The modeling of complex transients in Nuclear Power Plants remain a challenging topics for Best Estimate computational tools. Nowadays, such calculations are performed through the so called coupled code method, which consists in incorporating three-dimensional (3D) neutron modeling of reactor core into system codes. This technique is extensively used for simulating transients that involve core spatial asymmetric phenomena and strong feedback effects between core neutronics and reactor loop thermal-hydraulics. In this framework the Peach Bottom BWR 2 Turbine Trip test is considered since it involves a rapid (water hammer transient) pressure wave induced positive reactivity addition into the core. To perform a numerical simulation of such phenomenon a reference code case was run and an overall data comparison was carried out. The results show good agreements between the calculations and most of the significant global aspects observed experimentally. However, the test was revealed very sensitive to the feedback modeling and requires a tightly accurate simulation of the thermal-hydraulic and the cross sections parameters. For this purpose, sensitivity studies have been carried out in order to identify the most influent parameters that govern the transient behavior.
Analysis of the Peach Bottom BWR turbine trip pressure wave propagation and its effect on the kinetic core dynamics
D'AURIA, FRANCESCO SAVERIO
2004-01-01
Abstract
The modeling of complex transients in Nuclear Power Plants remain a challenging topics for Best Estimate computational tools. Nowadays, such calculations are performed through the so called coupled code method, which consists in incorporating three-dimensional (3D) neutron modeling of reactor core into system codes. This technique is extensively used for simulating transients that involve core spatial asymmetric phenomena and strong feedback effects between core neutronics and reactor loop thermal-hydraulics. In this framework the Peach Bottom BWR 2 Turbine Trip test is considered since it involves a rapid (water hammer transient) pressure wave induced positive reactivity addition into the core. To perform a numerical simulation of such phenomenon a reference code case was run and an overall data comparison was carried out. The results show good agreements between the calculations and most of the significant global aspects observed experimentally. However, the test was revealed very sensitive to the feedback modeling and requires a tightly accurate simulation of the thermal-hydraulic and the cross sections parameters. For this purpose, sensitivity studies have been carried out in order to identify the most influent parameters that govern the transient behavior.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
