The 12th International Conference on Environmental ... - Events
The 12th International Conference on Environmental ... - Events
The 12th International Conference on Environmental ... - Events
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Sessi<strong>on</strong> 12 Abstracts<br />
directly opposite to those of plant root biomass. A high level 14Cof 14C radioactivity was observed <strong>on</strong> the entire root surface of n<strong>on</strong>sterilized<br />
root in the incubati<strong>on</strong> experiment, and 14C radioactivity in the soluti<strong>on</strong> also remarkably decreased from 7 h to 96 h after<br />
the 14C additi<strong>on</strong>. <str<strong>on</strong>g>The</str<strong>on</strong>g>se results suggest that the amount of 14C-acetic acid absorbed by the plant through the roots is very small.<br />
However, the plant absorbs 14C-acetic acid through breaks in the roots. Once 14C-acetic acid is inside the plant, it immediately<br />
transfers to the shoots. Degradati<strong>on</strong> of 14C radioactivity in the soluti<strong>on</strong> and 14C fixati<strong>on</strong> <strong>on</strong> the root surface arise from the c<strong>on</strong>text<br />
of microbial activities.<br />
C) CHARACTERISTICS ON THE SAP-BASED WASTEFORM CONTAINING<br />
RADIOACTIVE MOLTEN SALT WASTE - 16137<br />
Hwan-Seo Park, In-Tae Kim, Hwan-Young Kim,<br />
Byeung-Gil Ahn, Han-Soo Lee, Korea Atomic Energy Research Institute (Korea)<br />
This study investigated a unique wasteform c<strong>on</strong>taining molten salt wastes which are generated from the pyro-process for the<br />
spent fuel treatment. Using a c<strong>on</strong>venti<strong>on</strong>al sol-gel process, SiO2-Al2O3-P2O5 (SAP) inorganic material reactive to metal chlorides<br />
were prepared. By using this inorganic composite, a m<strong>on</strong>olithic wasteform were sucessfully fabricated via a simple process, reacti<strong>on</strong><br />
at 650℃ and sintering at 1100℃. This unique wasteform should be qualified if it meets the requirements for final disposal.<br />
For this reas<strong>on</strong>s, this paper characterized its chemical durability, physical properties, morphology and etc. In the SAP, there are<br />
three kinds of chains, Si-O-Si as a main chain, Si-O-Al as a side chain and Al-O-P/P-O-P as a reactive chain. Alkali metal chlorides<br />
were c<strong>on</strong>verted into metal aluminosilicate(LixAlxSi1-xO2-x ) and metal phosphate(Li3PO4 and Cs2AlP3O10 ) while alkali earth<br />
and rare earth chlorides were changed into <strong>on</strong>ly metal phosphates (Sr5(PO4)3Cl and CePO4). <str<strong>on</strong>g>The</str<strong>on</strong>g>se reacti<strong>on</strong> products were compatible<br />
to borosilicate glasses which were functi<strong>on</strong>ed as a chemical binder for metal aluminosilicate and a physical binder for metal<br />
phosphates. By these phenomena, the wasteform was formed homogenously above μm scale. This would affect the leaching behaviors<br />
of each radi<strong>on</strong>uclides or comp<strong>on</strong>ent of binder. <str<strong>on</strong>g>The</str<strong>on</strong>g> leach rates of Cs and Sr under the PCT-A test c<strong>on</strong>diti<strong>on</strong> were about 10- 3g/m2day. <str<strong>on</strong>g>The</str<strong>on</strong>g> physical properties (Cp, k, ρ, Hv, and etc) were very reas<strong>on</strong>able. Other leaching tests (ISO, MCC-1P) are <strong>on</strong>-going.<br />
From these results, it could be c<strong>on</strong>cluded that SAP can be c<strong>on</strong>sidered as an effective stabilizer <strong>on</strong> metal chlorides and the method<br />
using SAP will give a chance to minimize the waste volume for the final disposal of salt wastes through further researches.<br />
D) REALISTIC INTEGRATION OF SORPTION PROCESSES IN TRANSPORT<br />
PROGRAMS FOR LONG-TERM SAFETY ANALYSIS - 16370<br />
Madlen Stockmann, FZ Dresden-Rossendorf (Germany);Vinzenz Brendler, Forschungszentrum Dresden-Rossendorf e.<br />
(Germany) Ulrich Noseck, Gesellschaft für Anlagen- und Reaktorsicherheit (GRS) mbH (Germany)<br />
Safety assessment of radioactive waste repositories in salt rock formati<strong>on</strong>s c<strong>on</strong>siders the overlying sedimentary rock above the<br />
salt domes as important barrier. Sorpti<strong>on</strong> <strong>on</strong> mineral surfaces of the sediment can retard the transport of many c<strong>on</strong>taminants, namely<br />
radi<strong>on</strong>uclides, c<strong>on</strong>siderably. Previously, the retenti<strong>on</strong> of radi<strong>on</strong>uclides has been described in respective computer programs by<br />
temporally c<strong>on</strong>stant distributi<strong>on</strong> coefficients.<br />
In the present study, an existing transport program r3t is extended towards a more realistic descripti<strong>on</strong> of the radi<strong>on</strong>uclide<br />
migrati<strong>on</strong> under changing geochemical c<strong>on</strong>diti<strong>on</strong>s. <str<strong>on</strong>g>The</str<strong>on</strong>g> methodology developed here is based <strong>on</strong> a descripti<strong>on</strong> of the sorpti<strong>on</strong> of<br />
radi<strong>on</strong>uclides as a functi<strong>on</strong> of important influence factors such as pH, pCO2, i<strong>on</strong>ic strength, and the mineral phases being present.<br />
Applying surface complexati<strong>on</strong> models, multidimensi<strong>on</strong>al matrices of smart Kd-values can be computed a-priori. <str<strong>on</strong>g>The</str<strong>on</strong>g> reactive<br />
transport model r3t then can call for each time-space point Kd values adapted for the correct geochemical c<strong>on</strong>diti<strong>on</strong>s. <str<strong>on</strong>g>The</str<strong>on</strong>g> biggest<br />
challenge here was finding a fast and robust algorithm for search and averaging in multidimensi<strong>on</strong>al matrices with n<strong>on</strong>-equidistant<br />
populati<strong>on</strong>. First results are presented for a test case where respective site-specific geochemical c<strong>on</strong>diti<strong>on</strong>s in the overlying rock<br />
have been evaluated, mainly c<strong>on</strong>sisting of tertiary and quaternary sands and clays.<br />
E) EMERGING CHALLENGES IN NUCLEAR WASTE MANAGEMENT IN INDIA<br />
IN VIEW OF ITS EXPANSION PROGRAMME - 16364<br />
Murty.S Ganti, Andhra University (India)<br />
Presently the c<strong>on</strong>tributi<strong>on</strong> of nuclear power to the total power producti<strong>on</strong> in India is around 4000 MWe and about 2500 MWe<br />
will be added by the year 2010. Plans are are ahead to add another 15000 MWe by the end of XI th plan with import opti<strong>on</strong>s.<br />
Estimates show that in India about 2000 t of natural uranium was irradiated in PHWRs 533t in research reactors and 397t in<br />
BWR by the end of the year 2000. How ever the BWR fuel which is slightly enriched and spplied remained unprocessed ( as spent<br />
fuel) while the rest is under reprocessing. Thisese operati<strong>on</strong>s generated about 5000 cubic meters of HLW 35000 cubic meters of<br />
ILW.<br />
India’s reprocessing was initiated in 1964 with PUREX technology with Al clad natural uranium from Canada India research<br />
reactorat Trombay. Based <strong>on</strong> this experiance reprocessing facilities for power reactor fuels was developed sucesfully.Further fast<br />
Breeder test reactor mixed carbide fuel reprocessing plant was installed at kalpakkam with a view to process fuels from FBR with<br />
mixed oxide and metallic fuels in future.<str<strong>on</strong>g>The</str<strong>on</strong>g> challenges to be addressed in tackling these future fuels with high burn up levels will<br />
be highlighted.<br />
F) TOWARDS AN IMPLEMENTING GEOLOGICAL DISPOSAL TECHNOLOGY PLATFORM IN EUROPE - 16365<br />
Marjatta Palmu, Posiva Oy, (Finland); Torsten Eng, SKB (Sweden)<br />
Several European waste management organizati<strong>on</strong>s have started the work <strong>on</strong> creating a technology platform to accelerate the<br />
implementati<strong>on</strong> of deep geological disposal of radioactive waste in Europe. <str<strong>on</strong>g>The</str<strong>on</strong>g>re is an increasing c<strong>on</strong>sensus in the internati<strong>on</strong>al<br />
community about geological disposal as the preferred opti<strong>on</strong> for solving the l<strong>on</strong>g-term management of spent fuel, high-level waste,<br />
and other l<strong>on</strong>g-lived radioactive wastes. At the same time, the European citizens have a widespread wish for a soluti<strong>on</strong> for highlevel<br />
radioactive waste disposal. A majority of the European countries with nuclear power have active waste management programmes,<br />
but the current status and the main challenges of those programmes vary. <str<strong>on</strong>g>The</str<strong>on</strong>g> most advanced waste management programmes<br />
in Europe (i.e. Sweden, Finland and France) are prepared to start the licensing process of deep geological disposal facilities<br />
within the next decade. Despite the differences between the timing and the challenges of the different programmes, there is a<br />
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