VAPOR HYDRATATION OF NUCLEAR WASTE GLASS SUBATECH Department Prof. Abdesselam ABDELOUAS abdesselam.abdelouas@subatech.in2p3.fr 1
IMT Atlantique IMT Atlantique is an engineering school of the French ministry of industry located in the north-west of France, member of the Institut Mines-Télécom
Biography • Pr. of Radiochemistry at IMT Atlantique (since 2000) • Adjunct Pr. at MODY Univ. (Rajasthan, India) • Adjunct Pr. at IFCEN (Sun Yat-sen Univ., Zhuhai, China) • Head of Radiochemistry Group (44 staff) • Head of SNEAM Nuc. Eng. Master program (since 2011) • Coordinator of EMJMD Nuc. Eng. SARENA (since 2018) • H.D.R. in Radiochemistry 2004 (Univ. Nantes, France) • PhD in Geochemistry 1996 (Univ. Strasbourg, France)
Subatech Laboratory From fundamental to applications and health NUCLEAR - The UNIVERSE at HIGH ENVIRONMENT ENERGY Energy and Materials - Quark Gluon plasma - Cosmic rays SUBATECH - Dark matter - Radiochemistry Shared research unit - Radio-detection - Waste storage IMT Atlantique - Theory, Simulation of - Migration studies CNRS/IN2P3 ion collisions - Radiolysis Nantes University - Detectors for CERN - Transmutation - Reactor modelling - Non-proliferation - Instrumentation - Radionuclides - Detectors NUCLEAR - HEALTH - Imaging: 3g,Xe liq. - SMART (environmental - Nanomedecine monitoring) - Cyclotron - Cyclotron
Fuel Cycle Ventilation Filters The DU penetrator of a 30 mm round Resins Mill tailings Spent fuel Open mine Cladding… Glass
The reprocessing of Nuclear Spent Fuel Fresh fuel Rotary dissolver Spent fuel Cladding Glass
Waste Inventory in France (m 3 ) Waste category Forecasts made in 2013 HLW 10 000 ILW-LL 72 000 LLW-LL 180 000 LILW-SL 1 900 000 VLLW 2 200 000 TOTAL 4 300 000 Forecasts at the end of all facilities service life
Geological Disposal (ANDRA 2005) HLW glass containing radionuclides Stainless steel primary envelope
Repository Evolution n 4 phases during glass alteration in the repository: Corrosion of steel over-packs and concrete reinforcements Vapor Tight Aqueous Liberation of H 2 in the closed repository hydration container alteration Delay in the arrival of groundwater to the site V initial Glass alteration rate Alteration of glass in vapor phase (unsaturated V hydration medium) V residual 1 2 3 4 Time ü Alteration mechanisms, secondary phases formation and role, effect of radiolysis, modeliing, effect of near-field materials etc.
Glass Vapor Hydration Glass vapor phase hydration can be defined as the process of altering the chemical and/or physical properties of surface by means of exposure to water vapor in contrast to exposure to liquid water, which leads to elemental dissolution and leaching.
History of Glass Hydration – Natural Glasses Interest in hydration of glasses was first driven by Friedman and coll. during the 60s for development of new dating method for artifacts made from obsidian. l = k × t 1/2 where l is the thickness of the hydration layer, t is the hydration time, and k the proportionality constant, which describes the temperature dependence of the process. I. Friedman, R.L. Smith: A new dating method using obsidian: Part I, The development of the method, Am. Antiq. 25 , 476– Obsidian - Wikipedia 493 (1960). en.wikipedia.org
History of Glass Hydration – Natural Glasses Two parameters were highlighted as important for obsidian hydration: • The temperature, • Relative humidity. Water sorption expressed as mass gain ( µ g) of obsidian hydrated at 23°C and 84% RH Still a reliable method for obsidian dating • Increase of accuracy of depth measurement (SIMS, FTIR) W.L. Ebert et al., “The sorption of water on obsidian and a nuclear waste glass,” Phys. Chem. Glasses., 32 [4] 133-137 (1991).
History of Glass Hydration – Commercial Glasses ü Moriya and Nogami studied in 1980 the hydration of silicate glasses in steam atmosphere. • Water speciation in the glass matrix using FTIR • The role of oxides (Na, Ca) on hydration rates ü In early 80s Bates and coll. Applied first the vapor hydration methodology on nuclear waste glasses. • Safety analysis of HLW repository Wikipedia - The proposed design en.wikipedia.org
History of Glass Hydration – Commercial Glasses ü The essential early work on nuclear waste glasses hydration was done during the 1980s and early 1990s by Bates and collaborators. ü Bates et al. proposed the methodology to perform the hydration tests and presented the first results of glass hydration. Experimental apparatus for glass vapor hydration developed by Pacific Northwest National Laboratory (PNNL), USA. A. Abdelouas, J. Neeway, B. Grambow: Chemical durability of glasses, Handbook of Glass, Springer (2019).
History of Glass Hydration – Commercial Glasses ü French scientists with the support of WMO (ANDRA) restarted in late 2000s R&D on nuclear waste glasses vapor hydration according to refined evolution scenarios (H 2 migration). ü Abdelouas and coll. proposed a new methodology to perform the hydration tests with a fine control of RH. Experimental apparatus for glass vapor hydration developed by SUBATECH Laboratory, France. J. Neeway et al.: Vapor hydration of SON68 glass from 90 °C to 200 °C: A kinetic study and corrosion products investigation, J. Non-Cryst. Solids 358, 2897–2905 (2012).
Water Sorption on Silicate Glasses ü A major study on water sorption on obsidian and the SRL165 borosilicate nuclear waste glass was conducted by Ebert et al. • The water sorption occurs primarily at silanol (SiOH) sites and the sorption to other sites remaining very low. • A water film is generated at RH above 95%. Water sorption isotherms on the SRL165 borosilicate nuclear waste glass at 23°C. Data were obtained with experiments using increasing or decreasing humidity techniques. W.L. Ebert et al., “The sorption of water on obsidian and a nuclear waste glass,” Phys. Chem. Glasses., 32 [4] 133-137 (1991).
Methodology for Measurement of Hydration Layer ü The absence of leachate makes the determination of hydration rate limited to glass surface analysis (depth measurement). • Light microscope measurement based on the difference in refractive index between the pristine glass and hydrated glass. Hydrated HLP-09 low-activity waste glass at 300°C for 3 d, adapted from Schulz et al. 1 mm R.I. Schulz et al.: Hanford immobilized LAW product acceptance: tanks focus area testing data package II. Pacific Northwest National Laboratory. PNNL-13344 (2000).
Methodology for Measurement of Hydration Layer • Scanning and transmission electron microscope measurements. b a Pris(ne glass Layer Pris(ne glass 2 µm 1 mm SEM (a) and TEM (b) picture of SON68 glass hydrated at 200°C and 92% RH. J. Neeway: The alteration of the SON68 reference waste glass in silica saturated conditions and in the presence of water vapor. PhD Thesis, University of Nantes, France (2011).
Methodology for Measurement of Hydration Layer • Time-of-flight secondary ions mass spectrometry (ToF- SIMS). ToF-SIMS profile of boron and 18 O/ 16 O isotopic ratio for SON68 glass hydrated at 125°C and 95% RH for 600 d. The depth profile is about 5 µ m. R. Bouakkaz, A., Abdelouas, B. Grambow. Kinetic study and structural evolution of SON68 nuclear waste glass altered from 35 to 125 °C under unsaturated H 2 O and D 2 O 18 vapour conditions. Corrosion Science 134, 1-16 (2018).
Methodology for Measurement of Hydration Layer • Nuclear Reaction Analysis (NRA). ü Water diffusion coefficients of 2.31–7.34 × 10 − 21 m 2 /s Protons profile in ISG borosilicate glass hydrated at 175°C at 98% RH. A. Abdelouas et al.: A preliminary investigation of the ISG glass vapor hydration, Intern. J. Appl. Glass Sci. 4, 307-316 (2013).
Methodology for Measurement of Hydration Layer • Fourier Transform Infra-Red spectroscopy (FTIR). Experimental and deconvoluted FTIR spectra of SON68 glass hydrated at 125°C and 95% RH. • H. Tomozawa, M. Tomozawa: Diffusion of water into a borosilicate glass, J. Non-Cryst. Solids 109, 311-317 (1989) • Efimov et al. J. Non-Cryst. Solids., 332 93-114 (2003).
Methodology for Measurement of Hydration Layer • Fourier Transform Infra-Red spectroscopy (FTIR). ü 0.1 absorbance = 1 µ m of hydration layer ISG 175°C ; 98% RH 0.8 SON68 150°C ; 90% RH SiOH absorbance SON68 200°C ; 92% RH 0.6 0.4 0.2 0.0 0 20 40 60 80 Days The growth of the SiOH peak at 3595 cm -1 for the SON68 and ISG glasses hydrated at different temperatures and relative humidity values. • A. Abdelouas et al.: A preliminary investigation of the ISG glass vapor hydration, Intern. J. Appl. Glass Sci. 4, 307-316 (2013). • J. Neeway et al.: Vapor hydration of SON68 glass from 90 °C to 200 °C: A kinetic study and corrosion products investigation, J. Non-Cryst. Solids 358, 2897–2905 (2012).
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