ITER is a multibillion-dollar international research and development project to demonstrate the scientific and technological feasibility of fusion power and to enable studies of self-heating burning plasmas. It will require hundreds of tons of complex stainless steel components that must withstand the temperatures associated with being in the proximity of a plasma heated to more than 100 million degrees Celsius.
The ITER device will be assembled in Cadarache, France, using components fabricated in the United States and in the other partner nations – China, the European Union, India, Japan, the Republic of Korea and the Russian Federation. It is based on the tokamak concept, in which a hot gas is confined in a torus-shaped vessel using a magnetic field. When operational, the device will produce some 500 MW of fusion power.
Jeremy Busby of the ORNL Materials Science and Technology Division said the ITER shield modules present a particular challenge. “The United States must produce nearly 100 of these modules that are 3–4 tons each and include geometric shapes and openings,” he explained, adding that drilling holes in solid steel would result in the removal and loss of 30 percent of the material.
Busby said casting the steel into a near-final shape was another alternative, but it weakens its properties. “We’re working to improve the materials’ properties to reduce the amount of machining and welding and allow for better performance,” he said. “The use of casting can have potential value engineering benefits resulting in cost savings on the order of 20 to 40 percent as compared to machining, so this could be a fairly significant economic issue, both for ITER and in other future uses.”
Busby and his team have worked on the effort for some 18 months, after being approached by Mike Hechler, USIPO manager of Blanket Shielding and Port Limiter systems. “He talked with us because of ORNL’s materials science expertise,” Busby said. “He was familiar with our industry work and hopeful that we could help provide a solution.”
The team has utilized a science-based approach involving modeling, advanced analytical techniques and industrial experience, building upon past R&D 100 award-winning efforts with other cast steels. The availability of advanced materials property simulations at ORNL also played a significant role. “We have used all the science tools available to us at the laboratory,” Busby added.
The effort began with the preparation of test steel compositions in small batches that will be scaled up to more representative geometries. Focus areas include improvements in fracture properties, tensile strength, microstructure properties, welds, impact properties, corrosion performance and radiation resistance.
Busby is hopeful about when the new material might be needed for ITER. The overall design of the device is being tweaked as part of an international review held earlier this year. “We expect to hear fairly soon about how our cast stainless steel may be used in this groundbreaking project,” he said.
ORNL is managed by UT-Battelle for the Department of Energy. U.S. ITER is a DOE Office of Science project.
Bonnie Hebert | Newswise Science News
An innovative high-performance material: biofibers made from green lacewing silk
20.01.2017 | Fraunhofer-Institut für Angewandte Polymerforschung IAP
Treated carbon pulls radioactive elements from water
20.01.2017 | Rice University
An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
19.01.2017 | Event News
10.01.2017 | Event News
09.01.2017 | Event News
20.01.2017 | Awards Funding
20.01.2017 | Materials Sciences
20.01.2017 | Life Sciences