Hostname: page-component-848d4c4894-x24gv Total loading time: 0 Render date: 2024-05-16T18:32:30.027Z Has data issue: false hasContentIssue false

Processing of large-Scale radwaste-containing blocks using exothermic metallic mixtures

Published online by Cambridge University Press:  10 February 2011

M. I. Ojovan
Affiliation:
SIA “Radon”, 7th Rostovskii per., 2/14, Moscow 119121 Russia;
G. A. Petrov
Affiliation:
SIA “Radon”, 7th Rostovskii per., 2/14, Moscow 119121 Russia;
S. V. Stefanovsky
Affiliation:
SIA “Radon”, 7th Rostovskii per., 2/14, Moscow 119121 Russia;
B. S. Nikonov
Affiliation:
Institute of Geology of Ore Deposits RAS, Staromonetnii per., 35, Moscow 109017 Russia.
Get access

Abstract

The parameters of processing of large-scale (50-100 kg) radwaste-containing blocks were studied. Batches consisted of exothermic mixture, oxidizer, mineral additive, and radwaste surrogate. Such mixtures provide process temperature up to ˜2400 K. In the present work exothermic mixtures composed of Ca-Fe silicide, zirconium, silicon, and boron were intermixed with oxidizer (mixture of KMnO4 and V2O5), natural zircon concentrate as mineral additive, and cerium oxide (actinide surrogate). Tests were carried out in a bench-scale plant. Burning of the reaction mixture was remotely initiated from electric supply unit. Melt formation started in the nearbottom area sustained upwards frontally, The melt temperature ranged between 1600 and 1900 K. The melt formation rate during the tests ranged between 0.7 and 2.5 kg/s. Melt cooling after reaction completion was kept for about 15-18 hours. Volatile aerosols were essentially retained in the bulk. The initial volume of the mixture was reduced after reaction by factors of 2 to 3. The densities of the blocks were ranged between 3.2 and 3.9 kg/dm3.

Samples of the materials obtained were examined by optical microscopy, X-ray diffraction, and scanning electron microscopy. The product consisted of glass-like body with metallic spheres (˜0.5-1.5 mm) distributed within. The base was composed of glass (˜60-80 vol.% of total) and crystalline phases (mainly zirconia). Monoclinic baddeleyite was found to be the major crystalline phase. The minor phase was tetragonal zirconia. Cerium (actinide surrogate) was partitioned among the glass and zirconia. The Ce2O3 concentration in glass ranged between ˜0.4 wt.% and ˜0.8 wt.% whereas its content in zirconia was found to be lower (up to ˜0.3 wt %). The metallic constituent consisted of vanadium and Fe-V-Si alloy whose average composition wasFe7O2V19.3Mn1.1 Si9.4.

Type
Research Article
Copyright
Copyright © Materials Research Society 1999

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Design and Operation of High Level Waste F'rijicaluon and Storage Facilities. Techn. Rep. Ser. No. 339, Vienna, IAEA, 1992.Google Scholar
2. Ringwood, A. E., Kesson, S. E., Reeve, K. D., Levins, D. M., Ramm, E. J., in Radioactive Waste Formsfor the future, edited by Lutze, W., and Ewing, R. C. (Elsevier Science Publishers B.V., 1988) pp. 233334.Google Scholar
3. Lutze, W., Gong, W., Abdelouas, A., Ewing, R. C., Scales, C., in Scientific Basis for Nuclear Waste Management XXI, edited by McKinley, I. G. and McCombie, C. (Mat Res. Soc. Symp Proc. 506, Warrendale, PA, 1998) pp.223230.Google Scholar
4. Knyazev, O. A, Nikonov, B. S., Omelianenko, B. I., Stefanovsky, S. V, Yudintsev, S. V, Day, R. A., Vance, E. R., in SPECTRUM'96 Proceedings:. itternational Topical Meeting on Nuclear and Hazardous Waste Management, 1996, pp. 21302137.Google Scholar
5. Sobolev, I. A., Stefanovsky, S. V., Knyazev, O. A., Lashtchenova, T. N., Vlasov, V. I., Lopukh, D. B., in Proceedings of the Sixth international Conference on Radioactive Wastemantagement and Environmental Remedialion, ICEM'97, ASME, 1997, p. 265272.Google Scholar
6. Karlina, O. K., Ojovan, M. I., Stefanovsky, S. V., Varlakova, G. A., in Scientfc Basis.for Nuclear Waste Management XXI, edited by McKinley, I. G. and McCombie, C. (Mat. Res. Soc Symp.Proc 506, Warrendale, PA, 1998) pp. 561564.Google Scholar
7. Sobolev, I. A., Ojovan, M. I., Petrov, G. A., Klimov, V. L., Tarasov, V. L., in IT3 ConJerence. International Conference on Incineration and Thermal 7reatment Technologies. Proceedings, 1998, p. 311.Google Scholar
8. Campbell, B. E., Thompson, L. E., McElroy, J. L., in Proceedings of SPECTRUM'98 Intlermttional Conference on Decommissioning and Decontamination and on Nuclear atnd Hazardous Waste Management, 1998, pp. 10281033.Google Scholar
9. Zircon concentrate. Russian standard OST 48-82-81. Gosstandart of Russia.Google Scholar
10. Weber, W. J., Ewing, R. C., Lutze, W., in Scienltfic Basis for Nuclear Waste Management XIX, edited by Murphy, W. M. and Knecht, D. A. (Mat. Res. Soc. Syrnp. Proc. 412, 1996, Pittsburgh, PA, 1996) pp.25–32Google Scholar
11. Thermodynamic constants of substances. Directoiy (Russ.), edited by Glushko, V.P., AN SSSR, 1974.Google Scholar
12. Nuclear Waste Materials Handbook, US Report No. DOE/TIC-11400, 1983 (Materials Characterization Center, Hanford, WA).Google Scholar