Validation of CATHENA Against the CS28-1 High Temperature Experiment Under an Impaired Cooling Condition

The loss of cooling flow to the fuel channel in CANDU reactor can result in high fuel temperatures and low steamflowrates over extended periods of time. Under these conditions, high temperatures can increase the quantity of fission products releasedfrom the fuel, and the production of large quantities of hydrogen gas, and eventually may cause failure of pressure tuhe. The CHAN-llA code has been designed to simulate rhe behaviour of the CANDU fuel channel under these extreme conditions and validated against the CS28·j expuiments. Howelʹer, the code over-estimates fuel temperature transient and hydrogen production. It is observed that subchannel model and simple radiation model ill fuel rings would contribute to under-estimation of heat removal in fuel channel. The CATHENA code, whiGh-has been developed for the analysis of two-phase flow and heat transfer in piping network and fuel channel, sliow.\" the good agreement with the CS28-1 experimental data.