طراحي نوترونيك قلب يك راكتور هسته‌اي VVER-1000 همراه با ارزيابي ترموهيدروليكي كانال داغ با استفاده از سوخت مقاوم به حادثه و تحليل پايداري قلب.

Neutronic Design of VVER-1000 Reactor Core with Thermal – Hydraulic eva‎luation of the Hot Channel Using Accident – Tolerant Fuel an‎d Core Stability Analysis

مهندسي هسته‌اي

Severe nuclear accidents such as Fukushima an‎d Three Mile Islan‎d have highlighted the necessity of enhancing reactor safety an‎d operational stability. One of the most promising approaches is the development of Accident Tolerant Fuels (ATFs), designed to mitigate hydrogen generation, improve heat transfer, an‎d prevent fuel melting under accident conditions [1–5]. In this study, the neutronic design of a VVER-1000 reactor core employing accident-tolerant fuel an‎d cladding materials was performed, followed by a comprehensive thermohydraulic eva‎luation of the hot channel an‎d a dynamic stability analysis of the core. The neutronic modeling was carried out using the MCNPX code, while ANSYS Fluent was employed to calculate fuel, cladding, an‎d coolant temperature distributions, as well as key thermal parameters such as the heat transfer coefficient (h) an‎d MDNBR. The nonlinear dynamic response of the core was subsequently investigated using MATLAB/Simulink. The results indicate that UC-SiC fuel-cladding combination significantly improve heat transfer, reduce peak fuel temperature, an‎d enhance the safety margin against critical heat flux compared with conventional UO₂-Zr systems. Furthermore, stability analyses demonstrated a more stable dynamic response under transient conditions. Overall, the findings confirm that implementing ATF concepts in VVER-1000 reactors can effectively improve safety, thermal efficiency, an‎d dynamic stability of the core.

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