Studies on hydrolysis and radiolysis of N,N,N′,N′-tetraoctyl-3-oxapentane-1,5-diamide

2002 ◽  
Vol 90 (3) ◽  
Author(s):  
Y. Sugo ◽  
Y. Sasaki ◽  
S. Tachimori
Keyword(s):  
Gamma Irradiation ◽  
Room Temperature ◽  
Degradation Products ◽  
Liquid Waste ◽  
Amide Bond ◽  
Radioactive Liquid Waste ◽  
Ether Bond ◽  
Nuclear Fuel Reprocessing ◽  
High Level ◽  
Fuel Reprocessing

SummaryHydrolytic and radiolytic stabilities of a promising extractant, N,N,N′,N′-tetraoctyl-3-oxapentane-1,5-diamide (TODGA), for actinides in high-level radioactive liquid waste from nuclear fuel reprocessing were investigated in air at room temperature. Hydrolysis by nitric acid was not observed, whereas radiolysis by gamma irradiation was notably observed. The radiolysis study showed that an amide-bond, an ether-bond, and a bond adjacent to the ether-bond tended to be broken by gamma irradiation, and dioctylamine and various N,N-dioctylmonoamides were identified as the main degradation products by GC/MS and NMR analyses. The

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

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.

Production of Synroc Ceramics from Titanate Gel Microspheres

1993 ◽  
Vol 333 ◽  
Author(s):  
Erden Sizgek ◽  
J.R. Bartlett ◽  
J.L. Woolfrey ◽  
E.R. Vance
Keyword(s):  
Spray Drying ◽  
Nuclear Fuel ◽  
High Level Waste ◽  
Nuclear Fuel Reprocessing ◽  
Controlled Porosity ◽  
High Level ◽  
Precursor Powders ◽  
Fuel Reprocessing ◽  
Titanate Ceramic

Synroc is a multi-component titanate ceramic, designed to immobilise High Level Waste (HLW) from nuclear fuel reprocessing plants [1]. Synroc precursor powders have been previously produced by various methods, such as oxide and alkoxide-hydrolysis routes [2]. However, various technological aspects of HLW processing make the use of free-flowing, dustfree, highly sinterable precursor powders desirable. Such powders have been produced by spray-drying colloidal precursors, yielding microspherical particles with controlled porosity.

Removal of ruthenium from high-level radioactive liquid waste generated during reprocessing of spent fuel

2013 ◽  
Vol 52 (1-3) ◽  
pp. 514-525 ◽  
Author(s):  
Khushboo Singh ◽  
N.L. Sonar ◽  
T.P. Valsala ◽  
Y. Kulkarni ◽  
Tessy Vincent ◽  
...  
Keyword(s):  
Liquid Waste ◽  
Spent Fuel ◽  
Radioactive Liquid Waste ◽  
High Level
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