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The human factor in licensing and operating the next generation of nuclear plants
As human factors specialists working at the intersection of human performance and nuclear operations, we are witnessing one of the nuclear sector’s most significant transitions in decades. The emergence of small modular reactors, microreactors, and other advanced designs is reshaping the industry’s landscape. Digital instrumentation and controls, passive safety systems, and increased automation are creating opportunities for greater safety margins and more flexible operation. These same features also fundamentally redefine what it means to “operate” a nuclear plant. Interactions among human roles, automation, and passive systems shape how people maintain awareness, exercise judgment, and intervene when necessary. These developments affect both operational realities and the regulatory foundations on which nuclear safety is built.
Yassin A. Hassan, Hagop R. Barsamian
Nuclear Technology | Volume 128 | Number 1 | October 1999 | Pages 58-74
Technical Paper | Thermal Hydraulics | doi.org/10.13182/NT99-A3014
Articles are hosted by Taylor and Francis Online.
The dynamic subgrid-scale (DSGS) closure model is used in a large eddy simulation computer program for incompressible isothermal flows. One of the advantages of the DSGS model is the exclusion of a model coefficient. This model coefficient is evaluated dynamically at each nodal location for a given time step by filtering operations on the grid level and a test filter level. A nonstaggered array tube bundle geometry arrangement is considered in doubly periodic boundary conditions for two-dimensional simulations at high Reynolds number. Results of the DSGS simulation are obtained in the form of power spectral densities and visualization of flow characteristics. The DSGS model simulation results are compared to the Smagorinsky eddy viscosity model simulation and available experimental data. The DSGS model simulation is found to be in good agreement with spectral data available from experiments in similar bundle arrangements. Coherent eddy structures were observed. Body forces acting on the tubes showed satisfactory characteristics. Integral length and timescales are evaluated using correlation functions that describe the turbulence structure. The applicability of large eddy simulation to complex engineering flow situations has been shown using the DSGS model with applications to steam generator bundles for understanding of flow-induced vibration problems revealing the physical phenomena of the flow.