Solidification/stabilization of technetium in cement-based grouts

Gilliam, T.M.; Spence, R. M.; Bostick, W.D.; Shoemaker, J.L.

doi:10.1016/0304-3894(90)87009-7

Cited by 48 publications

(45 citation statements)

References 5 publications

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“…A number of studies have demonstrated that BFS, when used as a part of cementitious waste forms, is known to attenuate Tc(VII) release through reduction of Tc(VII) to Tc(IV) (Gilliam et al 1988(Gilliam et al , 1990Langton 1988a,b;Lukens, et al 2005, Lockrem 2005, Aloy et al 2007, Spence and Shi 2005, Cooke et al 2009. Typically, BFS has reductive capacities that range from 0.82 to 4.79 meq/g (Lukens, et al 2005, Aloy et al 2007, Gilliam et al 1990) therefore, when incorporated into a waste form can effectively reduce Tc (VII) to Tc (IV), thus reducing its diffusivity.…”

Section: Such Large Diffusivity Discrepancies Between Re and 99mentioning

confidence: 99%

Waste Acceptance Testing of Secondary Waste Forms: Cast Stone, Ceramicrete and DuraLith

Mattigod¹,

Westsik²,

Chung³

et al. 2011

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Section: Such Large Diffusivity Discrepancies Between Re and 99mentioning

confidence: 99%

Waste Acceptance Testing of Secondary Waste Forms: Cast Stone, Ceramicrete and DuraLith

Mattigod¹,

Westsik²,

Chung³

et al. 2011

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“…The lower leachability for the 99 Tc was attributed to the capability of the BFS to reduce 99 Tc to a more immobile species than the nitrate. Their key conclusion was that in the future, the source of BFS should be driven by economics rather than performance (see Gilliam et al 1990 for additional details). However, Sundaram et al (2011) found some unexpectedly high quantity of calcium sulfate mineral phases in the BFS used in Phase II testing that may have deleteriously impacted rheological properties, so they recommended obtaining the slag directly from the steel manufacture if possible as opposed to vendors who may add other material, such as the calcium sulfate, for concrete building purposes.…”

Section: Starting Materialsmentioning

confidence: 99%

“…The raw data do show comparable fractions of 99 Tc and nitrate leached from this Saltstone variant with no BFS. Gilliam et al (1990) solidified a filtrate liquid waste from "raffinate" from uranium recovery and equipment decontamination operations at the Portsmouth Gaseous Diffusion Plant in Portsmouth, Ohio. The acidic raffinate was diluted and the pH adjusted with sodium hydroxide to a value of 8.2 to 8.5.…”

Section: 2mentioning

confidence: 99%

“…Gilliam et al's conclusion was that in the future, the source of BFS should be driven by economics rather than concerns about performance because any BFS seemed to lower 99 Tc release similarly. Gilliam et al (1990) also investigated adding technical-grade sodium sulfide (Na 2 S•9H 2 O ~ 80% pure) to a grout dry-solids blend that consisted only of cement and fly ash. The added sodium sulfide significantly improved the retention of 99 Tc as evidenced by the increase in 99 Tc LI from 6.8 to 9.4.…”

Section: 2mentioning

confidence: 99%

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Data Package for Secondary Waste Form Down-Selection—Cast Stone

Serne¹,

Westsik²

2011

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Executive SummaryThe objective of the data packages being generated for four potential waste forms for solidification/ stabilization of Hanford liquid secondary waste streams is to identify, evaluate, and summarize the existing information. This Cast Stone data package includes information available in the open literature and from data obtained from testing currently underway at Pacific Northwest National Laboratory (PNNL). As used at Hanford, the term Cast Stone describes a "grout"-based waste form made predominantly with fly ash and blast furnace slag (BFS) with lesser amounts of Portland cement as the starting dry blend. At Savannah River, this waste form is called Saltstone. The blend of grout reagents in Saltstone has been constant (45 weight percent [wt%] Grade 100 slag cement, 45 wt% Class F fly ash, and 10-wt% Type I/II Portland cement) since the Saltstone Disposal Facility began production in the early 1990s. At Hanford, some cementitious variants to Cast Stone have also been investigated, in which either the fly ash or the BFS is absent or replaced with another material. In this data package, these Cast Stone variants are included for completeness in the review. However, almost all the current Cast Stone waste form testing performed at PNNL uses a dry blend consisting of 47-wt% blast furnace slag (Grade 100), 45-wt% fly ash (Class F), and 8-wt% Portland cement (Type I/II). The sources of the three dry blend ingredients used at Hanford and Savannah River differ and may have subtle impacts on the physical and chemical attributes of the subsequent waste forms. The compositions of the secondary waste simulants used for the PNNL Cast Stone studies also differ from the simulants and actual wastes solidified at Savannah River; although both are caustic-, saline-and sodium-dominated solutions. The Hanford secondary waste simulants anion composition contains much less nitrate/nitrite than the waste streams solidified at Savannah River.Available literature on Cast Stone and Saltstone was reviewed with an emphasis on determining how Cast Stone and related grout waste forms performed in relationship to various criteria that will be used to decide whether a specific type of waste form meets acceptance criteria for disposal in the Integrated Disposal Facility (IDF) at Hanford. The draft waste acceptance criteria include the following requirements or targets:• acceptable leachate concentrations (less than the Universal Treatment Standards in 40 CFR 268) for Resource Conservation and Recovery Act (RCRA) metals using the Toxicity Characteristic Leach Procedure (TCLP) leach test• low bleed water criteria (i.e., no bleed water is tolerated after 28 days of curing)• low leachability index (LI) values for sodium (LI>6), technetium-99 (target LI>9) and iodine-129 (target LI>11)• minimum compressive strength of 500 psi (3.45 MPa).Other attributes of the Cast Stone process were compared with additional criteria, such as:• worker and public safety concerns• cost effectiveness versus other candidate waste forms in regard to ...

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“…al., 1989;Langton, 1989;Gilliam et. al., 1990;Spence et al, 1995;Clark and Wilhite, 1991;Wong, 1991] Palmer, 1990;Sahu and Diamond, 1996A and B;Shi and Day, 1996;Bostick, et al, 1990;Tallent, et al, 1988;Serne, et al, 1992, Allan andKukacka, 1997].…”

Section: Wsrc-tr-2001-00359 Revision 0 July 31 2001mentioning

confidence: 99%

State of the Art Report on High-Level Waste Tank Closure

Langton¹

2002

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Solidification/stabilization of technetium in cement-based grouts

Cited by 48 publications

References 5 publications

Waste Acceptance Testing of Secondary Waste Forms: Cast Stone, Ceramicrete and DuraLith

Waste Acceptance Testing of Secondary Waste Forms: Cast Stone, Ceramicrete and DuraLith

Data Package for Secondary Waste Form Down-Selection—Cast Stone

State of the Art Report on High-Level Waste Tank Closure

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