Dynamic sensitivity analysis of a small lead cooled reactor during an unprotected transient overpower

A sensitivity analysis of a transient in small lead cooled reactor was performed using a point kinetics - lumped parameter model called BELLA. The transient in consideration was an unprotected transient overpower (UTOP). It was found that the most sensitive parameters were the gap between fuel and clad, the fuel conductivity and the Rehme correlation used to calculate the pressure drop across the reactor. Other moderately sensitive parameters were the fuel heat capacity, the lead heat capacity and all the reactivity feedback coefficients. In any case, the uncertainties never bring the reactor beyond safety limits. (author)