SIMULATIONS OF THE EBR-Ⅱ TESTS SHRT-17 AND SHRT-45R

摘要

A four-year International Atomic Energy Agency coordinated research project is currently being performed on two EBR-Ⅱ Shutdown Heat Removal Tests. The goal of this project is to improve design and simulation capabilities in fast reactor thermal hydraulics, neutronics, plant dynamics, and safety analyses through benchmark analysis of the protected and unprotected loss of flow tests, SHRT-17 and SHRT-45R. Argonne is both the lead technical organization and a benchmark participant in the modeling and simulation work. In its role as a participant, Argonne has continued to develop a model of EBR-Ⅱ with the fast reactor safety analysis code SAS4A/SASSYS-1. Recent model analysis has focused on improving agreement with the recorded temperatures and flows. Improvements in flow rate predictions were achieved through adjustments to pump speed models and locked rotor loss coefficients. Examination and reinterpretation of several key temperature measurements resulted in much improved agreement between model results and recorded data for temperatures in the upper plenum and at the Z-Pipe inlet. Several of the model predictions, such as the IHX temperatures and flow rate through the reflector and blanket subassemblies, still disagree with the measured test data. These discrepancies may be due to uncertainties in the measurements at low-flow conditions or phenomena that cannot be captured by the model and will be the focus of future analysis.