Transmutation of Long-Lived Nuclear Wastes

Abstract

JAEA is conducting research and development on an Accelerator Driven System (ADS), aiming at reduction of burden for high-level radioactive wastes. To tackle technical challenges on ADS, JAEA is planning to build the Transmutation Experimental Facility as the Phase-2 program of J-PARC. Moreover, JAEA is considering the collaboration with the MYRRHA project proposed by Belgian Nuclear Research Center.

Overview of the Nuclear Fuel Cycle Strategies and the Spent Nuclear Fuel Management Technologies in Taiwan

“…In the case of MAs transmutation, the time period further shortens down to approximately 300 years. The radiotoxicity trend as a function of time in this figure is much similar to those of literature [24,26]. Therefore, the P&T technology is regarded as a good method of reducing the nuclear waste generation and the burden on the dry storage and final disposal in radioactive waste management size.…”

“…Some long-lived FPs (LLFPs) are also important due to their high solubility in groundwater. These LLFPs play a critical role in the long-term safety assessment of final disposal based on the groundwater release scenario of the biosphere model [26].…”

“…These advanced facilities have attracted considerable international research interests owing to their flexibility in burning Pu, MAs and FPs. As a result, these facilities can greatly reduce the radiotoxicity of HLW by a factor of 100 [26].…”

Laser-based photonuclear production of medical isotopes and nuclear waste transmutation

“…The electron and gamma-ray spectra originating from the relativistic RST regime of a 135 TW laser pulse are shown in figure 2. Regarding the gamma spectrum, it drops as 1/E γ in accordance with the Bethe-Heitler formula [28] for low energy, E γ ≲ 3 MeV, and for E γ ≳ 50 MeV it has an exponential decay with a temperature of (30)(31)(32)(33)(34)(35) MeV, defined by the maximum electron energy (see [29]). To smoothly approximate the intermediate spectral energy range, which is most interesting for photonuclear reactions, we used a two-temperature exponential distribution in qualitative theoretical estimates:…”

“…After spent fuel reprocessing goes through the chemical separation of plutonium, minor actinides (MA) and fission products, the LLFPs and MA are the main components of radiotoxic waste. For relatively safe storage of this leftover waste the deep geological disposal needs to isolate LLFPs from the biosphere or their transmutation into short-lived or stable isotopes are required [34]. The conventional methods of nuclear waste utilization are based upon neutron transmutation in accelerator-driven reactors [34].…”