Thermal-hydraulic Fluctuations in Trillo NPP with CTF/PARCSv2.7 Coupled Code

Autores UPV
Año
CONGRESO Thermal-hydraulic Fluctuations in Trillo NPP with CTF/PARCSv2.7 Coupled Code

Abstract

The low frequency noise is a phenomenon observed in some PWR reactors causing an influence on the normal operational behavior of the power plant. Fluctuations in the neutron flux density, in the low frequency range up to 4Hz, generate noise in the neutron instrumentation (in-core and ex-core neutron detectors) that could affect to the limitation and protection system of the reactor core, even it can activate a scram signal due to high neutron flux. This activity is included as a complementary study of our ongoing efforts in the study of the neutronic noise in the PWR reactor cores and their associated instrumentation. In this project, a deep analysis of the behaviour of a PWR reactor core has been carried out when a set of inlet thermal-hydraulic perturbations are applied. A set of inlet mass flow perturbations have been simulated with the CTF/PARCSv2.7 coupled code, which provides 3D results in both termal-hydraulics and neutronics. The cross sections have been obtained using the SIMTAB methodology and the signal of incore and excore neutron detectors are directly extracted from PARCS through modifications incorporated in the code.