Part 1 of 2 Parts
   With the cooling pools at nuclear plants filling up with spent nuclear fuel, some nuclear power plants will have to shut down if those spent fuel rods cannot be moved out of the pools. The U.S. had plans for a permanent geological repository at Yucca Mountain but those plans were cancelled in 2009. Now the soonest that a repository can be sited, licensed and constructed is 2050. So the spent fuel has to be moved but it will have to be to temporary storage for a few decades either onsite at the power plant or at an temporary storage facility. In order to store the spent nuclear fuel assemblies, concrete and steel cannisters are used.
     The storage canisters which are currently being used for spent nuclear fuel have an intended lifespan of a few decades. However, as the spent fuel continues to accumulate, it is probable that the cylinders already in use may be needed for much longer than originally intended according to Tito Bonano who is nuclear energy fuel cycle manager at Sandia National Laboratory.
      Sandia is carrying out research on the durability of the current nuclear storage canisters. Three twenty-two ton sixteen and one half foot long stainless steel storage canisters are being fitted with heaters and instrumentation which is intended to simulate nuclear waste. These three cylinders were received at Sandia last November. They have never contained any nuclear materials. The purpose of the research is to study the accumulation of salt on canisters over time. The researchers will also study the possibility of salt and stress causing corrosion in another batch of canisters in the next phase of the program.
     More data is needed to validate and guide how the nuclear industry should manage nuclear storage canisters for longer than they were originally designed for. Bonano said “Salt can be present in the ambient air and environment anywhere, not just near the ocean. We need to be able to plan for extended long-term storage of spent nuclear fuel at nuclear power plants for the foreseeable future — it’s a national reality.” Bonano went on to say that his team expects that the project to have very important implications for public health and safety, industry best practices, regulatory frameworks and laying out future research paths.
     The three-year project at Sandia is being funded by the U.S. Department of Energy (DoE) office. Fifteen DoE-owned storage canisters which have never been used are being sent to Sandia and two other national laboratories, an industry research institute and an independent storage facility at an operating nuclear power plant.
     Nuclear power plants use uranium pellets stuffed inside a metal coated tube called a fuel rod. When the nuclear fuel in the rods has been burned up, the rod has to be removed from the reactor and stored onsite before being taken to another storage facility that is either permanent or temporary. Samuel Durbin is a mechanical engineer and Sandia’s canister project lead. He said, “When fuel is removed from a reactor, it’s very hot, both in temperature and radioactivity. The utility loads it into a pool for about five years to cool down. After that, the spent fuel can be offloaded into a dry storage canister.”
Please read Part 2