The Experts below are selected from a list of 315 Experts worldwide ranked by ideXlab platform
Hyunsik Park - One of the best experts on this subject based on the ideXlab platform.
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comparison of three small break loss of coolant accident tests with different break locations using the System integrated modular advanced reactor integral test loop facility to estimate the Safety of the smart design
Nuclear Engineering and Technology, 2017Co-Authors: Hwang Bae, Sung Uk Ryu, Dong Eok Kim, Hyunsik ParkAbstract:Abstract Three small-break loss-of-coolant accident (SBLOCA) tests with Safety Injection pumps were carried out using the integral-effect test loop for SMART (System-integrated Modular Advanced ReacTor), i.e., the SMART-ITL facility. The types of break are a Safety Injection System line break, shutdown cooling System line break, and pressurizer Safety valve line break. The thermal–hydraulic phenomena show a traditional behavior to decrease the temperature and pressure whereas the local phenomena are slightly different during the early stage of the transient after a break simulation. A Safety Injection using a high-pressure pump effectively cools down and recovers the inventory of a reactor coolant System. The global trends show reproducible results for an SBLOCA scenario with three different break locations. It was confirmed that the Safety Injection System is robustly safe enough to protect from a core uncovery.
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Code validation on a passive Safety System test with the SMART-ITL facility
Journal of Nuclear Science and Technology, 2016Co-Authors: Byong Guk Jeon, Sung Uk Ryu, Hwang Bae, Yeon-sik Cho, Yeon-sik Kim, Jae-seung Suh, Hyunsik ParkAbstract:ABSTRACTA thermal-hydraulic integral effect test facility, SMART-ITL, was constructed to examine the System performance of SMART, a 330 MWt integral type reactor, and to provide data for validation of related thermal-hydraulic models in the System analysis codes. SMART is equipped with various passive Systems such as a passive residual heat removal System (PRHRS), a passive Safety Injection System (PSIS), and an automatic depressurization System (ADS). The PSIS of SMART is made up of four core makeup tanks (CMTs), four Safety Injection tanks (SITs), and related piping. Over 10 tests have been performed to investigate the behavior of a single train of a PSIS (a CMT and a SIT) in connection with PRHRSs and an ADS. Using a System analysis code, MARS-KS, we validated the experimental results for a representative test. All geometrical and thermal-hydraulic conditions of SMART-ITL were reflected in the code input construction. Through the validation process, several models, including a break flow model, heat tr...
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an experimental study on the thermal hydraulic phenomena in the hybrid Safety Injection tank using a separate effect test facility
Annals of Nuclear Energy, 2016Co-Authors: Sung Uk Ryu, Hyobong Ryu, Hyunsik ParkAbstract:Abstract This paper reports an experimental research for investigating thermal hydraulic phenomena of Hybrid Safety Injection Tank (Hybrid SIT) using a separate effect test facility in Korea Atomic Energy Research Institute (KAERI). The Hybrid SIT is a passive Safety Injection System that enables the Safety Injection water to be injected into the reactor pressure vessel throughout all operating pressures by connecting the top of the SIT and the pressurizer (PZR). The separate effect test (SET) facility of Hybrid SIT, which is designed based on the APR+ power plant, comprises a PZR, Hybrid SIT, pressure balancing line (PBL), Injection line (IL), nitrogen gas line, and refueling water tank (RWT). Furthermore, the pressure loss range of the SET facility was analyzed and compared with that of the reference nuclear power plant. In this research, a condition for balancing the pressure between the Hybrid SIT and PZR is examined and the effects of different variables affecting the pressure balancing, which are flow rate, Injection velocity of steam and initial water level, are also investigated. The condition for balancing the pressure between the Hybrid SIT and PZR was derived theoretically from a pressure network for the Hybrid SIT, pressurizer, and reactor pressure vessel. Additionally, a sensitivity analysis as a theoretical approach was conducted on the pressure variations in relation to the rate of steam condensation inside the Hybrid SIT. The results showed that pressure of the Hybrid SIT was predominantly determined by the rate of steam condensation. The results showed that if the rate of condensation increased or decreased by 10%, the Hybrid SIT pressure at the pressure balancing point decreased or increased roughly by 10%, respectively.
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an experimental investigation on thermal hydraulic interaction between core makeup tank and Safety Injection tank of an integral small reactor during a small break loss of coolant accident
ASME JSME KSME 2015 Joint Fluids Engineering Conference, 2015Co-Authors: Hwang Bae, Sung Uk Ryu, Hyobong Ryu, Woo Shik Kim, Hyunsik ParkAbstract:A passive Injection test was conducted using a core makeup tank (CMT), a Safety Injection tank (SIT) and an automatic depressurization System (ADS), which consists of a passive Safety System (PSS) of the SMART reactor. This paper investigates the thermal-hydraulic interaction between CMT and SIT during sequential Injections of coolant from these two tanks to a high-temperature and high-pressure reactor pressure vessel using an integral effect test facility of SMART-ITL (System-Integrated Modular Advanced ReacTor-Integral Test Loop). Both CMT and SIT were connected to the reactor pressure vessel by a pressure balance line (PBL) and Injection line (IL). A steady-state condition was maintained for 1,000 seconds before the start of the Injection. The major parameters agreed well with the target value. After one of Safety Injection System line was simulated to be broken, a transient Injection test was conducted according to the small-break loss-of-coolant accident (SBLOCA) scenario. Coolant Injections from a CMT and SIT were started sequentially by opening quick-opening valves installed on the IL and PBL piping, respectively. Several thermal-hydraulic phenomena such as direct contact condensation, thermal stratification, and coupling effects between the CMT and SIT were locally observed during the SBLOCA scenario. The results show that the adopted passive Safety Injection System functions well as an emergency core cooling System.Copyright © 2015 by KSME
P Vanini - One of the best experts on this subject based on the ideXlab platform.
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a single stage high pressure steam injector for next generation reactors test results and analysis
International Journal of Multiphase Flow, 1995Co-Authors: Gaia Cattadori, Luca Galbiati, Luigi Mazzocchi, P VaniniAbstract:Abstract Steam injectors can be used in advanced light water reactors (ALWRs) for high pressure makeup water supply; this solution seems to be very attractive because of the “passive” features of steam injectors, that would take advantage of the available energy from primary steam without the introduction of any rotating machinery. The reference application considered in this work is a high pressure Safety Injection System for a BWR; a water flow rate of about 60 kg/s to be delivered against primary pressures covering a quite wide range up to 9 MPa is required. Nevertheless, steam driven water injectors with similar characteristics could be used to satisfy the high pressure core coolant makeup requirements of next generation PWRs. With regard to BWR application, an instrumented steam injector prototype with a flow rate scaling factor of about 1:6 has been built and tested. The tested steam injector operates at a constant inlet water pressure (about 0.2 MPa) and inlet water temperature ranging from 15 to 37°C, with steam pressure ranging from 2.5 to 8.7 MPa, always fulfilling the discharge pressure target (10% higher than steam pressure). To achieve these results an original double-overflow flow rate-control/startup System has been developed.
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A single-stage high-pressure steam injector for the ALWR
Transactions of the American Nuclear Society, 1993Co-Authors: Gaia Cattadori, Luca Galbiati, Luigi Mazzocchi, P VaniniAbstract:Steam injectors can be used in advanced light water reactors (ALWRs) for high-pressure makeup water supply; this appears to be very attractive because of tile [open quotes]passive[close quotes] features of steam injectors, which take advantage of the available energy from primary steam without any rotating machinery. The reference application considered here is a high-pressure Safety Injection System for a boiling water reactor (BWR); a water flow rate of [approximately]60 kg/s must be delivered against primary pressures covering a wide range up to 9 MPa.
Sung Uk Ryu - One of the best experts on this subject based on the ideXlab platform.
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Estimation of pressure-equalizing time for a hybrid Safety Injection tank used in a passive Safety Injection System
Annals of Nuclear Energy, 2018Co-Authors: Jae Min Kim, Sung Uk Ryu, Myoung Jun Kim, Sang Hee KangAbstract:Abstract In this paper, a method for estimating the time required to reach the equalizing pressure between two tanks for a hybrid Safety Injection tank (SIT) System is proposed. The hybrid SIT allows a coolant Injection over a wide range of operating pressures without using active Systems such as a high-pressure pump. The pressure of the SIT can be equated to that of the reactor vessel through a pipe connected between the SIT and the pressurizer (PZR). Thus, the coolant is injected into the reactor vessel via the gravitational head of water. In this study, a zero-dimensional calculation with a simple approach was employed to estimate the pressure-equalizing time of the hybrid SIT. The real gas equation of state was used to estimate the time with mixture properties. The mass of the injected steam was calculated using the relationship between the pressure difference and mass. The results showed that the difference in the pressure-equalizing times is less than 5% compared to the test results. Accordingly, a guideline is proposed for the design of hybrid SITs for new nuclear power plants. Appropriate pipe loss coefficients for a pressure balancing line (PBL) were suggested for an integral effect test facility.
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comparison of three small break loss of coolant accident tests with different break locations using the System integrated modular advanced reactor integral test loop facility to estimate the Safety of the smart design
Nuclear Engineering and Technology, 2017Co-Authors: Hwang Bae, Sung Uk Ryu, Dong Eok Kim, Hyunsik ParkAbstract:Abstract Three small-break loss-of-coolant accident (SBLOCA) tests with Safety Injection pumps were carried out using the integral-effect test loop for SMART (System-integrated Modular Advanced ReacTor), i.e., the SMART-ITL facility. The types of break are a Safety Injection System line break, shutdown cooling System line break, and pressurizer Safety valve line break. The thermal–hydraulic phenomena show a traditional behavior to decrease the temperature and pressure whereas the local phenomena are slightly different during the early stage of the transient after a break simulation. A Safety Injection using a high-pressure pump effectively cools down and recovers the inventory of a reactor coolant System. The global trends show reproducible results for an SBLOCA scenario with three different break locations. It was confirmed that the Safety Injection System is robustly safe enough to protect from a core uncovery.
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Code validation on a passive Safety System test with the SMART-ITL facility
Journal of Nuclear Science and Technology, 2016Co-Authors: Byong Guk Jeon, Sung Uk Ryu, Hwang Bae, Yeon-sik Cho, Yeon-sik Kim, Jae-seung Suh, Hyunsik ParkAbstract:ABSTRACTA thermal-hydraulic integral effect test facility, SMART-ITL, was constructed to examine the System performance of SMART, a 330 MWt integral type reactor, and to provide data for validation of related thermal-hydraulic models in the System analysis codes. SMART is equipped with various passive Systems such as a passive residual heat removal System (PRHRS), a passive Safety Injection System (PSIS), and an automatic depressurization System (ADS). The PSIS of SMART is made up of four core makeup tanks (CMTs), four Safety Injection tanks (SITs), and related piping. Over 10 tests have been performed to investigate the behavior of a single train of a PSIS (a CMT and a SIT) in connection with PRHRSs and an ADS. Using a System analysis code, MARS-KS, we validated the experimental results for a representative test. All geometrical and thermal-hydraulic conditions of SMART-ITL were reflected in the code input construction. Through the validation process, several models, including a break flow model, heat tr...
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an experimental study on the thermal hydraulic phenomena in the hybrid Safety Injection tank using a separate effect test facility
Annals of Nuclear Energy, 2016Co-Authors: Sung Uk Ryu, Hyobong Ryu, Hyunsik ParkAbstract:Abstract This paper reports an experimental research for investigating thermal hydraulic phenomena of Hybrid Safety Injection Tank (Hybrid SIT) using a separate effect test facility in Korea Atomic Energy Research Institute (KAERI). The Hybrid SIT is a passive Safety Injection System that enables the Safety Injection water to be injected into the reactor pressure vessel throughout all operating pressures by connecting the top of the SIT and the pressurizer (PZR). The separate effect test (SET) facility of Hybrid SIT, which is designed based on the APR+ power plant, comprises a PZR, Hybrid SIT, pressure balancing line (PBL), Injection line (IL), nitrogen gas line, and refueling water tank (RWT). Furthermore, the pressure loss range of the SET facility was analyzed and compared with that of the reference nuclear power plant. In this research, a condition for balancing the pressure between the Hybrid SIT and PZR is examined and the effects of different variables affecting the pressure balancing, which are flow rate, Injection velocity of steam and initial water level, are also investigated. The condition for balancing the pressure between the Hybrid SIT and PZR was derived theoretically from a pressure network for the Hybrid SIT, pressurizer, and reactor pressure vessel. Additionally, a sensitivity analysis as a theoretical approach was conducted on the pressure variations in relation to the rate of steam condensation inside the Hybrid SIT. The results showed that pressure of the Hybrid SIT was predominantly determined by the rate of steam condensation. The results showed that if the rate of condensation increased or decreased by 10%, the Hybrid SIT pressure at the pressure balancing point decreased or increased roughly by 10%, respectively.
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an experimental investigation on thermal hydraulic interaction between core makeup tank and Safety Injection tank of an integral small reactor during a small break loss of coolant accident
ASME JSME KSME 2015 Joint Fluids Engineering Conference, 2015Co-Authors: Hwang Bae, Sung Uk Ryu, Hyobong Ryu, Woo Shik Kim, Hyunsik ParkAbstract:A passive Injection test was conducted using a core makeup tank (CMT), a Safety Injection tank (SIT) and an automatic depressurization System (ADS), which consists of a passive Safety System (PSS) of the SMART reactor. This paper investigates the thermal-hydraulic interaction between CMT and SIT during sequential Injections of coolant from these two tanks to a high-temperature and high-pressure reactor pressure vessel using an integral effect test facility of SMART-ITL (System-Integrated Modular Advanced ReacTor-Integral Test Loop). Both CMT and SIT were connected to the reactor pressure vessel by a pressure balance line (PBL) and Injection line (IL). A steady-state condition was maintained for 1,000 seconds before the start of the Injection. The major parameters agreed well with the target value. After one of Safety Injection System line was simulated to be broken, a transient Injection test was conducted according to the small-break loss-of-coolant accident (SBLOCA) scenario. Coolant Injections from a CMT and SIT were started sequentially by opening quick-opening valves installed on the IL and PBL piping, respectively. Several thermal-hydraulic phenomena such as direct contact condensation, thermal stratification, and coupling effects between the CMT and SIT were locally observed during the SBLOCA scenario. The results show that the adopted passive Safety Injection System functions well as an emergency core cooling System.Copyright © 2015 by KSME
Shin-yeol Park - One of the best experts on this subject based on the ideXlab platform.
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Multi-phased development of a real-time control System and its validation through real-time simulation
Proceedings of IEEE. IEEE Region 10 Conference. TENCON 99. 'Multimedia Technology for Asia-Pacific Information Infrastructure' (Cat. No.99CH37030), 1999Co-Authors: Yongwoo Park, Shin-yeol ParkAbstract:In this paper we describe a multi-phased development method for a real-time System based on the TMO (time-triggered message-triggered object) model and its validation by using the real-time simulation technique. Through multiple development phases, the System/subSystem model based on the TMO model is applied. In each phase, real-time simulation is performed to validate the model developed in the phase. In order to examine the effectiveness of our approach, we have applied the approach to the development of the SIS (Safety Injection System) simulator and it shows the same functionality and timing behaviors as the SIS simulator currently used in the KEPRI (Korea Electric Power Research Institute).
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COMPSAC - Time-triggered message-triggered object modeling of a distributed real-time control application for its real-time simulation
Proceedings 24th Annual International Computer Software and Applications Conference. COMPSAC2000, 1Co-Authors: Moon Hae Kim, Jung-guk Kim, Kyungdoo Kim, Myeong-soo Lee, Shin-yeol ParkAbstract:The time-triggered message-triggered object (TMO) has been devised as the basic component model for high level distributed real time programming as well as real time application System/subSystem design and modeling. One of the strengths of the TMO is its facilitation of multi-phased top-down modeling of real time distributed computing application Systems. TMO-structured models are capable of representing both a real time control System and its controlled facilities (composed of sensors, actuators, and monitored infrastructure) in a uniform fashion. Also, TMO-structured real time simulation models can be generated in attractively simple forms and they can be executed to enable examination of not only the logical accuracy of a real time control System being developed but also the correctness of its timing behavior. A case study of such simulation modeling has been conducted in the context of constructing a real time simulator of a real time control System called the Safety Injection System (SIS) which is a subSystem of a nuclear power plant. In the course of this case study, some tools that support efficient real time simulation have been developed. The refined modeling steps, the support tools developed, and the cost-effectiveness confirmed in the course of this case study are the main subjects discussed.
Gaia Cattadori - One of the best experts on this subject based on the ideXlab platform.
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a single stage high pressure steam injector for next generation reactors test results and analysis
International Journal of Multiphase Flow, 1995Co-Authors: Gaia Cattadori, Luca Galbiati, Luigi Mazzocchi, P VaniniAbstract:Abstract Steam injectors can be used in advanced light water reactors (ALWRs) for high pressure makeup water supply; this solution seems to be very attractive because of the “passive” features of steam injectors, that would take advantage of the available energy from primary steam without the introduction of any rotating machinery. The reference application considered in this work is a high pressure Safety Injection System for a BWR; a water flow rate of about 60 kg/s to be delivered against primary pressures covering a quite wide range up to 9 MPa is required. Nevertheless, steam driven water injectors with similar characteristics could be used to satisfy the high pressure core coolant makeup requirements of next generation PWRs. With regard to BWR application, an instrumented steam injector prototype with a flow rate scaling factor of about 1:6 has been built and tested. The tested steam injector operates at a constant inlet water pressure (about 0.2 MPa) and inlet water temperature ranging from 15 to 37°C, with steam pressure ranging from 2.5 to 8.7 MPa, always fulfilling the discharge pressure target (10% higher than steam pressure). To achieve these results an original double-overflow flow rate-control/startup System has been developed.
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A single-stage high-pressure steam injector for the ALWR
Transactions of the American Nuclear Society, 1993Co-Authors: Gaia Cattadori, Luca Galbiati, Luigi Mazzocchi, P VaniniAbstract:Steam injectors can be used in advanced light water reactors (ALWRs) for high-pressure makeup water supply; this appears to be very attractive because of tile [open quotes]passive[close quotes] features of steam injectors, which take advantage of the available energy from primary steam without any rotating machinery. The reference application considered here is a high-pressure Safety Injection System for a boiling water reactor (BWR); a water flow rate of [approximately]60 kg/s must be delivered against primary pressures covering a wide range up to 9 MPa.
