CSR1000 single channel thermal hydraulic stability analysis using response matrix method

Highlights: •System response matrix method analyzes thermal-hydraulic stability of CSR1000. •Single channel analysis decouples neutronics from thermal-hydraulic analysis. •A modular code is presented to solve the system response matrix of CSR1000. •Stability is a function of system pressure, power, flow rate and number of nodes. •Inlet orifice plate can be designed to stabilize the reactor in steady operation. -- Abstract: To analyze the thermal-hydraulic stability of CSR1000 (a Chinese supercritical reactor), a Single Channel Thermal-Hydraulic Stability Analysis Code has been developed. This code follows the system response matrix method to determine the stability in time domain, by linearizing the perturbed conservation differential equations. The stability is represented as decay ratio, which is calculated axially at each node in the single channel. A parametric study is performed and it is found that system becomes stable by increasing mass flow rate and decreasing reactor power. The analysis becomes less sensitive for greater values of inlet orifice diameter ratios. The size of mesh has a great effect on the results of analysis. Increasing the system pressure also tends to stabilize the reactor. Using the results of this code, a method is devised to design and realize the concept of inlet orifice in CSR1000.