Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Aging in irradiated materials: First predictive model of the microstructure of irradiated iron

19.01.2005


Researchers from the CEA’s Nuclear Energy Division have, for the first time, been able to make a quantitative prediction of the evolution of radiation-induced defects in a structural material. The results obtained for iron, using multi-scale simulation techniques based on the atomic scale, will help provide greater insight into material aging phenomena in existing nuclear power plants and may be applied to nuclear systems of the future. They are to be published in the "Nature Materials" journal on January 4, 2005.



The evolution kinetics of radiation-induced defects in a material has a direct impact on changes in its microstructure and consequently on its mechanical properties. This makes the quantitative prediction of this kinetics and the phenomena governing it a major challenge for the nuclear industry.

This challenge can now be taken up by intercoupling computer simulation techniques operating on different scales. This is what is meant by multi-scale simulation; the numerical results obtained on one time and space scale were taken and used as input data for modeling on the next higher scale:


- first of all, ab initio computer simulations rooted in quantum mechanics described the structure and migration of defects and defect clusters. These simulations, which call for considerable computing resources, were performed by drawing intensively on the capabilities of the CCRT (research and technology computing center) set up on the CEA’s Bruyères-le-Châtel site.

- the second stage consisted in taking these elementary properties and reconstructing, on the basis of a kinetic model , the evolution of defects and their effects on the macroscopic properties of an irradiated iron sample one micron (a thousandth of a millimeter) in size, over a period of about one hour.

The simulations were compared with indirect experimental measurements . The excellent agreement obtained demonstrates the realism of this multi-scale model, which highlights the role played by the hitherto unsuspected migration of small interstitial and vacancy clusters. They challenge the interpretation of several earlier experiments and simulations and open the way for the quantitative simulation of more complex irradiated materials such as industrial steels. They will be used in interpreting the mechanical behavior of the ferritic steels used as structural materials in existing nuclear fission plants, as well as those proposed for future fusion plants.

Anne-Gabrielle Dauba-Pantanacce | alfa
Further information:
http://www.cea.fr

More articles from Physics and Astronomy:

nachricht Engineering team images tiny quasicrystals as they form
18.08.2017 | Cornell University

nachricht Astrophysicists explain the mysterious behavior of cosmic rays
18.08.2017 | Moscow Institute of Physics and Technology

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

Engineering team images tiny quasicrystals as they form

18.08.2017 | Physics and Astronomy

Researchers printed graphene-like materials with inkjet

18.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>