Articles techniques et présentations

Previous to the present work, a formal calculation was approved [1,2] to support the operation of the High Flux Isotope Reactor (HFIR) Horizontal Beam-Tube 1 of 4 (HB-1). The present calculation [3,4] repeats the previous work using COMSOL Multiphysics® software and extends the analysis to cover a broader range of coolant flow. In addition, this new calculation expands the analysis much further than the previous work to include (1) material properties as a function of temperature, (2) investigated available two-equation turbulence models, (3) investigated quadratic finite element basis functions, (4) included mesh-convergence studies, and (5) included a fully-coupled thermal-fluid-structure interaction due to the thermal expansion of the solid materials in the model. The analysis was performed at both normal power levels, and to address nuclear safety concerns, at extreme power levels. The purpose of the calculation was to allow the HB-1 system engineers to choose an extended operating range for the cooling water flow rate, and most importantly, assure that the aluminum components of HB-1 would not exceed a threshold temperature of 250 F [5] and cause undesirable changes in the temper properties of the aluminum components. And finally, in order to improve the analysis further, some additional recommendations are included for consideration.