Cementitious Barriers Partnership (CBP): Using the CBP Software Toolbox to Simulate Sulfate Attack and Carbonation of Concrete Structures - 13481

Conference · Mon Jul 01 00:00:00 EDT 2013

OSTI ID:22225064

Brown, K. G.; Kosson, D. S.; Garrabrants, A. C.; Sarkar, S. ^[1]; Flach, G.; Langton, C.; Smith, III, F. G.; Burns, H. ^[2]; Van der Sloot, H. ^[3]; Meeussen, J. C.L. ^[4]; Seignette, P. F.A.B. ^[5]; Samson, E. ^[6]; Mallick, P.; Suttora, L. ^[7]; Esh, D.; Fuhrmann, M.; Philip, J. ^[8]

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1. Vanderbilt University, School of Engineering, CRESP, Nashville, TN 37235 (United States)
2. Savannah River National Laboratory, Aiken, SC 29808 (United States)
3. Hans Van der Sloot Consultancy, Dorpsstraat 216, 1721BV Langedijk (Netherlands)
4. Nuclear Research and Consultancy Group, Westerduinweg 3, Petten (Netherlands)
5. Energy Research Center of The Netherlands, Petten (Netherlands)
6. SIMCO Technologies, Inc., Quebec (Canada)
7. U.S. Department of Energy, Washington, DC (United States)
8. U.S. Nuclear Regulatory Commission, Washington, DC (United States)

The Cementitious Barriers Partnership (CBP) Project is a multi-disciplinary, multi-institutional collaboration supported by the U.S. Department of Energy Office of Tank Waste Management. The CBP project has developed a set of integrated modeling tools and leaching test methods to help improve understanding and prediction of the long-term hydraulic and chemical performance of cementitious materials used in nuclear applications. State-of-the-art modeling tools, including LeachXS{sup TM}/ORCHESTRA and STADIUM{sup R}, were selected for their demonstrated abilities to simulate reactive transport and degradation in cementitious materials. The new U.S. Environmental Protection Agency leaching test methods based on the Leaching Environmental Assessment Framework (LEAF), now adopted as part of the SW-846 RCRA methods, have been used to help make the link between modeling and experiment. Although each of the CBP tools has demonstrated utility as a standalone product, coupling the models over relevant spatial and temporal solution domains can provide more accurate predictions of cementitious materials behavior over relevant periods of performance. The LeachXS{sup TM}/ORCHESTRA and STADIUM{sup R} models were first linked to the GoldSim Monte Carlo simulator to better and more easily characterize model uncertainties and as a means to coupling the models allowing linking to broader performance assessment evaluations that use CBP results for a source term. Two important degradation scenarios were selected for initial demonstration: sulfate ingress / attack and carbonation of cementitious materials. When sufficient sulfate is present in the pore solution external to a concrete barrier, sulfate can diffuse into the concrete, react with the concrete solid phases, and cause cracking that significantly changes the transport and structural properties of the concrete. The penetration of gaseous carbon dioxide within partially saturated concrete usually initiates a series of carbonation reactions with both dissolved ions and the hydrated cement paste. The carbonation process itself does not have a negative effect, per se, on the paste physical properties and can even result in reduced porosity and can help form a protective layer at the surface of concrete. However, carbonation has been shown to increase leaching of some constituents and can potentially have a detrimental effect on reinforced concrete structures by lowering pH to ca. 9 and de-passivating embedded steel (e.g. rebar) and accelerating corrosion, which are important processes related to high-level waste tank integrity and closure evaluations. The use of the CBP Software Toolbox to simulate these important degradation phenomena for both concrete vaults and high-level waste tanks are demonstrated in this paper. (authors)

• Research Organization: WM Symposia, 1628 E. Southern Avenue, Suite 9-332, Tempe, AZ 85282 (United States)
• OSTI ID: 22225064
• Report Number(s): INIS-US-13-WM-13481; TRN: US14V0641046019
• Resource Relation: Conference: WM2013: Waste Management Conference: International collaboration and continuous improvement, Phoenix, AZ (United States), 24-28 Feb 2013; Other Information: Country of input: France; 13 refs.
• Country of Publication: United States
• Language: English

Related Subjects

12 MANAGEMENT OF RADIOACTIVE WASTES, AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
36 MATERIALS SCIENCE
CARBON DIOXIDE
CARBONATES
CEMENTS
COMPUTER CODES
COUPLING
CRACKING
DIFFUSION BARRIERS
HIGH-LEVEL RADIOACTIVE WASTES
LEACHING
MONTE CARLO METHOD
PH VALUE
PHYSICAL PROPERTIES
POROSITY
RADIOACTIVE WASTE MANAGEMENT
REINFORCED CONCRETE
SIMULATION
SIMULATORS
STEELS
SULFATES
VENTILATION BARRIERS