A Benchmark Test of CHF Test Facility in CIAE to Columbia University HTRF

Abstract Critical heat flux (CHF) is one of the most concerned thermal hydraulic phenomena in reactor design and safety analysis. As CHF involves complex two-phase flow heat transfer mechanism, and hasn’t been fully understood, the prediction of CHF mainly relies on CHF correlations obtained under limited experimental conditions. At present, CHF tests of a new type of PWR fuel assembly are being carried out on the Thermal-hydraulic Comprehensive Test Facility (TCTF) in China Institute of Atomic Energy (CIAE). In order to verify the reliability of the facility, testing method and measurements, a benchmark test has been performed on TCTF, which repeated the CHF test performed on the Heat Transfer Research Facility (HTRF) at Columbia University in the United States. The test section on TCTF was a 5 × 5 uniformly-heated rod bundle with spacer grids, and its sizes were the same as prototype. The range of test conditions covered the local pressure of 7.4∼16.8 MPa, the inlet mass flux of 1.0∼4.0 t/m2s, and the inlet temperature of 120∼266 °C. Verifications including the redundant measurements comparison, the repeatability of test data under the same thermal hydraulic parameters, the thermal balance verification and linearity of data were carried out to prove the reliability of the test data. And CHF test data comparison between TCTF test and HTRF test has been carried out. The comparation results showed that the deviation of the CHF values in TCTF test from HTRF test was within 6.6%, which indicated that the CHF tests in HTRF have been well repeated on TCTF. The benchmark test verified the accuracy and reliability of TCTF, testing methods and measurements, and TCTF can perform CHF tests to obtain reliable CHF data to evaluate the thermal-hydraulics performance of new PWR fuel assemblies.