Oxford, August 20, 2014 - Researchers at the University of Michigan, Ann Arbor, Los Alamos National Laboratory, Idaho National Laboratory, Idaho Falls and TerraPower based in Bellevue, Washington, have demonstrated the power of high-energy beams of charged particles (ions). The ions can rapidly and consistently damage samples of ferritic-martensitic steel, the material used in certain nuclear reactor components. The significance of the result is that the breakdown closely replicates that seen when high-energy neutrons from a nuclear reactor interact with the material - damage accrues in a matter of days, rather than decades.
The structural components of advanced reactors such as the sodium fast reactor and the traveling wave nuclear reactor must be able to withstand the extreme levels of radioactivity from the fission reaction itself at temperatures well above 400 Celsius. Unfortunately, standard tests of such components are expensive, require increasingly rare test reactors and test periods that are impractical. Moreover, the samples themselves also become radioactive making subsequent studies and examination time consuming and expensive. Nevertheless, understanding how these structural components are affected by radiation at the microscopic level is critical to building long-lasting, robust and safe nuclear reactors.
To demonstrate the proof of principle with ion beams instead of conventional reaction irradiation, the team of researchers preloaded reactor components of ferritic-martensitic steel with atoms of helium gas, to simulate alpha particles. They irradiated the samples with an ion beam from a particle accelerator at 5 million electronvolts energy and a temperature of 460 degrees Celsius for several hours, and after which used transmission electron microscopy (TEM) to characterize the damage caused by the energetic ions penetrating the steel and observed microscopic holes (voids), dislocations and precipitates within the steel - none of which were present before ion irradiation.
Comparing this ion-beam damage with that seen in actual components of the same batch of steel used in a sodium fast reactor during the period 1985-1992, it was found that the types of defects (as well as their sizes and numbers) caused by neutron bombardment from the nuclear reaction to be closely reproduced by that with the ion beam experiments.
Lead author Gary Was hopes that their research will help develop "a stronger understanding of how to use ion irradiation to emulate neutron irradiation to enable the rapid development of new materials for advanced reactors as principal sources of clean energy". With additional work, a rapid, standardized experimental procedure may be developed for the routine evaluation of materials, facilitating the creation of more resilient components for nuclear reactors of the not-so-distant future.
Notes for editors
This article is "Emulation of reactor irradiation damage using ion beams" by G.S. Was, Z. Jiao, E. Getto, K. Sun, A.M. Monterrosa, S.A. Maloy, O. Anderoglu, B.H. Sencer and M. Hackett. It appears in Scripta Materialia, Volume 88, 1 October 2014, Pages 33-36 published by Elsevier. The article is available for free at http://www.
About Scripta Materialia
Scripta Materialia is a letters journal of Acta Materialia, providing a forum for the rapid publication of short communications on the relationship between the structure and the properties of inorganic materials.
About Materials Today
Materials Today is a community dedicated to the creation and sharing of materials science knowledge and experience. Supported by Elsevier, we publish high impact peer-reviewed journals, organize academic conferences, broadcast educational webinars and so much more.
Elsevier is a world-leading provider of information solutions that enhance the performance of science, health, and technology professionals, empowering them to make better decisions, deliver better care, and sometimes make groundbreaking discoveries that advance the boundaries of knowledge and human progress. Elsevier provides web-based, digital solutions -- among them ScienceDirect, Scopus, Elsevier Research Intelligence, and ClinicalKey -- and publishes nearly 2,200 journals, including The Lancet and Cell, and over 25,000 book titles, including a number of iconic reference works.
The company is part of Reed Elsevier Group PLC, a world leading provider of professional information solutions in the Science, Medical, Legal and Risk and Business sectors, which is jointly owned by Reed Elsevier PLC and Reed Elsevier NV. The ticker symbols are REN (Euronext Amsterdam), REL (London Stock Exchange), RUK and ENL (New York Stock Exchange).
+44 1865 843344