An Experimental Comparison of Alternative Solid Forms for Savannah River High-Level Wastes

1981 ◽  
Vol 6 ◽  
Author(s):  
John A. Stone

ABSTRACTSamples of borosilicate glass, high-silica glass, tailored ceramic, and SYNROC, incorporating simulated Savannah River high-level defense waste sludges, were leached by the MCC-1 procedure for times up to 28 days. Cesium, uranium, and cerium leach rates are reported for waste forms containing a composite sludge, at 40°C in deionized water, and at 90°C in deionized water, silicate water, and brine. The ordering of the waste forms from best to worst differs for each element leached, and none of the forms show a clear advantage for all the key radwaste elements. Some cesium leach rates for forms containing high-aluminum or high-iron sludges also are presented. So far, only small effects of sludge type have been observed, with one exception. This study is one of several inputs for selection of an alternative waste form for Savannah River waste.

1981 ◽  
Vol 6 ◽  
Author(s):  
Ned E. Bibler

ABSTRACTAt the Savannah River Plant, the reference process for the immobilization of defense high-level waste (DHLW) for geologic storage is vitrification into borosilicate glass. During geologic storage for 106y, the glass would be exposed to ∼3 × 1010 rad of β radiation, ∼1010 rad of γ radiation, and 1018 particles/g glass for both α and α-recoil radiation. This paper discusses tests of the effect of these radiations on the leachability and density of the glass. No effect of the radiations was detected that reduced the effectiveness of the glass for long-term storage of DHLW even at doses corresponding to 106 years storage for the actual glass. For the tests, glass containing simulated DHLW was prepared from frit of the reference composition. Three methods were used to irradiate the glass: external irradiations with beams of ∼200 keV or Pb ions, internal irradiations with Cm–244 doped glass, and external irradiations with Co–60 γ rays. Results with both Xe and Pb ions indicate that a dose of 3 × 1013 ions/cm2 (simulating >106 years storage) does not significantly increase the leachability of the glass in deionized water. Tests with Cm–244 doped glass show no increase in leach rate in deionized water up to a dose of 1.3 × 1018 α and α-recoils/g glass. The density of the Cm–244 doped glass has decreased by 1% at a dose of 1018 particles/g glass. With γ-radiation, the density has changed by <0.05% at a dose of 8.5 × 1010 rad. Results of leach tests in deionized water and brine indicated that this very large dose of γ-radiation increased the leach rate by only 20%. Also, the leach rates are 3 to 4 times lower in brine.


1981 ◽  
Vol 6 ◽  
Author(s):  
Leslie J. Jardine ◽  
Gerald T. Reedy ◽  
William J. Mecham

ABSTRACTStandardized comparative drop weight impact tests were conducted on solid alternative waste forms under consideration for immobilizing Savannah River Laboratory (SRL) defense wastes. The fragment size distributions were measured in the size ranges of ֮5 to 8000 μm. All waste form fragment size distributions could be described accurately by lognormal plots. Respirable sizes (≤10 μm) were measured. Borosilicate glass and SYNROC specimens yielded the same mass fractions of respirable sizes; FUETAP concrete, high silica and alkoxide glass specimens yielded ֮2–3 times more mass fractions of particles of respirable sizes, whereas tailored (Spinel) ceramic specimens yielded the smallest mass fractions of respirable sizes, ֮2–1/2 times less.


1981 ◽  
Vol 11 ◽  
Author(s):  
D.E. Clark ◽  
C.A. Maurer ◽  
A.R. Jurgensen ◽  
L. Urwongse

ABSTRACTThe effects of waste composition and percent loading in a borosilicate glass designed for US defense high level wastes (HLW) have been evaluated. Three types of simulated wastes were investigated; high alumina, high iron and a composite representative of an average waste composition from Savannah River Plant (SRP) waste tanks. Corrosion resistance of the borosilicate glass is significantly enhanced by the presence of any of the three types of wastes. Additionally, corrosion resistance is improved as the % waste loading is increased in the glass. The best corrosion performance was obtained with the high alumina waste in deionized water.


1995 ◽  
Vol 10 (5) ◽  
pp. 1312-1320 ◽  
Author(s):  
Jau-Ho Jean ◽  
Tapan K. Gupta

Cristobalite is known to precipitate out of borosilicate glass (Corning 7740) and a binary glass mixture of borosilicate glass and high silica glass when these glasses are heated to elevated temperatures. To prevent cristobalite from forming in these glass systems, a devitrification inhibitor needs to be found. Among oxides selected for testing, both Al2O3 and Ga2O3 are found to prevent cristobalite from forming in these glass systems.


1986 ◽  
Vol 73 (2) ◽  
pp. 139-139
Author(s):  
Edward J. Hennelly ◽  
E. I. Du Pont de Nemours

1981 ◽  
Vol 11 ◽  
Author(s):  
J. H. Campbell ◽  
C. L. Hoenig ◽  
F. J. Ackerman ◽  
P. E. Peters ◽  
J. Z. Grens

In October 1981 SYNROC-D was selected as the reference alternate waste form to borosilicate glass for immobilization of defense wastes. A total of eight candidate waste forms competed in this selection process and the decision of which alternate waste form to choose was based primarily on performance properties.


1984 ◽  
Vol 44 ◽  
Author(s):  
B. A. Hamm ◽  
R. E. Eibling ◽  
M. A. Ebra ◽  
T. Motyka ◽  
H. D. Martin

AbstractAt the Savannah River Plant (SRP), a process has been developed for immobilizing high-level radioactive waste in a borosilicate glass. The waste is currently stored as soluble salts and insoluble solids. Insoluble waste as stored requires further processing before vitrification is possible. The processes required have been developed and demonstrated with actual waste. They include removal of aluminum in some waste, washing soluble salts out of the insoluble waste, and mercury stripping. Each of the processes and the results with actual SRP waste will be discussed. The benefits of each step will also be included.


1982 ◽  
Author(s):  
T. A. Bernadzikowski ◽  
J. S. Allender ◽  
J. L. Butler ◽  
D. E. Gordon ◽  
Gould, Jr., T. H. ◽  
...  

1984 ◽  
Vol 44 ◽  
Author(s):  
F. Bazan ◽  
J. Rego

AbstractA series of tests have been performed to characterize the chemical stability of a DWPF borosilicate glass sample as part of the Waste Package Task of the NNWSI Project. This material was prepared at the Savannah River Laboratory for the purpose of testing the 165-frit matrix doped with a simulated non-radioactive waste. All tests were conducted at 90°C using deionized water and J-13 water (a tuffaceous formation groundwater). In the deionized water tests, both monoliths and crushed glass were tested at various ratios of surface area of the sample to volume of water in order to compare leach rates for different sample geometries or leaching times. Effects on the leach rates due to the presence of crushed tuff and stainless steel material were also investigated in the tests with J-13 water.


1981 ◽  
Vol 11 ◽  
Author(s):  
Pedro B. Macedo ◽  
Aaron Barkatt ◽  
Joseoph H. Simmons

A model has been developed to predict the long-term leach or release rates of various waste-form materials under repository conditions.


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