hospital are described. The MC-50 cyclotron is designed to produce beams of protons, deuterons, He-3 and alpha particles of maximum energies 50MeV, 25MeV, 66MeV and 50MeV respectively to be used for neutron therapy and radioisotope production. The azimuthal field variation is produced by three sets of spiral ridges having a maximum spiral angle of $55^{\circ}$. The RF system, a two-dee quarter-wave system is designed to provide a continuously variable frequency from 15.5 to 26.8 MHz. The first external beam was obtained in January 1986. Subsequent internal ana external beam studies with protons and alphas show a well-behaved beam through the whole beam transport system.

• Journal of Radiation Protection and Research
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• 제24권4호
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• pp.231-233
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• 1999

This report will introduce the epitome about the subject, HANARO (Hi-flux Advanced Neutron Application Reactor designed by KAERI in early 1995) Utilization Education Training Program Development and Operation, which is one of the nuclear research basic expansion businesses executed from 1999. 12. to strengthen the usage of HANARO. This program consists of the basic reactor experiments program for university students who have specialty of nuclear and other engineering, and the special research education program for faculties from universities and researchers from industrial fields. Principle lessons are reactor operation, radioisotope production, neutron activation analysis, neutron radiography, radiation shield (health physics), nuclear fuel combustion measurement by gamma scanning arrangement, and CNS (Compact Nuclear Simulator) and so on.

• Nuclear Engineering and Technology
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• 제21권3호
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• pp.216-222
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• 1989

원자력병원에 설치되어 있는 MC-50 싸이클로트론은 중성자 치료와 의학용 동위원소 생산을 위해 가동중에 있다. 본 논문에서는 MC-50의 설계 특징, 기계적 구조, 가동 특성에 대하여 기술하고 있다. 본 싸이클로트론의 최적 가동 조건은 반복적인 운전에 의해 결정되었으며, 내부 빔의 성능은 싸이클로트론 반경의 함수로서 내부 빔의 세기 및 공간 분포 측정을 통해 조사되어졌다. 일상적으로, 인출효율이 61%일 때 40$\mu$A세기의 50 MeV 양성자 빔을 얻었다.

• Nuclear Engineering and Technology
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• 제3권3호
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• pp.148-154
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• 1971

원자로를 여러가지 불연속적 방법으로 가동시킬 때 얻어지는 방사성동위원소의 생성량을 구하는 식을 안출하였다. 특히 현재 우리나라 원자로의 가동조건인 월요일부터 목요일까지 매일 평균 8.2시간을 가동하고 금요일과 일요일은 가동치 않고 토요일은 평균 3.2시간으로 가동하는 조건을 중점적으로 다루었다. 이 경우의 activity를 구하는 식은 생성동위원소가 제 2의 핵반응으로 소실되지 않을 경우에는 (equation omitted) 가 된다. 여기서 A: activity (dps), $\Phi$: 중성자속(n $cm^{-2}$ sec$^{-1}$), No: 조사되기전 원자수, $\sigma$: 방사화단면적($\textrm{cm}^2$), λ: 생성방사성동위원소의 붕괴상수($hr^{-1}$), t： 조사하기 시작해서 끄집어낼 때까지의 시간(hr), n: 조사일수, m:금요일이 처음 나타날 때까지의 조사일 수, s, r, q: 조사기간중 금요일, 토요일 및 일요일이 나타난수를 각각 뜻한다. 윗식은 거의 고정항들로 구성되 있으므로 각 동위원소에 대해 이 고정항들을 계산하여 그 값을 구해 도표를 만들어 이 식이 보다 편리하게 이용되도록 하였다.

• 대한방사성의약품학회지
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• 제2권2호
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• pp.84-95
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• 2016

Considerably increasing interest in using the theranostic isotopes/ isotope pairs of radiometals like $^{44/47}Sc$ and $^{64/67}Cu$ for diagnosis and/or therapeutic applications in the nuclear medicine procedures necessitates its reliable production and supply. Separation and purification of no-carrier-added (NCA) isotopes from macro quantitates of the irradiated target matrix along with other impurities is a cardinal procedure amongst several other steps involved in its production. Multitudinous methods including but not limited to liquid-liquid (solvent) extraction, extraction chromatography (EXC), ion exchange, electrodeposition and sublimation are routinely applied either solitarily or in combination for the separation and purification of radioisotopes depending on their production routes, radioisotope of interest and impurities involved. However, application of EXC though has shown promises towards the numerous separation techniques have not received much attention as far as its application prospects in the field of nuclear medicine are concerned. Advances in the recent past for application of the EXC resins in separation and purification of the several medically important radioisotopes at ultra-high purity have shown promising behavior with respect to their operation simplicity, acidic and radiolytic stability, separation efficiencies and speedy procedures with the enhanced and excellent extraction abilities. In this mini review we will be talking about the recent developments in the application and the use of EXC techniques for the separation and purification of $^{44/47}Sc$ and $^{64/67}Cu$ for medical applications. Furthermore, we will also discuss the scientific and practical aspects of EXC in the view of separation of the NCA trace amount of radionuclides.

• Journal of Welding and Joining
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• 제25권5호
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• pp.64-71
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• 2007

The aim of this paper is to investigate the effects of welding parameters on the weld shape in seal-welding of STS304L capsule for manufacturing a radioisotope source which is widely used in nondestructive testing of metal structures using gamma ray. Pulsed gas tungsten arc (Pulsed GTA) welding is performed for thin cross sectional area of the capsule. Seven welding parameters including current waveform parameters and arc length etc. are selected as main process parameters using design of experiment. The weld shape such as bead width, penetration depth, weld area, aspect ratio and area rate is investigated to assess the effects of welding parameters. As results, the combination of pulse duty/welding speed largely affects on bead width, penetration depth, area and aspect ratio. Finally, it is concluded that the key parameters are the combination of pulse duty/welding speed, base current and arc length, and their optimal conditions are 50%/1.77mm/s, 6.4A and 1 mm.