Scientists propose using salt mines to store nuclear waste. Unlike storage in water basins, this method will allow you to contain spent fuel almost forever. Researchers write about this in their article published in the Vadose Zone Journal.
In the US, scientists are exploring several possible solutions for nuclear waste disposal. Phil Stauffer and researchers at the Los Alamos National Laboratory are working with the US Department of Energy and other national laboratories on a long-term and safe disposal solution – salt.
“The deep salt strata that already exist in the United States are promising candidates for long-term burial”, says Stauffer. – Highly active nuclear waste can create a lot of heat, in addition to the radioactivity that it contains. We need to develop a clear path for the disposal of this waste”.
Salt deposits are deep underground. They are self-healing, have very low permeability, and conduct heat well. All this is important for working with the natural heat of nuclear waste. Salt formations can be an excellent barrier to the long-term release of radionuclides into the human environment.
The USA and Germany already place low- and medium-level nuclear waste in storage facilities located in salt fields. But this waste does not create so much heat. Therefore, more research is needed to determine the safety and effectiveness of salt deposits for highly active nuclear waste.
Salt is not only a physical barrier but also a chemical one. Therefore, it is necessary to study how these salt deposits will respond to the presence of water, heat, and other geological factors.
Recent thermal tests underground began with the creation of a full-scale model of the “canister” for waste and its heating for almost a year. This is the first time such trials have been conducted in the United States since the late 1980s.
In parallel, a research team from the Department of Energy is conducting a campaign to study common nuclear waste storage facilities. This includes studying how water migrates to heat sources in salt.
Having drilled wells in salt deposits and performed heating tests in these holes surrounded by salt, the researchers received information for further decisions. Now they are faced with an even larger study of both the holes themselves and the brine extracted after the tests. Researchers intend to conduct long-term computer simulation and measurement of the chemical composition of the brine in real-time.
The project plans include a gradual scale-up of experiments with heaters in order to ultimately examine the availability of brine for spent nuclear fuel containers in a configuration that represents a possible future waste storage with a high level of activity.