Research Hub

ANSTO's research capabilities, led by the OPAL nuclear research reactor and associated instruments provide access to users investigating areas as diverse as materials, life sciences, climate change and mining/engineering.

ANSTO-SINAP Joint Research Centre

In December 2012, ANSTO signed a memorandum of understanding with the Shanghai Institute of Applied Physics (SINAP) for cooperation in the area of materials research and development.

Within the same week, the Institute of Materials Engineering (IME) was awarded a major grant from the Australia-China Science and Research Fund to conduct collaborative research with SINAP on advance Thorium Molten Salt Reactors (TMSR). The newly formed Joint Research Centre (JRC) covers a range of scientific disciplines in order to cover the challenges of next generation TMSRS.

The contributions of IME within the framework of the JRC are to provide materials performance assessment and to conduct independent research on the behaviour of nuclear materials exposed to corrosive molten salts at high temperature and in high radiation fields.

Learn more about the project areas:

Molten salt corrosion
Radiation damage effects
High temperature materials
Weld modelling

Project Areas

Molten Salt Corrosion

Figure 1. Controlled atmosphere molten salt furnace.

IME personnel have adapted two former electrochemistry rigs for testing of TMSR materials at elevated temperatures in fluoride and chloride molten salt systems.

Corrosion of materials within a molten salt environment is of major importance to a number of industries; of most relevance to this project is the nuclear industry.

The chemistry of the molten salt itself has a significant influence on the behaviour of the material being tested. A controlled atmosphere test cell environment has been developed, capable of testing a wide range of materials, in halide based molten salt systems, over a wide temperature range (up to 850°C).

The performance of materials, in a molten salt environment in-situ, is required to assess suitable candidature materials for future molten salt reactors.

Radiation Damage Effects

Figure 2. Texture map of Ni based alloy generated via Electron Backscatter Diffraction Analysis (EBSD).

In the short term, most of this work will be conducted using ion beam facilities and our own in-house plasma irradiator at ANSTO, with some in situ experiments being conducted at the ANU and overseas.

A small suite of samples are also being irradiated in OPAL and will be examined later, once sufficient neutron dose has been obtained.

This aspect of the JRC involves analysis of the defects produced in TMSR materials by radiation damage and the potential effects on important properties that relate to the materials application.

High Temperature Materials

Materials assessment and development in being conducted using metallographic techniques, mechanical testing, electron microscopy and microanalysis, and neutron scattering at OPAL.

The broad objective of the High Temperature Materials projext area is to Evaluate of the performance of candidate materials at high temperature by measurement of property changes and the determination of ageing mechanisms.

Evaluations are performed through observation of baseline mechanical properties and microstructural data. A broad range of techniques and expertise is applied through; tensile and small punch tests, microstructural characterisation by microscopic and diffraction techniques, thermal ageing tests and creep testing. The research has also led to the design and manufacture of purpose built high temperature and molten salt in-situ cells for mechanical testing apparatus.

Weld Modelling

There is currently a strong interest in quantifying the residual stresses in welds used in nuclear and conventional power stations; some of which have been in operation for more than two decades.

In most cases it is impractical to perform residual stress measurements for every single weld in a structure or assembly. Additionally, the dimensions of real structural components are typically large and usually inaccessible, hence non-destructive neutron and X-ray methods cannot be employed.

In such cases validated numerical methods may be the only method available for reliable determination of residual stress.



Figure 3. (a) Reality: physical processes involved in welding and driving forces in weld pool fluid flow [1]. (b) Model: physical processes and simplified ellipsoid moving heat source included in the present finite element models.

The aim of numerical weld simulations is to develop models that are usable for control and design of welding processes. The results obtained allow prediction of appropriate mechanical performance of the welded component. However,reliable prediction and validation of residual stresses in a weld structure remains, a difficult task because of the complexity of the welding process (Fig. 3).

ANSTO has developed its finite element (FE) capability to predict residual stresses associated with welds in both austentic steels as well as the more complex ferritic steels which undergo the solid-state phase transformation [2]. Additionally ANSTO has developed the capability to perform non-destructive (diffraction) and destructive (contour cutting technique) residual stress measurements when required for validation purposes.

Figure 4. Comparison of the predicted and synchrotron-measured transverse (11), normal (22) and longitudinal (33) residual stresses on the along the bead [2].

References:

Gilles, P., El-Ahmar, W., Jullien, J.F., 2009. Robustness analyses of numerical simulation of fusion welding NeT – TG1 application: single weld-bead-on-plate. International Journal of Pressure Vessels and Piping 86, 3–12.
Muránsky, O., Smith, M.C., Bendeich, P.J., Holden, T.M., Luzin, V., Martins, R.V., Edwards, L., 2012. Compehensive numerical analysis of a three-pass bead-in-slot weld and its critical validation using neutron and synchrotron diffraction residual stress measurements. International Journal of Solids and Structures 49, 1045-1062.

This Project is supported by the Commonwealth of Australia under the Australian-China Science and Research Fund