• 한국환경보건학회지
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• 제32권2호
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• pp.179-185
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• 2006

Effect of organic loading rate on UASB performance was evaluated under the renditions of some surface area/reactor volume ratio and different reactor diameter. At the low leading rate of 0.4 kg $COD/m^3{\cdot}d$, reactor performance was not affected by reactor diameter. At the organic loading rate of 6 kg $COD/m^3{\cdot}d$, however, volatile acid accumulation and low COD removal efficiency is observed in reactor having 6.4 cm diameter, while volatile acid is not accumulated at all and high COD removal efficiency is observed in reactor having 3 cm diameter. Such a difference of reactor performance depending on reactor diameter can be explained that sludge bed can be fluidized by evolved gas bubble in narrow reactor, while sludge bed ran not be fluidized by evolved gas bubble only in wide reactor. At a high organic loading rate of 20 kg $COD/m^3{\cdot}d$, it can be judged that there is no relation between reactor configuration and reactor performance because all reactors showed very low COD removal efficiencies regardless of reactor diameter. Narrow and tall type reactor is favorable condition for making sludge bed fluidization at a constant surface area/reactor volume ratio. Thus, it can be judged that reactor configuration and sludge bed fluidization have great influence to reactor performance.

• Nuclear Engineering and Technology
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• 제50권1호
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• pp.165-169
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• 2018

An assessment for determining N-16 activity concentrations during the operation condition of Bangladesh Atomic Energy Commission TRIGA Research Reactor was performed employing several governing equations. The radionuclide N-16 is a high energy (6.13 MeV) gamma emitter which is predominately created by the fast neutron interaction with O-16 present in the reactor core water. During reactor operation at different power level, the concentration of N-16 at the reactor bay region may increase causing radiation risk to the reactor operating personnel or the general public. Concerning the safety of the research reactor, the present study deals with the estimation of N-16 activity concentrations in the regions of reactor core, reactor tank, and reactor bay at different reactor power levels under natural convection cooling mode. The estimated N-16 activity concentration values with 500 kW reactor power at the reactor core region was $7.40{\times}10^5Bq/cm^3$ and at the bay region was $3.39{\times}10^5Bq/cm^3$. At 3 MW reactor power with active forced convection cooling mode, the N-16 activity concentration in the decay tank exit water was also determined, and the value was $4.14{\times}10^{-1}Bq/cm^3$.

• 생명과학회지
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• 제11권3호
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• pp.273-278
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• 2001

Removal of nitrogen compound from waste water is essential and often accomplished by biological process. Deni-trification bacterium. Paracoccus denitrificans(KCTC 2350) is employed to estimate the ability and the characteristics of denitrification. In the immobilized biological reactor system, the measurement of absolute amount of active strain in the reactor is comparatively difficult or impossible. In this study, strain immobilized denitrification reactor was designed with the unwoven texture wrapped peeped hole plastic tube to calculated the absolute amount of active strain by comparing the activity of the immobilized reactor adn the free cell reactor. The reactor system was continuous stirred tank reactor and the rate of substrate consumption was assumed to be Michaelis-Menten equation. As a result, we found that the amount of immobilized active strain was the half of the total active strain in the reactor and the time required to reach in the equilibrium state in the immobilized reactor system was shorter than that of the free cell reactor system.

• Nuclear Engineering and Technology
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• 제28권6호
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• pp.576-582
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• 1996

The integrity of reactor vessel support system of the Korean Standard Nuclear Power Plant (KSNPP) is investigated for a postulated reactor vessel closure head drop event. The closure head is disassembled from the reactor vessel during refueling process or general inspection of reactor vessel and internal structures, and carried to proposed location by the head lift rig. A postulated closure head drop event could be anticipated during closure head handling process. The drop event may cause an impact load on the reactor vessel and supporting system. The integrity of the supporting system is directly relevant to that of reactor vessel and reactor internals including fuels. Results derived by elastic impact analysis, linear and non-linear buckling analysis and elasto-plastic stress analysis of the supporting system implied that the integrity of the reactor vessel supporting system is intact for a postulated reactor vessel closure head drop event.

• KSBB Journal
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• 제24권4호
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• pp.353-360
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• 2009

본 연구에서는 혐기조 및 무산소조, 호기조로 구성된 상향류식 고정상 담체 반응장치와 호기조로 고정상 담체 대신에 유동상 담체를 사용한 Loop Reactor로 이루어진 장치에서 생활하수를 이용하여 성능실험을 수행한 후 HRT에 따른 유기물 및 T-N, T-P 등 오염물질의 제거 특성을 비교 분석하였다. 두 반응기 모두 평균 BOD 제거율과 SS 제거율은 HRT가 증가함에 따라 증가하다가 HRT 16 h 이상에서는 일정한 수치를 나타내고 있으며 HRT 16 h에서 고정상 담체 반응기와 Loop Reactor의 평균 BOD 제거율은 각각 86.6%, 90.9%이었으며 평균 SS 제거율은 각각 78.0%, 88.2%로 Loop Reactor의 경우가 각각 4.3%, 10.2%의 더 높은 BOD와 SS 제거율을 나타내었다. 또한 평균 $COD_{Cr}$, 제거율 및 평균 $COD_{Mn}$ 제거율은 BOD와 SS 제거율과 마찬가지로 HRT가 증가함에 따라 증가하다가 HRT 16 h에서 일정한 수치를 나타내고 있으며 고정상 담체 반응기와 Loop Reactor의 평균 $COD_{Cr}$, 제거율은 각각 63.5%, 75.2%이었으며 평균 $COD_{Mn}$ 제거율은 각각 60.7%, 73.6%로 Loop Reactor의 경우가 11.7%, 12.9% 더 높은 제거율을 나타내었다. 반면에 평균 T-N 제거율 및 T-P 제거율은 두 반응기 모두 HRT가 증가함에 따라 제거율은 계속 증가하는 양상을 보여주고 있으며 HRT 16 h에서 Loop Reactor의 경우 평균 T-N 제거율 및 평균 T-P 제거율은 각각 33.6%, 54.5%로 고정상 담체 반응기보다 14.1%, 10.8%의 더 높은 제거율을 나타내었다. 이상의 결과에서 Loop Reactor가 성능이 훨씬 더 우수하였으며 최적 HRT는 16 h임을 알 수 있었다.

• 한국물환경학회지
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• 제25권5호
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• pp.727-734
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• 2009

This study was carried out to evaluate the high rate biological reactor such as lab scale reactor before the application in site, and to get the basic data for possibility using liquid fertilizer with the effluent from biological reactor when the centrifugal machine was applied. The total volume of this reactor in 6 L, in composted of anoxic reactor (2 L), aerobic reactor (2 L), and nitification reactor (2 L). BOD removal efficiency rates when centrifugal machine was applied after effluent from biological reactor are over than 95%. This biological reactor was required post process to satisfy the effluent standards, and was need centrifugal machine to control the washout of microbes in the reactor. T-N removal efficiency rate in HRT 24 hr with centrifugation is 80.0%, and it is desirable to operate less than $1.3kgN/m^3{\cdot}d$ for 70% of T-N removal efficiency rate. T-P removal efficiency rate in HRT 24 hr is 68.2%, and become higher 71.3% after centrifugation. Considering in the 28.6% T-N removal efficiency rate, the nitrogen contents of the effluent from reactor is 0.34% to satisfy the liquid fertilizer.

• 한국환경농학회지
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• 제17권4호
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• pp.301-305
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• 1998

본 연구는 농가에서 사용하는 저류조, 연속 폭기조, 혐기성 정치식, 혐기성 교반식의 4가지 형태의 부숙조를 이용하여 액상 가축분 퇴비 부숙효율을 평가하기 위하여 수행하였다. 호기성 폭기조는 BOD 및 악취 제거율에서 혐기성 부숙방법보다 우수하였다. 반면에 질소는 초기농도의 47%가 손실되어 혐기성 부숙방법보다 심한 편이었다. 혐기성 부숙방법중 교반식과 정치식간에는 큰 차이는 인정되지 않았다. 그러나 혐기성 교반식이 정치식보다 대장균 제거율, 악취제거율은 더 높았으며, 질소 손실율은 더 낮게 나타났다. 농가에서 사용하는 저류조 형태의 부숙조는 혐기 또는 호기성 처리 방법보다 BOD, 대장균, 악취제거율등이 낮았다. 각 개별요인들의 효율을 종합 평가한 결과 액비 부숙효율은 혐기성 교반조>호기성 폭기조>무교반 혐기성조>저류조 순으로 높았다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1999년도 전력전자학술대회 논문집
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• pp.65-70
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• 1999

In this paper, the cost-effective design of output reactor which is used to suppress the over-voltage at the motor terminal in the Adjustable Speed Drives(ASD) application is proposed. In the elevator drive system, the power cable length is relatively shorter than other ASD applications and then the over-voltage at the motor terminal depends on the frequency characteristics of the output reactor at the over-voltage operating frequency. The over-voltage suppression mechanism of output reactor in ASD application is analyzed and the dominant parameters of output reactor for the over-voltage suppression are extracted. Using these parameters as the design values and considering the high frequency characteristics of iron core in the reactor, a new cost-effective structure of output reactor is proposed. Experimental results of the conventional reactor and the proposed reactor with a 15kW induction motor are given to verify the proposed scheme.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.582-582
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• 2012

Characteristics of a fusion-driven transmutation reactor was investigated. A compact reactor concept is desirable from an economic viewpoint. For the optimal design of a reactor, a radial build of reactor components has to be determined by considering the plasma physics and engineering constraints which inter-relate various reactor components. In a transmutation reactor, design of blanket and shield play a key role in determining the size of a reactor; the blanket should produce enough tritium for tritium self-sufficiency, the transmutation rate of waste has to be maximized, and the shield should provide sufficient protection for the superconducting toroidal field (TF) coil. To determine the radial build of the blanket and the shield, not only a radiation transport analysis but also a burnup calculation were coupled with the system analysis and it allowed the self-consistent determination of the design parameters of a transmutation reactor.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 D
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• pp.2166-2168
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• 2001

Reactor Noise is defined as the fluctuations of measured instrumentation signals during full-power operation of reactor which have informations on reactor system dynamics such as neutron kinetics. The Reactor internal structures which consist of many complex components are subjected to flow-induced vibration due to high temperature and pressure in reactor coolant system. The above flow-induced vibration causes degradation of structural integrity of the reactor and may result in loosing mechanical binding component which might impact other equipment and component or cause flow blockage. It is important to analyze reactor noise signal for the early detection of potential problem or failure in order to diagnosis reactor integrity in the point of view of safety and plant economics. Detailed design of hardware diagnostic system reactor internal structures using neutron noise(RIDS).