NEUTRONIC AND THERMAL-HYDRAULIC ANALYSIS OF SMART 330 MW(T) NUCLEAR REACTOR USING SRAC AND ANSYS FLUENT CODES WITH JENDL 3.3 AND JENDL 4.0 NUCLEAR DATA LIBRARIES AT THE SUB-CHANNELS OF 3X3 FUEL ASSEMBLY

• Main Author: Usman, Jakaria
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/75325
• Institution: Institut Teknologi Bandung

The SMART reactor is a modular reactor being developed by South Korea's KAERI with an output of 330 MW(t) or 90 MW(e). In this research, a neutronic and thermal-hydraulic analysis was carried out. Neutronic calculations were carried out starting from the cell, fuel assembly (FA) and core levels using SRAC with nuclear data libraries JENDL 3.3 and 4.0. As for the thermal-hydraulic analysis, calculations were carried out on a 3 x 3 fuel rod matrix using CFD ANSYS Fluent with the input parameter in the form of power density obtained from CITATION SRAC calculations. At the fuel cell level, enrichment variations of 2.82%, 3.25% and 4.95% were carried out. At the FA level, 3 types of variations (A, B and C) were carried out with the FA composition consisting of 4.95% enriched, Gd2O3 – UO2 rods and Shim Rods (Al2O3 – B4C). Meanwhile, for the core level, the SMART reactor manufacturer design was used which consisted of 57 FA. From the neutronic results it was found that with an enrichment of 4.95% and the arrangement of the FA and the reactor core model of the SMART reactor manufacturer, it was technically able to maintain criticality for 990 EFPD (3 years of operation) with an initial operating k-eff of 1.1539 and a reactor reactivity of 0.13. Then the power density of each FA A, B and C using the CITATION module was obtained sequentially, namely: 28,853 watts/cc, 67,805 watts/cc and 164,225 watts/cc. Forward, from the power density value obtained, it will be used as a volumetric heat source input in Ansys Fluent. In the thermal-hydraulic analysis, the k-omega SST turbulent flow model will be used with a fluid flow rate of 1.12 kg/s. So that the velocity of the fluid entering the inlet is 1.41336 m/s and the velocity of the fluid leaving the outlet ranges from 0.746436 m/s to 1.80131m/s, where the maximum velocity is in the sub-channel. The speed of this turbulent flow is strongly influenced by the viscosity stress, fluid friction stress, and several physical parameters such as Reynolds number, Nusselt, Prandtls, viscosity and diffusivity. Furthermore, from the Fluent results, the fuel, cladding and cooling fluid temperatures will be obtained for each type of input power density at a 3x3 FA size. In the model simulated in this study using k-omega SST fluid flow, there is a temperature increase in the subchannel of 31,234 oC and an increase in fluid temperature on the inlet - outlet side between 28,813 oC - 41,442 oC. the amount of increase in sub-channels and coolant obtained is still within the safety level and design of the SMART reactor itself. In addition, the fluid temperature from the results of this study is still below the saturation temperature of water at a pressure of 15 MPa (342.24 oC). So that the fluid does not sustain boiling as is characteristic of the PWR type reactor. In addition, the cladding temperature is also in the range where ZrH2 is relatively not formed in the Zr-4 cladding at high temperatures (< 500 oC), which greatly affects the life and safety of the reactor during operation.