Denitration of simulated high-level liquid waste by formic acid for the connection of PUREX process with TRPO process

2017 ◽  
Vol 314 (1) ◽  
pp. 221-229 ◽  
Author(s):  
Wenbing Li ◽  
Wuhua Duan ◽  
Taoxiang Sun ◽  
Changjian Liu ◽  
Jianchen Wang ◽  
...  
Author(s):  
Meng Wei ◽  
Xuegang Liu ◽  
Jing Chen

To reduce the long-term risk of the high-level liquid waste (HLLW) and the waste disposal cost, transuranium (TRU) elements should be removed from HLLW. A so-called TRPO process has been developed by Chinese scientists to partition HLLW. In this process, the extractant, trialkyl phosphine oxide (TRPO), is able to extract TRU elements into organic phase completely, which makes the treatment and disposal of raffinate HLLW much easier. However, the treatment of extracted TRU elements in organic phase, in return, becomes new troublesome issue. Generally, there are three promising ways to treat the extracted TRU elements: (1)transmutation; (2)conditioning; (3)recycling U+Pu in Purex-TRPO Integrated Process. In any of the three ways, the back extraction agents and processes play significant roles. In this paper, the investigations on back extraction agents for TRU elements, such as TTHA, DTPA, AHA, HEDPA, DOGA, and carbonates are introduced. The corresponding back extraction processes and experimental results are reviewed.


2001 ◽  
Vol 89 (3) ◽  
Author(s):  
W. Jianchen ◽  
S. Chongli

The crown ether strontium extraction(CESE) process for partitioning strontium from HLLW was studied. A hot test was carried out in a counter current mode with genuine HLLW by using a miniature centrifugal contactor set. 0.1 mol/L DCH18C6 in 1-octanol was used as extractant. The feed solution was the HLLW raffinate of TRPO process after removing TRU elements. Acidity of the feed was 1.45 mol/L HNO


2012 ◽  
Vol 560-561 ◽  
pp. 637-643
Author(s):  
Yong Li ◽  
Xue Gang Liu ◽  
Jin Chen

The proper management of spent fuel arising from nuclear power production is a key issue for the sustainable development of nuclear energy. While conventional reprocessing process, PUREX process, was successful to recover uranium and plutonium, in recent years some countries have turned to focus on advanced reprocessing process, which features of partitioning of minor actinides (MA) and long-lived fission products(LLFP). Most advanced reprocessing processes under development involve new extractants and additional extraction cycles. In China, TRPO extraction process has been developed to partition MA/LLFP from high-level liquid waste(HLLW) since early 1980’s. In parallel to R&D work on separation technologies, studies on concentration & denitration process have been evolved to prepare feed solutions to suit qualifications of extraction. Industrially, concentration & denitration is the internationally recognized standard to treat HLLW released from PUREX before vitrification. It enables to minimize the volume of interim storage, to restrain the corrosion of storage tank, to recover nitric acid in HLLW and to reduce the required evaporation duty of the vitrification process. Generally, the constitution of concentrated HLLW has little impact on the following vitrification process. But when concentration & denitration acts as pretreatment process of partitioning, the composition of actinides, fission products, and nitric acid in concentrated HLLW solution plays significant role in extraction process. A series of technical issues relevant to the connection between concentration ﹠denitration and extractions should be solved. This paper describes current status of concentration & denitration technology utilized in industry and under reprocessing plants. The specific separation requirements in advanced reprocessing process and challenges to apply concentration & denitration process are addressed. Besides, concentration & denitration process was tested in laboratory to adjust feed solutions for TRPO and Cyanex301 partitioning. Results demonstrate its promising prospect in advanced reprocessing process.


2000 ◽  
Vol 88 (12) ◽  
Author(s):  
O. Courson ◽  
M. Lebrun ◽  
R. Malmbeck ◽  
G. Pagliosa ◽  
K. Römer ◽  
...  

The French DIAMEX process shows very promising capabilities in separating minor actinides from HLLW. A counter-current centrifugal extractor experiment has been conducted to investigate the capabilities and possibilities of the DIAMEX process (hydraulic and extraction behaviour), for the separation of lanthanides from a simulated High Level Liquid Waste (HLLW), corresponding in concentration to a raffinate from the PUREX process.A ´´hot´´ batch test, using genuine HLLW, and a continuous counter-current experiment have verified the excellent extraction and hydraulic behaviour, respectively.With only four extraction stages in the cold experiment, lanthanide decontamination factors were higher than 2000, except for europium. Co-extraction of molybdenum and zirconium was efficiently prevented using oxalic acid in the feed solution. The back-extraction was very efficient, yielding in 4 stages more than 99% recovery of lanthanides. Palladium and ruthenium were more difficult to back-extract and for these elements further investigations are needed.


2000 ◽  
Vol 88 (12) ◽  
Author(s):  
R. Malmbeck ◽  
O. Courson ◽  
G. Pagliosa ◽  
K. Römer ◽  
B. Sätmark ◽  
...  

Among several processes proposed world-wide, the French DIAMEX (DIAMide EXtraction) process seems to be very efficient for the removal of Minor Actinides (MA) from genuine High Level Liquid Waste (HLLW). The MA are in this process directly extracted from the PUREX (Plutonium Uranium Redox EXtraction) raffinate together with fission lanthanides using the completely combustible diamide extractant. In this work a hot demonstration of the DIAMEX process using genuine high-level PUREX raffinate is reported. The continuous counter-current experiment was carried out in a 16 stage centrifugal extractor battery, installed in a hot cell. In order to produce a representative HLLW a PUREX process was applied on dissolved fuel using the same equipment. In the DIAMEX process up to 6 extraction stages were sufficient to achieve feed decontamination factors between 100 and 230 for lanthanides and above 300 for minor actinides. Co-extraction of molybdenum and zirconium were efficiently prevented using oxalic acid scrubbing. The back extraction proved to be very efficient, yielding in 4 stages more than 99.9% recovery of both the lanthanides and the actinides. Co-extracted ruthenium, technetium, palladium and neptunium are less efficiently back-extracted requiring further process development.


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