Neutronic analysis of IFMIF-DONES test cell cooling system

Abstract

IFMIF-DONES (International Fusion Materials Irradiation Facility - DEMO-Oriented Neutron Source) is an accelerator based d-Li neutron source currently under development within the framework of EUROfusion Power Plant and Technology (PPPT) programme. The purpose of the IFMIF-DONES device is to qualify promising materials for the future fusion technologies. The neutron source is designed to produce high energy neutron emission comparable to large scale nuclear fusion reactors running with deuterium and tritium fuel. Test Cell (TC) is a section of accelerator facility where material specimens are being irradiated. Neutron irradiation affects not only specimens, but also supporting structures and confinement that include steel liner and the water-cooled concrete walls. The neutron induced activation and subsequent decay heat generation of the cooling pipes needs to be assessed for the maintenance, decommissioning and waste management purposes and related safety analyses. This paper presents the analyses performed within the ENS (Early Neutron Source) project of EUROfusion/PPPT with an aim to provide up-to-date estimates of the activity inventories and the decay heat generation in the DONES TC facility shielding wall and pipes. A series of coupled MCNP particle transport and FISPACT inventory calculations were performed using the 2017 DONES TC model and nuclear cross-section data from the JEFF-3.1.2 data library. The paper discusses activation characteristics propagated by neutron irradiation in the biological shielding cooling system. Activities, decay heat, dose rates are presented as function of the decay time after irradiation.