THE USE OF REALISTIC CODES IN SOLVING THE PROBLEMS OF ANALYSIS OF REACTOR SAFETY
24th Symposium of AER on VVER Reactor Physics and Reactor Safety (2014, Sochi, Russia)
Reactor dynamics and safety analysis
Abstract
THE USE OF REALISTIC CODES
IN SOLVING THE PROBLEMS OF ANALYSIS OF REACTOR SAFETY
Semenovich O.V., Shaparau V.A., JIPNR‒Sosny of NASB, Belarus
ABSTRACT
System thermohydraulic codes ‒ software systems, designed for the simulation parameters of the coolant throughout the reactor facility. The coolant in pressurized water reactors during normal modes is a single phase liquid. In emergencies the coolant boils, turning into a vapor-liquid mixture. In the coolant implemented various modes of flow and heat transfer. Correctly describe such processes can only simulating vapor-liquid mixture in the approximation of a separate phase flow. System codes in which the coolant is described in the approximation of a separate phase flow have been called ‒ best estimate codes. Number of modern best estimate codes is small: about a dozen families. Here, the “family code” ‒ code and its modifications. The authors used a version of the software package ATHLET ‒ ATHLET/Mod2.2 (Cycle-A).
The authors thank the GRS (Germany) for licensed code ATHLET/Mod2.2(Cycle A) and for providing data for computational experiments.
The results of numerical simulation of the blowdown scenarios at the BC V-213 test facility, which are models of the hermetic compartments of NPP confinement (VVER- 440/213) with a full-scale fragment of bubble condenser, and all major equipment necessary for the test facility operation and testing, were presented in the report. It was shown how im- portant in simulation of the experimental facility to take into consideration the fragments of the “clipped” devices, which are located up to closed valves and, therefore, are parts (even a dead end) of circuit.