Particle losses in storage rings occur due to a variety of processes, including lifetime scattering, injection losses and beam trips. Six collimators will be installed in the Diamond-II storage ring to provide protection for sensitive machine components. As a result of the losses, electromagnetic showers of various secondary particles will be generated downstream of the collimators. These can potentially damage components, including by causing demagnetization of the permanent-magnet (PM) blocks in the longitudinal variable-bends (DL). This paper presents modelling of the likely neutron fluence impacting the PM blocks. The results reveal that even after 30 years of Diamond-II operation, the neutron dose is expected to be well below the demagnetization limit.