  Transport calculations for neutronic design require accurate nuclear data and
validated computational tools. In the Spallation Physics Group, at the European
Spallation Source, we perform shielding and neutron beam calculations to help
the deployment of the instrument suite for the current high brilliance (top)
moderator, as well for the design of the high intensity bottom moderator,
currently under study for the facility. This work includes providing the best
available nuclear data in addition to improving models and tools when
necessary. In this paper we present the status of these activities, which
include a set of thermal scattering kernels for moderator, reflector, and
structural materials, the development of new kernels for beryllium considering
crystallite size effects, nanodiamonds, liquid hydrogen and deuterium based on
path integral molecular dynamics, and the use of the software package NCrystal
to assist the development of nuclear data in the framework of the new HighNESS
project.
