• Nuclear Engineering and Technology
• /
• 제11권3호
• /
• pp.219-229
• /
• 1979

The current status of the computational methods and computer codes for the analysis of reactor kinetics is reviewed. Computational methods which have been developed for space-dependent transient analyses are presented and recent progress in the development of methods is discussed.

• 방사선산업학회지
• /
• 제7권2_3호
• /
• pp.127-134
• /
• 2013

Bombesin receptors are overexpressed in many kinds of human tumors. In particular, the gastrin releasing peptide receptor (GRPR) which is also called bombesin receptor subtype 2, has been identified in prostate cancer. In the present study, we developed a bombesin antagonist-based $^{177}Lu$-labeled peptide, $^{177}Lu$-DOTA-$Ala(SO_3H)$-Aminooctanoyl-Gln-Trp-Ala-Val-N methyl Gly-His-Statine-Leu-$NH_2$ (DOTA-sBBNA). DOTA-sBBNA was prepared using a solid phase synthesis method. It was labeled with $^{177}Lu$ by a high radiolabeling yield (>98%), and its Log P value was -2.05. The radiolabeled peptide was highly stable in serum incubation at $37^{\circ}C$ for 48 hr. A competitive displacement of $^{125}I-[Tyr^4]$-Bombesin on the PC-3 human prostate carcinoma cells revealed that the $IC_{50}$ value of the peptide was 6.76 nM indicating a highly nanomolar binding affinity for GRPR. These results suggest that $^{177}Lu$-DOTA-sBBNA can be a potential candidate for targeting prostate cancer, and further studies to evaluate its biological characteristics are needed.

• 방사선산업학회지
• /
• 제7권2_3호
• /
• pp.191-200
• /
• 2013

In this study, a novel bombesin (BBN) analogues, DOTA-Ala($SO_3H$)-4 aminobenzoyl-Gln-Trp-Ala-Val-Gly-His-Leu-Met-$NH_2$ (DOTA-sBBN) and DOTA-Lys(glucose)-4 aminobenzoyl-Gln-Trp-Ala-Val-Gly-His-Leu-Met-$NH_2$ (DOTA-gluBBN), were synthesized and radiolabeled, and their binding affinities were evaluated. Peptides were prepared by a solid phase synthesis method and their purities were over 98%. DOTA is the chelating agent for $^{177}Lu$-labeling, and the DOTA-conjugated peptides were radiolabeled with $^{177}Lu$ by a high radiolabeling yield (>98%). The Log P values of DOTA-sBBN and DOTA-gluBBN were -2.20 and -2.79, respectively. 50.41% of $^{177}Lu$-DOTA-sBBN and 72.97% of $^{177}Lu$-DOTA-gluBBN were left undegraded by the serum incubation at $37^{\circ}C$ for 48 hr. A competitive displacement of $^{125}I-[Tyr^4]$-BBN on the PC-3 human prostate carcinoma cells revealed that 50% inhibitory concentration ($IC_{50}$) were 1.46 nM of DOTA-sBBN and 4.67 nM of DOTA-gluBBN indicating a highly nanomolar binding affinity for GRPR. Therefore, it is concluded that $^{177}Lu$-DOTA-sBBN and $^{177}Lu$-DOTA-gluBBN can be potential candidates as a targeting modality for the Gastrin-releasing peptide receptor (GRPR)-over-expressing tumors, and further studies to evaluate their biological and pharmacological characteristics are needed.

• 한국원자력학회:학술대회논문집
• /
• 한국원자력학회 1997년도 추계학술발표회논문집(1)
• /
• pp.58-63
• /
• 1997

This paper is concerned with an algorithm based on neural networks to calculate the axial power distribution using excore defector signals in the nuclear reactor core. The fundamental basis of the algorithm is that the detector response can be fairly accurately estimated using computational codes. In other words, the training set, which represents relationship between detector signals and axial power distributions, for the neural network can be obtained through calculations instead of measurements. Application of the new method to the Yonggwang nuclear power plant unit 3 (YGN-3) shows that it is superior to the current algorithm in place.

• 한국재료학회지
• /
• 제15권2호
• /
• pp.126-133
• /
• 2005

Mechanical properties of zirconium cladding were evaluated by ring tension test to simulate Reactivity-Initiated Accident (RIA) at high burnup situation as an out-reactor test. Zircaloy-4 cladding was hydrided up to 1000 ppm as well as oxidized up to $100\;{\mu}m$ to simulate high-burnup situation. After simulated high-burnup treatment, ring tension test was carried out from 0.01 to 1/sec to correlate with actual RIA event. The results showed that ductility and circumferential toughness decreased with the hydrogen content and oxide thickness. Hydride generated inside cladding acted as brittle failure. Oxygen influenced cladding tube by the reduction of load bearing area, oxygen embrittlement, and thermal aging. Correlation between in-reactor RIA parameter like fuel enthalpy and out-reactor toughness was performed and showed a reasonable result.

• 산업경영시스템학회지
• /
• 제36권4호
• /
• pp.18-24
• /
• 2013

A document control system (DCS), ANSIM (KAERI Advanced Nuclear Safety Information Management) was designed for the purpose of documents preparation, review, and approvement for JRTR (Jordan Research and Training Reactor) project. The ANSIM system consists of a document management, document container, project management, organization management, and EPC (Engineering, Procurement and Construction) document folder. The document container folder run after specific contents, a revision history of the design documents and drawings are issued in KAERI. The EPC document work-scope is a registry for incoming documents in ANSIM, the assignment of a manager or charger, document review, preparing and outgoing PM memorandum as attached the reviewed paper. On the other hand, KAERI is aiming another extra network server for the NRR (New Research Reactor) by the end of this year. In conclusion, it is the first, computation system of DCS that provides document form, document number, and approval line. Second, ANSIM increases the productivity of performance that can be recognized the document work-flow of oneself and all participants. Finally, a plenty of experience and knowledge of nuclear technology can be transmitted to next generation for the design, manufacturing, testing, installation, and commissioning. Though this, ANSIM is expected to allow the export of a knowledge and information system as well as a research reactor.

• 한국전산유체공학회지
• /
• 제17권4호
• /
• pp.41-48
• /
• 2012

A numerical analysis of thermal stratification in the upper plenum of the MONJU fast breeder reactor was performed. Calculations were performed for a 1/6 simplified model of the MONJU reactor using the commercial code, CFX-13. To better resolve the geometrically complex upper core structure of the MONJU reactor, the porous media approach was adopted for the simulation. First, a steady state solution was obtained and the transient solutions were then obtained for the turbine trip test conducted in December 1995. The time dependent inlet conditions for the mass flow rate and temperature were provided by JAEA. Good agreement with the experimental data was observed for steady state solution. The numerical solution of the transient analysis shows the formation of thermal stratification within the upper plenum of the reactor vessel during the turbine trip test. The temporal variations of temperature were predicted accurately by the present method in the initial rapid coastdown period (~300 seconds). However, transient numerical solutions show a faster thermal mixing than that observed in the experiment after the initial coastdown period. A nearly homogenization of the temperature field in the upper plenum is predicted after about 900 seconds, which is a much shorter-term thermal stratification than the experimental data indicates. This discrepancy is due to the shortcoming of the turbulence models available in the CFX-13 code for a natural convection flow with thermal stratification.

• 한국미생물·생명공학회지
• /
• 제9권3호
• /
• pp.165-171
• /
• 1981

E. coil ATCC 9637의 균체를 젤라틴과 DEAE-cellulose의 혼합 성형 후 글루트알데히드 가교법으로 제조론 고정화 penicillin amidase의 differential column reactor에서의 반응속도를 논의하였다. 이러한 반응조의 최적 조작조건은 효소충진량 1g, 기질농도30mM(0.1M 인산완충액, pH8.0), 유출속도 4 $m\ell$/min, 온도 4$0^{\circ}C$이었다. 이 최적조건에서 고정화효소의 일반적인 성질을 조사하였다. Km 상수는 4.8mM 이었고 specific activity 308 units/g 고정화 효소이 었다. 또한 고정화효소에서는 기질에 의한 효소반응 저해효과가 보이지 않았다. 이러한 differential column reactor에서는 column내에서의 pH 감소효과 및 외부 화산효과가 없어지기 때문에 이러한 외부적 영향을 받지 않는 고정화효소의 반응 속도론적 연구에 적합함을 알았다.

• Nuclear Engineering and Technology
• /
• 제40권7호
• /
• pp.615-624
• /
• 2008

In this paper, the contribution of task types and error types involved in the human-related unplanned reactor trip events that have occurred between 1986 and 2006 in Korean nuclear power plants are analysed in order to establish a strategy for reducing the human-related unplanned reactor trips. Classification systems for the task types, error modes, and cognitive functions are developed or adopted from the currently available taxonomies, and the relevant information is extracted from the event reports or judged on the basis of an event description. According to the analyses from this study, the contributions of the task types are as follows: corrective maintenance (25.7%), planned maintenance (22.8%), planned operation (19.8%), periodic preventive maintenance (14.9%), response to a transient (9.9%), and design/manufacturing/installation (6.9%). According to the analysis of the error modes, error modes such as control failure (22.2%), wrong object (18.5%), omission (14.8%), wrong action (11.1 %), and inadequate (8.3%) take up about 75% of the total unplanned trip events. The analysis of the cognitive functions involved in the events indicated that the planning function had the highest contribution (46.7%) to the human actions leading to unplanned reactor trips. This analysis concludes that in order to significantly reduce human-induced or human-related unplanned reactor trips, an aide system (in support of maintenance personnel) for evaluating possible (negative) impacts of planned actions or erroneous actions as well as an appropriate human error prediction technique, should be developed.

• 자원리싸이클링
• /
• 제15권1호
• /
• pp.20-27
• /
• 2006

열가소성수지인 PVC는 우수한 물성을 가지고 있어 다양한 용도로 사용되지만 높은 염소함량으로 인하여 폐기할 때 환경문제를 야기한다. PVC로부터의 탈염소반응이 기타 플라스틱 열분해 반응보다 낮은 온도에서 일어나는 점을 이용하여 전처리공정으로의 탈염소반응 연구를 수행하였다. 반응기는 교반능력이 우수한 2축 스크류반응기를 사용하였다. 실험변수는 1차반응기온도, 2차반응기온도, 혼합플라스틱의 PVC농도, 혼합플라스틱 점도, 공급량, 2차반응기의 스크류회전수이다. 적절한 공정조건하에서 탈염소율은 $90\%$ 이상이었으며 탈염소공정에서 배출되는 염소가스를 물에 흡수하여 염산으로 회수가 가능하였다. 염소 물질수지를 취하여 스크류반응기 전후의 염소 흐름을 분석하였다.