Experimental demonstration of CHF in a simulated 54 rod bundle and validation of predictive models

CHF plays an important role in deciding the thermal margin of a reactor. Due to complex mechanism of CHF, an accurate model does not exist in the literature which would predict within the reasonable level of confidence. Full scale bundle data generated worldwide under reactor conditions are proprietary in nature. Moreover, CHF strongly depends on the geometry of the fuel cluster and it must be experimentally determined for a new cluster design like that of AHWR for licensing. These experiments are conducted on electrically heated Fuel Rod Cluster Simulator. However, for typical bundles used in reactors, the power requirement for such experiments is very high. The availability of such high power and complexity of associated process systems makes such experiments very expensive. In view of this, a new concept has been proposed for experiments which use symmetry sector (1/6^th) of the 54 rod bundle assembly. This reduces the cost and time involved for experiments significantly. Such a strategy of conducting rod bundle CHF with the proposed simplification has not been reported in the literature to the best of author's knowledge. The development of symmetry sector of rod bundle is a challenge in terms of the geometry simulation, pressure boundary penetrations of thermocouples for detection of CHF under the operating conditions of the rector