BISON is a finite-element based, multidimensional fuel performance code developed at Idaho National Laboratory. In this paper, we present BISON modeling developments for Zircaloy nuclear fuel cladding behavior under loss-of-coolant accident (LOCA) conditions and code validation to separate-effects experiments. Code developments include models for cladding high-temperature creep, crystallographic phase transition, high-temperature steam oxidation and failure due to burst. Code validation is performed against a substantial number of experimental tests for ballooning and burst behavior of Zircaloy claddings under LOCA conditions. Validation calculations are completed using 2D axisymmetric models. Additionally, we present a 3D calculation that demonstrates simulation of the cladding response in presence of azimuthal temperature variations. Calculated results are systematically compared to experimental data of cladding temperature, inner pressure and time at burst failure. Several of the presented BISON validation cases were developed in the framework of the IAEA Coordinated Research Project FUMAC. BISON modeling developments for UO₂ fuel behavior under LOCA conditions and code validation to integral fuel rod experiments are presented in a complementary paper.

BISON是爱达荷州国家实验室开发的基于有限元素的多维燃油性能代码。在本文中，我们介绍了在失水事故（LOCA）条件下Zircaloy核燃料包壳行为的BISON建模开发以及对单独效果实验的代码验证。代码开发包括熔覆高温蠕变，结晶相变，高温蒸汽氧化和破裂引起的失效的模型。针对LOCA条件下Zircaloy覆层的膨胀和破裂行为的大量实验测试，进行了代码验证。验证计算使用2D轴对称模型完成。此外，我们提出了一个3D计算，该计算演示了在存在方位角温度变化的情况下对包层响应的仿真。系统将计算结果与破裂温度下的包层温度，内部压力和时间的实验数据进行了比较。在国际原子能机构协调研究项目FUMAC的框架下，开发了几种提出的BISON验证案例。针对UO的BISON建模开发₂在补充文件中介绍了LOCA条件下的燃料行为和对整体燃料棒实验的代码验证。