SALTSTONE MATRIX CHARACTERIZATION AND STADIUM SIMULATION RESULTS

PDF Version Also Available for Download.

Description

SIMCO Technologies, Inc. was contracted to evaluate the durability of the saltstone matrix material and to measure saltstone transport properties. This information will be used to: (1) Parameterize the STADIUM{reg_sign} service life code, (2) Predict the leach rate (degradation rate) for the saltstone matrix over 10,000 years using the STADIUM{reg_sign} concrete service life code, and (3) Validate the modeled results by conducting leaching (water immersion) tests. Saltstone durability for this evaluation is limited to changes in the matrix itself and does not include changes in the chemical speciation of the contaminants in the saltstone. This report summarized results obtained to ... continued below

Creation Information

Langton, C. July 30, 2009.

Context

This report is part of the collection entitled: Office of Scientific & Technical Information Technical Reports and was provided by UNT Libraries Government Documents Department to Digital Library, a digital repository hosted by the UNT Libraries. It has been viewed 15 times . More information about this report can be viewed below.

Who

People and organizations associated with either the creation of this report or its content.

Author

Publisher

Provided By

UNT Libraries Government Documents Department

Serving as both a federal and a state depository library, the UNT Libraries Government Documents Department maintains millions of items in a variety of formats. The department is a member of the FDLP Content Partnerships Program and an Affiliated Archive of the National Archives.

Contact Us

What

Descriptive information to help identify this report. Follow the links below to find similar items on the Digital Library.

Description

SIMCO Technologies, Inc. was contracted to evaluate the durability of the saltstone matrix material and to measure saltstone transport properties. This information will be used to: (1) Parameterize the STADIUM{reg_sign} service life code, (2) Predict the leach rate (degradation rate) for the saltstone matrix over 10,000 years using the STADIUM{reg_sign} concrete service life code, and (3) Validate the modeled results by conducting leaching (water immersion) tests. Saltstone durability for this evaluation is limited to changes in the matrix itself and does not include changes in the chemical speciation of the contaminants in the saltstone. This report summarized results obtained to date which include: characterization data for saltstone cured up to 365 days and characterization of saltstone cured for 137 days and immersed in water for 31 days. Chemicals for preparing simulated non-radioactive salt solution were obtained from chemical suppliers. The saltstone slurry was mixed according to directions provided by SRNL. However SIMCO Technologies Inc. personnel made a mistake in the premix proportions. The formulation SIMCO personnel used to prepare saltstone premix was not the reference mix proportions: 45 wt% slag, 45 wt% fly ash, and 10 wt% cement. SIMCO Technologies Inc. personnel used the following proportions: 21 wt% slag, 65 wt% fly ash, and 14 wt% cement. The mistake was acknowledged and new mixes have been prepared and are curing. The results presented in this report are assumed to be conservative since the excessive fly ash was used in the SIMCO saltstone. The SIMCO mixes are low in slag which is very reactive in the caustic salt solution. The impact is that the results presented in this report are expected to be conservative since the samples prepared were deficient in slag and contained excess fly ash. The hydraulic reactivity of slag is about four times that of fly ash so the amount of hydrated binder formed per unit volume in the SIMCO saltstone samples is less than that expected for saltstone containing the reference amount of slag (45 wt.% of the total cementitious mixture versus 21 wt.% used in the SIMCO samples). Consequently the SIMCO saltstone samples are expected to have lower strengths, and tortuosity and higher porosity, water diffusivity, and intrinsic permeability compared to the reference case MCU saltstone. MCU reference saltstone contains nonradioactive salt solution with a composition designed to simulate the product of the Modular Caustic Side Solvent Extraction (MCU) Unit [Harbour, 2009]. The SIMCO saltstone samples were cast in molds and cured for three days under plastic with a source of water to prevent drying. Details of the sample preparation process are presented in Attachment 2. The molds were then removed and the samples were cured at a constant temperature (76 F, 24 C) and 100 percent relative humidity for up to one year. Selected samples were periodically removed and characterized the evolution of the matrix as a function of age. In order to preserve the age dependent microstructure at the specified curing times it is necessary to stop hydration. This was accomplished by immersing the samples in isopropanol for 5 days to replace water with alcohol. The microstructure of the matrix material was also characterized as a function of aging. This information was used as a base line for comparison with leached microstructures. After curing for 137 days, specimens were cut into 20 mm disks and exposed to deionized water with a pH maintained at 10.5. Microstructure and calcium sulfur leaching results for samples leached for 31 days are presented in this report. Insufficient leached material was generated during the testing to date to obtain physical and mineralogical properties for leached saltstone. Longer term experiments are required because the matrix alteration rate due to immersion in deionized water is slow.

Notes

available

Language

Item Type

Identifier

Unique identifying numbers for this report in the Digital Library or other systems.

  • Report No.: SRNS-STI-2009-00477
  • Grant Number: DE-AC09-08SR22470
  • DOI: 10.2172/964995 | External Link
  • Office of Scientific & Technical Information Report Number: 964995
  • Archival Resource Key: ark:/67531/metadc928942

Collections

This report is part of the following collection of related materials.

Office of Scientific & Technical Information Technical Reports

Reports, articles and other documents harvested from the Office of Scientific and Technical Information.

Office of Scientific and Technical Information (OSTI) is the Department of Energy (DOE) office that collects, preserves, and disseminates DOE-sponsored research and development (R&D) results that are the outcomes of R&D projects or other funded activities at DOE labs and facilities nationwide and grantees at universities and other institutions.

What responsibilities do I have when using this report?

When

Dates and time periods associated with this report.

Creation Date

  • July 30, 2009

Added to The UNT Digital Library

  • Nov. 13, 2016, 7:26 p.m.

Description Last Updated

  • Dec. 12, 2016, 1:07 p.m.

Usage Statistics

When was this report last used?

Yesterday: 0
Past 30 days: 0
Total Uses: 15

Interact With This Report

Here are some suggestions for what to do next.

Start Reading

PDF Version Also Available for Download.

International Image Interoperability Framework

IIF Logo

We support the IIIF Presentation API

Langton, C. SALTSTONE MATRIX CHARACTERIZATION AND STADIUM SIMULATION RESULTS, report, July 30, 2009; South Carolina. (digital.library.unt.edu/ark:/67531/metadc928942/: accessed October 20, 2018), University of North Texas Libraries, Digital Library, digital.library.unt.edu; crediting UNT Libraries Government Documents Department.