A review of the calculation results obtained in 2008–2020, using the creep energy theory (CET) criterion (CET-criterion) of fuel element cladding failure, is given and the contradicting concepts of the fourth strength criterion (SC4) ingressed in the normative system of VVER fuel element acceptance criteria developed by A.A. Bochvar High-technology Research Institute of Inorganic Materials and the CET-criterion are compared. It is shown that the SC4 criterion is not applicable to the strongly nonlinear process of cladding damage parameter accumulation, it does not allow us to take into account the true and exact fuel loading history, SC4 neglects the main physical mechanism of cladding damage parameter accumulation, and it has practically uncertain limiting components. As the calculation model of the normative cladding damage parameter is uncertain, the SC4 criterion cannot be used for nuclear fuel performance optimization. In order to overcome the principal shortcomings of the SC4 criterion, the CET-criterion of cladding failure is proposed and its synergic concept is explained. An example of using the CET-criterion for prediction of cladding failures and nuclear fuel optimization is described.

使用 燃料元件包壳破坏的蠕变能量理论（CET）准则（CET-准则），回顾了2008-2020年获得的计算结果，并在规范中引入了与第四强度准则（SC4）相矛盾的概念AA Bochvar无机材料高科技研究所开发的VVER燃料元件验收标准系统和CET标准 比较。结果表明，SC4准则不适用于包层损伤参数累积的强非线性过程，它不能让我们考虑真实和精确的燃料加载历史，SC4忽略了包层损伤参数累积的主要物理机制，并且它实际上具有不确定的限制成分。由于标准包层损伤参数的计算模型不确定，因此SC4标准不能用于核燃料性能优化。为了克服SC4准则的主要缺陷，提出了包层破坏的CET准则，并解释了其协同概念。描述了使用CET准则预测包壳故障和核燃料优化的示例。