Linking Microstructure to Neutron Irradiation Defects in Advanced Manufacture of Steels

The UK is about to embark upon a new era of nuclear power. This nuclear new build has become increasingly important, given the impending shutdown of many coal-fired stations to meet agreed CO2 emission limits. Thus, the design, build and maintenance of next generation nuclear reactors must be underpinned by new research into ageing and degradation of the structural materials. Small modular reactors lie at the heart of a UK strategy to target a renaissance in the nuclear market, in fission reactors. The reactor pressure vessel is a critical component of a nuclear fission reactor. Small modular reactors research represents a clear opportunity for the development of novel manufacturing methods to fabricate key aspects of the reactor pressure vessel (RPV) that will directly improve the overall lifetime of these safety critical components. Hence, the long-term stability, strength and toughness of RPV steels are of vital importance for the power-generating industry.

This research is part of collaborative project, with partners at Imperial College, CCFE and the University of Manchester, and industrial partners Nation Nuclear Laboratory, Rolls Royce and ANSTO (Australia), to characterise neutron irradiation-induced solute clustering in RPV steels.

Specifically in this project, atom probe tomography (APT) characterisation will be used in the study of neutron irradiated RPV steels. APT is a cutting edge microscopy technique enabling a three-dimensional, atom-by-atom imaging of the steel microstructure, providing unique insight into the still poorly understood fundamental mechanisms of Nickel-Manganese-Silicon solute cluster formation and evolution and the resulting embrittlement. Specimens for APT analysis will be prepared via focussed ion beam (FIB) techniques. Active specimens will be prepared using facilities at the CCFE. APT analysis will be in close collaboration partners undertaking complementary high-resolution microscopy (Manchester), mechanical testing (ANSTO) and modelling studies (Imperial) of radiation damage. The project will also incorporate the effect of new processing on the development of irradiation damage in these steels and the performance of welded sections subject to the extreme fission reactor conditions.

The project directly addresses the EPSRC themes, Energy and Manufacturing the Future. It also directly contributes to EPSRC priority areas such as: Nuclear Fission, Materials Characterisation and Structural Integrity and Materials Behaviour.

Themes:
Energy
Engineering
Manufacturing the future
Physical sciences
Research infrastructure