Advances in neutronics and radiological protection of HiPER 4a

The HiPER project, phase 4a, is evolving. In this study we present the progress made in the field of neutronics and radiological protection for an integrated design of the facility. In the current model, we take into account the optical systems inside the target bay, as well as the remote handling requirements and related infrastructure, together with different shields. The last reference irradiation scenario, consisting of 20 MJ of neutron yields, 5 yields per burst, one burst every week and 30 years of expected lifetime is considered for this study. We have performed a characterization of the dose rates behavior in the facility, both during operation and between bursts. The dose rates are computed for workers, regarding to maintenance and handling, and also for optical systems, regarding to damage. Furthermore, we have performed a waste management assessment of all the components inside the target bay. Results indicate that remote maintenance is mandatory in some areas. The small beam penetrations in the shields are responsible for some high doses in some specific locations. With regards to optics, the residual doses are as high as prompt doses. It is found that the whole target bay may be fully managed as a waste in 30 years by recycling and/or clearance, with no need for burial.

► We have performed an overview of the radiological response of the facility in burst operation, period between bursts and decommissioning.
► The facility is divided in three areas, from the least to the most exposed: area 1, 2 and 3.
► During the operation, entrance is forbidden in area 1 and 2. The pinholes are responsible for the dose rates in area 2.
► Between burst, entrance is forbidden inside the chamber and in area 1.
► All the components of the facility can undergo clearance or manual maintenance within 30 years after the final shutdown.