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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.
Michitsugu Mori
Nuclear Technology | Volume 121 | Number 3 | March 1998 | Pages 260-274
Technical Paper | RETRAN | doi.org/10.13182/NT98-A2838
Articles are hosted by Taylor and Francis Online.
The benchmarking and qualification analyses of RETRAN-03 (RETRAN-3D) for boiling water reactor (BWR) stability analyses were carried out by comparison with the frequency-domain stability analysis code NUFREQ-NPT with the stability test data of the Peach Bottom Unit 2. The sensitivities of model parameters were studied in terms of the type of equation model, vapor-liquid interface heat transfer coefficient in upper downcomer, method of characteristics (MOC) model, proportionality constant in the pressure change mass transfer term, and nodalization of a core for the turbine trip test analyses. The sensitivity studies of the model parameters to the decay ratio in stability analyses were performed on the number of core channels, type of equation model, nodalization of a core, perturbation type of disturbance, slip model, proportionality constant in the pressure change mass transfer term, Courant number, MOC model, and kinetics model. The models were selected for the turbine trip tests analyses and for stability tests analyses, based on the sensitivity studies. The model used to analyze stability in RETRAN-03 adopted the five-equations with the MOC, and two-channel models for the core heating region divided into 40 nodes despite 24 nodes used for the turbine trip test analyses. The validation of the model was confirmed by the analyses of the turbine trip tests of the Peach Bottom Unit-2. The stability analyses with the test data and the benchmarking of RETRAN-03 compared with the frequency-domain stability analysis code NUFREQ-NPT in BWR stability exhibit verification and validation within the applicable limitation of the code.
