Share device of China Nuclear Power Technology Research Institute (CNPRI)

3.1 IVR (2D In-Vessel Retention Test Facility)

The two-dimensional IVR test facility was built to investigate theExternal Vessel Cooling (ERVC) of the lower plenum of RPV in order to achieve in-vessel melt retention, and avoid the molten corium melting through the RPV and fission products leaking out to the containment. Tests are conducted on the facility to study on the critical heat flux (CHF) along the outer wall of RPV, optimization and verification of the flow channel, the characteristics of two-phase flow in different flow conditions, the effect of coolant additives on CHF, etc. Test data are of great significance for the mechanical research and engineering application of Reactor Pit Flooding System.
The test facility has following technical parameters:
·         Scaling: 1:1
·         The height of circulation: 7.64m.
·         Circulation Mode: natural or forced circulation.
·         Test section: two dimensional slice (150mm width).
·         Heating sections: 24 independent pcs.
·         Maximum heating power: >1.2MW.
·         Maximum heat flux: 2.4MW/m2.

3.2 COTHYD (Containment Of Thermal-hydraulic and HYdrogen Distribution)

COTHYD test facility is built to study the containment thermal hydraulics behavior and the hydrogen risk in PWR containment during severe accidents (SA). COTHYD is under construction, and it will come into service by the mid of 2015. There are two main objectives for the facility: a) to understand the physics of gas mixing and distribution in confined geometries during SA and b) to provide high quality data for validation of codes.

Main characteristics of the facilities are:
·         1/8 scale containment to a typical HL-1000 with a diameter of 5.625m, a height of about 10m (a sump including) and a total volume of 180 m3. The design temperature of the facility is 200 °C, and the design pressure is 0.6MPa;
·         The containment is equipped with rock wool for isolation and the vertical wall is divided into three independent temperature regulation zones.The temperature controller is outside the containment;
·         The injection gases include helium (simulating the hydrogen) and steam. The flow rate is constant and dependent on the sonic nozzles. The steam injection range is 5g/s~500g/s, and the helium injection range is 1g/s~70 g/s;
·         Simple compartment can be placed inside the containment. And there are mitigation device simulators, such as spray system and PARs (only simulate a heat source);
·         The temperature and concentration of the gases can be acquired by thermocouples and mass spectrometerat more than 100 measure points in the free space. Additionally more than 200 thermocouples are fixed on the wall;
·         There are 20 windows on the containment wall for PIV and LDV measurement. The windows are designed in 5 altitudes, and each altitude has 4 windows. One can get the velocity filed information either in the center or near the wall.

3.3 FUSAM (Fuel building Severe Accident Mitigation research)

The facility is mainly used for the research of air natural circulation in the spent fuel building and hydrogen mixing and distribution characteristics in the cases of coolant loss accidents. It is aimed to develop and validate safety measures to enhance natural circulation cooling capacity and mitigate hydrogen explosion risk.The facility is under construction, and it will come into service in the middle of 2015.
The test section is designed in 1:8 scaleto the CPR1000’s spent fuel building. Itconsistsmainly of two regular cuboid boxes, simulating the upper building space and the spent fuel pool. Both are fabricated from stainless steel. The upper space has a size of about 3.6m in length, 1.9m in width and 2.4m in height, and the pool has a size of 1m in length, 1.58m in width and 1.5m in depth. Electrical heaters with a total power of 30kW standing in the pool simulates the spent fuel assemblies with decay heat. A group of solid cone spray nozzles can spread (water or air) with a total flow rate of 5L/min hang on the building roof just above the pool. Nozzles are spaced evenly to ensure the spray cover the whole pool.
The facility is equipped with a (Whole name of QMS) (QMS) to measure the concentration of different components of the mixing gases with up to 80 sampling lines. A (whole name of PIV) (PIV) system is applied to acquire the flow field in the building space.