Thomas Davis speaks at the American Nuclear Society’s Winter Meeting in Washington, D.C.

20 Nov 2019 | News

Company Director, Thomas Davis, was invited to present at the American Nuclear Society’s 2019 Winter Meeting. His talk was on “Microstructural Evolution of Neutron Irradiated T91 Steel in the ATR” within the ‘Nuclear Field and Materials in Fast Reactors’ session. The talk discussed the findings of his PhD research whilst working as a visiting researcher at the Centre for Advanced Energy Studies, Idaho National Laboratory, USA, with the University of Oxford.

The structural materials selection is vital to the safety and economics of any future fission reactor. T91 ferritic-martensitic steel (also known as Mod 9Cr-1Mo, P91/F91 or Grade 91) is a candidate for the major structural material for sodium-cooled fast reactors (e.g. fuel cladding, ducts and structural components). The selection of this structural material relies on understanding its degradation during operation. Current nuclear regulation requires the predictability of the steel’s performance over the expected operational range of temperatures, stresses, , irradiation, corrosion and types of coolants.

Irradiation is the driving force for microstructural and microchemical evolution which has detrimental effects on the mechanical performance, which could limit the reactor structural components. The objective of this study was to use atom probe tomography (APT) and nanoindentation techniques to investigate the segregation of Mn, Si and Ni, which forms Mn-Si-Ni ppts, and Cr under neutron irradiated conditions as a function of dose.

Links between these Mn-Si-Ni ppts and changes in nanohardness could provide an insight into the direct effect of irradiation on the steel’s properties.

The published transaction of the talk can be found here.

The American Nuclear Society provides its members with opportunities for professional development. It also serves the nuclear community by creating a forum for sharing information and advancements in technology, and by engaging the public and policymakers through communication outreach. The 2019 ANS Winter Meeting and Technology Expo is the premier North American nuclear science and technology conference.


Davis & Musgrove Ltd develops novel technologies for fusion energy, holds expertise in advanced nuclear energy, and supports the defence industry. We also provide technical and regulatory-based consultancy. We are expanding at a fast pace in the energy and defence sectors. Through collaboration with industry, academia, and government, the company has expanded into patent and product development in fusion technology, as well as expanding its services into defence & energy strategy.

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