skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Performance Impact of Fast Flow Paths Through Grout Monoliths Used for Radioactive Waste Disposal - 13224

Conference ·
OSTI ID:22224978
;  [1]; ;  [2]
  1. Southwest Research Institute - SwRI, Geosciences and Engineering Division, San Antonio, Texas (United States)
  2. U.S. NRC, Office of Federal and State Materials and Environmental Management Programs, Division of Waste Management and Environmental Protection, Rockville, Maryland (United States)

Empty HLW handling and storage tanks at SRS and INL contain residual radioactivity; these tanks are being stabilized with cementitious grout during closure operations. The US NRC directed the Center for Nuclear Waste Regulatory Analyses (CNWRA{sup R}) to develop physical analogs of cementitious grout monoliths to investigate their potential to form fast flow pathways such as macro-cracks, separations between grout lifts, and annuli around pipes, supports, and along tank walls. CNWRA developed and tested 15 55-gal-drum-scale specimens and 2 larger specimens of tank-filling cementitious grout, and 9 specimens of pipe-filling grout. These experiments demonstrated that the size of fast flow pathways that develop and the peak temperatures attained during hydration are proportional to the scale of the specimen, and that annular apertures and bulk grout permeability generally increased with time post-placement. Cracks developed overnight following placement of each grout lift in the largest specimen, but developed more slowly in smaller specimens, perhaps due to a ∼20 deg. C difference in peak temperatures, which influence the thermal gradients that can induce cracking. Plastic and drying shrinkage commonly led to poor grout-to-metal and grout-to-grout bonding. Cracks, annular gaps, and grout flow lobe seams transmitted fluids during injection testing. Macro-scale flow pathways such as these are not readily observed in bench-scale specimens of cementitious tank grout. (authors)

Research Organization:
WM Symposia, 1628 E. Southern Avenue, Suite 9-332, Tempe, AZ 85282 (United States)
OSTI ID:
22224978
Report Number(s):
INIS-US-13-WM-13224; TRN: US14V0427045933
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; 17 refs.
Country of Publication:
United States
Language:
English