High-Level Liquid Waste Treatment: Process Development Studies in the WIPE Facility—Part I

1989 ◽  
Vol 85 (3) ◽  
pp. 314-323
Author(s):  
T. Sampat Sridhar
2020 ◽  
Vol 266 ◽  
pp. 121884 ◽  
Author(s):  
Haogui Zhao ◽  
Jing Yang ◽  
Zheng Li ◽  
Yiyun Geng ◽  
Jie Li ◽  
...  

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.


Author(s):  
R. Do Quang ◽  
V. Petitjean ◽  
F. Hollebecque ◽  
O. Pinet ◽  
T. Flament ◽  
...  

The performance of the vitrification process currently used in the La Hague commercial reprocessing plants has been continuously improved during more than ten years of operation. In parallel COGEMA (industrial Operator), the French Atomic Energy Commission (CEA) and SGN (respectively COGEMA’s R&D provider and Engineering) have developed the cold crucible melter vitrification technology to obtain greater operating flexibility, increased plant availability and further reduction of secondary waste generated during operations. The cold crucible is a compact water-cooled melter in which the radioactive waste and the glass additives are melted by direct high frequency induction. The cooling of the melter produces a soldified glass layer that protects the melter’s inner wall from corrosion. Because the heat is transferred directly to the melt, high operating temperatures can be achieved with no impact on the melter itself. COGEMA plans to implement the cold crucible technology to vitrify high level liquid waste from reprocessed spent U-Mo-Sn-Al fuel (used in gas cooled reactor). The cold crucible was selected for the vitrification of this particularly hard-to-process waste stream because it could not be reasonably processed in the standard hot induction melters currently used at the La Hague vitrification facilities: the waste has a high molybdenum content which makes it very corrosive and also requires a special high temperature glass formulation to obtain sufficiently high waste loading factors (12% in molybednum). A special glass formulation has been developed by the CEA and has been qualified through lab and pilot testing to meet standard waste acceptance criteria for final disposal of the U-Mo waste. The process and the associated technologies have been also being qualified on a full-scale prototype at the CEA pilot facility in Marcoule. Engineering study has been integrated in parallel in order to take into account that the Cold Crucible should be installed remotely in one of the R7 vitrification cell. This paper will present the results obtained in the framework of these qualification programs.


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