Analysis of Thermal Hydraulic Fluctuations in Trillo NPP With CTF/PARCS v. 2.7 Coupled Code

Abstract

The lowfrequency noises are fluctuations in the neutron flux density, in the lowfrequency range up to 4آ Hz, which generate noise in the neutron instrumentation and could affect the limitation and protection system of the reactor core. Some European pressurized water reactors (PWRs) experienced the effect of lowfrequency noise, opening a new research line for the verification of the neutronkinetics/thermalhydraulic coupled codes. A CTF/PARCS v. 2.7 simulation study to verify whether periodical fluctuations in the core inlet temperature could activate the core protection system has been done, obtaining the frequency spectrum of the power oscillation amplitudes.