A Proposed Framework for an Integration of an Experimental Apparatus to a Computational Model of a Whole Nuclear Power Plant Model for Online Feedback

摘要

Coupling is achieved by choosing the stream generator as a connecting point and transferring heat flux and surface temperature between LabVIEW and RELAP5. Interface manager software has been developed to control two codes and to handle the data transfer between them. The manager invokes RELAP call, LabVIEW call, write and read test files subroutines in a correct sequence. In order to reach synchronization, RELAP5 is used as the interface manager and it needs to pass LabVIEW time step. At each time step, RELAP writes heat flux into a test file, passes time advancement to LabVIEW, invokes LabVIEW dynamic link library to compute new time surface temperatures, and uses temperature values to calculate heat flux going into LabVIEW. RELAP performs this procedure at an advancement to avoid losing date due to de-synchronization. A simplified one loop pressure water reactor model is used to test steady state. Results show that data is successfully transferred between two codes. Comparing steam generator heat structure surface temperatures at steady state condition, LabVIEW gives comparable results; the percentage difference of heat is about 1.2%. RELAP5 also returns reasonable heat flux values to LabVIEW. Coupling code gives about 1.0% difference in heat flux values during steady state simulation. A more complicated model is used to test a transient event - Loss of Coolant Accident (LOCA). Test is done with a four-loop typical Pressure Water Reactor (PWR) model. One of four loops simulates a small break at primary piping system; the other three loops are coalesced together and modeled as one intact loop. Comparing steam generator heat structure surface temperatures during transient, LabVIEW gives comparable results; the percentage difference of surface temperature is less than 1.6%. Coupling code also correctly predicts the steam generator heat flux behavior during LOCA transient event. Eventually, this coupling will allow to integrate an experimental apparatus for a component in the secondary coolant loop to the whole model of a nuclear power plant since LabVIEW (used in the coupling) has specific modules to connect experimental sensors to computational module.