ANALYSIS OF ZIRCALOY REWETTING EXPERIMENTS AND THEIR IMPLICATION FOR REACTOR FUEL
This report describes the analysis of single tube rewetting experiments in the REFLEX rig. The primary aim was to apply the Grenoble k-2 rewetting model to study rewetting of Zircaloy tubes with controlled oxide layers up to 75 mum thick and develop a correlation of the parameter k-2 and assess the implication of these experiments to reactor fuel. In the absence of a two-dimensional conduction code at Winfrith containing the k-2 heat flux boundary condition, three existing codes, TRAC-PD2, QUENCH and REWET were modified to incorporate such a boundary condition, the first being a transient code and the others a quasi-steady-state. Due to the limited range of the conditions in the Zircaloy series, the earlier inconel data were first analyzed, but it was found that the Grenoble correlation for k-2 was unable to predict the data particularly at the lower powers and subcoolings. A new correlation has therefore been developed which involves the rewetting temperature as well as the system variables pressure, mass flow rate and subcooling at the quench front. The codes have also been used to study the effect of gas- gap and oxide layers on PWR fuel pin rewetting, showing that oxide should have a similar effect to that demonstrated in the REFLEX Zircaloy tube experiment.
Bibliographic Reference: EUR 10077 EN (1985) FS, 74 P., BFR 300, EUROFFICE, LUXEMBOURG, POB 1003
Availability: Can be ordered online
Record Number: 1989123121500 / Last updated on: 1987-01-01
Available languages: en