Innovative Grouting and Retrieval at the Idaho National Engineering and Environmental Laboratory, Idaho Falls, Idaho

Site Name:

Idaho National Engineering and Environmental Laboratory

Location:

Idaho Falls, ID

Period of
Operation:

- Summer of 1994 (innovative grouting and retrieval)
- Summer of 1995 (polymer grouting)
- Summer of 1996 (variety of grouting materials)

Cleanup
Type:

Full-scale demonstration and field demonstrations

Technology:
Innovative Grouting and Retrieval (IGR)
- Demonstrated on a waste pit (10 ft3), loaded with 55-gal cardboard and steel drums, and cardboard boxes (4 ft3) filled with waste and rare-earth tracer designed to simulate transuranic (TRU) pits
- Three phases - jet grouting, application of demolition grout, and retrieval of the waste
- Jet grouting - CASA GRANDE drill system and a high pressure displacement pump used to inject grout at a nominal 6,000 psi; total of 24 yds3 of Portland cement injected into 36 grout holes, creating a monolith
- Demolition grouting - immediately following jet grouting, thin-walled, spiral-wrapped tubes were inserted into the holes and allowed to cure, after which the demolition grout (BRISTAR) was added to the tubes; however, the grout did not expand as planned and the soil/waste matrix was not fractured
- Retrieval - a backhoe bucket was used to remove the monolith

Wall Stabilization Technique Using Jet Grouting for Hot Spot Removal
- Created a U-shaped wall by jet grouting Portland cement into an existing cold test pit at INEEL containing drums and boxes
- Jet grouting phase - 52 holes jet grouted to create the wall (30 ft along back and sides of U extended 8 feet); used jet grouting apparatus at 6,000 psi; total of 24 yds3 of Portland cement injected
- Stabilization evaluation phase - wall excavated and visually examined; no collapse or structural damage to wall during excavation and no visible voids; grout mixed with soil and formed a soilcrete material that filled some voids; neat Portland cement filled other voids

Jet Grouted Polymer for Waste Stabilization or as an Interim Technique Before Retrieval
- Demonstrated on two waste pits designed to simulate TRU pits containing drums; used 55-gallon drums containing cloth, paper, metal, wood, and sludge; tracer placed in each drum to simulate plutonium oxide
- Tested two formulations of an acrylic polymer - one to produce a hard, durable material for long-term encapsulation; one to form a soft material for retrieval
- Hard polymer pit - 18 holes jet grouted into 4.5 x 9 x 6 ft pit; after curing, hard polymer was fractured and removed
- Soft polymer pit - 15 holes jet grouted into 4.5 x 9 x 6 ft pit; after curing, removed with a backhoe

In Situ Stabilization
- Demonstrated variety of grouting materials - TECT grout, WAXFIT, Hermite, water-based epoxy, and Type H cement; jet grouted to form monoliths of buried waste

Cleanup Authority:
Not identified

Technical Contact:
G.G. Loomis
Lockheed Martin
Idaho Technologies Company
INEEL
P.O. Box 1625, MS 3710
Idaho Falls, ID 83415
Telephone: 208-526-9208
E-mail: guy@inel.gov
DOE Contacts:
Skip Chamberlain
Subsurface Contaminants
Focus Area HQ Lead
DOE EM50
Germantown, MD
Telephone: 301-903-7248

James Wright
Subsurface Contaminants
Focus Area Program Manager
DOE Savannah River
Aiken, SC
Telephone: 803-725-5608

Contaminants:
- Radioactive and nonradioactive wastes
- Demonstration used nonradioactive tracer to simulate radioactive materials

Waste Source:
Buried drums and waste from DOE operations

Type/Quantity of Media Treated:
Soil and debris
- Steel drums; cardboard boxes containing metal pipe, wire, and plate steel; paper

Purpose/Significance of Application:
Field demonstration of innovative jet grouting and retrieval techniques that are applicable to TRU wastes

Regulatory Requirements/Cleanup Goals:
- Purpose of the demonstrations was to evaluate different jet grouting techniques for use in stabilization and hot-spot retrieval of waste; nonradioactive wastes used for demonstrations
- No specific cleanup goals were identified

Results:
- IGR - produced stable monolith; monolith was removed in 5 hrs; general soilcrete mix easily removed; grouted waste that were more difficult to retrieve included grouted boxes containing metal pipe, wire, and plate steel and grouted computer paper, which disintegrated during removal
- Wall - produced a solid wall with no visible voids; wall was stable and excavated intact
- Soft polymer - soft polymer material was removed easily; however, tracer material was detected at two-orders of magnitude above background; determined that one of the containers was not penetrated during drilling; but was punctured during removal releasing tracer
- Hard polymer - produced cured, stabilized monolith with no voids; easily fractured with a backhoe and removed
- Various grout materials - TECT, WAXFIT, and Type H materials are easily jet grouted and produced stable monoliths; Hermite and water-based epoxy cannot be jet grouted
- In general, grouting techniques did not spread tracer, indicating that release of radioactive particulates would be minimized during operations

Cost Factors:
- Costs projected for IGR, jet grouting using TECT, and jet grouting using WAXFIT; costs developed for 1-acre; for IGR costs also developed for 4-acre TRU contaminated site
- IGR - projected cost is $19 million (1-acre) and $64 million (4-acre), including grouting and waste management, excavation, secondary waste management, and D&D equipment
- TECT - projected cost is $15 million, assuming pit is left in place permanently; includes costs for grouting and waste management and secondary waste management, but no costs for caps
- WAXFIT - projected costs is $20 million, assuming waste pit is a soft polymer and is retrieved; includes costs for grouting and waste management and retrieval operations
- Jet grouting technologies were less expensive than the baseline retrieval, packaging, and storage ($200 million for 1-acre; $305 million for 4-acres)

Description:
Between 1994 and 1996, a number of different innovative jet grouting techniques were demonstrated at INEEL to determine their potential for use in stabilization and retrieval of buried transuranic (TRU) and other wastes at DOE facilities. Nonradioactive debris containing a rare-earth tracer were tested on waste pits designed to simulate those found at TRU sites. Technologies demonstrated included innovative grouting and retrieval, wall stabilization techniques using jet grouting for hot-spot removal, jet grouted polymer for waste stabilization, and various grouting materials for stabilization.

The results of the demonstrations indicated that a number of the jet grouting technologies produce stable waste forms that are generally easy to remove, thus making the technology suitable for stabilization and for hot-spot removal. In addition, the costs for jet grouting and retrieval is up to 90% less than the costs for the baseline technology of retrieval, packaging, and storage. Further testing is need of the BRISTAR demolition grout, which did not perform as expected, and long-term durability studies of the materials are recommended, including development of monitoring systems to ensure complete encapsulation of the waste.