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VERSION:2.0
PRODID:-//CERN//INDICO//EN
BEGIN:VEVENT
SUMMARY:Radionuclide containing solid phases on the inner surface of a Zir
 caloy-4 cladding tube
DTSTART;VALUE=DATE-TIME:20171030T061500Z
DTEND;VALUE=DATE-TIME:20171030T063000Z
DTSTAMP;VALUE=DATE-TIME:20260513T214822Z
UID:indico-contribution-350-1215@events01.synchrotron.org.au
DESCRIPTION:Speakers: Ernesto González-Robles Corrales (Karlsruhe Institu
 te of Technology)\nZircaloy claddings of fuel rods for nuclear reactors ar
 e considered as first technical barrier for retention of radionuclides pro
 duced in the nuclear fuel. The integrity of the cladding is influenced by 
 various processes during reactor operation and beyond\, e.g. oxidation\, h
 ydrogen uptake\, PCI\, fission product precipitation\, -decay\, and rad
 iation damage. Composition of agglomerates found on the inner surface of t
 he plenum section of an irradiated Zircaloy-4 cladding tube are investigat
 ed by SEM-EDX\, XPS\, and synchrotron based techniques.\nµ-XRF investigat
 ions show uranium hot spots and fission products. Grooves from cladding tu
 be production contain uranium residues from fuel pellets insertion. Pluton
 ium\, cesium and rubidium are present ibidem. Another type of agglomerates
  contains cesium\, rubidium\, and minor amounts of actinides. Cesium and r
 ubidium may originate from three sources: uranium traces within the claddi
 ng\, uranium residues in surface grooves\, and Cs/Rb released from subjace
 nt fuel pellets.\n\nhttps://events01.synchrotron.org.au/event/51/contribut
 ions/1215/
LOCATION:
URL:https://events01.synchrotron.org.au/event/51/contributions/1215/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Modelling the Corrosion of Spent Nuclear Fuel Inside a failed Wast
 e Container
DTSTART;VALUE=DATE-TIME:20171030T033000Z
DTEND;VALUE=DATE-TIME:20171030T040000Z
DTSTAMP;VALUE=DATE-TIME:20260513T214822Z
UID:indico-contribution-350-1192@events01.synchrotron.org.au
DESCRIPTION:Speakers: David Shoesmith (Western University)\nThe internatio
 nally accepted approach for the disposal of spent nuclear fuel is to seal 
 it in corrosion-resistant metal containers and bury it in a stable deep ge
 ologic repository. If containers were to fail\, and the fuel become expose
 d to groundwater\, radiolytic corrosion of the fuel could release radionuc
 lides to the groundwater\, the critical first step in their transport into
  the environment. Two corrosion fronts will exist within a failed containe
 r\, one on the fuel surface driven by radiolytic oxidants and a second on 
 the carbon steel vessel sustained by water reduction. Based on an extensiv
 e series of electrochemical\, corrosion and chemical dissolution studies\,
  a finite-element based model has been developed to determine this evoluti
 on in redox conditions and its influence on fuel corrosion. Particular att
 ention will be paid to the influence of hydrogen\, produced radiolytically
  and by corrosion of the steel container vessel\, on the corrosion rate.\n
 \nhttps://events01.synchrotron.org.au/event/51/contributions/1192/
LOCATION:
URL:https://events01.synchrotron.org.au/event/51/contributions/1192/
END:VEVENT
BEGIN:VEVENT
SUMMARY:NEW ASPECTS OF THE MECHANISM OF HYDROGEN EFFECT ON SPENT FUEL DISS
 OLUTION
DTSTART;VALUE=DATE-TIME:20171030T040000Z
DTEND;VALUE=DATE-TIME:20171030T041500Z
DTSTAMP;VALUE=DATE-TIME:20260513T214822Z
UID:indico-contribution-350-1191@events01.synchrotron.org.au
DESCRIPTION:Speakers: Kastriot Spahiu (SKB\, Stockholm\, Sweden and Chalme
 rs University of Technology\, Gothenburg\, Sweden)\nOur experimental data 
  indicate that the hydrogen effect is a complex phenomenon and has several
  aspects. The decomposition of hydrogen peroxide on the surface of SIMFUEL
  is followed by the reaction of the produced hydroxyl radicals with hydrog
 en to give water\, or their reaction with H2O2 to give O2. Only a very sma
 ll part of the initial hydrogen peroxide (\n\nhttps://events01.synchrotron
 .org.au/event/51/contributions/1191/
LOCATION:
URL:https://events01.synchrotron.org.au/event/51/contributions/1191/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Development of solid state MAS NMR techniques for the characteriza
 tion of alteration products formed during the dissolution of spent nuclear
  fuel.
DTSTART;VALUE=DATE-TIME:20171030T044500Z
DTEND;VALUE=DATE-TIME:20171030T050000Z
DTSTAMP;VALUE=DATE-TIME:20260513T214822Z
UID:indico-contribution-350-1170@events01.synchrotron.org.au
DESCRIPTION:Speakers: Beng Thye Tan (University of Cambridge\, Singapore N
 uclear Research and Safety Initiative)\nThe migration of radionuclides fro
 m underground nuclear waste repositories will involve the formation of ura
 nium secondary minerals when ground water reacts with the spent nuclear fu
 el. \n\nDuring oxic or anoxic spent fuel dissolution\, amorphous phases ca
 n precede the development of well-defined crystalline mineral phases.  Nuc
 lear magnetic resonance (NMR) can probe the structure of these amorphous a
 lteration products and trace the evolution of secondary phases. \n\nTo dev
 elop the technique\, potential secondary phases of $^{17}$O-enriched urani
 um minerals have been fabricated to establish the oxygen environments of b
 ecquerelite\, Ca(UO$_2$)$_6$O$_4$(OH).8(H$_2$O)\, andersonite\, Na$_2$Ca(U
 O$_2$)(CO$_3$)3.6H$_2$O and grimselite\, K$_3$Na(UO$_2$)(CO$_3$)$_3$.(H$_2
 $O). These contain calcium (Ca$^2+$)\, carbonate (CO$_3$$^{2+}$)\, and oth
 er ubiquitous ions. \nSolid state $^{17}$O MAS-NMR spectra of uranium mine
 rals have been obtained in a 9.39T magnetic field.\n\n Detailed difference
 s in oxygen local environments such as uranyl bond lengths and interlayer 
 OH and H$_2$O can be distinguished by analyzing the spectra\, which can el
 ucidate the alteration of UO$_2$ by $^{17}$O water.\n\nhttps://events01.sy
 nchrotron.org.au/event/51/contributions/1170/
LOCATION:
URL:https://events01.synchrotron.org.au/event/51/contributions/1170/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Impact of lanthanide elements on the dissolution of uranium dioxid
 e
DTSTART;VALUE=DATE-TIME:20171030T041500Z
DTEND;VALUE=DATE-TIME:20171030T043000Z
DTSTAMP;VALUE=DATE-TIME:20260513T214822Z
UID:indico-contribution-350-1169@events01.synchrotron.org.au
DESCRIPTION:Speakers: Nicolas DACHEUX (University of Montpellier)\nDue to 
 the concomitant formation of oxygen vacancies in the fluorite structure\, 
 it was found that the incorporation of trivalent lanthanide elements in Th
 O2 or CeO2 strongly affect their chemical durability during dissolution or
  leaching tests [1-4]. On the contrary\, the impact of such elements on th
 e dissolution of UO2 remains largely unknown. For this purpose\, several l
 anthanide – uranium mixed based samples incorporating 1 to 20 mol.% of a
  mixture of lanthanide elements (with the mole ratio : 13 % La \; 7.4 % Y 
 \; 25.6 % Ce \; 12 % Pr \; 42 % Nd) were prepared through quantitative oxa
 late precipitation. After conversion to the final oxides then sintering\, 
 they were characterized from chemical and microstructural points of view a
 nd finally submitted to multiparametric dissolution tests in several nitri
 c acid solutions and at various temperatures. Contrarily to Th- and Ce-bas
 ed mixed oxides\, the presence of lanthanide elements in UO2 did not affec
 t significantly the normalized dissolution rates in concentrated nitric ac
 id solutions (C > 1M). On the contrary\, the effect was more important in 
 less concentrated solutions (e.g. a factor or 100 compared to pure UO2 obs
 erved in 0.5M HNO3) when the role of surface-controlling reactions on the 
 overall dissolution become predominant. Such observations related to the m
 acroscopic description of the dissolution were connected to in operando fo
 llowing of the evolving solid/liquid interface that underlined the prefere
 ntial dissolution of lanthanide enriched grain boundaries and triple junct
 ions.\n \n1. Horlait\, D. et al.\, Inorg. Chem.\, 51\, 3868-3878\, 2012\n2
 . Horlait\, D. et al.\, J. Nucl. Mater.\, 429\, 237-244\, 2012\n3. Horlait
 \, D. et al.\, J. Mater. Chem. A\, 2\, 5193-5203\, 2014\n4. Claparede\, L.
  et al.\, Inorg. Chem.\, 50\, 11702-11714\, 2011\n\nhttps://events01.synch
 rotron.org.au/event/51/contributions/1169/
LOCATION:
URL:https://events01.synchrotron.org.au/event/51/contributions/1169/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Effect of platinoid elements on the dissolution of uranium dioxide
DTSTART;VALUE=DATE-TIME:20171030T053000Z
DTEND;VALUE=DATE-TIME:20171030T060000Z
DTSTAMP;VALUE=DATE-TIME:20260513T214822Z
UID:indico-contribution-350-1167@events01.synchrotron.org.au
DESCRIPTION:Speakers: Nicolas DACHEUX (University of Montpellier)\nDissolu
 tion or leaching of the spent nuclear fuels (SNF) is a key step either in 
 the field of their reprocessing or their long-term storage in underground 
 repository. Moreover\, SNF contain a wide variety of fission products incl
 uding platinoid elements (PGM’s) either incorporated in the UO2 matrix\,
  or present in various separated phases for which the specific impact on t
 he overall dissolution kinetics has not been yet fully discriminated. In o
 rder to answer this question\, several samples doped with 0.6 to 3 mol.% o
 f PGM’s (55 % Ru \; 9.6 % Rh \; 35.4 % Pd) were prepared from hydroxide 
 based synthesis [1\,2]. After conversion then sintering\, the prepared pel
 lets were submitted to multiparametric dissolution tests in various media 
 (0.1 to 4 M HNO3) and temperatures (25°C to 60°C). The macroscopic descr
 iption of the dissolution showed that the normalized dissolution rates wer
 e significantly increased for UO2 doped with PGM’s compared to pure UO2 
 used as reference compound. This effect was strengthened in less acid medi
 a. As instance\, a factor of 4500 was observed after 175 days of leaching 
 in 0.1M HNO3. Simultaneously\, the dissolution of the pellets was followed
  in operando by ESEM. The combination of macroscopic and microscopic appro
 aches confirmed the modification of the preponderant mechanism occurring a
 t the solid/liquid interface from redox-controlled dissolution in strong n
 itric acid media to surface-controlled dissolution for less acidic media.\
 n\n1. Martinez\, J. et al.\, J. Nucl. Mater.\, 462\, 173-181\, 2015\n2. Ma
 rtinez\, J. et al.\, J. Europ. Ceram. Soc.\, 35\, 4535-4546\, 2015\n\nhttp
 s://events01.synchrotron.org.au/event/51/contributions/1167/
LOCATION:
URL:https://events01.synchrotron.org.au/event/51/contributions/1167/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Activation energy for parabolic corrosion kinetics of Zircaloy-4 b
 y consecutive hydrogen measurement at 30 – 80℃
DTSTART;VALUE=DATE-TIME:20171030T064500Z
DTEND;VALUE=DATE-TIME:20171030T070000Z
DTSTAMP;VALUE=DATE-TIME:20260513T214822Z
UID:indico-contribution-350-1155@events01.synchrotron.org.au
DESCRIPTION:Speakers: Tomofumi Sakuragi (Radioactive Waste Management Fund
 ing and Research Center)\nOn the issue related on a safe disposal of spent
  fuel claddings is the corrosion and the subsequent gas and radionuclides 
 release. The Zircaloy corrosion under a prospected disposal condition has 
 recently been investigated by sensitive hydrogen measurements at 30℃\, a
 nd reported that the kinetics in the rate around nm/y follows the paraboli
 c rate law.\nIn the present work\, an improved equipment to be usable even
  at higher temperatures up to 80℃ has been applied for measuring hydroge
 n gas generated from Zricaloy-4 corrosion for 90 days. The Arrhenius relat
 ion of the parabolic rate constants for the corrosion kinetics has showed 
 the activation energy of 84.4 ± 8.4 kJ/mol\, the value of which is lower 
 than that for the general pre-transition corrosion under the in-pile tempe
 rature above 260℃ (i.e. 113-135 kJ/mol)\, suggesting that simple mass tr
 ansfer through a thin and firm oxide film is limiting the low temperature 
 corrosion of Zircaloy.\n\nhttps://events01.synchrotron.org.au/event/51/con
 tributions/1155/
LOCATION:
URL:https://events01.synchrotron.org.au/event/51/contributions/1155/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Aqueous leaching of high burnup UO2 fuel under hydrogen conditions
DTSTART;VALUE=DATE-TIME:20171030T043000Z
DTEND;VALUE=DATE-TIME:20171030T044500Z
DTSTAMP;VALUE=DATE-TIME:20260513T214822Z
UID:indico-contribution-350-1132@events01.synchrotron.org.au
DESCRIPTION:Speakers: Anders Puranen (Studsvik Nuclear)\nLeaching results 
 on fragments of high burnup (65 MWd/kgU) UO2 fuel from a commercial pressu
 rized water reactor are presented. The experiments were performed in simpl
 ified granitic groundwater under a hydrogen pressure of up to 5 MPa\, repr
 esenting conditions in a water intrusion scenario for a Swedish KBS-3 desi
 gn spent nuclear fuel repository. The freshly crushed fragments were pre-w
 ashed under aerated conditions for 6 days to remove part of the instant re
 lease fraction of the radionuclide inventory and transferred to an autocla
 ve for leaching under hydrogen conditions. Following an initial release of
  U attributed to dissolution of oxidized phases from the aerated handling\
 , the U concentration decreased to levels of 2-5x10-9 M\, in-line with the
  solubility of amorphous UO2. The release of radionuclides such as Cs and 
 Sr gradually declined indicating a transition towards inhibition of the fu
 el matrix dissolution.\n\nhttps://events01.synchrotron.org.au/event/51/con
 tributions/1132/
LOCATION:
URL:https://events01.synchrotron.org.au/event/51/contributions/1132/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Comparison of calculated and measured radionuclide inventory of a 
 Zircaloy-4 cladding tube plenum section
DTSTART;VALUE=DATE-TIME:20171030T063000Z
DTEND;VALUE=DATE-TIME:20171030T064500Z
DTSTAMP;VALUE=DATE-TIME:20260513T214822Z
UID:indico-contribution-350-1126@events01.synchrotron.org.au
DESCRIPTION:Speakers: Michel Herm (Karlsruhe Institute of Technology)\nCla
 dding tubes of water-cooled nuclear reactors are usually made of Zircaloy 
 and are an important retaining element for radionuclides present in the fu
 el. However\, cladding integrity is affected by various processes during r
 eactor operation and beyond\, e.g. oxidation\, hydrogen uptake\, PCI\, fis
 sion product precipitation\, alpha-decay\, and radiation damage. Using exp
 erimental and modelling methods\, the radionuclide inventory of an irradia
 ted Zircaloy-4 plenum section is analyzed.\nQuantities of U-235/238\, Np-2
 37\, Pu-238/239/240/241/242\, Am-241/243\, Cm-243/244 besides C-14\, Fe-55
 \, Sb-125\, Cs-134/137 were (radio-)chemically determined in digested Zirc
 aloy-4 subsamples. Measured inventories of activation products in the Zr-a
 lloy are in good agreement with calculated values. However\, amounts of ac
 tinides and fission products exceed the calculated inventory by factor ~50
  (Pu isotopes) and ~120 (Cs-137). Excess Pu and part of excess Cs inventor
 y originate from fuel residues on the inner cladding surface\, whereas vas
 t amount of cesium is volatilized from subjacent fuel pellets and transpor
 ted to the plenum.\n\nhttps://events01.synchrotron.org.au/event/51/contrib
 utions/1126/
LOCATION:
URL:https://events01.synchrotron.org.au/event/51/contributions/1126/
END:VEVENT
BEGIN:VEVENT
SUMMARY:The Corrosion of Copper Nuclear Waste Containers under Deep Geolog
 ic Disposal ConditionsF
DTSTART;VALUE=DATE-TIME:20171030T060000Z
DTEND;VALUE=DATE-TIME:20171030T061500Z
DTSTAMP;VALUE=DATE-TIME:20260513T214822Z
UID:indico-contribution-350-1113@events01.synchrotron.org.au
DESCRIPTION:Speakers: David Shoesmith (Western University)\nThe corrosion 
 of high level copper nuclear waste containers under permanent disposal con
 ditions can occur via a number of processes which change in importance as 
 the environment within a deep geologic repository evolves from warm and ox
 ic to cool and anoxic. Under warm and oxic conditions the container could 
 be exposed to gamma irradiated conditions which evolve from aerated vapour
  to fully saturated aqueous conditions. During this period the possibility
  of localized corrosion (e.g.\, pitting) must be considered. Over extended
  exposure periods when anoxic conditions prevail corrosion will be sustain
 ed by reaction with sulphide produced either by remote microbial activity 
 or the dissolution of sulphides present in the clays compacted around the 
 container. Studies to understand and quantify both these corrosion process
 es are underway. In this presentation these studies will be discussed and 
 their use in the development of corrosion models described.\n\nhttps://eve
 nts01.synchrotron.org.au/event/51/contributions/1113/
LOCATION:
URL:https://events01.synchrotron.org.au/event/51/contributions/1113/
END:VEVENT
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