Chain and Sprocket Analysis of Control Rod Drive Mechanism of HTGR Experimental Power Reactor

Abstract

High Temperature Gas Cooled Reactor (HTGR) is being developed through a national program called Non-Commercial Experimental Reactor (Reaktor Daya Eksperimental; RDE). One of most important system in controlling the reactor is Control Rod Drive Mechanism (CRDM). CRDM has ten control rods that working for controlling reactivity which is driven by a mechanism that uses chain and sprocket transmission. To assure that the chain and sprocket components will work properly for the designed life time, a stress analysis is importantly required. Therefore, this study has been conducted to determine the strength and stress of chain and sprocket made by Inconel 625 at operational temperature of 150-750°C using finite element method. The analysis results show that the chain and sprocket could hold up the maximum stress up to 409.51 MPa and 398.94 MPa, respectively. These stresses are still below the maximum allowable stresses Inconel 625, 517 MPa. Accordingly, the chain-sprocket using Inconel 625 alloy in the RDE design is safe to be applied up to temperature of 750°C.