• 산업경영시스템학회지
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• 제34권4호
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• pp.49-56
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• 2011

The Project of Jordan Research and Training Reactor (JRTR) officially launched in Aug. 2010. JRTR is the first made-in-Korea nuclear system to be built abroad by year 2015, and Korea Atomic Energy Research Institute (KAERI) is responsible for the design of major systems including the reactor core. While the PDCS (Project Document Control System) being operated by EPC company controls all the documents of the whole Project, KAERI is supposed to have its own system for KAERI documents. Meeting such a need; KAERI has implemented a document control for the JRTR Project into already existing ANSIM (KAERI Advanced Nuclear Safety Information Management) system. The documents of JRTR project to be controlled are defined in the PPM (Project Procedures Manual), QAP (Quality Assurance Procedure) and PEP (Project Execution Program). The ANSIM consists of the document management holder, document container holder and organization management holder. The document management holder, which is the most important part of ANSIM-JRTR, consists of the DDA (Document Distribution for Agreement), IOC (Inter-office Correspondence), PM Memo. (Project Manager Memorandum) and cover sheets of design documents. Other materials such as meeting minutes, sub-department materials and design information materials are stored in an independent COP (Community of Practice). This established computerized document control system, ANSIM, could lessen a burden for project management team and enhance the productivity as well.

• Nuclear Engineering and Technology
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• 제41권3호
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• pp.327-334
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• 2009

Elastic wave is one of the most useful tools for non-destructive tests in nuclear power plants. Since the elastic properties are indispensable for analyzing the behaviors of elastic waves, they should be predetermined within an acceptable accuracy. Nuclear power plants are exposed to harsh environmental conditions and hence the structures are degraded. It means that the Young's modulus becomes unreliable and in-situ measurement of Young's modulus is required from an engineering point of view. Young's modulus is estimated from the group velocity of propagating waves. Because the flexural wave of a plate is inherently dispersive, the group velocity is not clearly evaluated in temporal signal analysis. In order to overcome such ambiguity in estimation of group velocity, Wigner-Ville distribution as the time-frequency analysis technique was proposed and utilized. To verify the proposed method, experiments for steel and acryl plates were performed with accelerometers. The results show good estimation of the Young's modulus of two plates.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.1116-1120
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• 2004

In the nuclear power plant, there are several cylindrical vessels such as reactor vessel, pressuriser and so on. The vessels are usually constructed by welding large rolled plates, forged sections or nozzle pipes together. In order to assure the integrity of the vessel, these welds should be periodically inspected using sensors such as ultrasonic transducer or visual cameras. This inspection is usually conducted under water to minimize exposure to the radioactively contaminated vessel walls. The inspections have been performed by using a conventional inspection machine with a big structural sturdy column, however, it is so huge and heavy that maintenance and handling of the machine are extremely difficult. It requires much effort to transport the system to the site and also requires continuous use of the utility's polar crane to move the manipulator into the building and then onto the vessel. Setup beside the vessel requires a large volume of work preparation area and several shifts to complete. In order to resolve these problems, we have developed an underwater mobile robot guided by the laser pointer, and performed a series of experiments both in the mockup and in the real reactor vessel. This paper introduces our robotic inspection system and the laser guidance of the mobile robot as well as the results of the functional test.

• Nuclear Engineering and Technology
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• 제45권2호
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• pp.249-256
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• 2013

In accordance with the US Nuclear Regulatory Commission (US NRC), Regulatory Guide 1.20, the reactor vessel internals comprehensive vibration assessment program (RVI CVAP) has been developed for an Advanced Power Reactor 1400 (APR1400). The purpose of the RVI CVAP is to verify the structural integrity of the reactor internals to flow-induced loads prior to commercial operation. The APR1400 RVI CVAP consists of four programs (analysis, measurement, inspection, and assessment). Thoughtful preparation is essential to the measurement program, because data acquisition must be performed only once. The optimized design of a vibration and stress measurement system for the RVI CVAP is essential to verify the integrity of the APR1400 RVI. We successfully designed a vibration and stress measurement system for the APR1400 RVI CVAP based on the design materials, the hydraulic and structural analysis results, and performance tests of transducers in an extreme environment. The measurement system designed in this paper will be utilized for the APR1400 RVI CVAP as part of the first construction project in Korea.

• Nuclear Engineering and Technology
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• 제53권1호
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• pp.178-187
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• 2021

Dual-cooled annular fuel allows a significant increase in power density while maintaining or improving safety margins. However, the dual-cooled design brings much higher Zircaloy charge in reactor core, which could cause a great threaten of hydrogen explosion during severe accidents. Hence, an innovative fuel combined dual-cooled annular geometry and SiC cladding was proposed for the first time in this study. Capabilities of fuel design and behavior simulation were developed for this new fuel by the upgrade of FROBA-ANNULAR code. Considering characteristics of both SiC cladding and dual-cooled annular geometry, the basic fuel design was proposed and preliminary proved to be feasible. After that, a design optimization study was conducted, and the optimal values of as-fabricated plenum pressure and gas gap sizes were obtained. Finally, the performance simulation of the new fuel was carried out with the full consideration of realistic operation conditions. Results indicate that in addition to possessing advantages of both dual-cooled annular fuel and accident tolerant cladding at the same time, this innovative fuel could overcome the brittle failure issue of SiC induced by pellet-cladding interaction.

• Journal of Microbiology and Biotechnology
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• 제3권1호
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• pp.39-45
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• 1993

The effect of concentrations of phosphate buffer and acrylonitrile, pH, and various salts on the operational stability of the immobilized cells of Brevibacterium CH2 in a packed bed reactor were investigated. The effects of salts and carriers on the swelling of the immobilized beads during hydrolysis in a columnreactor were also investigated. Immobilization of the cells in Ba-alginate was more desirable than those in polyacrylamide and Ca-alinate for the swelling of the immobilized beads and the desired quality of the acrylamide produced. High quality acrylamide was produced using the Ba-alginate beads in a recycle fed-batch reactor without using an isotonic substrate. The conversion yield was nearly 100％, including a trace amount of acrylic acid produced as a by-product.

• Nuclear Engineering and Technology
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• 제31권6호
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• pp.1-7
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• 1999

An innovative concept for a passive reactor shutdown system, so called self-actuated shutdown system(SASS), is inevitably required for the inherent safety in liquid metal reactor, which is designed with the totally different concept from the usual reactor shutdown system in LWR. SASS using Curie point electromagnet(CPEM) was selected as the passive reactor shutdown system for KALIMER (Korea Advanced Liquid MEtal Reactor). A mock-up of the SASS was designed, fabricated and tested. From the test it was confirmed that the mockup was self-actuated at the Curie point of the temperature sensing material used in the mockup. An articulated control rod was also fabricated and assembled with the CPEM to confirm that the control rod can be inserted into core even when the control rod guide tube is deformed due to earthquake. The operability of SASS in the actual sodium environment should be confirmed in the future. All the design and test data will be applied to the KALIMER design.

• International Journal of Safety
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• 제10권2호
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• pp.1-5
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• 2011

The structural integrity assessment of APR1400 (Advanced Power Reactor 1400) reactor vessel internals has been being performed referring the US Nuclear Regulatory Commission regulatory guide 1.20 comprehensive vibration assessment program prior to commercial operation. The program is composed of a hydraulic and structural analysis, a vibration measurement, and an inspection. This paper describes the hydraulic and structural analysis on the reactor vessel internals due to hydraulic loads caused by the turbulence of reactor coolant. Three-dimensional models were built for the hydraulic and structural analysis and then hydraulic loads and structural responses were predicted for five analysis cases with CFX and ANSYS respectively. The structural responses show that the APR1400 reactor vessel internals have sufficient structural integrity in comparison with the acceptance criteria.

• Nuclear Engineering and Technology
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• 제56권9호
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• pp.3585-3593
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• 2024

Radioisotopes tend to play important roles in many fields, such as industry, healthcare, agriculture, aerospace, etc. Radioisotope production is mainly through accelerators or research reactors, and high flux research reactor is one of the most effective approaches for radioisotope production. The physical basis of preparing radioisotope relies on nuclear reactions occurring in the reactor core, which includes fission, (n,γ), (n,α), and (n,p) reaction, etc. Among them, fission and (n,γ) reaction are most important in the nuclear reactor. For example, the ⁹⁹Mo could be generated by uranium fission and extracting from the fission products, or through the radiative capture reaction from enriched ⁹⁸Mo. As for the fission method, the irradiation target is gradually transitioning from high enriched uranium (HEU) target to low enriched uranium (LEU) target due to the requirement of non-proliferation. In this paper, studies on the impacts of different fission targets on radioisotope productions are conducted. Moreover, an optimized study on the radiative capture method is performed to improve the production efficiency. It is concluded that it is advantageous to use radiative capture method to generate radioisotopes in high flux reactor, which helps to improve the specific activity with environmental friendliness.

• Nuclear Engineering and Technology
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• 제56권5호
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• pp.1574-1583
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• 2024

Small Modular Reactors (SMRs) are compact nuclear reactors designed to generate electric power up to 300 MWe. They could be assembled in factory, and then transported to be directly installed on-stie. CAREM (Central Argentina de Elementos Modulares) is a national SMR development project, based on light water reactor technology supervised by Argentina's National Atomic Energy Commission (CNEA). It is a natural circulation-based SMR with an indirect-cycle, including specific items and parts that simplify the design and improve safety performance. In this paper, the thermal-hydraulic study of CAREM-25 advanced small modular reactor is conducted by using COBRA-EN modified code and the Porous Media Approach (PMA) for the first time. According to PMA approach, each fuel assembly is modeled and divided into a network of lumped regions. While complex geometries are defined, the thermal-hydraulic parameters such as temperature and density are calculated for coolant and fuel rods. The obtained results show that the temperature in the fuel center may reach a peak around 1280 K in the hottest fuel assembly. Finally, the comparison of results from both methods (modified COBRA-EN and PMA) presented an appropriate consistency.