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Can nuclear waste be disposed safely by mixing it into a cement grout?
The best way to dispose nuclear waste is by mixing it into a cement grout and storing it in large concrete vaults. However, there is still a chance that it may seep through solidified grout.

How can leakage from cement with nuclear waste be measured?
Dr. Zachary Grasley, an associate professor at Texas A&M University, is currently conducting experiments for the Savannah River National Lab (SNRL) in the purpose of preventing this leakage. Thanks to Zachary Grasley’s modern technology, these experiments can now be done within minutes or few hours. These tests include taking grout samples, saturating them with water, and exposing them to high levels of water pressure inside a pressure vessel. Subjecting the cement to high levels of water pressure will make the surface of the sample equalize to the pressure the vessel is subjected to, causing the material to contract until the same pressure level is reached. But the pressure level inside the sample remains much lower, because the solid structure of the grout is bearing most of the pressure. However, slowly liquids flow from the high pressure areas to the lower pressure areas. This water will therefore begin to flow into the pore network of the sample as long as the pressure is sustained. As water permeates the material, it begins filling the pores in the sample, causing the cement to expand and regrow.

The rate at which the cement sample expands after the initial contraction allows for an accurate calculation of the permeability of the sample. This process takes less than an hour, compared to previous testing techniques that could take weeks to complete.

The rate of expansions show the likelihood of leakage. The technology makes it easier for researchers to conduct tests and to come up with preventative measures of leakage.

The team is well aware of the environmental safety and human health, as if it is not handled properly, nuclear waste could leak into the environment, groundwater, and surface water.

While we aren't at risk of an attack from a giant radioactive lizard, like you see in films, remnants of nuclear weapons or the byproducts of nuclear power plants still exist and very much real. This waste must be disposed safely, otherwise it would pose a threat to humans.

Source: https://phys.org/news/2017-02-aims-nuclear-seepage.html

Research aims to prevent nuclear waste seepageCredit: Texas A&M University

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