The effects of the glass surface area/solution volume ratio on glass corrosion: A critical review

Abstract

Argonne National Lahoratory. wi1th facilitie, in the states of liiinois and Idaho. is owned by the united States govern lent, and operated by The Un diversity of Chicago under the provisions of a contract with thie department of Enery. DISCLAIM ER THE FFFECTS OF THE GLASS SURFACE AREA/SOLUTION VOLUME RATIO ON GLASS CORROSION: A CRITICAL REVIEW William L. Ebert ABSTRACTThis report reviews and summarizes the present state of knowledge regarding the effects of the glass surface area/solution volume (SA/V) ratio on the corrosion behavior of borosilicate waste glasses. The SA/V ratio affects the rate of glass corrosion through the extent of dilution ok corrosion products released from the glass into the leachate solution: glass corrosion products are diluted more in tests conducted at low SA/V ratios than they are in tests conducted at high SAN ratios. Differences in the solution chemistries generated in tests conducted at different SA/V ratios then affect the observed glass corrosion behavior. Corrosion of borosilicate waste glasses results in the dissolution of soluble components and the accumulation of sparingly soluble components in a layer on the surface of the corroding glass. Laboratory tests performed to distinguish the effects of the solution chemistry and the surface layer on the glass corrosion rate have shown the rate to be controlled primarily by the solution chemistry. Therefore, any testing parameter that affects the solution chemistry will also affect the glass corrosion rate. The results of static leach tests conducted to assess the effects of the SAN are discussed with regard to the effects of SAN on the solution chemistry. The effects of the SA/V ratio observed in static tests can be understood based on the effects of the solution chemistry on glass corrosion behavior. Test results show several remaining issues with regard to the long-term glass corrosion behavior: Can the SAN ratio be used as an accelerating parameter to characterize the advanced stages of glass corrosion relevant to long disposal times? Is the alteration of the glass surface the same in tests conducted at different SAN, and in tests conducted with monolithic and crushed glass samples? What are the effects of the SAN and the extent of glass corrosion on the disposition of released radionuclides? These issues will bear on the prediction of the long-term performance of waste glasses during storage. The results of an experimental program conducted at ANL to address these and other remaining issues regarding the effects of SA/V on glass corrosion are described. I 2 SUMMARYThis report reviews and summarizes the present state of knowledge regarding the effects of the glass surface area/solution volume ratio (SA/V) on the corrosion behavior of borosilicate waste glasses. The effects of the SA/ occur through dilution of corrosion products and through the effects of the corrosion products on the glass corrosion mechanism and rate. Therefore, the effects of the SA/V on glass corrosion are discussed in terms of the various effects of t...

Accounting for a Vitrified Plutonium Waste Form in the Yucca Mountain Repository Total System Performance Assessment (Tspa)

“…5b with corresponding values from previous tests conducted under the same conditions with reference DWPF glasses made with frits SRL 131 and SRL 202 (Ebert 1994). The glass made with SRL 131 frit was formulated to represent Purex glass and the glass made with SRL 202 frit was formulated to represent the design basis glass.…”

Fluidized Bed Steam Reformer (Fbsr) Product: Monolith Formation and Characterization

“…penetrable by the inert gas (nitrogen for this work) are accounted for in the surface area. This surface area may be different from the surface area penetrable by water during a leaching test 38 but is the best measurement available. The SA/V ratio is simply calculated by dividing the measured BET surface area by the leachant volume:…”

Colloid-Associated Radionuclide Concentration Limits: ANL

“…Data used in these analyses include at least ten years of testing for the static glass tests (Ebert 1995;Buck and Bates 1999; DTN: LL991110251021.099), over ten years of testing for the glass drip tests Fortner et al 1997aFortner et al , 1997b; DTN: LL000205551021.118), and over four years of testing for the spent fuel tests (Finn et al 1994a(Finn et al , 1994b; DTN: LL991001251021.090). The methods employed for colloid characterization in this section are TEM and filtration (analysis of filtrates with inductively coupled plasma-mass spectrometry (ICP-MS) or alpha spectroscopy).…”

“…A summary of the test results and a detailed description of the test procedure and glass compositions is found elsewhere (Ebert andBates 1993, Ebert 1995). The types of glasses used in the tests were Savannah River Laboratory (SRL) 202A (actinide doped), 202U (no actinides except uranium), and 131A (actinide doped).…”

“…Data used in these analyses include normalized mass loss (NL) data on the corrosion of the waste form and normalized rate (NR) of formation of Pu-associated with colloids. The data encompasses several years of testing for the static glass tests (Ebert 1995), over ten years of testing for the glass drip tests Fortner et al 1997aFortner et al , 1997bDTN: LL000205551021.118), and testing data from 1.6 to 4.8 years of spent fuel tests (Finn et al 1994a(Finn et al , 1994b; DTN: LL991001251021.090). The methods employed for colloid quantification in this section are filtration (analysis of filtrates with ICP-MS or alpha spectroscopy).…”