Hostname: page-component-cd9895bd7-jkksz Total loading time: 0 Render date: 2024-12-27T01:36:17.389Z Has data issue: false hasContentIssue false
  • English
  • Français

Investigation of Pu-Doped Ceramics Using Modified MCC-1 Leach Test

Published online by Cambridge University Press:  21 March 2011

Elena V. Nikolaeva  and
Boris E. Burakov
Elena V. Nikolaeva
Affiliation:
V.G.Khlopin Radium Institute, 28, 2-nd Murinskiy ave., St.Petersburg, 194021, Russia
Boris E. Burakov
Affiliation:
V.G.Khlopin Radium Institute, 28, 2-nd Murinskiy ave., St.Petersburg, 194021, Russia
Get access

Abstract

Leach testing is an important tool for the investigation of chemical durability of radioactive waste forms. The data obtained from these tests allows for the selection of the most durable ceramics for the immobilization of weapons-grade plutonium. Ceramics based on cubic zirconia, (Zr,Gd,Pu)O2, doped with 10 wt.% 239Pu, zircon, (Zr,Pu)SiO4, doped with separately 5-6 and 10 wt.% 239Pu, pyrochlore, (Ca,Pu,Gd,Hf,U)2Ti2O7, doped with 10 wt.% 239Pu were studied using MCC-1 leach test. Ceramic samples were placed in test vessels with deionized water and set temperatures of 25°C and 90°C in an oven for 28 days. The leaching solution was removed and replaced with fresh deionized water after 3 and 14 days from the start of the test. Only data obtained after 14 and 28 days were used for the interpretation. No saturation of leach solution with Pu was observed in any experiments. It was found that the (without correction for porosity) normalized Pu mass loss (in g/m2 ) after 14 and 28 days was:

- for the zirconia ceramic – 2 × 10−2 to 4 × 10−2 at 90°C and 8 × 10−3 to 9 × 10−3 at 25 °C;

- for zircon doped with 5-6 wt.% of Pu – 7.0 × 10−3 to 8.2 × 10−3 at 90°C and 1.0 × 10−3 to 1.2 × 10−3 at 25 °C;

- for zircon doped with 10 wt.% of Pu – 0.2 to 0.2 at 90°C and 3.0 × 10−2 to 4.0 × 10−2 at 25 °C;

- for pyrochlore – 1.0 × 10−3 to 1.0 × 10−3 at 90°C and 2.0 × 10−3 to 3.0 × 10−3 at 25 °C.

It was shown that the high leach rate for zircon based ceramic doped with 10 wt.% Pu was caused by the presence of the separated inclusions of PuO2 phases observed in ceramic matrix. The results obtained so far allow us to conclude that ceramics based on zircon, zirconia and pyrochlore are characterized by similar chemical resistance to leaching in deionized water. Based on its low porosity, zircon may be most durable ceramic host phase for Pu.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 713: Symposium JJ – Scientific Basis for Nuclear Waste Management XXV , 2002 , JJ11.18
Copyright
Copyright © Materials Research Society 2002

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. Heimann, R.B., Vandergraaf, T.T., J. Mater. Science Letters, 7, 583–586 (1988).Google Scholar
2. Burakov, B.E., Proc. Intern. Conf. Safe Waste'93, 2, 19–28 (1993).Google Scholar
3. Ewing, R.C., Lutze, W., Weber, W.J., J. Mater. Research, 10, 243–246 (1995).Google Scholar
4. Ewing, R.C., Weber, W.J., Lutze, W., Disposal of Weapon Plutonium ed. Merz, E.R. and Walter, C.E., Kluwer Academic Publishers, Dordrecht, pp. 65–83 (1996).Google Scholar
5. Burakov, B.E., anderson, E.B.et al., Disposal of Weapon Plutonium ed. Merz, E.R. and Walter, C.E., Kluwer Academic Publishers, Dordrecht, pp. 85–89 (1996).Google Scholar
6. Burakov, B.E., anderson, E.B.et al., Mater. Res. Soc. Symp. Proc. (in press) (2000).Google Scholar
7. Donald, I.W., Metcalfe, B. L. and Taylor, R. N. J., J. Mater. Sci., 32, 5851 (1997).Google Scholar
8. Kesson, S. E. and Ringwood, A. E., The Scientific Basis for Nuclear Waste Management VII, ed. McVay, G., Elsevier Science Publishing Co., New York, pp. 507–512 (1984).Google Scholar
9. Harker, A.B. and Flintoff, J. F., The Scientific Basis for Nuclear Waste Management VII, ed. McVay, G., Elsevier Science Publishing Co., New York, pp. 513–520 (1984).Google Scholar
10. Morgan, P. E. D., Shaw, T. M. and Pugar, E. A., Advances in Ceramics, Vol. 8, ed. Wicks, G. G. and Ross, W. A., Am. Ceram. Soc., Inc., Columbus, Ohio, pp. 209–221 (1984).Google Scholar
11. Morgan, P. E. D., Harker, A. B.et al., Advances in Ceramics, Vol. 8, ed. Wicks, G. G. and Ross, W. A., Am. Ceram. Soc., Inc., Columbus, Ohio, pp. 234–246 (1984).Google Scholar
12.ASTM C1220-92, Annual Book of ASTM Standards, pp.710–724, (1995).Google Scholar
13. Burakov, B.E., anderson, E.B., Excess Weapons Plutonium Immobilization in Russia ed. Jardine, L.J., Borisov, G.B., UCRL-ID-138361, Proc. of the Meeting for Coordination and Review of Work, St. Petersburg, Russia, 1–4/11/1999, 167–179 (2000).Google Scholar