Annual Report 2009/2010 - JUWEL - Forschungszentrum Jülich

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(USiO 2 2 H 2 O) may form [7]. Also coffinite may not be the only phase replacing uranite and spent fuel under these conditions. Recently an unnamed uranium silicate with a stoichiometry close to U 3 SiO 8 has been reported [6]. In conclusion that means that in case of the U 3 Si 2 -fuel corrosion under reducing conditions the presence of these alteration products may not be ignored. The measured Pu concentrations were in the range of 10 -7 to 10 -6 other studies these concentrations might describe a mixture of Pu-IV, Pu-V and Pu-VI hydro (oxy) species [6]. The determined final Am concentrations for the UAl x -Al fuel sample was about 10 -9 M and about 10 -8 M for the U 3 Si 2 -Al sample. These values are lower as the solubility of amorphous Am (OH) 3 (s). Runde [8] measured that amorphous Am (OH) 3 (s) is expected as solubility controlling phase in high concentrated salt solutions and the solubility of amorphous Am (OH) 3 (s) was determined to be about 10 -7 M. Processes which may retain Am are coprecipitation with secondary U phases and sorption on iron corrosion products. In general the concentrations for the radionuclides U, Pu and Am were determined to be about one order of magnitude higher for the used U 3 Si 2 -Al fuel sample in comparison to the UAl x -Al fuel sample. As discussed above the formation of U and Si containing solids as corrosion products cannot be excluded. These U/Si containing solids may influence the radionuclide concentrations through their solubilities and their retention capacities. Conclusion and Outlook Results of this work confirm the instantaneously corrosion of the research reactor UAl x -Al and U 3 Si 2 -Al fuel types within the test period of 3.5 years in the presence of iron-II and in the MgCl 2 -rich brine. The complete corrosion of the fuel samples was confirmed by the final Sr concentration in solution which represented the initial complete Sr inventory in the fuel. Especially the concentration of the trivalent actinide Am in solution is orders of magnitude lower than the solubility of pure Am(III) hydroxide phase and appear to be controlled by co precipitation phenomena. Comparing the behaviour of both fuel-types an influence of Si was observed. In the presence of Si the solubilities of U, Pu and Am are one order of magnitude higher. This can be due to the formation of U/Si containing solids. Further research is recommended to determine the influence of Si in detail. The synthesis of coffinite, the determination of its solubility and the formation of solid solutions with trivalent actinides are aspired. In conclusion, both investigated dispersed research reactor spent fuel samples completely dissolve in MgCl 2 -rich brine in the presence of Fe 2+ within the time period of 3.5 years. In view of the long-time scale of final disposal, this means that the radionuclides which were embedded in the fuel matrices were mobilized instantaneously. The complete inventory of Cs and Sr was found in solution. Hence, these radionuclides were classified as mobile species. To contribute to performance assessment calculations the estimation of the boundary conditions for radionuclide release from the so-called “source term” must be known. From the present results, under the experimental conditions used, clearly Cs and Sr can be regarded as mobile species. In contrast, the low concentrations of U and Pu in solution seemed to be determined by their solubility controlling solid phases. This result shows, that secondary phases which could be formed during the contact with groundwater, inhibit further radionuclide migration. For the long-lived actinide Am and for the lanthanide Eu the observed reimmobilization might be dominated by sorption on the formed secondary phases. Future 33
work will focus on the identification of these secondary phases in detail. This knowledge is needed in order to give reliable contributions to the radionuclide source term. References [1] Thamm, G.: Disposal of irradiated fuel elements from German research reactors – Status and Outlook; Trans. Int. Conf. Research Reactor Fuel Management (RRFM 1999), Bruges, Belgium, 159 (1999). [2] Metz, V., Loida, A., Bohnert, E., Schild, D., Dardenne, K., Effects of hydrogen and bromide on the -irradiated UO2(s) in NaCl brine, Radiochim. Acta 96, 637 (2008). [3] Loida, A., Grambow, B., Geckeis, H., Anoxic corrosion of various high burnup spent fuel samples, Journal of Nuclear Materials, 238, 11 (1996). [4] Curtius, H., Kaiser, G., Paprigas, Z., Ufer, K., Müller, E., Enge, R., Brücher, H., Untersuchungen zum Verhalten von Forschungsreaktorbrennelementen in den Wirtsgesteinsformationswässern möglicher Endläger, Berichte des <strong>Forschungszentrum</strong>s <strong>Jülich</strong>, 4237, ISSN 0944-2952. (2006). [5] Grambow, B., Müller, R., Chemistry of corrosion in high saline brines, Mater. Res. Soc. Symp. Proc. 176, 229 (1990). [6] Loida, A., Grambow, B., Geckeis, H., Dressler, P., Process controlling radionuclide release from spent fuel, Mat. Res. Soc. Symp. Proc. 353, 577 (1995). [7] Janeczek, J., Ewing, R.C., Coffinitization – A Mechanism for the Alteration of UO2 under Reducing Conditions, Mat. Res. Soc. Symp. Proc. 257, 497 (1992). [8] Runde, W., Zum chemischen Verhalten von drei- und fünfwertigen Americium in salinen NaCl-Lösungen” Dissertation, Technische Universität München (1993). 34
Page 1 and 2: Mitglied Mitglied der der Helmholtz
Page 4 and 5: Forschungszentrum Jülich GmbH Inst
Page 6 and 7: TABLE OF CONTENTS 1 Preface .......
Page 8: 6.2.2 Doctoral Thesis .............
Page 11 and 12: state of NRW. The collaborative pro
Page 13 and 14: 2 Institute’s Profile Due to the
Page 15 and 16: 2.2. Organization chart Reactor Saf
Page 17 and 18: 3 Key Research Topics 3.1. Long Ter
Page 19 and 20: actinide co-conversion into polyact
Page 21 and 22: Fig. 7: Non-destructive analytical
Page 23 and 24: Fig. 9: Thermal treatment of an AVR
Page 25 and 26: 3.8. Product Quality Control of Rad
Page 27 and 28: 3.8.2 Product Quality Control of Lo
Page 29 and 30: The advantage of working at low vac
Page 31 and 32: NdPO 4 powder sample, directly rece
Page 33 and 34: 4.5. Non-destructive assay testing
Page 35 and 36: 5 Scientific and Technical Reports
Page 37: Results and Discussion The irradiat
Page 41 and 42: Different solvents (iso-propanol an
Page 43 and 44: e & j) Aggregates of aluminium oxid
Page 45 and 46: Experimental details The corrosion
Page 47 and 48: Intensity [CPS] 500 400 300 200 100
Page 49 and 50: Fig. 24: Left: High resolution TEM
Page 51 and 52: a) MD model [10] b) Derived Lesukit
Page 53 and 54: 5.4. Minor actinide(III) recovery f
Page 55 and 56: Extensive extraction studies were p
Page 57 and 58: of the extraction properties of the
Page 59 and 60: Cm(III) together with the lanthanid
Page 61 and 62: using a mixture of CyMe4BTBP and TO
Page 63 and 64: A more challenging route studied wi
Page 65 and 66: These preliminary results show that
Page 67 and 68: The 1-cycle SANEX process is intend
Page 69 and 70: Continuous counter-current tests us
Page 71 and 72: Conclusion In this work, it was sho
Page 73 and 74: shaken by a vortex mixer for 15 min
Page 75 and 76: 100 100 Distribution ratio 10 1 0.1
Page 77 and 78: Tab. 15: The distribution ratios of
Page 79 and 80: 5.7. Synthesis and thermal treatmen
Page 81 and 82: Acid-Deficient Uranyl-Nitrate via d
Page 83 and 84: Optical investigation showed a noti
Page 85 and 86: TG /% 100 98 96 94 92 90 88 86 84 8
Page 87 and 88: Radiolysis in the aqueous solutions
Page 89 and 90:
is about 4% while the one of the rh
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Fig. 59: Compressibility curve for
Page 93 and 94:
Conclusion and outlook Monazite-typ
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Fig. 63: Description of the unit ce
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agents for the synthesis of neodymi
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100 TG 785°C Exo DSC 0,2 0,0 90 -0
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After synthesis the product was cen
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process of monazite and additional
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Tab. 18: Lattice parameters determi
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Conclusions For Sm 1-x Ce x PO 4 mo
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5.11. Raman Spectra of Synthetic Ra
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The numerical values of all measure
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knowledge, these special relationsh
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Fig. 80: Raman spectra of LaPO 4 ir
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5.12. MC simulation of thermal neut
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content was replaced by hydrogen. C
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constant for hydrogen concentration
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with a 0 1 -183.88 ± 8.55 and a 2
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5.13. An Improved Method for the no
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2 2 2 d0 R ds d0 dw la( )
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The relative uncertainty for the ac
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In the drum, 4 ‘hot spots’ for
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activity of Cs-137 is much more und
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gamma-ray detector approximated by
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shown in Fig. 96. In both cases the
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econstruction than the old calculat
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Neutron capture cross sections and
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Outlook The evaluated data will be
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from carbon-based HTR fuel elements
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Fig. 102: 3D volume reconstructions
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dislocate the 14 C atom from its pr
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It can be seen that nearly all trit
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Acknowledgement The authors like to
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development by investigations of ga
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Fig. 109: The left picture shows th
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[2] A European Roadmap for Developi
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from airborne SWIR Full Spectrum Im
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Fig. 113: Visualization of the vege
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number of training samples up to 19
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Acknowledgements The work presented
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three approaches has severe drawbac
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neighbours from the list of merge c
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it gives a difference in segmentati
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[6] I. Niemeyer, F. Bachmann, A. Jo
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Monitoring 3 cooperated intensively
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facilities and other treaty related
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parameters of the SAR system, such
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The MGD products used in the study
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Fig. 134 contains the result for th
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[2] H. Maître (ed.), Processing of
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Preparatory Committee to allocate t
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unconditional security assurances f
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safeguards was also requested. Deci
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[16] United Nations Security Counci
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5.24. Development and Application o
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Hardware layer The hardware layer i
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So in most applications the scale u
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The ENDF-B/V and ENDF-B/VI librarie
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5.26. Product control of waste prod
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Polysiloxane which has been investi
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acceptance requirements [3]. In the
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Fig. 145: List of description and d
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6.1. Courses taught at universities
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Umwelt / Energy & Environment 2010;
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6.5. Institute Seminar The IEK-6 or
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6.5.3 Invited talks 2009 30.04.2009
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21.09.2010 Dr. N. Evans: The Chemis
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8 Selected R&D projects 8.1. EU pro
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K. Aymanns: Nominated as deputy re
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Bukaemskiy A.A., Barrier D., Modolo
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11.2. Publications 2009 11.2.1 Jour
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Rezniczek, A.; Richter, B.; Jussofi
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Daniels, H.: Co-conversion of actin
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11.3. Publications 2010 11.3.1 Jour
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Sypula, M.; Wilden, A.; Schreinemac
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(Partitioning) - Stabilitätsunters
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Modolo, G.; Bosbach, D.; Geist, A.;
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12 How to reach us Postal Address F
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By train: Take the train from Aache
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Schriften des Forschungszentrums J
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