Advanced accident tolerant cladding materials have brought up the potential to delay the deleterious consequences of loos of coolant accidents related to slowing down hydrogen formation from reaction of zirconium with steam in order to minimize the additional heat generation and improve fuel and cladding retention of fission products. The performance improvement offered by these advanced materials may expand the operating envelope of existing light water reactors. This paper examines the neutronic performance of the VVER-1000 light water reactor for the application of accident tolerant cladding in order to realize the endurance of severe accident conditions. This study includes a detailed analysis of the control rod worth, reactivity coefficient, fuel cycle length, and power distribution for three accident tolerant cladding candidates of Ferritic-based alloy (FeCrAl), silicon carbide (SiC), and chromium coating application on zirconium claddings (ZrCr). The analysis was performed using diffusion-based core code PARCS, and lattice physics code DRAGON, including a developed package for regeneration of cross-sections in PMAX format.

The reactor performance analysis indicates that the SiC cladding would have improved performance in terms of fuel cycle length, fuel and moderator temperature reactivity coefficients, and control rod worth. The cycle length would significantly decrease in magnitude for FeCeAl. Therefore, decreasing the cladding thickness by half and increasing the fuel enrichment by factor of 1.1875 made it possible to satisfy the required cycle length. A higher enrichment is also necessary for ZrCr cladding to increase the fuel burnup limits at nominal operating conditions.

先进的耐事故熔覆材料具有潜力，可以延缓与冷却剂事故相关的不良后果，这些冷却剂事故与减缓锆与蒸汽反应产生的氢形成有关，以最大程度地减少额外的热量生成并改善裂变产物的燃料和熔覆保留。这些先进材料提供的性能改进可能会扩大现有轻水反应堆的运行范围。本文研究了VVER-1000轻水反应堆在耐事故包壳方面的中子性能，以实现对严重事故条件的承受力。这项研究包括对控制杆价值，反应系数，燃料循环长度，铁素体基合金（FeCrAl），碳化硅（SiC）和铬覆层（ZrCr）上的铬涂层三个耐候性熔覆层的功率分布和功率分布。使用基于扩散的核心代码PARCS和晶格物理学代码DRAGON（包括用于PMAX格式的横截面再生的开发包）进行分析。

反应堆性能分析表明，SiC包层在燃料循环长度，燃料和慢化剂温度反应性系数以及控制棒价值方面将具有改善的性能。对于FeCeAl，循环长度将显着减小。因此，将包层厚度减小一半，并使燃料富集度增加1.1875倍，就可以满足所需的循环长度。ZrCr覆层还需要更高的浓缩度，以增加标称工况下的燃耗极限。