Missile Safety Analysis of Nuclear Steam Turbine

This paper introduced the basic turbine missile safety analysis process for the Shanghai Turbine Plant’s nuclear power station. The turbine-generator unit is not considered as part of a nuclear power plant’s safety related equipment, but there is still the possibility that a high-energy missile created by failure of the low-pressure turbine disks could penetrate the stationary barriers of the turbine (especially the last stage of the low-pressure turbine), and damage plant safety-related equipment. The failure mechanisms of the turbine failure that could hypothetically generate missiles were described. Rotor damage due to stress corrosion cracking with brittle fracture and ductile fracture and destructive over-speed protection control system failure were discussed as the main elements to evaluate the safety of the turbine unit. Rotor stress analysis using FEA was used to evaluate the strength of the turbine rotor. Key factors that influence fracture mechanisms were discussed. Crack initiation and growth to the critical size was estimated. The strike probability of the turbine missile was accessed to assure the safety of the nuclear safety related equipment from a steam turbine unit generated missile.