In-situ grouting of the low-level radioactive waste disposal silos at ORNL`s Solid Waste Storage Area Six
- Oak Ridge National Lab., TN (US)
- Stansfield (Robert G.), Knoxville, TN (US)
At Oak Ridge National Laboratory (ORNL), one method of solid low-level radioactive waste disposal has been disposed of in below-grade cylindrical concrete silos. Located in Solid Waste Storage Area 6 (SWSA 6), each silo measures 8 ft in diameter and 20 ft deep. Present day operations involve loading the silos with low-level radioactive waste and grouting the remaining void space with a particulate grout of low viscosity. Initial operations involving the disposal of wastes into the below-grade silos did not include the grouting process. Grouting was stated as a standard practice (in late 1988) after discovering that {approximately}75% of the silos accumulated water in the bottom of the silos in the {approximately}2 years after capping. Silo water (leachate) contained a wide range of types and concentrations of radionuclides. The migration of contaminated leachate out of the silo into adjoining soil and groundwater was considered to be a serious environmental concern. This report describes how a specially designed particulate-base grout was used to grout 54 silos previously filled with low-level radioactive waste. Grouting involved three steps: (1) silo preparation, (2) formulation and preparation of the grout mixture, and (3) injection of the grout into the silos. Thirty-five of the 54 silos grouted were equipped with a 3-in.-diam Polyvinyl Chloride (PVC) pipe used to monitor water levels in the silos. A method for rupturing the bottom section of these PVC wells was developed so that grout could be pumped to the bottom of those silos. Holes (2-in. diam) were drilled through the {approximately}18 in. thick concrete to fill the remaining 19 wells without the PVC monitoring wells. The formulation of grout injected into the silos was based on a Portland Type I cement, flyash, sand, and silica fume admixture. Compressive strength of grout delivered to SWSA6 during grouting operations averaged 1,808 lb/in{sup 2} with a bulk density of 3,549 lb/yd{sup 3}.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC05-84OR21400
- OSTI ID:
- 10170328
- Report Number(s):
- ORNL/TM-12283; ON: DE93017241; TRN: 93:016695
- Resource Relation:
- Other Information: DN: Environmental Sciences Division Publication No. 4026; PBD: Jul 1993
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
GROUTING
VISCOSITY
BULK DENSITY
LOW-LEVEL RADIOACTIVE WASTES
RADIOACTIVE WASTE DISPOSAL
DISPOSAL WELLS
SEALS
WATERPROOFING
ORNL
WASTE STORAGE
OAK RIDGE
RADIONUCLIDE MIGRATION
PVC
MONITORING
052002
WASTE DISPOSAL AND STORAGE