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[en] Generation IV (Gen-IV) reactors aim a number of design goals including improved safety, sustainability, efficiency, cost, and proliferation resistance. A Sodium-cooled Fast Reactor (SFR) is one of Gen-IV reactors, and SFRs are in development progress for up to the commercialization level. One of key elements to fulfill Gen-IV goals is a refueling system. An efficient but reliable refueling method can make not only constructional but also operational costs low. But the design task of a refueling system, nevertheless, sees hurdles in order to satisfy all the design criteria due to a number of constraints such as opacity of sodium coolant, unique working environment in sodium and inert gas environment, a moving path across the pressure boundary, radiation risk, tight construction layout, and so forth. In this paper, we briefly review refueling components of the Prototype Gen-IV Sodium-cooled Fast Reactor (PGSFR), and its refueling system type. In this paper, the PGSFR refueling components were reviewed, and we discussed briefly about functions, benefits and disadvantages of the system.
[en] As the research and development environment has been changed recently, the necessity of the systematic R and D management has been raised. Up to present, R and D management has been performed on individual projects. However, the development of an integrated and systematic R and D management system has been requested for project with a 'The Long-term Gen IV SFR Draft Action Plan', which was established in December 2007. From these aspects, we developed the SFR R and D management system based on the enterprise project management (EPM) solution. The functional goal of the integrated R and D management system was set to check on the progress periodically, and modify a project, if necessary, through an effective management of activities, resources and schedule, etc. In addition, the production of reliable information of progress, performance and utilization of resources using this R and D management system could assist researchers in successfully accomplishing the R and D project
[en] Since late 1980s, power reactor innovative small module (PRISM) liquid-metal reactor has been developed in U.S., and Korea Advanced Liquid Metal Reactor (KALIMER) in Korea as a Sodium Fast Reactor (SFR). Recently, further elaborating is encouraged on the research and development program for Generation IV reactors, and in collaboration with other interested countries through the Generation IV International Forum (GIF). Korea also takes part in that program and plans to construct a demonstration reactor of SFR. In light of the development of SFRs in the midst of the licensing and safety basis primarily tailored to Light Water Reactors (LWRs), there is an urgent need to establish a new licensing and safety analysis framework that is reliably applicable to SFR. The insights from the Probabilistic Safety Assessment (PSA) tend to be increasingly used to improve the deterministic approaches. And, in the early 2000s U.S. NRC has developed Technology-Neutral Framework (TNF). TNF also has been criticized because the reliability of PSA in its design step is suspected and the conventional deterministic approach has played a successful role for the safety of LWR. The objective of this study is to derive technical insight from critical review of past safety analysis approach for a regulatory framework for safety analysis of SFR in the position of deterministic approach with partially adopting the strong points of risk-informed approach for TNF approach in future
[en] This study presents a R and D performance monitoring system that is applicable for managing the generation IV sodium-cooled fast reactor development. The prime goal of this system is to furnish project manager with reliable and accurate information of status of progress, performance and resource allocation, and attain traceability and visibility of project implementation for effective project management. In this study, the work breakdown structure, the related schedule and the expected outputs were established to derive the interfaces between projects and the above parameters was loaded PCs. The R and D performance monitoring system is composed of about 750 R and D activities within 'Development of Basic Key Technologies for Gen IV SFR' project in 2007. The Microsoft Project Professional software was used to monitor the progress, evaluate the results and analyze the resource distribution to activities
[en] It is important to guarantee a passive nuclear safety regarding enhanced negative reactivity by fragmenting the molten fuel. In the SFR, it has a strong point that the negative reactivity is immediately introduced when the metal fuel is melted by the UTOP or ULOP accident. These characteristics of the metal fuel can prevent from progressing in severe accidents such as core disruptive accidents (CDA). As key phenomena in the accidents, fuel-coolant interaction (FCI) phenomena have been studied over the last few decades. Especially, several previous researches focused on instability and fragmentation of a core melt jet in water. However, the studies showed too limited phenomena to fully understand. In the domestic SFR technology development, researches for severe accidents tend to lag behind ones of other countries. Or, South Korea has a very basic level of the research such as literature survey. Recently, the SAS4A code, which was developed at Argonne National Laboratory (ANL) for thermal-hydraulic and neutronic analyses of power and flow transients in liquid-metal-cooled nuclear reactors (LMRs), is still under development to consider for a metal fuel. The other countries carried out basic experiments for molten fuel and coolant interactions. However, in a high temperature condition, methods for analysis of structural interaction between molten fuel and fuel cladding are very limited. The ultimate objective of the study is to evaluate the possibility of recriticality accident induced by fuel-coolant interaction in the SFR adopting metal fuel. It is a key point to analyze the molten-fuel behavior based on the experimental results which show fuel-coolant interaction with the simulant materials. It is necessary to establish the test facility, to build database, and to develop physical models to understand the FCI phenomena in the SFR; molten fuel-coolant interaction as soon as the molten fuel is ejected to the sodium coolant channel and molten fuel-coolant interaction between the remaining sodium pool and the molten fuel dropped into the bottom plenum. The current study can be divided into two phases in progress. The first phase is to select the simulant material for simulating the FCI phenomena. In the phase, an application of the observed FCI phenomena to determine the design parameters to establish an integrated FCI facility for a SFR fuel assembly design is involved. Next, the second phase is to design the integrated FCI facility which simulates the sodium coolant channel and analyze behaviors of the molten fuel in accordance with controlling parameters which might be initial temperature, injection or an up-stream velocity and the pressure for the molten fuel and the sodium coolant