The 12th International Conference on Environmental ... - Events

Session 12 Abstracts
directly opposite to those of plant root biomass. A high level 14Cof 14C radioactivity was observed on the entire root surface of nonsterilized
root in the incubation experiment, and 14C radioactivity in the solution also remarkably decreased from 7 h to 96 h after
the 14C addition. <strong>The</strong>se results suggest that the amount of 14C-acetic acid absorbed by the plant through the roots is very small.
However, the plant absorbs 14C-acetic acid through breaks in the roots. Once 14C-acetic acid is inside the plant, it immediately
transfers to the shoots. Degradation of 14C radioactivity in the solution and 14C fixation on the root surface arise from the context
of microbial activities.
C) CHARACTERISTICS ON THE SAP-BASED WASTEFORM CONTAINING
RADIOACTIVE MOLTEN SALT WASTE - 16137
Hwan-Seo Park, In-Tae Kim, Hwan-Young Kim,
Byeung-Gil Ahn, Han-Soo Lee, Korea Atomic Energy Research Institute (Korea)
This study investigated a unique wasteform containing molten salt wastes which are generated from the pyro-process for the
spent fuel treatment. Using a conventional sol-gel process, SiO2-Al2O3-P2O5 (SAP) inorganic material reactive to metal chlorides
were prepared. By using this inorganic composite, a monolithic wasteform were sucessfully fabricated via a simple process, reaction
at 650℃ and sintering at 1100℃. This unique wasteform should be qualified if it meets the requirements for final disposal.
For this reasons, this paper characterized its chemical durability, physical properties, morphology and etc. In the SAP, there are
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
were converted into metal aluminosilicate(LixAlxSi1-xO2-x ) and metal phosphate(Li3PO4 and Cs2AlP3O10 ) while alkali earth
and rare earth chlorides were changed into only metal phosphates (Sr5(PO4)3Cl and CePO4). <strong>The</strong>se reaction products were compatible
to borosilicate glasses which were functioned as a chemical binder for metal aluminosilicate and a physical binder for metal
phosphates. By these phenomena, the wasteform was formed homogenously above μm scale. This would affect the leaching behaviors
of each radionuclides or component of binder. <strong>The</strong> leach rates of Cs and Sr under the PCT-A test condition were about 10- 3g/m2day. <strong>The</strong> physical properties (Cp, k, ρ, Hv, and etc) were very reasonable. Other leaching tests (ISO, MCC-1P) are on-going.
From these results, it could be concluded that SAP can be considered as an effective stabilizer on metal chlorides and the method
using SAP will give a chance to minimize the waste volume for the final disposal of salt wastes through further researches.
D) REALISTIC INTEGRATION OF SORPTION PROCESSES IN TRANSPORT
PROGRAMS FOR LONG-TERM SAFETY ANALYSIS - 16370
Madlen Stockmann, FZ Dresden-Rossendorf (Germany);Vinzenz Brendler, Forschungszentrum Dresden-Rossendorf e.
(Germany) Ulrich Noseck, Gesellschaft für Anlagen- und Reaktorsicherheit (GRS) mbH (Germany)
Safety assessment of radioactive waste repositories in salt rock formations considers the overlying sedimentary rock above the
salt domes as important barrier. Sorption on mineral surfaces of the sediment can retard the transport of many contaminants, namely
radionuclides, considerably. Previously, the retention of radionuclides has been described in respective computer programs by
temporally constant distribution coefficients.
In the present study, an existing transport program r3t is extended towards a more realistic description of the radionuclide
migration under changing geochemical conditions. <strong>The</strong> methodology developed here is based on a description of the sorption of
radionuclides as a function of important influence factors such as pH, pCO2, ionic strength, and the mineral phases being present.
Applying surface complexation models, multidimensional matrices of smart Kd-values can be computed a-priori. <strong>The</strong> reactive
transport model r3t then can call for each time-space point Kd values adapted for the correct geochemical conditions. <strong>The</strong> biggest
challenge here was finding a fast and robust algorithm for search and averaging in multidimensional matrices with non-equidistant
population. First results are presented for a test case where respective site-specific geochemical conditions in the overlying rock
have been evaluated, mainly consisting of tertiary and quaternary sands and clays.
E) EMERGING CHALLENGES IN NUCLEAR WASTE MANAGEMENT IN INDIA
IN VIEW OF ITS EXPANSION PROGRAMME - 16364
Murty.S Ganti, Andhra University (India)
Presently the contribution of nuclear power to the total power production in India is around 4000 MWe and about 2500 MWe
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 options.
Estimates show that in India about 2000 t of natural uranium was irradiated in PHWRs 533t in research reactors and 397t in
BWR by the end of the year 2000. How ever the BWR fuel which is slightly enriched and spplied remained unprocessed ( as spent
fuel) while the rest is under reprocessing. Thisese operations generated about 5000 cubic meters of HLW 35000 cubic meters of
ILW.
India’s reprocessing was initiated in 1964 with PUREX technology with Al clad natural uranium from Canada India research
reactorat Trombay. Based on this experiance reprocessing facilities for power reactor fuels was developed sucesfully.Further fast
Breeder test reactor mixed carbide fuel reprocessing plant was installed at kalpakkam with a view to process fuels from FBR with
mixed oxide and metallic fuels in future.<strong>The</strong> challenges to be addressed in tackling these future fuels with high burn up levels will
be highlighted.
F) TOWARDS AN IMPLEMENTING GEOLOGICAL DISPOSAL TECHNOLOGY PLATFORM IN EUROPE - 16365
Marjatta Palmu, Posiva Oy, (Finland); Torsten Eng, SKB (Sweden)
Several European waste management organizations have started the work on creating a technology platform to accelerate the
implementation of deep geological disposal of radioactive waste in Europe. <strong>The</strong>re is an increasing consensus in the international
community about geological disposal as the preferred option for solving the long-term management of spent fuel, high-level waste,
and other long-lived radioactive wastes. At the same time, the European citizens have a widespread wish for a solution for highlevel
radioactive waste disposal. A majority of the European countries with nuclear power have active waste management programmes,
but the current status and the main challenges of those programmes vary. <strong>The</strong> most advanced waste management programmes
in Europe (i.e. Sweden, Finland and France) are prepared to start the licensing process of deep geological disposal facilities
within the next decade. Despite the differences between the timing and the challenges of the different programmes, there is a
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