Study of SIMFUEL corrosion under hyper-alkaline conditions in the presence of silicate and calcium

ABSTRACTCement has been considered as a possible material present in the Deep Geological Disposal (DGD) [1] . In order to determine the effect of cementitious waters on the oxidation of the surface of Spent Fuel (SF), a series of electrochemical experiments were performed, to study the influence of two main components of cementitious water: calcium and silicate.Test solutions with Na2SiO3 and/or CaCl2 were prepared at pH 12 and NaCl 0.1 mol·dm-3 as ionic medium. A 3 at.% doped SIMFUEL was used to perform cyclic voltammetric (CV), potentiostatic and corrosion potential (ECORR) experiments. After potentiostatic and ECORR experiments, the SIMFUEL surface was analyzed using X-Ray Photoelecton Spectroscopy (XPS).The results showed that the presence of silicate decreased the SIMFUEL oxidation between -100 mV and 300 mV. When Ca2+ was added, the whole oxidation process was shifted to higher potentials which indicated a protective effect of the combination of Ca2+ and SiO32- . The XPS results obtained after potentiostatic experiments at 200 mV showed that the presence of silicate partially suppressed the oxidation of SIMFUEL, as indicated by the contribution of both U(IV) and U(V) XPS to the U 4f7/2 band (∼ 38%). After the addition of calcium, the predominant uranium oxidized state contribution on the surface was U(V) (40%). After the ECORR experiments, the ECORR values were similar either with or without silicate in solution (-80 mV and -70 mV respectively). The resulting surface also exhibited a similar composition. When calcium was added to the electrolyte, the ECORR value was suppressed to -105 mV, and XPS showed that the surface was less oxidized than with the other two electrolytes.

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Specific outcomes of the research on the spent fuel long-term evolution in interim dry storage and deep geological disposal

Journal of Nuclear Materials ◽

10.1016/j.jnucmat.2006.02.061 ◽

2006 ◽

Vol 352 (1-3) ◽

pp. 246-253 ◽

Cited By ~ 41

Author(s):

C. Ferry ◽

C. Poinssot ◽

C. Cappelaere ◽

L. Desgranges ◽

C. Jegou ◽

...

Keyword(s):

Long Term Evolution ◽

Spent Fuel ◽

Geological Disposal ◽

Dry Storage ◽

Term Evolution ◽

Deep Geological Disposal

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Zirconia Inert Matrix Fuel for Plutonium and Minor Actinides Management in Reactors and as an Ultimate Waste Form

MRS Proceedings ◽

10.1557/proc-1104-nn03-01 ◽

2008 ◽

Vol 1104 ◽

Cited By ~ 3

Author(s):

Claude Degueldre ◽

Wolfgang Wiesenack

Keyword(s):

Near Field ◽

Fission Products ◽

Minor Actinides ◽

Spent Fuel ◽

Geological Disposal ◽

Inert Matrix Fuel ◽

Inert Matrix ◽

Fuel Pellets ◽

Reducing Conditions ◽

Deep Geological Disposal

AbstractA plutonia stabilised zirconia doped with yttria and erbia has been selected as inert matrix fuel (IMF) at PSI. The results of experimental irradiation tests on yttria-stabilised zirconia doped with plutonia and erbia pellets in the Halden research reactor as well as a study of zirconia solubility are presented. Zirconia must be stabilised by yttria to form a solid solution such as MAz(Y,Er)yPuxZr1-yO2-ζ where minor actinides (MA) oxides are also soluble. (Er,Y,Pu,Zr)O2-ζ (with Pu containing 5% Am) was successfully prepared at PSI and irradiated in the Halden reactor. Emphasis is given on the zirconia-IMF properties under in-pile irradiation, on the fuel material centre temperatures and on the fission gas release. The retention of fission products in zirconia may be stronger at similar temperature, compared to UO2. The outstanding behaviour of plutonia-zirconia inert matrix fuel is compared to the classical (U,Pu)O2 fuels. The properties of the spent fuel pellets are presented focusing on the once through strategy. For this strategy, low solubility of the inert matrix is required for geological disposal. This parameter was studied in detail for a range of solutions corresponding to groundwater under near field conditions. Under these conditions the IMF solubility is about 109 times smaller than glass, several orders of magnitude lower than UO2 in oxidising conditions (Yucca Mountain) and comparable in reducing conditions, which makes the zirconia material very attractive for deep geological disposal. The behaviour of plutonia-zirconia inert matrix fuel is discussed within a burn and bury strategy.

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Behavior of UO2 in the RBMK-1000 Spent Fuel under Oxidizing Conditions

MRS Proceedings ◽

10.1557/proc-824-cc8.51 ◽

2004 ◽

Vol 824 ◽

Author(s):

A. B. Kolyadin ◽

V. Ya. Mishin ◽

K. Ya. Mishin ◽

A. S. Aloy ◽

T. I. Koltsova

Keyword(s):

Thermal Oxidation ◽

Spent Nuclear Fuel ◽

Oxidation Process ◽

Spent Fuel ◽

X Ray Diffraction ◽

X Ray ◽

Dry Storage ◽

Different Temperatures ◽

Xrd Techniques

AbstractThe oxidation of UO2–type spent nuclear fuel (SNF) in gaseousmedia was studied at different temperatures and oxygen contents using gravimetric and powder X-ray diffraction (XRD) techniques. The aim of the study was to determine the mechanism(s) of thermal-oxidation alteration of SNF during long-term dry storage. The samples used in the experiments were chips of RBMK-1000 fuel rods.Oxidation of UO2with a mean burn-up of 10.7 and 19.73 MW d/kg in humid air was observed at a temperature as low as 150°C. At 200°C nearly all of the UO2was transformed into U3O8 between 3500-4000 hours. In a humid nitrogen environment containing of 0.05-1.3 vol. % oxygen at 300°C, the UO2 completely transformed to U3O8 between 2500-3000 hours. Oxidation of UO2in samples with small amounts of jacket damage (e.g., <0.04 MM2)ll progresses more slowly and after â3000 hours the oxygen-to-uranium ratio was 2.56.Stabilization of the oxidation process was not observed in the fuel samples upto an O/U ratio of 2.4, which may be attributed to the smallburn-up of the fuel under investigation.

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Partitioning and transmutation contribution of MYRRHA to an EU strategy for HLW management and main achievements of MYRRHA related FP7 and H2020 projects: MYRTE, MARISA, MAXSIMA, SEARCH, MAX, FREYA, ARCAS

EPJ Nuclear Sciences & Technologies ◽

10.1051/epjn/2019038 ◽

2020 ◽

Vol 6 ◽

pp. 33

Author(s):

Hamid Aït Abderrahim ◽

Peter Baeten ◽

Alain Sneyers ◽

Marc Schyns ◽

Paul Schuurmans ◽

...

Keyword(s):

Waste Management ◽

Nuclear Power ◽

Power Plants ◽

Fuel Cycle ◽

Economic Feasibility ◽

Potential Contribution ◽

Spent Fuel ◽

Geological Disposal ◽

Deep Geological Disposal ◽

Partitioning And Transmutation

Today, nuclear power produces 11% of the world's electricity. Nuclear power plants produce virtually no greenhouse gases or air pollutants during their operation. Emissions over their entire life cycle are very low. Nuclear energy's potential is essential to achieving a deeply decarbonized energy future in many regions of the world as of today and for decades to come, the main value of nuclear energy lies in its potential contribution to decarbonizing the power sector. Nuclear energy's future role, however, is highly uncertain for several reasons: chiefly, escalating costs and, the persistence of historical challenges such as spent fuel and radioactive waste management. Advanced nuclear fuel recycling technologies can enable full use of natural energy resources while minimizing proliferation concerns as well as the volume and longevity of nuclear waste. Partitioning and Transmutation (P&T) has been pointed out in numerous studies as the strategy that can relax constraints on geological disposal, e.g. by reducing the waste radiotoxicity and the footprint of the underground facility. Therefore, a special effort has been made to investigate the potential role of P&T and the related options for waste management all along the fuel cycle. Transmutation based on critical or sub-critical fast spectrum transmuters should be evaluated in order to assess its technical and economic feasibility and capacity, which could ease deep geological disposal implementation.

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Microbial Reduction of Fe(III) under Alkaline Conditions Relevant to Geological Disposal

Applied and Environmental Microbiology ◽

10.1128/aem.03063-12 ◽

2013 ◽

Vol 79 (11) ◽

pp. 3320-3326 ◽

Cited By ~ 43

Author(s):

Adam J. Williamson ◽

Katherine Morris ◽

Sam Shaw ◽

James M. Byrne ◽

Christopher Boothman ◽

...

Keyword(s):

Magnetic Circular Dichroism ◽

Microbial Reduction ◽

Geological Disposal ◽

X Ray ◽

Electron Shuttles ◽

Disposal Facility ◽

Transmission Electron ◽

Alkaline Conditions ◽

Set Up ◽

Final Extent

ABSTRACTTo determine whether biologically mediated Fe(III) reduction is possible under alkaline conditions in systems of relevance to geological disposal of radioactive wastes, a series of microcosm experiments was set up using hyperalkaline sediments (pH ∼11.8) surrounding a legacy lime working site in Buxton, United Kingdom. The microcosms were incubated for 28 days and held at pH 10. There was clear evidence for anoxic microbial activity, with consumption of lactate (added as an electron donor) concomitant with the reduction of Fe(III) as ferrihydrite (added as the electron acceptor). The products of microbial Fe(III) reduction were black and magnetic, and a range of analyses, including X-ray diffraction, transmission electron microscopy, X-ray absorption spectroscopy, and X-ray magnetic circular dichroism confirmed the extensive formation of biomagnetite in this system. The addition of soluble exogenous and endogenous electron shuttles such as the humic analogue anthraquinone-2,6-disulfonate and riboflavin increased both the initial rate and the final extent of Fe(III) reduction in comparison to the nonamended experiments. In addition, a soluble humic acid (Aldrich) also increased both the rate and the extent of Fe(III) reduction. These results show that microbial Fe(III) reduction can occur in conditions relevant to a geological disposal facility containing cement-based wasteforms that has evolved into a high pH environment over prolonged periods of time (>100,000 years). The potential impact of such processes on the biogeochemistry of a geological disposal facility is discussed, including possible coupling to the redox conditions and solubility of key radionuclides.

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Preliminary modelling of radionuclide migration in the argillaceous sediments of the Sumer Formation (Northwestern Bulgaria)

Geologica Balcanica ◽

10.52321/geolbalc.49.3.13 ◽

2020 ◽

Vol 49 (3) ◽

pp. 13-18

Author(s):

Dimitar Antonov ◽

Madlena Tsvetkova ◽

Doncho Karastanev

Keyword(s):

Radioactive Waste Disposal ◽

High Level Waste ◽

Spent Fuel ◽

Radionuclide Migration ◽

Geological Disposal ◽

Disposal Facility ◽

Deep Geological Disposal ◽

High Level ◽

Host Rocks ◽

Selection Of

In Bulgaria, from the preliminary analyses performed for site selection of deep geological disposal of high-level waste (HLW) and spent fuel (SF), it was concluded that the most promising host rocks are the argillaceous sediments of the Sumer Formation (Lower Cretaceous), situated in the Western Fore-Balkan Mts. The present paper aims to compare the transport of three major radionuclides from a hypothetical radioactive waste disposal facility, which incorporates an engineering barrier of bentonite into the argillaceous (marl) medium. The simulations were performed by using HYDRUS-1D computer programme. The results are used for a preliminary estimation of argillaceous sediments as a host rock for geological disposal of HLW.

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Uranium-Series Studies in Bedrock for the Safety Case of Deep Geological Disposal of Spent Fuel

10.1557/proc-1124-q07-04 ◽

2008 ◽

Author(s):

Kari Rasilainen ◽

Juhani Suksi ◽

Petteri Pitkänen ◽

Nuria Marcos ◽

Torbjorn Carlsson

Keyword(s):

Spent Fuel ◽

Geological Disposal ◽

Uranium Series ◽

Deep Geological Disposal ◽

Safety Case

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An Analysis of the Deep Geological Disposal Concepts Considering Spent Fuel Rods Consolidation

Journal of the Nuclear Fuel Cycle and Waste Technology(JNFCWT) ◽

10.7733/jnfcwt.2014.12.4.287 ◽

2014 ◽

Vol 12 (4) ◽

pp. 287-297

Author(s):

Jongyoul Lee ◽

Hyeona Kim ◽

Minsoo Lee ◽

Geonyoung Kim ◽

Heuijoo Choi

Keyword(s):

Spent Fuel ◽

Fuel Rods ◽

Geological Disposal ◽

Deep Geological Disposal

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Needs of countries with longer timescale for deep geological repository implementation

EPJ Nuclear Sciences & Technologies ◽

10.1051/epjn/2019042 ◽

2020 ◽

Vol 6 ◽

pp. 22

Author(s):

Bálint Nős

Keyword(s):

Nuclear Power ◽

Power Plants ◽

High Level Waste ◽

Deep Geological Repository ◽

Spent Fuel ◽

International Consensus ◽

Geological Disposal ◽

Geological Repository ◽

Deep Geological Disposal ◽

High Level

Countries operating nuclear power plants have to deal with the tasks connected to spent fuel and high-level radioactive waste management. There is international consensus that, at this time, deep geological disposal represents the safest and most sustainable option as the end point of the management of high-level waste and spent fuel considered as waste. There are countries with longer timescale for deep geological repository (DGR) implementation, meaning that the planned date of commissioning of their respective DGRs is around 2060. For these countries cooperation, knowledge transfer, participation in RD&D programmes (like EURAD) and adaptation of good international practice could help in implementing their own programmes. In the paper the challenges and needs of a country with longer implementation timescale for DGR will be introduced through the example of Hungary.

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