Elevated temperature (hydrothermal) stability of cementitious sealants for a deep geological repository in tuff

Grout formulations have been investigated in Nevada Nuclear Waste Storage Investigations Project, for possible nuclear waste repository sealing applications focused in the Yucca Mountain Area (in welded tuff). A shrinkage compensated cement was chemically modified with siliceous reactants to enhance...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Veröffentlicht in:Waste management (Elmsford) 1989, Vol.9 (4), p.253-259
Hauptverfasser: Scheetz, B.E., Roy, D.M., Duffy, C.
Format: Artikel
Sprache:eng
Online-Zugang:Volltext
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
Beschreibung
Zusammenfassung:Grout formulations have been investigated in Nevada Nuclear Waste Storage Investigations Project, for possible nuclear waste repository sealing applications focused in the Yucca Mountain Area (in welded tuff). A shrinkage compensated cement was chemically modified with siliceous reactants to enhance the chemical compatibility with a siliceous tuff. Fluids in contact with the grouts were measured at 150 °C and 200 °C, and the solids were characterized. Well-crystallized Al-substituted tobermorite and truscottite were observed, and sometimes xonotlite as dominant cementitious phases. Comparisons of solid phases and solution phases are made with a second grout incorporating siliceous modifiers in a Class H cement. Exposures to 150 °C hydrothermal conditions have not produced significant detrimental mechanical behavior of the seal material. The thermal decomposition of ettringite, an expansive calcium sulfate aluminate hydrate, resulted in a small increase in the porosity of the grout, but on a very small fine scale.
ISSN:0956-053X
1879-2456
DOI:10.1016/0956-053X(89)90409-1