scholarly journals Treatment of Spent Nuclear Fuel for Separation, Immobilization and Disposal of Heat Generating High Level Fission Products, Caesium and Strontium

2017 ◽  
Vol 30 (1) ◽  
pp. 37-42
Author(s):  
Md Akhlak Bin Aziz ◽  
Afrin Ahsan ◽  
Md Monsurul Islam Khan ◽  
Zahid Hasan Mahmood

Separation of heat generating, high level fission product caesium and strontium from spent nuclear fuel boosts the capacity of waste repositories by as much as fifty times. For efficient use of already scarce repositories, separation of such fission products is mandatory. Separations of caesium and strontium using Chlorinated Cobalt Dicarbollide (CCD), PEG (Polyethylene Glycol), UNEX process and by Calixarenes or Fission Product Extraction Process (FPEX) were discussed. The UNEX method was then proposed as the most feasible method option. Following separation, nuclear waste immobilization techniques for such high-level fission product were discussed. The techniques included usage of concrete, glass and synthetic rock. Among them synthetic rock was identified as the most suitable one for immobilization of high-level nuclear waste. Finally, a safe disposal system with necessary required geology was shown for safe disposal of the waste.Journal of Chemical Engineering, Vol. 30, No. 1, 2017: 37-42

Author(s):  
Jerzy Narbutt

<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>


Author(s):  
J A Richardson

Commercial reactor nuclear power generation in the United States is produced by 107 units and, during 1996, represented over 21 per cent of the nation's electricity generation in 34 of the 50 states and, through electric power wheeling, between states in most of the 48 contiguous states. Spent fuel is stored in fuel pools at 70 sites around the country and the projected rate of spent fuel production indicates that the current pool storage will be exceeded in the out years of 2000, 2010 and 2020 at 40, 67 and 69 of these sites respectively. The total accumulation projected by the end of 1996 at reactor sites is 33 700 metric tons of heavy metal (MTHM), with projections for increasing accumulations at annual rates of between 1800 and 2000 to produce an end of life for all commercial nuclear reactors of about 86 000 MTHM. There are presently eight facilities in six states with out-of-pool dry storage amounting to 1010 MTHM and this dry storage demand will increase. Based on all current commercial reactors achieving their 40 year licensed operation lifetimes, the dry storage needs will increase to 3128 MTHM at 28 sites and 20 states by 2000 and 11 307 MTHM at 58 sites in 32 states by 2010; the year 2010 is the present scheduled operation date for the federal mined geological disposal repository being characterized by the USDOE at Yucca Mountain, Nevada. The enabling statute for the federal high-level radioactive waste management programme is the 1982 Nuclear Waste Policy Act (NWPA) which charges the USDOE with the responsibility for the disposal of HLW and spent nuclear fuel. The Act also charges the utilities with the responsibility for managing their spent nuclear fuel until the USDOE can accept it into the federal waste management system. The funding for the federal programme is also stipulated by the Act with the creation of the Nuclear Waste Fund, through which the electric utilities entered into contract with the USDOE by payment of a fee of 1 mill per kilowatt hour sold and for which the USDOE would start collection of spent fuel from the reactor sites starting 31 January 1998.


2021 ◽  
Vol 13 (19) ◽  
pp. 10780
Author(s):  
Anna V. Matveenko ◽  
Andrey P. Varlakov ◽  
Alexander A. Zherebtsov ◽  
Alexander V. Germanov ◽  
Ivan V. Mikheev ◽  
...  

Pyrochemistry is a promising technology that can provide benefits for the safe reprocessing of relatively fresh spent nuclear fuel with a short storage time (3–5 years). The radioactive waste emanating from this process is an electrolyte (LiCl–KCl) mixture with fission products included. Such wastes are rarely immobilized through common matrices such as cement and glass. In this study, samples of ceramic materials, based on natural bentonite clay, were studied as matrices for radioactive waste in the form of LiCl–KCl eutectic. The phase composition of the samples, and their mechanical, hydrolytic, and radiation resistance were characterized. The possibility of using bentonite clay as a material for immobilizing high-level waste arising from pyrochemical processing of spent nuclear fuel is further discussed in this paper.


2019 ◽  
pp. 52-57
Author(s):  
T. Maltseva ◽  
А. Shyshuta ◽  
S. Lukashyn

The paper is devoted to the history of development and the current state of technological and scientific advances in radiochemical reprocessing of spent nuclear fuel from water-cooled power reactors. Regarding spent nuclear fuel (SNF) of NPP power reactors, long-term energy security involves adopting a version of its radiochemical treatment, conditioning and recirculation. Recycling SNF is required for the implementation of a closed fuel cycle and the re-use of regeneration products as energy reactor fuels. The basis of modern technological schemes for the reprocessing of the spent nuclear fuel is the “Purex” process, developed since the 60s in the USA. The classic approach to the use of U and Pu nuclides contained in spent nuclear fuel is to separate them from fission products, re-enrich regenerated uranium and use plutonium for the production of mixed-oxide (MOX) fuel with depleted uranium. The modern reprocessing plants are able to deal with fuel with further increase of its main characteristics without significant changes in the initial project. In order to close the fuel cycle, it is needed to add the following technological steps: (1) removal of high-level and long-lived components and minor actinides; (2) return of actinides to the technological cycle; (3) safe disposal of unused components. Each of these areas is under investigation now. Several new promising multi-cycle hydrometallurgical processes based on the joint extraction of trivalent lanthanides and minor actinides with their subsequent separation have been developed. A number of promising materials is suggested to be potential matrices for the immobilization of high-level components of radioactive wastes. To improve the compatibility of fuel processing with the environment, non-aqueous technologies are being developed, for instance, pyro-chemical methods for the reprocessing of various types of highly active fuels based on metals, oxides, carbides, or nitrides. An important scientific and technological task under investigation is transmutation of actinides. The results of international large-scale experiments on the partitioning and transmutation of fuel with various minor actinides and long-lived fission products confirm the real possibility and expediency of closing the nuclear fuel cycle.


2010 ◽  
Vol 1265 ◽  
Author(s):  
Lars Werme ◽  
Sergei Butorin ◽  
Peter M Oppeneer

AbstractAfter a few hundred years, the actinides will dominate the radiotoxicity of spent nuclear fuel. This does not necessarily mean that the actinides will dominate the dose to organisms at the surface above a geologic repository. Quite the contrary, in most performance assessments this dose is dominated by long-lived fission products, activation products and, in the very long perspective, actinide daughters.This makes the far-field migration properties of the actinides less interesting for further research. There are, however, other aspects of the presence of actinides in spent nuclear fuel and some of these and SKB's research in these fields is presented and discussed here.


2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
A. Schwenk-Ferrero

Germany is phasing-out the utilization of nuclear energy until 2022. Currently, nine light water reactors of originally nineteen are still connected to the grid. All power plants generate high-level nuclear waste like spent uranium or mixed uranium-plutonium dioxide fuel which has to be properly managed. Moreover, vitrified high-level waste containing minor actinides, fission products, and traces of plutonium reprocessing loses produced by reprocessing facilities has to be disposed of. In the paper, the assessments of German spent fuel legacy (heavy metal content) and the nuclide composition of this inventory have been done. The methodology used applies advanced nuclear fuel cycle simulation techniques in order to reproduce the operation of the German nuclear power plants from 1969 till 2022. NFCSim code developed by LANL was adopted for this purpose. It was estimated that ~10,300 tonnes of unreprocessed nuclear spent fuel will be generated until the shut-down of the ultimate German reactor. This inventory will contain ~131 tonnes of plutonium, ~21 tonnes of minor actinides, and 440 tonnes of fission products. Apart from this, ca.215 tonnes of vitrified HLW will be present. As fission products and transuranium elements remain radioactive from 104to 106years, the characteristics of spent fuel legacy over this period are estimated, and their impacts on decay storage and final repository are discussed.


MRS Bulletin ◽  
1994 ◽  
Vol 19 (12) ◽  
pp. 16-19 ◽  
Author(s):  
R.C. Ewing ◽  
W. Lutze

The materials science of radioactive waste forms and containment materials has long been a subject of interest to the Materials Research Society. One of the earliest (and continuing) MRS symposia, the Scientific Basis for Nuclear Waste Management, has been held 18 times since 1978. This symposium rotates abroad every third year: Berlin in 1982, Stockholm in 1985, Berlin in 1988, Strasbourg in 1991, and Kyoto this past October. Nearly 170 papers were presented at the Kyoto meeting.Materials science issues for nuclear waste disposal are unique in their scale and consequences. The wastes include an extremely wide variety of materials: spent nuclear fuel from commercial and research reactors; high-level liquid waste produced at West Valley, New York, during the reprocessing of commercial spent nuclear fuel; high-level waste (HLW) generated by the nuclear weapons program; nearly pure plutonium from the dismantling of nuclear weapons; highly enriched uranium from weapons; low-level, medium-level, and mixed waste from laboratories and medical facilities; and, finally, mill tailings from uranium mines and the residues from chemical processing, such as the radium-bearing filtrate presently in storage at Fernald, Ohio, and Niagara Falls, New York. Some material can be simply stabilized and monitored in situ, as is done for most uranium mill tailings and residues, but other materials require retrieval, processing, immobilization, and permanent disposal. The volumes of material that will require handling, immobilization, and disposal are enormous. In the United States, much of the weapons program waste is stored in tanks at Hanford, Washington and Savannah River, South Carolina.


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