Jun 27, 2011 07:07 GMT  ·  By
This experiment shows how damage from radiation affects the mechanical properties of copper
   This experiment shows how damage from radiation affects the mechanical properties of copper

A collaboration of physicists in the United States announces the development of a new technique for testing nuclear materials, that could have significant practical applications. The approach is meant to ensure that nuclear power plants are operating within safety parameters.

The renewed interest in nuclear safety was produced by the nuclear disaster affecting the Fukushima Daiichi nuclear power planet, in Japan. The facility was heavily affected by the magnitude 9 tremor that struck the Asian nation on March 11.

When the cascade of safety measures failed to protect the cores from overheating, nations around the world began investigating their own installation, in order to ensure that they are operating within optimal parameters.

In the United States, experts at the US Department of Energy's (DOE) Lawrence Berkeley National Laboratory (Berkeley Lab), and Los Alamos National Laboratory (LANL), in cooperation with colleagues at the University of California in Berkeley (UCB), developed the new testing method.

According to the joint team, the work becomes very important when we consider that more than 70 percent of all emissions-free energy in the country comes from nuclear power. An estimated 20 percent of all electricity produced in the US comes from nuclear installations.

The nanoscale testing technique for irradiated materials that the team created provides macroscale materials-strength properties, experts say. The data can then be used to accelerate the development of new materials for nuclear applications.

As an added benefit, it may also become possible to reduce the amount of material required for testing the nuclear facilities that already in service, producing energy, engaged in research, or responsible for the creation of radioactive materials for medical applications.

“Nanoscale mechanical tests always give you higher strengths than the macroscale, bulk values for a material. This is a problem if you actually want use a nanoscale test to tell you something about the bulk-material properties,” scientist Andrew Minor explains.

“We have shown you can actually get real properties from irradiated specimens as small as 400 nanometers in diameter, which really opens up the field of nuclear materials to take advantage of nanoscale testing,” the expert adds.

He holds an appointment as a faculty scientist at the National Center for Electron Microscopy (NCEM) and is also an associate professor in the materials science and engineering department at UCB.

“This small-scale testing technique could help extend the lifetime of a nuclear reactor,” adds Peter Hosemann, a coauthor of the new study, and also an assistant professor at the UCB Department of Nuclear Engineering.

“By using a smaller specimen, we limit any safety issues related to the handling of the test material and could potentially measure the exact properties of a material already being used in a 40-year-old nuclear facility to make sure this structure lasts well into the future,” the expert concludes.

Details of the work appear in a paper entitled “In situ nanocompression testing of irradiated copper,” which is published in the latest online issue of the top journal Nature Materials.