[ RadSafe ] High Density Concrete for Nuclear Waste Casks

[McCarty, Mike (DEQ)]

Radsafers

 

I just stumbled onto this article.


MIT engineers find way to slow concrete creep to a crawl 


http://web.mit.edu/newsoffice/2009/creep-0615.html

 

excerpt:

"There is a search by industry to find an optimal method for creating such ultra-high-density materials based on packing considerations in confined spaces, a method that is also environmentally sustainable," said Ulm. "The addition of silica fumes is one known method in use for changing the density of concrete; we now know from the nanoscale packing why the addition of fumes reduces the creep of concrete. From a nanoscale perspective, other means now exist to achieve such highly packed, slow-creeping materials." 

"The insight gained into the nanostructure puts concrete on equal footing with high-tech materials, whose microstructure can be nanoengineered to meet specific performance criteria: strength, durability and a reduced environmental footprint," said Vandamme, who earned a PhD from MIT's Department of Civil and Environmental Engineering in 2008 and is now on the faculty of the Ecole des Ponts ParisTech, Université Paris-Est. 

In their PNAS paper, the researchers show experimentally that the rate of creep is logarithmic, which means slowing creep increases durability exponentially. They demonstrate mathematically that creep can be slowed by a rate of 2.6. That would have a truly remarkable effect on durability: a containment vessel for nuclear waste built to last 100 years with today's concrete could last up to 16,000 years if made with an ultra-high-density (UHD) concrete. 

Mike

 

Michael J. McCarty

Michigan Department of Environmental Quality

Radiological Protection Section

815 Terminal Road

Lansing, MI  48906

 

Phone: 517-335-8196

Fax:  517-335-9551

 

mccartym1 at michigan.gov