A method for assessing 3D decay heat and temperature considering accurate distributions of the decay gamma fields

The decay heat has a strong impact in the design of the fusion facility due to its importance on safety, remote handling and waste management among others. For these applications, the energy deposition due to alpha and beta particles can be considered local, since the mean free path of these particles is small. On the contrary, the photons can travel longer distances affecting to the distribution of the heating, and consequently, on the temperature. Nowadays, most of the advanced tools dedicated to simulate accurate decay photon fields in fusion facilities do not estimate the decay heat, because alpha and beta heating is not coupled to photon heating. This article proposes a methodology, suitable to advanced mesh based R2S, which enables the estimation of the decay heat in each material with high spatial resolution. The aim to develop this methodology is to consider the accurate 3D decay photon field in the estimation of the decay heat. Furthermore, this methodology incorporates ELMER FEM code to calculate the temperature field taking into account the decay heat. This methodology was applied to a pre-conceptual DEMO blanket to quantify the importance of the photon transport in the estimation of the decay heat distribution as well as the temperature field.