Thermal Hydraulic Test Facility

ORNL small-break LOCA tests Experimental investigation of heat transfer and reflood analysis was made under conditions similar to those expected in a small-break LOCA. These tests were performed in a large, high-pressure, electrically heated test loop of the ORNL Thermal Hydraulic Test Facility. The analysis utilized a heat transfer model that accounts for forced convection and thermal radiation to steam. The results consist of a high-pressure, high-temperature database of experimental heat transfer coefficients and local fluid conditions. 

A fundamental design of Large Scale Thermal Hydraulic Test Facility was completed. 

Energy to develop the MASLWR design and conduct initial safety testing and code benchmarks has recently been completed. A 1/3-height and 1/254.7 thermal-hydraulic test facility capable of full system pressure and temperature been constructed and successfully operated at OSU. The test facility is capable 600 kW, which represents the full-scale MASLWR power density. REALP5 the test data have been performed by INEEL. 

Various transients and accidents were analyzed for the SMART basic design with the computer code developed by KAERI, and the results confirm that safety is ensured with sufficient margins in any postulated transient and accident. The integral effect tests to evaluate the computer code used for safety and performance analysis of SMART is underway at a high temperature and high-pressure thermal hydraulic test facility of 1 96 scale. Figure 5 shows the thermal hydraulic test facility for integral effect tests. 

FIG. 5. Thermal hydraulic test facility for integral effect tests. 

High temperature, high-pressure integrated system thermal-hydraulic test facility... 

Eoh, J.H., et al., 2013. Design features of a large-scale sodium thermal-hydraulic test facility STELLA. In Internal Conference on East Reactors and Related Euel Cycles (FR13), Paris, France. 

In Fig. 1, some European test facilities capable to perform thermal-hydraulic tests with passive safety systems are shown. It is evident that the wide spread of power and pressures will allow the testing of the same component in several facilities of different size and thus increasing the confidence in the assessment of the effectiveness of this component. It has to be mentioned that the PANDA test facility has a larger volume than the other test facilities. 

FIG. 1. European test facilities to perform thermal-hydraulic tests with passive safety systems. 

The NOKO test facility located at the Institute for Safety Research and Reactor Technology of the Research Center Julich is a thermal hydraulic test rig, which was constructed within the framework of a research task in a joint project of the Research Center Julich (FZJ) and SIEMENS AG, Power Generation Division (KWU), with support from the German Federal Ministry of Education, Science, Research and Technology and German utilities. The facility is suited for a broad spectrum of experiments in the field of thermodynamics and fluid dynamics of water, water vapor and non-condensable gases. Different passive safety systems can be investigated with only minor modifications. 

JAEA conducted an improvement of the RELAP5 MOD3 code (US NRC, 1995), the system analysis code originally developed for LWR systems, to extend its applicability to VHTR systems (Takamatsu, 2004). Also, a chemistry model for the IS process was incorporated into the code to evaluate the dynamic characteristics of process heat exchangers in the IS process (Sato, 2007). The code covers reactor power behaviour, thermal-hydraulics of helium gases, thermal-hydraulics of the two-phase steam-water mixture, chemical reactions in the process heat exchangers and control system characteristics. Field equations consist of mass continuity, momentum conservation and energy conservation with a two-fluid model and reactor power is calculated by point reactor kinetics equations. The code was validated by the experimental data obtained by the HTTR operations and mock-up test facility (Takamatsu, 2004 Ohashi, 2006). 

The CAREM reactor under development in Argentina is a 100 MW(th) (about 27 MW(e)) design based on natural circulation. It has an integrated primary circuit comprising the core, steam generators, control rods with their drive mechanisms and the entire primary coolant. Several experiments examining core neutronics and thermal hydraulics have been conducted in test facilities. The construction of a prototype is planned. 

The Passive Containment Cooling System (PCC) prototype supplied by ENEL, has been tested at the Siet facility in Piacenza. The confirmation tiiat the design meets the thermal-hydraulic performance requirements for use in the GE-SBWR and is adequate to assure the structural integrity of the unit for the expected SBWR lifetime severe conditions, was reach. ... 

Vapor—aerosol interactions which are assumed to take place in the primary system were studied in detail in the British Falcon test facility. This facility, which is schematically shown in Fig. 7.19. (according to Beard et al., 1991), has been specifically designed to investigate the transport and deposition behavior of fission products under severe accident conditions. To produce representative aerosols, fuel pellets containing simulant fission products as well as trace-irradiated fuel pellets, both cladded in Zircaloy, were heated up to 2000 K in a steam—helium atmosphere in the presence of bulk-core materials. Fission product transport could be studied along a pathway which was designed to represent the upper plenum, hot-leg structures and containment. Considerable efforts were made to ensure that, as far as possible, the thermal-hydraulic conditions represented those of a selected accident. 

The AGT 5 is concerned with the thermal-hydraulics and mechanics of the core and core components. The contact forces between sub-assemblies distorted as a consequence of irradiation effects were investigated in the CHARDIS HI rig (Risley). The dynamic behaviour of core arrays during earthquakes was examined in the RAPSODBB test facility (Saclay). Flow patterns at the core outlet and between sub-assembly hexagonal wrapper tubes were simulated in the HIPPO test rig (Risley). 

Related to the Reactor Core Coolant System, modeling and qualification are boosted by the testing performed in a high pressure natural circulation rig (CAPCN), covering thermal hydraulics, reactor control and operating techniques. Several sets of experiments were conducted at nominal and ex-nominal conditions. The CAPCN facility may also test the second shutdown system and some in-vessel instrumentation probes. 

Krepper, E., Prasser, H.-M., 1999. Natural circulation experiments at the ISB-VVER integral test facility and calculations using the thermal-hydraulic code ATHLET. Nuclear Technology 128, 75-86. 

OECD NUCLEAR ENERGY AGENCY, N. Aksan, F. D Auria, H. Glaeser, R. Pochard, C. Richards, A. Sjoberg, Eds, A Separate Effects Test Matrix for Thermal-Hydraulic Code Validation Phenomena Characterization and Selection of Facilities and Tests -Vols. I and E, OECD/CSNI Rep. OCDE/GD (94) 82, Paris, 1993. 

Abstract Results from the four-year long heating phase of the Drift-Scale Heater Test at the Exploratory Studies Facility at Yucca Mountain, Nevada, provide a basis to evaluate conceptual and numerical models used to simulate thermal-hydrological coupled processes expected to occur at the proposed repository. A three-dimensional numerical model was built to perform the analyses. All model simulations were predicated on a dual (fracture and matrix) continuum conceptualization. A 20-percent reduction in the canister heat load to account for conduction and radiation heat loss through the bulkhead, a constant pressure boundary condition at the drift wall, and inclusion of the active fracture model to account for a reduction in the number of fractures that were hydraulically active provided the best agreement between model results and observed temperatures. The views expressed herein are preliminary and do not constitute a final judgment of the matter addressed or of the acceptability of its use in a license application... 

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