INVESTIGATION OF EFFECT PRODUCED BY FLUID TRANSVERSE FLOWS BETWEEN VVER FUEL ASSEMBLIES TO CONSERVATISM OF THERMAL-HYDRAULIC ANALYSIS IN A CONSISTENT SOLUTION OF NEUTRONIC AND THERMAL-HYDRAULIC TASKS
24th Symposium of AER on VVER Reactor Physics and Reactor Safety (2014, Sochi, Russia)
Advances in spectral and core calculation methods
Abstract
INVESTIGATION OF EFFECT PRODUCED BY FLUID TRANSVERSE FLOWS BETWEEN VVER FUEL ASSEMBLIES TO CONSERVATISM OF THERMAL-HYDRAULIC ANALYSIS IN A CONSISTENT SOLUTION OF NEUTRONIC AND THERMAL-HYDRAULIC TASKS
Shumskiy B.E., Kotsarev A.V., Lizorkin M.P. NRC “Kurchatov Institute”, Moscow, Russia
ABSTRACT
The report describes the agreed three-dimensional neutronic and thermal-hydraulic models of calculation of the VVER reactor core for software complexes NOSTRA and TRETON and complex ATHLET/BIPR-VVER. Using these models, studies the influence of transverse flow of fluid between the FA on the thermo physical parameters (temperature of coolant, of fuel, of fuel rod cladding, departure from nucleate boiling) used in the analysis of thermal reliability and safety of operation of fuel rod. The results of the calculation of thermal-hydraulic parameters obtained in the framework of the in-channel and three- dimensional models of the VVER-1000 core are compared.
When the agreed three-dimensional thermo-hydraulic and neutron-physical calculations of processes in the VVER core with fuel assemblies without covers the effect of feedbacks can rebuild the field of energy release adversely in relation to the characteristics of thermal reliability. This leads to the fact that the results of the thermo physical parameters calculation obtained using the three-dimensional model of heat hydraulics are more conservative in relation to the results of in-channel models. The effect of the coolant flow rate value through the core to the difference between the results of the in-channel and three-dimensional calculation also are studied.