For a dedicated transmutation system, Japan Atomic Energy Agency (JAEA) has been proceeding with the research and development on an accelerator-driven subcritical system (ADS). The ADS proposed by JAEA is a lead-bismuth eutectic (LBE) cooled fast subcritical core with 800 MWth. JAEA has started a comprehensive research and development (R&D) program since the fiscal year of 2002 to acquire knowledge and elemental technology that are necessary for the validation of engineering feasibility of the ADS. In this paper, the outline and the results in the first three-year stage of the program are reported. Items of R&D were concentrated on three technical areas peculiar to the ADS: (1) a superconducting linear accelerator (SC-LINAC), (2) the LBE as spallation target and core coolant, and (3) a subcritical core design and reactor physics of the ADS. For R&D on the accelerator, a prototype cryomodule was built and its good performance in electric field was examined. For R&D on the LBE, various technical data for ma...

https://www.tandfonline.com/doi/pdf/10.1080/18811248.2007.9711312

Research and Development Program on Accelerator Driven Subcritical System in JAEA

Thermochromatography study of volatile polonium species in various gas atmospheres

Polonium evaporation from dilute liquid metal solutions

Equilibrium evaporation of trace polonium from liquid lead–bismuth eutectic at high temperature

Analysis of the 207Bi, 194Hg/Au and 173Lu distribution in the irradiated MEGAPIE target

Experimental study using the transpiration method investigates equilibrium evaporation behavior of radionuclide polonium (210Po) generated and accumulated in liquid lead-bismuth eutectic (LBE) cool...

https://www.tandfonline.com/doi/pdf/10.1080/18811248.2006.9711230

Equilibrium Evaporation Behavior of Polonium and Its Homologue Tellurium in Liquid Lead-Bismuth Eutectic

Equilibrium evaporation behavior was experimentally investigated for polonium ({sup 210}Po) in liquid lead-bismuth eutectic (LBE) and for rare-earth elements gadolinium (Gd) and europium (Eu) in LBE to understand and clarify the transfer behavior of toxic impurities from LBE coolant to a gas phase. The experiments utilized the 'transpiration method' in which saturated vapor in an isothermal evaporation pot was transported by inert carrier gas and collected outside of the pot. While the previous paper ICONE12-49111 has already reported the evaporation behavior of LBE and of tellurium in LBE, this paper summarizes the outlines and the results of experiments for important impurity materials {sup 210}Po and rare-earth elements which are accumulated in liquid LBE as activation products and spallation products. In the experiments for rare-earth elements, non-radioactive isotope was used. The LBE pool is about 330-670 g in weight and has a surface area of 4 cm x 14 cm. {sup 210}Po experiments were carried out with a smaller test apparatus and radioactive {sup 210}Po produced through neutron irradiation of LBE in the Japan Materials Testing Reactor (JMTR). We obtained fundamental and instructive evaporation data such as vapor concentration, partial vapor pressure of {sup 210}Po in the gas phase, and gas-liquidmore » equilibrium partition coefficients of the impurities in LBE under the temperature condition between 450 and 750 deg. C. The {sup 210}Po test revealed that Po had characteristics to be retained in LBE but was still more volatile than LBE solvent. A part of Eu tests implied high volatility of rare-earth elements comparable to that of Po. This tendency is possibly related to the local enrichment of the solute near the pool surface and needs to be investigated more. These results are useful and indispensable for the evaluation of radioactive materials transfer to the gas phase in LBE-cooled nuclear systems. (authors)« less

Ryoei Katsura

Papers

Equilibrium Evaporation Behavior of Polonium and Its Homologue Tellurium in Liquid Lead-Bismuth Eutectic

Experimental Investigation of Evaporation Behavior of Polonium and Rare-Earth Elements in Lead-Bismuth Eutectic Pool