• steam generator (SG);
• condenser;
• deairator;
• high and low pressure reheaters (HPR and LPR);
• condensate and feedwater pumps.

       The test facility is designed and rated for the operational parameters and operating modes of the secondary circuit of a VVER-1000 NPP. The unique feature of the test facility is that it was designed and constructed to model all the major components of the secondary circuit of a VVER-1000 NPP certain scale.
       The active and heat-exchange components are made of standard structural materials used for the components of the secondary circuit of a VVER-1000 NPP. The design of the heat exchange equipment of the test facility allows for disassembling, inspection and replacement of the tubing.
       Besides that, the test facility is equipped with:

• water chemistry control and support systems (condensate treatment, corrective coolant processing system, deairator, SG blow-down system, etc.);
• system for collection and preparation of coolant samples from different points in the circuit;
• system for an automated chemical control system of coolant’s samples;
• cells for installation of detectors of measuring instrumentation, operated at high values of parameters (temperature and pressure);
• state of the art computer-aided system for collection and processing of information;
• instrumentation and controls for automated control of the installation and for maintaining the prescribed operation mode.

        Preparation of the coolant’s samples and automatic chemical control of those samples is carried out by means of systems of the preparation of samples and measurements developed at the JSC “EREC”. The detailed description of the preparation of samples and measurements is given in the issue “New developments and technological solutions for the NPPs”.
        The automated control system of the V-3 test facility consists of two subsystems: monitoring and control system for thermo-mechanical equipment (MCS TME) and monitoring and control system for water chemistry modes- MCS WCM test prototype.
       MCS TME is designed for remote and automated control of the thermo-mechanical equipment of the test facility. The MCS TME is based on the Teleperm ME software and hardware, it controls 193 actuators, and includes 107 measurement channels. The V-3 test facility is equipped with the instrumentation for measuring pressure, pressure differential, flow rate, level and temperature of the coolant.
       The MCS WCM (monitoring and control system for water chemistry made) test prototype is designed for testing the water chemistry control algorithms and its measurement, refinement of the methods for operative electrochemical monitoring of the water chemistry regime of the secondary circuit of the NPP with the VVER-1000.
       A chemical express-laboratory equipped with modern analytical chemistry instrumentation for water composition analysis is an integrated part of the test facility.

Main lines of experimental investigations

       The principles, underlying the design of the facility V-3 allow investigating a wide range of interrelated problems that cannot be solved at ordinary test facilitys. At the same time, during operation of industrial facilities it is difficult to obtain adequately «pure» information due to the interference of multiple operation-related factors; it might be unachievable when wide ranges of reagent concentrations are involved due to limitation of the water chemistry requirements and standards. Among many problems that can be solved on the V-3 test facility, the following are of the most current importance:

• reliability analysis of the PGV-1000 steam generator;
• pre-operational testing and refinement of the perspective and alternative water chemistry regimes;
• testing and refinement of the pre-shutdown conservation of the secondary circuit equipment;
• testing of the monitoring and control system of WCM in steady-state and transient conditions at MCS WCM test prototype;
• testing and refinement of the monitoring and control system components and expert systems;
• verification of the water chemistry mathematical models and control and measurement algorithms, both in the circuit as a whole and in its major components with future carrying over them to the real NPP

       The use of the V-3 test facility for solution of the problems above will contribute to the increase of the efficiency of the VVER-1000 NPPP process equipment, extension of its lifetime and increase of the load factor of the plants.

Results

       In 2004, «The Comprehensive Programme on Experimental Justification and Development of Recommendations for Ensuring Design Life Cycle of the Secondary Circuit Equipment and Units of Steam Generators of NPPs with VVER reactors (tests are performed at FSUE “EREC” at the V-3 test facility – full-scale model of the VVER NPP secondary circuit, at I&C-WC Testing Site) for 2004-2010» has been approved.
      The «Comprehensive Programme…» includes 4 sections as follows:

1. Updating of tools and methods of water chemistry monitoring, development of the automated water chemistry control system for the secondary circuit;
2. Updating of the technology for conduction of secondary circuit water chemistry to enhance VVER NPP reliability and safety;
3. Investigation of corrosion, erosion and mass transfer processes;
4. Updating of technology for washing and preservation of the secondary circuit equipment.

       The Programme was elaborated with consideration for suggestions of the following institutions: SRC RF-FEI, RC NRS, FSUE OKB «Gidropress», JSC VNIIAES, FSUE NITI, RCE «Centrenergo», RC KI, RPO TNIITMASH, FSUE SP-AEP, FSUE «GI VNIPIET», MEI (TU), FSUE TNIIKM «Prometei», IGEU.
       The Programme was approved by Concern «Ros­energoatom», DAE Minatom of RF, JSC «VNIIAES», FSUE NIPKII AEP, FSUE OKB «Gidropress», FSUE SP-AEP, FSUE NI AEP.
       In 2005 - 2006, in the context of the «Comprehensive Programme…» the following activities were performed under contract with concern «Rosenergoatom»:

• optimization of technological regimes and NPP equipment, VVER automated water chemistry monitoring system;
• performance of rig tests of NPP equipment in respect of development, certification and implementation of the high temperature corrosion monitoring system for VVER NPP secondary circuit, including instrument park and instrumentations;
• Technological algorithms of the top-level of the water chemistry monitoring and control system of the secondary circuit of NPP with the VVER-1000 reactor, including: 
  - Algorithms for identifying anomalies in the water chemistry; 
  - Algorithms for finding causes of violations of the water chemistry; 
  - Algorithm for the indirect determination of water chemistry parameters; 
  - Algorithms for ensuring the functioning of AWP (automatic working place) chemist - laboratore assistant (assayer).
  

• In the first mode the connection of the inside space of the SG model with the atmosphere was organized during the drainage. And then there was a natural cooling of the SG model.
• In the second mode after drainage a valve that situated on the bottom side of the frame was opened for the creation of ventilation inside spaces of the SG model. And then there was a natural cooling of the SG model.
• The third mode was carried out according to the scenario of the second mode, but in the presence of Fe3O4 on the inside surfaces of the SG model, including heat transfer tubes. 

       Results of "dry" conservation during different modes are shown below. 
       At present the work «Experimental investigations to verify codes according to calculations of non-uniformity of the vapor flow during the steam generation’s operation at high power» is carried out under the contract with OKB «Gidropress». Experimental data will be used for the verification of code STEG (STEam Generator), which developed by the JSC “EREC”. The code STEG is in an experimental and industrial exploitation in OKB «Gidropress».

Change of the relative air moisture in the frame of the SG-1000M model