Advanced treatment of zircaloy cladding high-temperature oxidation in severe accident code calculations

Heat and Mass Transfer during Hydrogen Generation in an Array of Fuel Bars of a BWR Using a Periodic Unit Cell

“…According to Veshchunov et al [18], the oxide layer consists of two sublayers in the temperature range of 1800 K to 2650 K: the tetragonal phase outside and the cubic phase inside. Later, the best-fit correlations were made at high temperature T > 1800 K and verified the applicability to different of temperature transient based in its experiments [9] and also reported by Shi and Cao [10]. Then, the next equations can be applied to compute the K ox kinetics parameter for the superficial oxidation that is predominant in these phenomena:…”

“…Urbanic and Heidrick [14] correlation for mass gain rate have two turning points: at T = 1853 K and T = 1873 K, because the authors consider the tetragonal to cubic transition temperature as T = 1853 K. Meanwhile, Fichot et al [9] consider that the transition temperature is lower and at the beginning of the tetragonal to cubic transition T ≈ 1800 K oxidation behavior runs gently and rates increase smoothly. The oxidation rates calculated by Prater and Courtright [16] and Urbanic and Heidrick [14] agree with the best-fitted values and the errors are very small at T > 1900 K. Nevertheless, the values calculated by Prater et al [16] are better than other two correlations at T > 1900 K [10].…”

“…The chemical reaction of oxidation is very large exothermic, which determines the hydrogen rate generation and the cladding brittleness and degradation [9]. As the cladding material construction, Zircaloy-4 (Zry-4), oxidation process has been extensively studied for decades, whether in gaseous medium with air or oxygen or steam [1][2][3][4][8][9][10]. Those studies showed that Zry-4 oxidation by air has similarities with oxidation in steam due to the common reaction partner oxygen, and also important differences.…”

Analysis of Early Severe Accident Initiated by LBLOCA for Qinshan Phase II Nuclear Power Project

“…Both RELAP5/SCDAP and MELCOR codes adopt the temperature transition of oxidation rate, the only difference between these two codes is that they take different correlations for ZrO thickness and weight gain, due to Cathcart-Pawel correlations below 1853 K are adopted in RELAP5/SCDAP code because their expressions give the best fit to the pooled data and Urbanic-Heidrick correlations are taken in MELCOR code. Therefore, the Cathcart-Pawel correlations are adopted between 1000~1800 K and verified Volchek-Zvonarev "bestfitted" (Volchek et al, 2004;Fichot et al, 2004) correlations are taken above 1800 K in SAP.…”

Overview of high-temperature fuel behaviour with relevance to CANDU fuel

“…Large accident modelling codes [127][128][129] generally describe the Zircaloy oxidation process using parabolic corrosion rate theory developed from laboratory experiments [130][131][132][133][134][135][136]. For the parabolic rate law…”