Development of High Temperature Transport Technologies for Molten Salt and Liquid Cadmium in Pyrometallurgical Reprocessing

Author(s):  
Takatoshi Hijikata ◽  
Tadafumi Koyama

Pyrometallurgical reprocessing technology is currently being focused in many countries for closing actinide fuel cycle because of its favorable economic potential and an intrinsic proliferation-resistant feature due to the inherent difficulty of extracting weapons-usable plutonium. The feasibility of pyrometallurgical reprocessing has been demonstrated through many laboratory scale experiments. Hence the development of the engineering technology necessary for pyrometallurgical reprocessing is a key issue for industrial realization. The development of high-temperature transport technologies for molten salt and liquid cadmium is crucial for pyrometallurgical processing; however, there have been very few transport studies on high-temperature fluids. In this study, a salt transport test rig and a metal transport test rig were installed in an argon glove box with the aim of developing technologies for transporting molten salt and liquid cadmium at approximately 773 K. It was demonstrated that; using a centrifugal pump, molten salt at 773 K could be transported at a controlled rate from 4 to 8 dm3/min against a 1 m head. The transport behavior of the molten salt was found to be similar to that of water, and could be predicted from their similarity of kinematic viscosity. On the other hand, the transportation of liquid cadmium at approximately 700 K could be controlled at a rate of 0.5 to 1.6 dm3/min against a 1.6 m head using the centrifugal pump.

Author(s):  
Takatoshi Hijikata ◽  
Tadafumi Koyama

Pyrometallurgical reprocessing is one of the most promising technologies for the advanced fuel cycle with favorable economic potential and intrinsic proliferation-resistance. The feasibility of pyrometallurgical reprocessing has been studied through many laboratory-scale experiments. Hence the development of the engineering technology necessary for pyrometallurgical reprocessing is a key issue for its industrialization. The development of high-temperature transport technologies for molten salt and liquid cadmium is crucial for pyrometallurgical processing; however, there have been a few transport studies on high-temperature fluids. In this study, a metal transport test rig was installed in an argon glove box with the aim of developing technologies for transporting liquid cadmium at approximately 773 K. The transport of liquid Cd using gravity was controlled by adjusting the valve. The liquid Cd was transported by a suction pump against a 0.93 m head and the transport amount of Cd was well controlled with the Cd amount and the position of the suction tube. The transportation of liquid cadmium at approximately 700 K could be controlled at a rate of 0.5–2.5 dm3/min against a 1.6 m head using a centrifugal pump.


Author(s):  
Takatoshi Hijikata ◽  
Tadafumi Koyama

Pyro-reprocessing is one of the most promising technologies for advanced fuel cycle with favorable economic potential and intrinsic proliferation resistance. The development of transport technology for molten salt is a key issue in the industrialization of pyro-reprocessing. As for pure molten LiCl-KCl eutectic salt at approximately 773 K, we have already reported the successful results of transport using gravity and a centrifugal pump. However, molten salt in an electrorefiner mixes with insoluble fines when spent fuel is dissolved in porous anode basket. The insoluble consists of noble metal fission products, such as Pd, Ru, Mo, and Zr. There have been very few transport studies of a molten salt slurry (metal fines - molten salt mixture). Hence, transport experiments on a molten salt slurry were carried out to investigate the behavior of the slurry in a tube. The apparatus used in the transport experiments on a molten salt slurry consisted of a supply tank, a 10° inclined transport tube (10 mm inner diameter), a valve, a filter, and a recovery tank. Stainless steel (SS) fines with diameters from 53 to 415 μm were used. To disperse these fines homogenously, the molten salt and fines were stirred in the supply tank by an impeller at speeds from 1200 to 2100 rpm. The molten salt slurry containing 0.2 to 0.4 vol.% SS fines was transported from the supply tank to the recovery tank through the transportation tube. In the recovery tank, the fines were separated from the molten salt by the filter to measure the transport behavior of molten salt and SS fines. When the velocity of the slurry was 0.02 m/s, only 1% of the fines were transported to the recovery tank. On the other hand, most of the fines were transported when the velocity of the slurry was more than 0.6 m/s. Consequently, the molten salt slurry can be transported when the velocity is more than 0.6 m/s.


2021 ◽  
Vol 11 (15) ◽  
pp. 6673
Author(s):  
Bruno Merk ◽  
Anna Detkina ◽  
Seddon Atkinson ◽  
Dzianis Litskevich ◽  
Gregory Cartland-Glover

Molten salt reactors have gained substantial interest in the last years due to their flexibility and their potential for simplified closed fuel cycle operation for massive expansion in low-carbon electricity production, which will be required for a future net-zero society. The importance of a zero-power reactor for the process of developing a new, innovative rector concept, such as that required for the molten salt fast reactor based on iMAGINE technology, which operates directly on spent nuclear fuel, is described here. It is based on historical developments as well as the current demand for experimental results and key factors that are relevant to the success of the next step in the development process of all innovative reactor types. In the systematic modelling and simulation of a zero-power molten salt reactor, the radius and the feedback effects are studied for a eutectic based system, while a heavy metal rich chloride-based system are studied depending on the uranium enrichment accompanied with the effects on neutron flux spectrum and spatial distribution. These results are used to support the relevant decision for the narrowing down of the configurations supported by considerations on cost and proliferation for the follow up 3-D analysis. The results provide for the first time a systematic modelling and simulation approach for a new reactor physics experiment for an advanced technology. The expected core volumes for these configurations have been studied using multi-group and continuous energy Monte-Carlo simulations identifying the 35% enriched systems as the most attractive. This finally leads to the choice of heavy metal rich compositions with 35% enrichment as the reference system for future studies of the next steps in the zero power reactor investigation. An alternative could be the eutectic system in the case the increased core diameter is manageable. The inter-comparison of the different applied codes and approaches available in the SCALE package has delivered a very good agreement between the results, creating trust into the developed and used models and methods.


2006 ◽  
Vol 29 (9) ◽  
pp. 1118-1121 ◽  
Author(s):  
K. Terasaka ◽  
Y. Suyama ◽  
K. Nakagawa ◽  
M. Kato ◽  
K. Essaki

2022 ◽  
Vol 165 ◽  
pp. 108638
Author(s):  
Jianhui Wu ◽  
Jingen Chen ◽  
Chunyan Zou ◽  
Chenggang Yu ◽  
Xiangzhou Cai ◽  
...  

CORROSION ◽  
2001 ◽  
Vol 57 (6) ◽  
pp. 489-496 ◽  
Author(s):  
M. Amaya ◽  
J. Porcayo-Calderon ◽  
L. Martinez

Abstract The performance of Fe-Si coatings and an iron aluminide (FeAl) intermetallic alloy (FeAl40at%+0.1at%B+10vol%Al2O3) in molten salts containing vanadium pentoxide (V2O5) and sodium sulfate (Na2SO4) is reported. Corrosion and fouling by ash deposits containing V2O5 and Na2SO4 are typical corrosion problems in fuel oil-fired electric power units. High-temperature corrosion tests were performed using both electrochemical polarization and immersion techniques. The temperature interval of this study was 600°C to 900°C, and the molten salts were 80wt%V2O5-20wt%Na2SO4. Curves of corrosion current density vs temperature obtained by the potentiodynamic studies are reported, as well as the weight loss vs temperature curves from molten salt immersion tests. Both Fe-Si coatings and FeAl40at%+0.1at%B+10vol%Al2O3 showed good behavior against molten salt corrosion. The final results show the potential of these coatings and alloys to solve the high-temperature corrosion in fuel oil-fired electric power units.


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