Facilities

Test facility was designed in such a way that it enables to conduct experiments at any inclination of the flow channel. Test facility will be also used for demonstrational and educational purposes. Transparency of the channel walls and the use of WMSs offer students great possibilities to get better understanding on the physics behind the flow behavior. Test section is equipped with in-house manufactured WMSs (32 × 32 wires). The sensors are recording the flow at 5000 frames/s. In addition, special channel section was designed and constructed that enables High-Speed Camera and PIV measurements by minimizing the optical distortions.

To study the behavior of the PCCS configuration planned to be used in the ABWR II concept and to gain experimental data for the validation work of MELCOR severe accident code, a scaled down PCCS model was designed and constructed at Lappeenranta University of Technology in Finland in 2012–2013. The PCCS model is connected to the drywell and wetwell compartments of PPOOLEX, which is acting as a host facility. Steam needed in the experiments is produced with the nearby PACTEL facility. The PCCS model consists of five horizontal U-tube shaped heat exchange tubes installed inside a secondary side liquid pool. The pool is in atmospheric pressure and covered by a lid with an exit pipe out of the laboratory and with viewing windows for video cameras.

The PPOOLEX facility consists of a pressure vessel containing a wet well compartment (condensation pool), dry well compartment, inlet plenum and air/steam line piping. An intermediate floor separates the compartments from each other but a route for gas/steam flow from the dry well to the wet well is created by a vertical blowdown pipe attached underneath the floor.

PACTEL is a volumetrically scaled (1: 305) facility including a pressurizer, high and low pressure emergency core cooling systems, and accumulators. The reactor vessel is simulated with a U-tube construction including separate downcomer and core sections. The core itself is consists 144 full-length, electrically heated fuel rod simulators. Component heights and relative elevations correspond to those of the full scale reactor to match the natural circulation gravitational heads in the reference system. Three coolant loops with double capacity steam generators are used to model six loops of the reference power plant. The facility is still in operation for example as an auxiliary system for the separate effect test facilities. Until now, 239 experiments have been carried out with the facility.

The PWR PACTEL facility consists of a reactor pressure vessel model, two loops with vertical steam generators, a pressurizer, and emergency core cooling systems. The new loops and steam generators of EPR style construction enable the PWR and EPR related experimental research. The pressure vessel model in PWR PACTEL comprises a U-tube construction modeling the downcomer, lower plenum, core and upper plenum. The core rod bundle consists of 144 electrically heated fuel rod simulators arranged in three parallel channels. The core can be powered by a maximum of 1 MW electric power supply. The maximum core power corresponds roughly to the scaled residual heating power of the EPR reactor. The total height of the PWR PACTEL pressure vessel model corresponds to the pressure vessel height of EPR. The volume ratio between the pressure vessels in PWR PACTEL and EPR is about 1/405.

ARIGS is one of the programs on the aerosol retention on the tubes surrounding the breach within the secondary side of the steam generator in the absence of water. Its development has been internationally framed within the EU-SGTR and the ARTIST programs. Experimental activities were focused on setting up a reliable database in which the influence of gas mass flow rate, breach configuration and particle nature in the aerosol retention are properly considered. Theoretical activities are aimed at developing a predictive tool (ARISG) capable of assessing source term attenuation in the scenario with reasonable accuracy. Given the major importance of jet aerodynamics, 3D CFD analyses are being conducted to assist both test interpretation and model development.
ARISG-I was a step forward in the modeling of the aerosol retention of the steam generator. According to this analysis the main areas where research is needed are: gas jet behavior across the tube bank; particle resuspension, erosion, and/or bouncing; and particle inertial impaction and turbulent deposition under foreseen conditions.

No description available.

Steam generator reliability and performance are serious concerns in the operation of pressurized water reactors. The aim of the SGTR project was to provide a database of fission product retention in steam generator tube rupture sequences and models, which could be applied to estimate the effectiveness of different accident management strategies in these kind of accidents.
The SGTR project made an important step forward to resolve uncertainties of physical models, especially in the aerosol deposition and mechanical resuspension in turbulent flows. There was one sampling at the injection line for the Optical Particle Counter (OPC) aimed at determining the aerosol size distribution and quantifying the mass concentration at the inlet. Within the vessel atmosphere eight samplings were taken to six filters and two cascade impactors, from which the mass concentration exiting the tube mini-bundle was estimated.
The test mini-bundle is a scaled mock-up of the first stage of the steam generator tube bundle. It consists of a squared arrangement housing inside a total of 117 tubes plus four supporting rods placed in the corners. The mini-bundle allows two possible locations of the broken tube. One place is just at the centre of the structure and the other place is three tubes away from the centre.