Missile Probability Analysis of Welding Nuclear Turbine Rotor

In this paper, a 1000MW nuclear turbine LP welded rotor was analyzed to assure the missile safety of the turbine, which is required by the Nuclear Regulatory Commission (NRC). Finite element analysis method was used to estimate the stress level of the rotor. Stress corrosion cracking (SCC) was considered as the main reason of the rotor failure. The probabilistic method was used to assess the missile safety of the turbine rotor. The high speed turbine rotor is one of the key components of the turbine-generator system which was related closely to the safety and economy of the Power Plant’s operation. In this paper the rotor design & analysis process for the Shanghai Turbine Plant’s nuclear 1000MW power station is described. The operation of the turbine rotors of the nuclear power plant suffered from the severe stresses because of high temperature and high speed during start-up, shutdown and load changes. The moisture steam environment due to the low nuclear steam temperature also increase the probability of the fatigue failure of the turbine rotor. The integrity of the turbine rotor was threatened by the material deterioration caused by fatigue and moisture corrosion of the rotor at some critical locations. The fatigue mechanisms of the turbine rotor are described. Key factors that influence missile probability are discussed. Rotor damage due to SCC is discussed and analyzed to evaluate the probability of the nuclear turbine rotor.