Open AccessStudy of reactor plant disturbed cooling condition modes caused by the VVER reactor secondary circuit
Author(s) -
Vladimir Ivanovich Belozerov,
Evgenij Nikolaevich Bot’ko,
Mihail Mihajlovich Zhuk
Publication year - 2016
Publication title -
nuclear energy and technology
Language(s) - English
Resource type - Journals
ISSN - 2452-3038
DOI - 10.1016/j.nucet.2016.11.006
Subject(s) - vver , nuclear power plant , nuclear engineering , nuclear reactor , pressurized water reactor , nuclear power , engineering , reliability (semiconductor) , power (physics) , computer science , reliability engineering , mechanical engineering , physics , nuclear physics , quantum mechanics
Based on the equations of energy, mass and momentum conservation for the three-dimensional unsteady flow of the two-phase mixture, simulations were made of reactor plant disturbed cooling condition modes caused by the VVER secondary circuit using computer thermohydraulic codes. The use of computer codes to investigate these modes makes it possible to analyze transient and some emergency processes, without involving the industrial testing method; this helps create a basis for solving the problems of reliability, operational safety, and efficiency of nuclear power plants.A modern nuclear reactor is a complex system which cannot be investigated or calculated by using only simple theoretical models. Thermohydraulic calculations are an essential part of most of the design and technological developments in the nuclear power industry. Since the NPP conditions exclude the traditional technical way to check and specify the results and conclusions of an aprioristic analysis based on industrial testing, in some instances, it is possible to examine and predict the parameters of thermohydraulic processes in the reactor circulation circuit involving computer simulations.The primary objective of this work is to calculate and investigate reactor disturbed plant cooling condition modes caused by the VVER secondary circuit in order to determine whether the calculated parameters conform to the acceptance criteria established in the regulatory documents.Based on the RELAP-5, TRAC, and TRACE software codes, reactor plant cooling condition malfunction modes caused by the VVER-1000 secondary circuit were simulated and investigated. Experimental data on the mode with the turbine-generator stop valve closing are presented. The obtained dependences made it possible to determine the maximum values of pressure and temperature in the circulation circuit as well as estimate the Minimum Critical Heat Flux Ratio (MCHFR). It has been found that, if any of the initial events occurs, safety systems are activated according to the set points; transient processes are stabilized in time; and the Critical Heat Flux (CHF) limit is provided. Therefore, in the event of emergency associated with the considered modes, the reactor plant safety will be ensured