I have often blogged about the problem with nuclear waste. Fission reactors produce spent nuclear fuel that is radioactive and can be dangerous for thousands of years. To date, the best solution to the accumulating spent nuclear fuel from the world’s nuclear power reactors is to bury it in deep underground geological repositories. Unfortunately, siting and constructing such repositories are very difficult and there have only been test repositories created during the seventy plus years of the Nuclear Age. The soonest that the U.S. will have one is 2050. The temporary solution to the spent nuclear fuel problem is to store the used fuel assemblies in steel cylinders encased in concrete called “dry casks”. These dry casks have their own problems. Now scientists are working on ways to speed up radioactive decay which could reduce the time required for nuclear waste to be lose most of its radioactivity.
Dr. Artūras Plukis is Head of Experimental Nuclear Physics Laboratory at the Center for Physical Sciences and Technology in Vilnius, Lithuania. He said, “Currently, the disposal of nuclear waste is comprised of either storing the waste in containers on above-surface level or burying them underground, depending on the decay period of the radioactive material. This method is raising safety concerns, as some of the waste is disposed not too far from densely populated areas, and highly radioactive waste has to be safely stored for up to tens of thousands of years.”
Light Conversion and Ekspla, two Lithuanian laser technology companies, have developed a very powerful, very fast laser called the SYLOS. The SYLOS high-density ultra-short pulse laser system may be able to accelerate the decay of radioactive isotopes in spent nuclear fuel and other radioactive wastes. Darius Gadonas is Head of the Scientific Laser Systems Division at Light Conversion. He said, “We do believe that lasers like SYLOS can be adapted to solve the nuclear waste issue globally without leaving it for future generations to deal with. How soon this could be achieved will depend on the political will of governments, since lasers and infrastructure of this kind could cost up to billions of euros per unit.”
Gadonas said, “There are now 44 laser industry-related companies in Lithuania, and most of them are located in Vilnius. The Lithuanian-made lasers take up more than 50 percent of the global market for the ultra-short pulse lasers. The lasers made in our country are used at NASA, CERN, and countless technologies companies, such as IBM, Hitachi, Toyota, and Mitsubishi. Finally, 90 of the world’s top 100 universities are using lasers made by scientists in Lithuania.”
The pulses from SYLOS are used to accelerate electrons to relativistic velocities. When these highly energetic electrons hit a target of solid matter, they generate powerful electromagnetic gamma rays. These gamma rays are able to induce fission in unstable nuclei such as the radioactive isotopes in nuclear wastes. The isotopes produced by such fission have significantly shorter half-lives than the isotope which were forced to fission by the gamma rays. This means that amount of time nuclear waste needed to be isolated can be significantly reduced.