Feasibility study of validating activation corrosion products calculations in cooling water loops at JET

Abstract

This paper presents the feasibility study for verifying the possibility to host an experiment in JET, during a future D-T campaign to validate calculation tools for predicting formation and migration of Activated Corrosion Products, generated by corrosion of base metals, in cooling loops of fusion experiment devices such as ITER. It has been estimated that Activated Corrosion Products inventory generated in an experimental loop with the test section under the neutron flux in a region close to the JET Vacuum Vessel, with the expected D-T campaign neutron fluence, were sufficient to produce a related measurable level in the ion exchange resin of that loop. A solution envisaged for hosting this loop is using vertical ports at the bottom of JET and its surrounding area. A general sketch of main elements required for constructing such a loop was drawn.The relevance for ITER is linked to its licensing, as the ACP radioactive inventory assessment has a two-fold relevance: 1) evaluating the mobilisable radioactive inventory in case of accidents and 2) assessing an important source of direct decay gamma irradiation to staff operating during routine maintenance. The envisaged loop in JET should include the most important materials in the ITER Primary Heat Transfer System loops (copper alloys and stainless steels).