Influence of Nuclear Power Plant Interface Complexity on Operator Performance: A Modeling Study

Abstract The main control room of the nuclear power plant is a complex human-machine tightly coupled system with frequent human-machine interactions, resulting in a high percentage of accidents/incidents due to operator factors. High temperature gas-cooled reactors adopt a multi-module design, with multiple reactor modules driving a single turbine. As a result, future high temperature gas cooled reactor - pebble-bed module nuclear power plants (HTR-PM) may require a single operator to monitor two or more nuclear steam supply system (NSSS), which may introduce new human factor safety issues. The rationality and ease of use of the human-machine interface (HMI) can reduce the cognitive load and the probability of error of the operator and ensure the safe operation of the nuclear power plant. In this paper, we conducted experiments on the HTR-PM600 simulator to simulate the main control room operator’s patrol task on two types of interfaces. And we simulate the cognitive behavior of operators in the above tasks based on the queuing network-model human processor (QN-MHP) method. The results of the simulations and experiments show that the QN-MHP method can well model the cognitive behavior of the nuclear power plant main control room operator. Moreover, the optimized HMI significantly reduces the operator’s task completion time and cognitive load, which proves that the QN-MHP method can support the optimization of HMI in nuclear power plants.