Three-Dimensional Transport Correction in Fast Reactor Core Analysis

Three-dimensional (3-D) transport corrections for K_eff, control rod worths, neutron spectra and power distributions are calculated for the fast critical assemblies ZPPR-9, -10 and -13. The calculations are performed in 7 energy groups using the 3-D and 2-D transport codes TRITAC and TWOTRAN-II. The evaluated 3-D transport corrections are compared with those predicted by a 2-D RZ model and a combined XY, RZ and R model to assess the accuracy of these 2-D models. The RZ model yielded some errors in estimating the transport corrections to K_eff, control rod worths, neutron spectrum and power distribution, while the combined model predicted them with good accuracy.     

Calculation of the Anisotropic Diffusion Coefficient

The one-group anisotropic diffusion coefficient is calculated for slab and square lattice cells with use made of Benoist's formula. In utilizing the integral transport theory, only several collisions suffered by a neutron have hitherto been considered. In this paper, we adopt the integral theory and take into consideration the effect of an infinite number of collisions suffered by a neutron, this being made possible by solving simultaneous equations. Further, we consider the anisotropic scattering through the generalized first-flight collision probability. Then we estimate the fundamental and the additional terms in the Benoist formula for slab and square lattice cells.     

An overview of instrumentation and control systems of a Korea standard nuclear power plant: A signal interface standpoint

This paper presents an overview of instrumentation and control (I&C) systems of a pressurized water reactor (PWR) type nuclear power plant (NPP) in Korea. Yonggwang unit 3, which was constructed as a basis model for a Korea standard nuclear power plant (KSNP), is selected as an example for the presentation. This overview is derived from analyzing the I&C systems based on a top-down approach. The I&C systems consist of 30 systems. The 183 I&C cabinets are also analyzed and mapped to the systems. The overview is focused on an interface between the systems and the cabinets. This information will be used to understand the implementation of the I&C systems and to group the systems for an upgrade.