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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.
Jae Jun Jeong, Dae Hyun Hwang, Bub Dong Chung
Nuclear Technology | Volume 156 | Number 3 | December 2006 | Pages 360-368
Technical Note | Thermal Hydraulics | doi.org/10.13182/NT06-A3797
Articles are hosted by Taylor and Francis Online.
MARS is a best-estimate system analysis code that is based on the RELAP5/MOD3 and COBRA-TF codes. The COBRA-TF code was adapted as a three-dimensional thermal-hydraulic module in MARS. It uses a two-fluid, three-field model for two-phase flows and has a subchannel flow mixing model. The subchannel flow mixing model of the MARS three-dimensional module was assessed by using the ISPRA 16-rod bundle test and the GE 9-rod bundle test data. These tests represent typical pressurized water reactor and boiling water reactor core thermal-hydraulic conditions, respectively. Two interconnected subchannel tests that were performed under atmospheric pressure conditions were also used for the assessment. From the results of the assessments, a simple modification of the subchannel flow mixing model was suggested to take into account the effects of the system pressure on the void drift phenomena.
