Contribution to the validation of the VVER-1000 Temelin NPP computing model for the ATHLET/DYN3D coupled codes

Abstract

Abstract This paper contains a description and evaluation of the thermal-hydraulic calculation of VVER-1000 transient connected with steam dump to atmosphere (SDA) opening during decreased reactor power to 20% of nominal power (Nnom). The calculation was performed with the thermal-hydraulic system program ATHLET coupled with the 3-D reactor dynamic code DYN3D. A comparison with the experiment was performed on the base of measured values during SDA project function test on the VVER-1000 Temelín NPP Unit 2. Results obtained from calculated vs. experimental values contribute to the validation of the ATHLET/DYN3D coupling.