Experimental and analytical dynamic analysis of coolant channel and its internals of Indian 540 MWe PHWR reactor

The horizontal coolant channel is one of the important parts of primary heat transport system in PHWR type of reactors. There are in all 392 channels in the core of Indian 540 MWe reactor. Each channel houses 13 natural uranium fuel bundles and shielding and sealing plugs one each on either side of the channel. The heavy water coolant flows through the coolant channel and carry the nuclear heat to outside the core for steam generation and power production in the turbo-generator. India has commissioned one 540 MWe PHWR reactor in September 2005 and another similar unit will be in operation very shortly. For a complete dynamic study of the channel and its internals under the influence of high coolant flow, experimental and analytical study has been carried out. The operating life of a typical coolant channel typically range from 10 to 15 full power years. Towards the end of its operating life, its health monitoring becomes an important activity. Vibration diagnosis plays an important role as a tool for life management of coolant. A good correlation has been achieved between the results of experimental and analytical models. Through the study dynamic characteristics of the coolant channel under simulated loading condition, an attempt has been made to develop a diagnostics to monitor the health of the coolant channel over its operating life. Experimental study has been also carried out to characterize PHWR fuel vibration under different flow conditions. Such results are published for the first time.