Cooperation Solidification of Cesium and Strontium

2012 ◽  
Vol 482-484 ◽  
pp. 58-61 ◽  
Author(s):  
Ming Fen Wen ◽  
Bo Yu ◽  
Min Luo ◽  
Jing Chen
Keyword(s):  
Solvent Extraction ◽  
Molecular Sieve ◽  
Liquid Waste ◽  
Fission Products ◽  
Radioactive Cesium ◽  
Energy Technology ◽  
High Level Liquid Waste ◽  
New Energy ◽  
Extraction Processes ◽  
High Level

The presence of long-lived radionuclides is a challenge to the management of high level liquid waste (HLLW). Separation of minor acitinides and long-lived fission products from the HLLW by partitioning process has the potential of significantly decreasing the costs of the immobilization and disposal of the radioactive waste by minimizing waste volumes. Several solvent extraction processes have been developed and demonstrated at the Institute of Nuclear and New Energy Technology (INET) for the separation of transuranic elements, 90Sr and 137Cs. In this work, using modified zeolite molecular sieve as a sorbent carrier, four kinds of solidification were prepared by soakage- absorption- calcination methods. It was found that the sample (HZCS-75) calcinated at 750°C was formed pollucite, a zeolite mineral, which will provide an option to immobilize the radioactive cesium and strontium.

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.

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.

scholarly journals New trends in the reprocessing of spent nuclear fuel. Separation of minor actinides by solvent extraction

2016 ◽  
Vol 71 (1) ◽  
pp. 123
Author(s):  
Jerzy Narbutt
Keyword(s):  
Solvent Extraction ◽  
Nuclear Fuel ◽  
Spent Nuclear Fuel ◽  
Fission Products ◽  
Natural Uranium ◽  
Heterocyclic Ligands ◽  
High Level Nuclear Waste ◽  
Extraction Processes ◽  
High Level

<p>Recycling of actinides from spent nuclear fuel by their selective separation followed by transmutation in fast reactors will optimize the use of natural uranium resources and minimize the long-term hazard from high-level nuclear waste. This paper describes solvent extraction processes recently developed, aimed at the separation of americium from lanthanide fission products as well as from curium present in the waste. Depicted are novel poly-N-heterocyclic ligands used as selective extractants of actinide ions from nitric acid solutions or as actinide-selective hydrophilic stripping agents.</p>

The Application Research of Concentration & Denitration Technology in Advanced Reprocessing Process

2012 ◽  
Vol 560-561 ◽  
pp. 637-643
Author(s):  
Yong Li ◽  
Xue Gang Liu ◽  
Jin Chen
Keyword(s):  
Nitric Acid ◽  
Nuclear Power ◽  
Liquid Waste ◽  
Fission Products ◽  
Extraction Process ◽  
Purex Process ◽  
Current Status ◽  
Spent Fuel ◽  
High Level Liquid Waste ◽  
High Level

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.

TRLIFS study of Eu(III) spectroscopic properties to obtain structural and thermodynamic informations on lanthanide-malonamide complexes in the Eu(III)/NaNO3/TetraEthylMalonAmide system

2004 ◽  
Vol 92 (7) ◽  
Author(s):  
Laurent Couston ◽  
M. C. Charbonnel ◽  
J. L. Flandin ◽  
Christophe Moulin ◽  
F. Rancier
Keyword(s):  
Liquid Waste ◽  
Fission Products ◽  
Spectroscopic Properties ◽  
High Level Liquid Waste ◽  
Trivalent Actinides ◽  
Nuclear Fuel Reprocessing ◽  
Chemical Studies ◽  
High Level ◽  
Fuel Reprocessing ◽  
The Eu

SummaryImprovement of the nuclear fuel reprocessing involves separating the minor actinides (Am(III) and Cm(III)) from the fission products. In the French strategy, the first step consists in the separation of the trivalent actinides and lanthanides from high-level liquid waste, for which malonamides RR´NCO(CHR´´)CONRR´ are promising ligands. These molecules have been optimized for reprocessing but still require basic chemical studies to describe the complexation mechanisms at a molecular scale. This paper discusses a thermodynamic and structural study of a Ln(III)-malonamide complex formed with the hydrosoluble tetraethylmalonamide ligand (TEMA=(C

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