“…Because of the economic losses and the operator's security, it becomes necessary to implement Monitoring and Diagnosis Systems (Maki and Loparo, 1997;Sydenham and Thorn, 1993;Clark, 1978;Echendu and Zhu, 1994). Many techniques using Artificial Intelligence have been used in Monitoring and Fault Diagnosis with the purpose to help the nuclear power plants operators, including the Fuzzy Logic (Goode, 1995), Artificial Neural Networks -ANN (Rovithakis et al, 2004;Samanta, 2004;Bueno, 2006;Bueno et al, 2010), the Group Method of Data Handling -GMDH (Bueno et al, 2011;Gonçalves, 2006), Genetic Algorithms -AG (Raymer et al, 2000;Rovithakis et al, 2004). The use of these techniques are justified because it is possible to model the process without using algebraic equations (Zupan et al, 1997), by using only a database which contains the plant information.…”