Application of THERP HCR model for valve overhaul in nuclear power plant

THERP (Technique for Human Error Rate Prediction) and HCR (Human Cognitive Reliability) are generally analytic methods in HEFA (Human factor event analysis). The two methods have their own features. THERP HCR is two method’s combination. After analysis the general overhaul steps of safety shell isolated valve in nuclear power plant, this paper utilize THERP HCR to calculate the error probability of every step and the valve overhaul. At the same time, the error probability of three levels including experts, common workers and novices is analyzed and compared.