An approach for evaluating the consequence of cyber attacks on nuclear power plants

Evaluating the effectiveness of cybersecurity measures implemented at a nuclear power plant requires an understanding of the types of attack that are possible and the consequences of those attacks. In this paper, a systematic approach to determining the system response to various cyber attack scenarios is described. Starting from the initial attack vector, the chain of events taking the plant from the initial state to a compromised state is constructed based on the type of components in the system and the method of attack. System response is evaluated using the standard thermal-hydraulics model of the plant. The paper demonstrates the approach by analyzing the low pressurizer pressure trip function of the reactor protection system and shows how an attack against plant network infrastructure can lead to a noticeable impact on the peak clad temperature following a small loss of coolant accident.