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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.
Ching-Hor Lee, Shi-Ping Teng
Nuclear Technology | Volume 101 | Number 1 | January 1993 | Pages 67-78
Technical Paper | Waste Management Special / Radioactive Waste Disposal | doi.org/10.13182/NT93-A34768
Articles are hosted by Taylor and Francis Online.
An analytical solution covering the entire range of sorption properties of rock has been derived for the migration of radionuclides along a discrete fracture in a porous rock matrix. The analysis takes into account the advective transport in the fracture, longitudinal hydrodynamic dispersion in the fracture, molecular diffusion from the fracture into the rock matrix, adsorption within the matrix, and the radioactive decay. For adsorption of radionuclide within the matrix, the effects of no sorption, linear nonequilibrium sorption, and linear equilibrium sorption are integrated into a generic transient analytical solution. Based on certain assumptions, the problem can be formulated into two coupled one-dimensional transport equations: one for the fracture and another for the porous matrix in a direction perpendicular to the fracture axis. The general solution is of a single semi-infinite integral form that can be evaluated by Gaussian quadrature. The results indicate that the assumption of equilibrium sorption within the rock results in underestimation of the concentration profile along the fracture in the early stages of migration. It is worth noting that the concentration profile of the nonequilibrium sorption case is slightly smaller than that of the equilibrium sorption case after a certain time. However, the profiles eventually approach the same value. It is also confirmed that the porosity of rock strongly affects radionuclide transport in a fracture.