Time response measurements of Angra I nuclear power plant using direct and indirect methodologies

Estimation of sensor response characteristics is necessary to satisfy requirements on allowable response time for nuclear power plants. The methodology currently used includes direct and indirect measurements each of them having its vantages and disadvantages. The objective of this work is to compare the time response measurements of temperature and pressure sensors of the Brazilian Angra I nuclear power plant obtained using direct and indirect methodologies. Direct methods give more precise results, but need special equipment do be carried out and interfere with the reactor operation. Indirect methodology is most practical of being performed; it does not interfere with the reactor operation because the sensors do not have to be out of operation. On the other hand, since the parameter identification depends on the noise characteristics, there are cases where indirect methodology is not suitable to predict time response. (author)