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The System-integrated Modular Advanced ReacTor (SMART) is a small modular integral-type reactor for the seawater desalination and small-scaled power generation under development in Korea. Although the SMART is innovative reactor with a sensible mixture of the proven technology and advanced design features aimed at enhanced safety, there is no valid prototype which can specify the structural dynamic characteristics of reactor internals. Thus, extensive research for the technology verification and standard design approval are in progress. One of them is to perform the dynamic characteristics identification of reactor internals. Especially, it is focused on the added mass effect caused by the fluid-structure interaction because the reactor internals is submerged in the reactor coolant. The extracted dynamic characteristics such as the natural frequencies and the vibratory mode shapes can be used as the basis on further dynamic analysis, for example, seismic analysis and a postulated pipe break analysis.Copyright © 2011 by ASME

The System-integrated Modular Advanced ReacTor (SMART) developed by KAERI includes components like a core, steam generators, coolant pumps, and a pressurizer inside the reactor vessel. Though the integrated structure improves the safety of the reactor, it can be excited by an earthquake and pump pulsations. It is important to identify dynamic characteristics of the reactor internals considering fluid-structure interaction caused by inner coolant for preventing damage from the excitations. Thus, the finite element model is constructed to identify dynamic characteristics and natural frequencies and mode shapes are extracted from this finite element model.Copyright © 2011 by ASME

In this study, the dynamic characteristics of a reactor coolant pump (RCP) which can be used for APR1400 nuclear power plant are investigated using an equivalent simplified solid model. An effective simplified solid mass model to preserve the behavior of the RCP is presented. The equivalent simplified solid model for the dynamic analysis is developed from the detailed FE model of RCP through iterative runs. The results show that the fundamental frequency of RCP resides around 11Hz in the bending mode.Copyright © 2011 by ASME

The present paper deals with the robust, accurate and efficient limiting strategy for discontinuous Galerkin methods for high speed compressible flow. The present limiting strategy is a continuous work of extending multi-dimensional limiting process (MLP), which has been successful in finite volume methods (FVM), into discontinuous Galerkin (DG) methods on triangular and tetrahedral meshes. Based on successful analyses and implementations of the MLP slope limiting in FVM, MLP is applicable into DG framework with the MLP-based troubled-cell marker and the MLP slope limiter. It is observed that the proposed approach yields outstanding performances in resolving non-compressive as well as compressive flow features.Copyright © 2011 by KSME

This paper presents a theoretical analysis for the hydroelastic vibration of a rectangular tank partially filled with an ideal liquid. The wet dynamic displacement of the tank is approximated by combining the orthogonal polynomials satisfying the simply supported boundary conditions, since the rectangular tank is composed of four rectangular plates. As the facing rectangular plates are geometrically identical, the vibration modes of the facing plates can be divided into two categories: symmetric modes and asymmetric modes with respect to the vertical centerlines of the plates. The liquid displacement potential satisfying the boundary conditions is derived and the wet dynamic modal functions of the four plates are expanded by the finite Fourier transformation for a compatibility requirement along the contacting surface between the tank and the liquid. The natural frequencies of the rectangular tank in the wet condition are calculated by using the Rayleigh-Ritz method. The proposed analytical method is verified by observing an excellent agreement with three-dimensional finite element analysis results.Copyright © 2010 by ASME

A procedure for generating preliminary homologous curves, which are used as an input for the safety analysis of SMART, was developed. A commercial code for the computational fluid dynamics was adopted as a tool for the procedure. To generate homologous curves, we define the homologous variables and construct a computational matrix. Computations were performed according to the matrix, and the results were compared and analyzed for the representative computational points among the matrix. A modification method to obtain the homologous curves from the results was suggested by using the similarity laws and the complete curves were generated. The curves were compared with available experimental data and the validity of the procedure was investigated.Copyright © 2004 by ASME

A new concept in implementing hydrogen embrittlement (HE) mitigation on nuclear piping materials was suggested by using electro-transport treatment. The electro-transport treatment can be applied to reduce HE susceptibility and thus make the material more resistant to hydrogen damage. To demonstrate the validation of the developed method, the effect of hydrogen on the tensile properties of SA-508 Grade 1A low alloy steel was investigated by slow strain rate test. Material characteristics were observed as a function of hydrogen charging condition and electro-transport treatment. Based on these experimental results, the electro-transport treatment was proposed as a potential method for mitigating the HE susceptibility to replace the conventional post-weld heat treatment.Copyright © 2004 by ASME

The performance prediction of SMART MCP was performed using a computational fluid dynamics code. A general capacity-head performance curve of MCP was obtained and it showed the typical type axial pump performance curve. When four MCPs operate in parallel and one of them stops while the others continue to operate, SMART is designed to operate with reduced power. A procedure for predicting the performance of this SMART operation mode was developed and verified with available experimental data. An analysis based on the developed procedure was performed for two cases; the impeller of stopped MCP is assumed to be fixed or free to rotate in the reverse direction. According to the results, 73% flow rate of normal operation enters the reactor core in the case of a fixed impeller. In the case of a free impeller, the flow rate entering the reactor core is 63.3%.Copyright © 2002 by ASME