Grounds of VVER-1000 fuel cladding life control

A VVER-1000 fuel element (FE) cladding failure estimation method based on creep energy theory (CET-method) is physically grounded. Using CET-method, the VVER-1000 regime and fuel design parameters that determine cladding failure conditions are found. It is shown that FE cladding rupture life at normal variable loading operation conditions can be controlled by an optimal assignment of coolant temperature regime and fuel assembly (FA) rearrangement algorithm. Using a FA rearrangement efficiency criterion, it is shown that CET-method allows us to create an automated program-technical complex making control of FE cladding durability and optimization of fuel rearrangements in VVER-1000.