Toward safer, long-life nuclear reactors—metal design could raise radiation resistance by 100 times December 16, 2016 by Katherine Mcalpine Please Register or Log in to view the hidden image! An electron microscope reveals the radiation-induced cavities inside samples of pure nickel and alloys. The cavities in nickel-cobalt-iron and nickel-cobalt-iron-chromium-manganese alloys are 100 times smaller than those in pure nickel. Credit: Wang Group, University of Michigan In findings that could change the way industries like nuclear energy and aerospace look for materials that can stand up to radiation exposure, University of Michigan researchers have discovered that metal alloys with three or more elements in equal concentrations can be remarkably resistant to radiation-induced swelling. The big problem faced by metals bombarded with radiation at high temperatures—such as the metals that make up nuclear fuel cladding—is that they have a tendency to swell up significantly. They can even double in size. "First, it may interfere with other parts in the structure, but also when it swells, the strength of the material changes. The material density drops," said Lumin Wang, U-M professor of nuclear engineering and radiological sciences. "It may become soft at high temperatures or harden at low Read more at: http://phys.org/news/2016-12-safer-long-life-nuclear-reactorsmetal-resistance.html#jCp
http://www.nature.com/articles/ncomms13564 Enhancing radiation tolerance by controlling defect mobility and migration pathways in multicomponent single-phase alloys Abstract A grand challenge in material science is to understand the correlation between intrinsic properties and defect dynamics. Radiation tolerant materials are in great demand for safe operation and advancement of nuclear and aerospace systems. Unlike traditional approaches that rely on microstructural and nanoscale features to mitigate radiation damage, this study demonstrates enhancement of radiation tolerance with the suppression of void formation by two orders magnitude at elevated temperatures in equiatomic single-phase concentrated solid solution alloys, and more importantly, reveals its controlling mechanism through a detailed analysis of the depth distribution of defect clusters and an atomistic computer simulation. The enhanced swelling resistance is attributed to the tailored interstitial defect cluster motion in the alloys from a long-range one-dimensional mode to a short-range three-dimensional mode, which leads to enhanced point defect recombination. The results suggest design criteria for next generation radiation tolerant structural alloys.
Japan can definitely use this to construct more robust earthquake resistant nuclear reactor containment.
Was failure in Japan due to radiation reducing structural integrity? Or was the issue an inherent flaw in their design (i.e. not up to withstanding earthquakes of that magnitude).
Some experts in the field would agree with my assessment that the Fukushima reactor vessels were already old enough to be replaced, being built in the 1970s. http://www.independent.co.uk/voices...-fukushima-reactors-is-their-age-2244155.html https://www.nrc.gov/docs/ML1114/ML111460369.pdf The ability of this new alloy to maintain strength that would otherwise be lost to pitting, structural microfractures and corrosion means that additional time would be afforded operators to better evaluate and manage emergency conditions produced by an earthquake or a tsunami before reactor containment became compromised. http://www.nbcnews.com/science/fuku...ean-plume-due-reach-us-waters-2014-8C11050755 Please Register or Log in to view the hidden image!
Metal clad rods are yesterday's tech. At best this metallurgical advance helps extend the useful life and safety of existing generation II plants, and the handful of generation III plants. Pebble bed is promising in near to medium term: http://www.nytimes.com/2011/03/25/business/energy-environment/25chinanuke.html Beyond that, the best option for fission plants is imo without a doubt molten salt designs that actually had their beginning in the 1950's: https://en.wikipedia.org/wiki/Molten_salt_reactor But their are competitors: https://en.wikipedia.org/wiki/Generation_IV_reactor
I read literature about the new Westinghouse reactor designs China seems to be so interested in at a local trade show as well. They looked promising as one of the newer "inherently safe" nuclear reactor technologies.
