Synthesis of soft N-donor isoPentyl-BTBP and study on its removal of actinides from high level liquid waste

2020 ◽  
Vol 108 (6) ◽  
pp. 425-431
Author(s):  
Shunyan Ning ◽  
Jie Zhou ◽  
Shichang Zhang ◽  
Wei Zhang ◽  
Yuezhou Wei
Keyword(s):  
Adsorption Kinetics ◽  
Contact Time ◽  
Porous Silica ◽  
Liquid Waste ◽  
Polymer Support ◽  
High Level Liquid Waste ◽  
Reduced Pressure ◽  
The Stability ◽  
High Level ◽  
Excellent Stability

AbstractTo directly separate actinides from high level liquid waste (HLLW), a novel molecule, i. e. isoPentyl-BTBP (6,6′-bis(5,6-bis(4-methylpentyl)-1,2,4-triazin-3-yl)-2,2′-bipyridines) was synthesized and characterized. A kind of isoPentyl-BTBP/SiO2-P adsorbent was obtained by impregnating isoPentyl-BTBP into porous silica/polymer support particles SiO2-P under reduced pressure. The effect of HNO3 concentration, contact time on the adsorption of isoPentyl-BTBP/SiO2-P towards 241Am(III) and 239Pu(IV) was studied. And the stability of isoPentyl-BTBP/SiO2-P in HNO3 medium was also evaluated. It turned out that isoPentyl-BTBP/SiO2-P had much higher affinity for 241Am(III) and 239Pu(IV) over FP elements in 3 M HNO3, fast adsorption kinetics towards 239Pu(IV), excellent stability in HNO3 medium, and should be a very promising adsorbent for separating 239Pu(IV) and 241Am(III) from HLLW.

Radiation Effects on Hollandite Ceramics developed for Radioactive Cesium Immobilization

2003 ◽  
Vol 792 ◽  
Author(s):  
V. Aubin ◽  
D. Caurant ◽  
D. Gourier ◽  
N. Baffier ◽  
S. Esnouf ◽  
...  
Keyword(s):  
Radiation Effects ◽  
Liquid Waste ◽  
Fission Products ◽  
Radioactive Cesium ◽  
Radioactive Liquid Waste ◽  
Epr Spectrum ◽  
Paramagnetic Resonance ◽  
Γ Radiation ◽  
The Stability ◽  
High Level

ABSTRACTProgress on separating the long-lived fission products from the high level radioactive liquid waste (HLW) has led to the development of specific host matrices, notably for the immobilization of cesium. Hollandite (nominally BaAl2Ti6O16), one of the main phases constituting Synroc, receives renewed interest as specific Cs-host wasteform. The radioactive cesium isotopes consist of short-lived Cs and Cs of high activities and Cs with long lifetime, all decaying according to Cs+→Ba2++e- (β) + γ. Therefore, Cs-host forms must be both heat and (β,γ)-radiation resistant. The purpose of this study is to estimate the stability of single phase hollandite under external β and γ radiation, simulating the decay of Cs. A hollandite ceramic of simple composition (Ba1.16Al2.32Ti5.68O16) was essentially irradiated by 1 and 2.5 MeV electrons with different fluences to simulate the β particles emitted by cesium. The generation of point defects was then followed by Electron Paramagnetic Resonance (EPR). All these electron irradiations generated defects of the same nature (oxygen centers and Ti3+ ions) but in different proportions varying with electron energy and fluence. The annealing of irradiated samples lead to the disappearance of the latter defects but gave rise to two other types of defects (aggregates of light elements and titanyl ions). It is necessary to heat at relatively high temperature (T=800°C) to recover an EPR spectrum similar to that of the pristine material. The stability of hollandite phase under radioactive cesium irradiation during the waste storage is discussed.

scholarly journals Vitrification of HLW Produced by Uranium/Molybdenum Fuel Reprocessing in COGEMA’s Cold Crucible Melter

2003 ◽  
Author(s):  
R. Do Quang ◽  
V. Petitjean ◽  
F. Hollebecque ◽  
O. Pinet ◽  
T. Flament ◽  
...  
Keyword(s):  
Atomic Energy Commission ◽  
Liquid Waste ◽  
Glass Layer ◽  
Cold Crucible ◽  
High Level Liquid Waste ◽  
Process Waste ◽  
Glass Formulation ◽  
High Level ◽  
Fuel Reprocessing ◽  
High Frequency Induction

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.

Agents and Processes Design for TRU Elements Back Extraction in TRPO Process

2009 ◽  
Author(s):  
Meng Wei ◽  
Xuegang Liu ◽  
Jing Chen
Keyword(s):  
Organic Phase ◽  
Liquid Waste ◽  
Back Extraction ◽  
High Level Liquid Waste ◽  
Trpo Process ◽  
Extraction Processes ◽  
Treatment And Disposal ◽  
High Level ◽  
Disposal Cost

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.

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