共查询到20条相似文献,搜索用时 15 毫秒
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V. A. Avramenko A. M. Egorin E. K. Papynov T. A. Sokol’nitskaya I. G. Tananaev V. I. Sergienko 《Radiochemistry》2017,59(4):407-413
The main sources of formation of liquid radioactive waste (LRW) containing seawater are determined, and the main problems arising in management of such waste are analyzed. Sorption methods for removing long-lived Cs and Sr radionuclides from highly mineralized (>1 g L–1) LRW are determined. The main physicochemical and sorption characteristics, advantages, and drawbacks of candidate sorbents for removing Cs and Sr radionuclides are described. Examples of using SRM and VS-5 chemical reaction sorption materials developed for removing Sr from LRW with the mineralization of up to 60 g L–1 are given. The results of studying composite materials based on BaSiO3 and resorcinol–formaldehyde resins, intended for removing Cs and Sr radionuclides from seawater, are analyzed. Composite sorbents of such type efficiently remove Cs and Sr radionuclides from seawater. Processes developed by the authors and brought into practice at various plants of the Far East for treatment of multicomponent LRW formed in the course of operation, repair, and decommissioning of nuclear-powered surface ships and submarines are described. 相似文献
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Sorbents based on hollow microspheres of entrained ash, with the surface modified by various chemical compounds (ferrocyanides,
phosphates, oxides, etc.), were synthesized. Their physical and ion-exchange characteristics were examined. These sorbents
show promise for treatment of low-and intermediate-level liquid waste of various origins in the dynamic and static sorption
modes. The use of microspheres as matrices is not only technically but also environmentally efficient, because waste from
thermal power engineering is utilized for disposal of nuclear waste.
Original Russian Text L.D. Danilin, V.S. Drozhzhin, 2007, published in Radiokhimiya, 2007, Vol. 49, No. 3, pp. 283–286. 相似文献
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Monte Carlo methods are used in a variety of applications such as risk assessment, probabilistic safety assessment and reliability analysis. While Monte Carlo methods are simple to use, their application can be laborious. A new microcomputer software package has been developed that substantially reduces the effort required to conduct Monte Carlo analyses. The Sensitivity and Uncertainty Analysis Shell (SUNS) is a software shell in the sense that a wide variety of application models can be incorporated into it. SUNS offers several useful features including a menu-driven environment, a flexible input editor, both Monte Carlo and Latin Hypercube sampling, the ability to perform both repeated trials and parametric studies in a single run, and both statistical and graphical output. SUNS also performs all required file management functions. 相似文献
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P K WATTAL 《Sadhana》2013,38(5):849-857
The primary objective of radioactive waste management is protection of human health, environment and future generation. This article describes, briefly, the Indian programme on management of different radioactive wastes arising in the entire nuclear fuel cycle adhering to this objective. 相似文献
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The relation of the structures of metamict mineral phases and non-crystalline solids is discussed; the question of radiation effects in solidified nuclear waste forms is considered in this regard. In ceramics, if the actinides can be concentrated in radiation-resistant phases such as uraninite or monazite, the overall radiation effects on the ceramics should be quite small. 相似文献
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The sorption of microamounts of Eu spiked with 152,154Eu on the artificial stone, pottery, was studied at varoius conditions. Three kinds of pottery (red, black, and white), in
addition to the raw material (potter’s clay) of the red kind, were tested. The pottery shows high sorption power with respect
to the radiotracer depending on the kind of pottery. The uptake percentages gradually increase with the contact time, weight
of pottery, or pH of the aqueous solution, attaining saturation at certain values. The amounts of Eu3+ required for the saturation are 7.38, 7.00, 5.93, and 1.64 (mmol Eu) (g pottery)−1 for raw, red, black, and white samples, respectively. This sequence is parallel to that of the uptake percentage, which is
related to the surface area of each material. The sorption presumably occurs via adsorption and ion exchange. The results
were applied to decontamination of low-level liquid radioactive waste by filtration through a pot of red pottery; the effluent
was free from the radiotracer.
Published in Russian in Radiokhimiya, 2006, Vol. 48, No. 4, pp. 352–356.
The text was submitted by the authors in English. 相似文献
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Matsui T Miura A Iiyama T Shinzato N Matsuda H Furuhashi K 《Journal of hazardous materials》2005,118(1-3):255-258
The performance of an immobilized continuous fluidized reactor for salad oil-containing model wastewater was examined at a high loading rate using polyurethane as a support, to be applied in fat- and oil-containing wastewater treatment, generated by daily activities in restaurant kitchens. At an organic loading rate higher than 0.6 kg/m3/day, there was a significant amount of white solid (WS), identified as a mixture of calcium di-stearate and di-palmitate, suggesting that saturated fatty acid degradation was limited at such a high loading rate, possibly due to its solubility in the wastewater. Increased oil dispersion by the addition of a surfactant ranging from 10 to 100 microm particle size could result in less than 30 mg/l oil concentration after the treatment at 5 kg/m3/day. 相似文献
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P. Finocchiaro M. Barbagallo L. CosentinoG. Greco G. GuardoA. Pappalardo C. Scirè S. Scirè 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》2011,652(1):143-145
A prototype demonstrator for the online monitoring of short-medium term radioactive waste repositories is currently under development at INFN-LNS. Such a system is planned to be distributed, fine-grained, robust, reliable, and based on low-cost components. With the main purpose of counting gamma radiation, we implemented a new kind of mini-detector based on silicon photomultipliers and scintillating fibers that behaves like a cheap scintillating Geiger-Muller counter and is suitable to be deployed in the shape of a grid around waste drums. 相似文献
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This paper briefly discusses the uncertainties associated with predictions made using biosphere models in assessments of radioactive waste repositories. Typical models, processes influencing transport and accumulation of radionuclides and the subsequent pathways evaluation are described. Reducible and non-reducible uncertainties are presented as well as some conclusions about the predictive power of the models. 相似文献
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We analyze the basic trends in the use of electric-arc plasma for radioactive waste decontamination. We present a scheme and
performance figures of a process for a shaft-type furnace with fuel-plasma heating. We present the results of numerical and
experimental investigations for a 150-kW direct-flow plasma reactor. 相似文献
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Radioactive waste generated during the reprocessing of fuel rods by the U.S. Department of Energy (DOE) is stored in underground tanks at Hanford, Savannah River and INEEL. The liquid fraction commonly referred to as sodium bearing waste (SBW), is a highly alkaline solution containing large amounts of sodium hydroxide, sodium nitrate and sodium nitrite. It has been shown that SBW can be mixed with a reducing agent and metakaolin and then calcined at 500°–700°C to form a calcine containing sodium aluminosilicate phases such as zeolite A, hydroxysodalite and/or cancrinite. Although calcination of the pretreated SBW produces a reasonable waste form in its own right, existing regulations require that granular calcines must be solidified before they can be shipped off site. It is possible to solidify the calcine in a number of ways. The calcine can be mixed with additional metakaolin and NaOH solution followed by mild curing (90°–200°C). The solid that forms (aka hydroceramic) has both strength and suitably low leachability. The current study examines the feasibility of using a more conventional Portland cement binder to solidify the calcine. Although strength was adequate, the leachabilities of the Portland cement solidified samples were higher than those of companion samples made with metakaolin. The zeolitic phases in the calcine acted like pozzolans and reacted with the Ca(OH)2 in the Portland cement binder forming additional calcium silicate hydrate (C—S—H). Typically C—S—H is unable to host large amounts of sodium ions in its structure, thus a majority of the sodium present in the zeolites became concentrated in the pore solution present in the Portland cement binder and readily entered the leachant during PCT testing. In this instance metakaolin mixed with NaOH proved to be a superior binder for solidification purposes. 相似文献
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A significant nuclear-physical feature of boron-containing systems, distinguishing them from all other, except fluoride, systems, is considerable flux of fast neutrons generated by the (α,n) reaction on boron nuclei. The neutron flux generated on boron nuclei is higher by approximately an order of magnitude than that excited on nuclei of other components of the borobasalt matrix. The calculated and measured neutron flux values are well consistent. The neutron generation is mainly determined by the reaction of α-particles with O, Si, and Al nuclei and is thus characteristic of any aluminosilicate system. 相似文献
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Satisfactory combination of small volume of compositions incorporating 137Cs, 90Sr, and 244Cm with the admissible heat release rate can be attained by crystallization of definite compounds from high-level solutions. The concentrate of cesium isotopes is obtained by their precipitation in the form of phosphoromolybdate and, after additional storage, in the form of CsMgPO4·6H2O; the concentrate of Am, Cm, Sr, Ba, and Ln can be obtained using the known but somewhat modified (increased pH of solution) OXAL process. It is appropriate to remove Am and long-lived Cm isotopes from this concentrate also after storage ensuring the decay of 90Sr and 244Cm. The remaining rare-earth elements with traces of Am and Cm and stable isotopes of Sr and Ba can be disposed of, e.g., in the form of a mineral-like phosphate. 相似文献
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Sejvar J Fero AH Gil C Hagler RJ Santiago JL Holgado A Swenson R 《Radiation protection dosimetry》2005,115(1-4):481-485
The inventory of radioactivity that must be considered in the decommissioning of a typical 1000 MWe Spanish pressurised water reactor (PWR) was investigated as part of a generic plant decommissioning study. Analyses based on DORT models (in both R-Z and R-theta geometries) were used with representative plant operating history and core power distribution data in defining the expected neutron environment in regions near the reactor core. The activation analyses were performed by multiplying the DORT scalar fluxes by energy-dependent reaction cross sections (based on ENDF/B-VI data) to generate reaction rates on a per atom basis. The results from the ORIGEN2 computer code were also used for determining the activities associated with certain nuclides where multi-group cross section data were not available. In addition to the bulk material activation of equipment and structures near the reactor, the activated corrosion-product (or 'crud') deposits on system and equipment surfaces were considered. The projected activities associated with these sources were primarily based on plant data and experience from operating PWR plants. 相似文献
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Physicochemical features of the sorption of Sr, Cs, and U radionuclides on natural mineral sorbents (montmorillonites of Na and Ca type, kaolinites, illites) were studied. The main processes responsible for binding and retention of radionuclides are ion exchange and formation of complexes on the mineral surface. The influence of pH, salt composition of the solution, specific surface area of the sorbent, and its pore size on the radionuclide immobilization efficiency was examined. 相似文献
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A comparative study of the physicochemical and performance properties of samples of Ti(OH)1.36·(HPO4)1.32·2.3H2O ion exchanger in the finely dispersed and granulated forms, utilized for commercial production, was made. The sorption of Cs and Sr cations from solutions of various compositions was studied in batch experiments, and the diffusion coefficients of the exchanging ions were determined. The hydrolytic stability of the ion exchangers was examined with the aim to determine the optimal operation conditions. Experiments showed that the cation exchangers based on titanium phosphate are the most efficient in removal from liquid radioactive waste of induced radioactive isotopes of corrosion products, which is due to formation of weakly dissociating compounds of nonferrous metal ions with functional groups of the ion exchangers in the sorbent phase. 相似文献
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The subseabed is currently being considered as a disposal site for nuclear waste, and if it does become an option, monitoring to detect escape of the disposed material will be essential. In this paper, we define types of nuclear waste and present the dimensions of the monitoring problems that would be encountered in ocean disposal. We then summarize the characteristics of a number of physical, chemical, biological, and ecological monitoring methods. We also describe the advances and developments that will be necessary before the monitoring functions and support systems can be employed. 相似文献