Influence of Silicone Carbide on the Reactivity of Nuclear Fuels Using Cerium Dioxide as a Surrogate Material

Author(s):  
Štěpán Foral ◽  
David Salamon ◽  
Karel Katovský ◽  
Jan Varmuža ◽  
Jakub Roleček

The most researched material in nuclear power industry is uranium dioxide however due to strict safety and sanitary restrictions this material can be researched only in specialized research institutes and universities which have sufficient technological background. For this reason it can be suitable to find material which would show physical properties similar to UO2 but would not suffer by the strict limitations in storage and handling. In this case much more workplaces could be incorporated in the material research and the list of investigated problems could be significantly enlarged. One of the possible substitutional materials is the cerium dioxide (CeO2) which shows similar chemical and physical properties like UO2 and in some cases shows also similar neutronic properties. The laboratory research was focused on comparing of the basic neutronic properties. For the comparison of nuclear properties the JANIS software [1] was used as it contains cross section libraries of both materials. It will be shown that similarity of both materials is significant and in several cases application of cerium dioxide as alternative material is possible with sufficient accuracy. As an example of the use of CeO2, research of influence of the SiC content on the reactivity of nuclear fuels is presented in this work.

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 670
Author(s):  
Jaroslav Legemza ◽  
Róbert Findorák ◽  
Branislav Buľko ◽  
Jaroslav Briančin

This article deals with material research of selected types of quartz and quartzites in order to determine the priority of their use in the production of ferrosilicon and pure silicon, respectively. The highest quality quartzes and quartzites are commonly used in metallurgy, but not all types of these silicon raw materials are suitable for the production of ferrosilicon and pure silicon, despite their similar chemical composition. Behavior differences can be observed in the process conditions of heating and carbothermic production of ferrosilicon and silicon. These differences depend, in particular, on the nature and content of impurities, and the granularity (lumpiness) and microstructure of individual grains. The research focused primarily on determining the physicochemical and metallurgical properties of silicon raw materials. An integral part of the research was also the creation of a new methodology for determining the reducibility of quartzes (or quartzites), which could be used for real industrial processes and should be very reliable. The results of the laboratory experiments and evaluation of the physicochemical and metallurgical properties of the individual quartzes (or quartzites) are presented in the discussion. Based on comparison of the tested samples’ properties, their priority of use was determined. This research revealed the highest quality in quartzite from Sweden (Dalbo deposit) and Ukraine (Ovruč deposit) and quartz from Slovakia (Švedlár deposit). The use of these raw materials in industrial conditions is expected to result in the achievement of better production parameters, such as higher yield and product quality and lower electricity consumption.


2020 ◽  
Vol 9 (3) ◽  
pp. 724
Author(s):  
Syazwani Mohd Fadzil ◽  
Shafi Qureshi ◽  
Sekhar Basu ◽  
K. Kasturirangan ◽  
Anil Kakodkar ◽  
...  

Here, safer nuclear fuels which can sustain in the high temperature and fluence environment of the reactor core are investigated to utilize nuclear energy peacefully. At Nuclear Fuel Complex in Hyderabad, nuclear fuels are being manufactured which are best suited for high temperature and fluence environment of the reactor core even in accidental scenarios. In this paper, nuclear fuels manufactured at NFC, Hyderabad are presented. The developed nuclear fuels have higher equivalent hydraulic diameter and breeding capability to produce U^233. Nuclear fuels having higher equivalent hydraulic diameter reduce the reactor core temperature substantially. These fuels have negative temperature coefficient of reactivity. Thus, in case of an accident, the fuel temperature never exceeds the safety limit. Therefore, the thermal heat available across the secondary of a heat exchanger can be utilized for different industrial processes. This allows the development of key technologies, such as safer co-generation of electricity and Hydrogen. The Three-Stage Indian Nuclear Power Program has been explained for nuclear disarmament. The product Hydrogen gas has been utilized in many ways for different applications. Moreover, the processing of iron ore with the energy obtained from the IHX secondary side, eliminates the burning of coals and CO2 emissions into the environment. Several radioisotopes have been developed for medical applications from spent fuel.  


Author(s):  
Steve Thomas

- UK electricity consumers have paid provisions for decommissioning since before 1980 but by 2002, there were still negligible funds available to pay for decommissioning civil nuclear facilities. By then, the two major UK nuclear companies, British Energy and British Nuclear Fuels Limited (BNFL), were both effectively bankrupt. This paper examines: the pre-2002 provisions for decommissioning and how they were lost; the Nuclear Decommissioning Authority, a new public body which took over ownership of BNFL's facilities including the duty to manage their decommissioning and how it expects to carry out and fund decommissioning of its sites; how the re-launched British Energy will contribute to decommissioning its eight plants; and government plans for collecting decommissioning provisions for any new plants.JEL classifications: L50, L38, H23, H44, L71Key words: Nuclear power, decommissioning cost, funding and polluter pays.


2020 ◽  
Vol 6 ◽  
pp. 40
Author(s):  
Stéphane Valance ◽  
Bruno Baumeister ◽  
Winfried Petry ◽  
Jan Höglund

Within the Euratom research and training program 2014–2018, three projects aiming at securing the fuel supply for European power and research reactors have been funded. Those three projects address the potential weaknesses – supplier diversity, provision of enriched fissile material – associated with the furbishing of nuclear fuels. First, the ESSANUF project, now terminated, resulted in the design and licensing of a fuel element for VVER-440 nuclear power plant manufactured by Westinghouse. The HERACLES-CP project aimed at preparing the conversion of high performance research reactor to low enriched uranium fuels by exploring fuels based on uranium-molybdenium. Finally, the LEU-FOREvER pursues the work initiated in HERACLES-CP, completing it by an exploration of the high-density silicide fuels, and including the diversification of fuel supplier for soviet designed European medium power research reactor. This paper describes the projects goals, structure and their achievements.


Author(s):  
Leyland J. Allison ◽  
Lisa Grande ◽  
Sally Mikhael ◽  
Adrianexy Rodriguez Prado ◽  
Bryan Villamere ◽  
...  

SuperCritical Water-cooled nuclear Reactor (SCWR) options are one of the six reactor options identified in Generation IV International Forum (GIF). In these reactors the light-water coolant is pressurized to supercritical pressures (up to approximately 25 MPa). This allows the coolant to remain as a single-phase fluid even under supercritical temperatures (up to approximately 625°C). SCW Nuclear Power Plants (NPPs) are of such great interest, because their operating conditions allow for a significant increase in thermal efficiency when compared to that of modern conventional water-cooled NPPs. Direct-cycle SCW NPPs do not require the use of steam generators, steam dryers, etc. allowing for a simplified NPP design. This paper shows that new nuclear fuels such as Uranium Carbide (UC) and Uranium Dicarbide (UC2) are viable option for the SCWRs. It is believed they have great potential due to their higher thermal conductivity and corresponding to that lower fuel centerline temperature compared to those of conventional nuclear fuels such as uranium dioxide, thoria and MOX. Two conditions that must be met are: 1) keep the fuel centreline temperature below 1850°C (industry accepted limit), and 2) keep the sheath temperature below 850°C (design limit). These conditions ensure that SCWRs will operate efficiently and safely. It has been determined that Inconel-600 is a viable option for a sheath material. A generic SCWR fuel channel was considered with a 43-element bundle. Therefore, bulk-fluid, sheath and fuel centreline and HTC profiles were calculated along the heated length of a fuel channel.


Fibers ◽  
2019 ◽  
Vol 7 (5) ◽  
pp. 44
Author(s):  
Sonny Widiarto ◽  
Edi Pramono ◽  
Suharso ◽  
Achmad Rochliadi ◽  
I Made Arcana

In this study, cellulose and cellulose nanofibers (CNF) were extracted and prepared from cassava peels (CPs). The method of the cellulose extraction was performed by alkali treatment followed by a bleaching process. The CNF were prepared by mechanical disruption procedure (homogenization and ultrasonication), and the results were compared with a common acid hydrolysis procedure. The resulting cellulose and CNF from both procedures were then analyzed using FTIR, SEM, TEM, XRD, and TGA. The results show that cellulose and CNF were successfully prepared from both procedures. The physical properties of the produced CNF were different; however, they had similar chemical properties.


Metals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1170
Author(s):  
Róbert Findorák ◽  
Jaroslav Legemza ◽  
Mária Fröhlichová ◽  
Gabriela Fabriciová ◽  
Martina Džupková

The use of lignin can be one of the methods of coke powder substitution in the agglomeration process. This article specifies the material research of lignin and the technological and ecological parameters of the agglomeration process in laboratory conditions using biomass lignin. The methodology of the Raman and infrared spectroscopy, representing a new approach in the analysis and assessment for the purposes of material characteristics for the agglomeration process, was applied to study the structure of carbonaceous matter. The material research of lignin has determined that its calorific value corresponds to ca. 80% of the calorific value of coke powder, while its reactivity is higher than that of the coke. Although the substitution of coke powder using different types of waste biomass (e.g., wood sawdust) in the production of the agglomerate is limited to the maximum of 8–15%, in case of lignin, more than 20% can be substituted, while the standard properties of the produced agglomerate are maintained. The lower emissions of sulfur and nitrogen oxides as well as the reduction of carbon footprint in the agglomeration process as a result of the so-called zero CO2 balance in the formation and processing of the biomass represent its positive aspects. Based on the laboratory research of lignin, up to a 50% substitution of coke powder with this type of biomass can be predicted for the technology of agglomerate production in real operation.


2015 ◽  
Vol 202 ◽  
pp. 71-77 ◽  
Author(s):  
Nathalia Carolina Fernandes Fagundes ◽  
Miquéias André Gomes Cardoso ◽  
Mayara Sabrina Luz Miranda ◽  
Raira de Brito Silva ◽  
Francisco Bruno Teixeira ◽  
...  

2008 ◽  
Vol 1104 ◽  
Author(s):  
Xianghong Wu ◽  
Mohan Singh Bharara ◽  
Brandon K Tate ◽  
Stephen A Tonks ◽  
Jonah Z Vilseck ◽  
...  

AbstractThe potential environmental and health concerns surrounding actinides and the use of nuclear fuels limits the acceptance of nuclear power by the public. This in turn, hinders the capability of this country to take advantage of nuclear power. Expanding our fundamental knowledge of actinide coordination chemistry will allow for the development of improved actinide sensors, new separations methods, or new means of radioactive waste remediation. We have designed and optimized a solution-phase parallel method for the synthesis of a library of symmetrical 2-quinoxalinol salens, Schiff-base type ligands with a 2-quinoxalinol incorporated into the salen backbone. This combines the rigid salen coordination framework with the quinoxaline properties that impart properties for use in colorimetric or fluorescent sensors. These have now been incorporated into organic soluble resins for metal extraction.


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