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Title: Current Understanding and Remaining Challenges in Modeling Long-Term Degradation of Borosilicate Nuclear Waste Glasses

Chemical durability is not a single material property that can be uniquely measured. Instead it is the response to a host of coupled material and environmental processes whose rates are estimated by a combination of theory, experiment, and modeling. High-level nuclear waste (HLW) glass is perhaps the most studied of any material yet there remain significant technical gaps regarding their chemical durability. The phenomena affecting the long-term performance of HLW glasses in their disposal environment include surface reactions, transport properties to and from the reacting glass surface, and ion exchange between the solid glass and the surrounding solution and alteration products. The rates of these processes are strongly influenced and are coupled through the solution chemistry, which is in turn influenced by the reacting glass and also by reaction with the near-field materials and precipitation of alteration products. Therefore, those processes must be understood sufficiently well to estimate or bound the performance of HLW glass in its disposal environment over geologic time-scales. This article summarizes the current state of understanding of surface reactions, transport properties, and ion exchange along with the near-field materials and alteration products influences on solution chemistry and glass reaction rates. Also summarized are the remaining technicalmore » gaps along with recommended approaches to fill those technical gaps.« less
Authors:
 [1] ;  [1] ;  [2] ;  [3]
  1. Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)
  2. CEA Marcoule, DTCD SECM, Bagnols-sur-Ceze (France)
  3. Dept. of Applied Quantum Physics and Nuclear Engineering, Kyushu University, Fukuoda (Japan)
Publication Date:
OSTI Identifier:
1115829
Report Number(s):
PNNL-SA--98870
Journal ID: ISSN 2041-1286; 47580; 42495; 46403; AF5865010; TRN: US1400350
DOE Contract Number:
AC05-76RL01830
Resource Type:
Journal Article
Resource Relation:
Journal Name: International Journal of Applied Glass Science; Journal Volume: 4; Journal Issue: 4
Publisher:
American Ceramic Society
Research Org:
Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English
Subject:
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES; GLASS; CORROSION; PERFORMANCE; WASTES; BOROSILICATE GLASS Nuclear; Long-term; Degradation; Model; Environmental Molecular Sciences Laboratory