For a CO 2 ingress accident into liquid sodium in a supercritical CO 2 power conversion system coupled with a sodium-cooled fast reactor, we investigated two major design issues: i) a wastage phenomenon in regard to structural damage adjacent to the leaking position, and ii) potential channel plugging due to the formation of a particulate reaction product. In order to understand the factors affecting the occurrence of these issues, two kinds of experiments were carried out: a wastage effect test and a self-plugging test. All experimental conditions were chosen to reasonably represent the normal operating conditions and realistic design parameters of the reference plant. The test results indicate the absence of wastage, which will not lead to additional tube ruptures and damage propagation. In the current experiment, the self-plugging of PCHE channels only took place under two limited conditions: i) the sodium temperature is over 500 C and ii) the equivalent diameter of the crack opening is less than 1.5 mm with a small leakage rate of far less than 1 g/s of CO 2 ingress.

No abstract

For a CO 2 ingress accident into liquid sodium in a supercritical CO 2 power conversion system coupled with a sodium-cooled fast reactor, we investigated two major design issues: i) a wastage phenomenon in regard to structural damage adjacent to the leaking position, and ii) potential channel plugging due to the formation of a particulate reaction product. In order to understand the factors affecting the occurrence of these issues, two kinds of experiments were carried out: a wastage effect test and a self-plugging test. All experimental conditions were chosen to reasonably represent the normal operating conditions and realistic design parameters of the reference plant. The test results indicate the absence of wastage, which will not lead to additional tube ruptures and damage propagation. In the current experiment, the self-plugging of PCHE channels only took place under two limited conditions: i) the sodium temperature is over 500 C and ii) the equivalent diameter of the crack opening is less than 1.5 mm with a small leakage rate of far less than 1 g/s of CO 2 ingress.

No abstract

This work will develop a 6 Degrees Of Freedom (DOF) precision aligner with a small size and a high resolution for the assembly of the micro-scale parts used in mobile electronics. The arrangement of actuators in the aligner is symmetrical, based on kinematic design. A VCM (Voice Coil Motor) actuator that is small and reliable will be applied to this aligner system. This paper presents the combination of two modules to form the mechanism for the 6-DOF precision aligner. The first is a stage that can control XY θZ motion, while the second can control Z motion, i.e. Z tilt motion. According to its specifications, it is expected to satisfy precision requirements. Several tests will be carried out to confirm the specifications with PID control.