The 13th International Conference on Environmental ... - Events

Abstracts
12) 40221 – Decontamination of Radioactive Concrete Wastes by <strong>The</strong>rmal and Mechanical Processes
B.Y. Min, Ki Won Lee, Un Soo Chung, W.K Choi, Kune-Woo Lee, KAERI (Korea Rep.)
<strong>The</strong> purpose of this paper is to provide the results of a series of volume reduction tests consucted in thermal and
mechanical processes. Korea Atomic Energy Research Institites (KAERI) has developed volume reduction technology
applocable to an activated heavy concrete waste generated by dismantled Korea research reactor 2 (KRR-2) and a
uranium conversion plant (UCP). the volume reductuin could be achieved above 70% by lab scale test by thermal and
mechanical separation processes. Pilot test were performed with radioactively contaninated dismantled concrete waste.
<strong>The</strong> developed processes were quite effective for volume reduction of radioactively contaminated dismantled concrete
waste.
13) 40302 – Latex Particles Functionalized with Transition Metals Ferrocyanides for Cesium Uptake and
Decontamination of Solid Bulk Materials
Dmitry Marinin, Valentin Avramenko, Dmitry Marinin, Valentin Sergienko,
Institute of Chemistry FEDRAS (Russia);
Veniamin Zheleznov, Irina Sheveleva, Russian Academy of Sciences (Russia)
Decontamination of spent ion-exchange resins, corrosion-unstable metal structures, soil, ground, and construction
materials contaminated by fission, corrosion and transuranic radionuclides remains one of the most urgent and
complicated ecological problems. Among the existing methods having different efficiencies in regard to such materials
decontamination, application of selective sorbents put into a humid medium to be decontaminated (ground, bulk
materials) appears to be rather extensive. However, the efficiency of such an approach is significantly limited by
difficulties concerned with uniform sorbent distribution in porous media and completeness of spent sorbents removal for
final disposal. In this paper we suggest a principally new approach to preparation of colloid-stable selective sorbents for
cesium uptake using immobilization of transition metals (cobalt, nickel, and copper) ferrocyanides in nanosized
carboxylic latex emulsions. <strong>The</strong> effects of ferrocyanide composition, pH, and media salinity on the sorption properties of
the colloid-stable sorbents toward cesium ions were studied in solutions containing up to 200 g/l sodium nitrate or
potassium chloride. <strong>The</strong> sorption capacities of the colloid sorbents based on mixed potassium/transition metals
ferrocyanides were in the range 1.45-1.86 mol Cs/mol ferrocyanide with the highest value found for the copper
ferrocyanide. It was shown that the obtained colloid-stable sorbents were capable to penetrate through bulk materials
without filtration that makes them applicable for decontamination of solids, e.g. soils, zeolites, spent ion-exchange resins
contaminated with cesium radionuclides. After decontamination of liquid or solid radioactive wastes the colloid-stable
sorbents can be easily separated from solutions by precipitation with cationic flocculants providing localization of
radionuclides in a small volume of the precipitates formed. Besides, functionalized latex particles can be used for
preparation of carbon fiber/ferrocyanide composite materials for cesium uptake using electrodeposition method.
Application of the carbon fibers as an inert support for ferrocyanides, in general, significantly improves the sorption
kinetics, but washing out of ferrocyanide fines from the fiber surface limits the potential of such materials. When
ferrocyanides are deposited in a form of nanocrystals stabilized by latexes which undergo electropolymerization on the
fiber surface, the thin polymeric film formed substantially improves the stability of the composite and prevents loss of
ferrocyanide during sorbent application. <strong>The</strong> effect of electrodeposition conditions on composite morphology,
ferrocyanide loading and cesium distribution coefficient in media with different salinity has been discussed.
SESSION H11: SF/TRU/HLW Poster
1) 40001 – Investigation of Colloid-facilitated Effects on the Radionuclides Migration in the Fractured Rock with
a Kinetic Solubility-Limited Dissolution Model
Chun-Ping Jen,Nation Chung Cheng University (Taiwan);
Neng-Chuan Tien, Energy and Environment Research Laboratories,
Industrial Technology Research Institute (Taiwan)
Nuclides can move with the groundwater either as solutes or colloids, where the latter mechanism generally results
in much shorter traveling time as they interact strongly with solid phases, such as actinides. It is therefore essential to
assess the relative importance of these two transport mechanisms for different nuclides. <strong>The</strong> relative importance of
colloids depends on the nature and concentration of colloids in groundwater. Plutonium (Pu), neptunium (Np), uranium
(U) and americium (Am) are four nuclides of concern for long-term emplacement of nuclear wastes at potential
repository sites. If attached to iron oxide, clay or silica colloids in groundwater. Strong sorption of the actinides by
colloids in groundwater may facilitate transport of these nuclides along potential flow paths. Solubility-limited
dissolution model models can be used to determine the release of the safety assessment for nuclear waste in geological
disposal sites. <strong>The</strong> present study investigates the effect of colloid on the transport of solubility limited nuclide under the
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