The IAEA is launching a new 5-year Coordinated Research Project (CRP) to assemble, validate and distribute fundamental data relevant for nuclear fusion energy development. The CRP is expected to provide experimental and theoretical data of hydrogen permeation in fusion reactor wall materials and components.
A viable nuclear fusion reactor will be operated with a magnetically confined hydrogen plasma as its fuel. The energy is gained by fusing hydrogen isotopes, deuterium (D) and tritium (T). These fusion processes take place in the core of the plasma at temperatures of 100×106 K. The significantly cooler outer regions of the D-T plasma will be interacting with the reactor’s inner walls. The wall materials must therefore withstand heat and particle loads from the plasma.
It is important to know as much as possible about the behavior of these materials with respect to permeation of hydrogen isotopes in order to assess their suitability for containing and isolating the radioactive T fuel of a fusion reactor from the surrounding components. Of particular concern is the trapping and retention of the short-lived T inside the reactor wall materials, and the possibility of T diffusing through the material finding its way into the coolant water of the reactor components, where it would pose a potentially serious environmental hazard.
Although the precise mechanism is not understood, it is well-known that trapped hydrogen reduces the ductility of many materials, including steels, a phenomenon known as hydrogen embrittlement, or may even lead to hydrogen-induced cracking. For safety and operational reasons, it is important to understand and mitigate the potential damage that could be caused to key components in a fusion reactor, including the large number of diagnostic ports needed in experimental fusion reactors, such as ITER.
The study of hydrogen permeation in these materials is further complicated by the elevated temperatures present under normal operation of a reactor and the anticipated damage the materials will suffer due to irradiation by the energetic neutrons produced in the fusion reactions. The effect of the material surface, which is altered by interaction with the plasma through erosion and sputtering is also relevant to this CRP
The CRP’s objective is to provide evaluated experimental data on hydrogen permeation in fusion-related in-vessel materials. The data will be used in benchmarking of modelling codes for hydrogen permeation in fusion-relevant conditions.
CRP Overall Objective:
The primary goal of this CRP is to increase the capacity of Member States to undertake experimental and theoretical fusion research. This CRP supports the development of novel techniques in fusion reactor design through the enhancement of the global knowledgebase on plasma-material interaction data with respect to hydrogen permeation in fusion reactor components.
Specific Research Objectives:
- Assemble, evaluate and recommend data needed for hydrogen permeation in fusion materials, particularly: diffusivity, retention, solubility, recombination and dissociation coefficients of hydrogen on unirradiated fusion materials.
- Assess the impact of irradiation on the response of relevant materials to hydrogen permeation, including the effect of radiation-induced damage, and solid and gaseous transmutation products.
- Assess the impact of materials' surfaces and microstructure on hydrogen permeation properties.
- Investigate the isotope dependence of hydrogen permeation.
- Assess the impact of geometrical effects (2D and 3D) on permeation.
How to join the CRP:
Please submit your Proposal for Research Contract or Agreement by email to the IAEA’s Research Contracts Administration Section using the appropriate template on the CRA website. Deadline for proposal submissions 30 April 2020.
For further information related to this CRP, potential applicants should write to the Research Contracts Administration Contact Point.
