| Abstract: | A pebble-bed high temperature gas-cooled reactor AVR located at Jülich, West Germany has a modification plan to include a process heat loop. In the plan, half of the primary helium heated up to 950°C by the AVR core is supplied to the process heat loop. The helium flow of the process heat loop influences the flow of the AVR loop and vice versa. Consequently, flow instabilities and reverse flow in the modified plant may possibly happen. In the paper, a computer simulation is performed to investigate the dynamic behavior of the primary helium flow in the modified plant. At first, dynamic experiments conducted at the AVR plant are simulated in order to grasp the accuracy of the computer code. Then, the modified plant is simulated. As a result, the behavior of the primary flow is rather moderate against the disturbances which are expected under the normal plant operation. Further, the condition when the reverse flow appears is evaluated analytically by using a simplified flow network model. |
