Determination of a non-measurable quantity using information from calculations and experimental measurements: application to the damage rate determination

This article presents a method dedicated to the determination of the best value of a required quantity which is estimated by calculation, using information closely related, obtained by measurements and calculations. This best value, called thereafter the “target”, is not measurable in most cases. DPA and high energy neutron fluence (typically higher than 1 MeV) involved in vessel surveillance programs, using measurements of dosimeters, are some examples of application of this methodology. This methodology is applied without spectrum adjustment, but the spectrum shape is implicitly taken into account. In this article, an example is presented based on the FLUOLE-2 experimental program, which is developed and conducted by CEA. Neutron information is derived from a set of different kinds of neutron dosimeters. The objective is to estimate the best value of reaction rate values for each kind of dosimeters. All calculations are carried out using TRIPOLI-4 3D pointwise Monte Carlo code, and DARWIN/PEPIN2 depletion code.