Road map

Nuclear industry codes have been emerged in the 1960s accomplished with the computers and simulation technologies. The road map of nuclear codes follows the routine from simplicity to complexity, starts from lamped parameter method of system analysis codes to detailed three-dimensional computational fluid dynamics (CFD) codes, evolves from conservative assumption to best estimate, and gradually results in more precise theory models and numerical methods. Initially, the system analysis codes applied the one-dimensional best estimate method in simulating nuclear system and fuel behavior to help safety analysis in reactor design. Furthermore, the subchannel models improve the simulation accuracy in a more detailed way. The CFD methods also have been applied to some phenomena such as coolant mixing, boron dilution, and thermal stratification which the previous codes cannot handle with. To compromise the calculation cost, multiscale coupled codes and platforms have become prior research interest in recent years. In contrast to traditional methods, as artificial intelligence and supercomputer technology rise, the new methods, including projection-based particle method, lattice Boltzmann method, artificial neural network, and temporal data mining, have emerged into the stage of nuclear codes. In the following chapter, the abovementioned codes and methods will be described in detail to present the development and characteristics of nuclear codes in past decades.