Hostname: page-component-586b7cd67f-dsjbd Total loading time: 0 Render date: 2024-11-25T18:21:12.371Z Has data issue: false hasContentIssue false
  • English
  • Français

Radioelement Behaviour in a Cementitious Environment

Published online by Cambridge University Press:  25 February 2011

S. Bayliss ,
A. Haworth ,
R. McCrohon ,
A.D. Moreton ,
P. Oliver ,
N.J. Pilkington ,
A.J. Smith  and
J.L. Smith-Briggs
S. Bayliss
Affiliation:
AEA Technology, Harwell Laboratory, Oxfordshire, OX 1I ORA, UK
A. Haworth
Affiliation:
AEA Technology, Harwell Laboratory, Oxfordshire, OX 1I ORA, UK
R. McCrohon
Affiliation:
AEA Technology, Harwell Laboratory, Oxfordshire, OX 1I ORA, UK
A.D. Moreton
Affiliation:
AEA Technology, Harwell Laboratory, Oxfordshire, OX 1I ORA, UK
P. Oliver
Affiliation:
AEA Technology, Harwell Laboratory, Oxfordshire, OX 1I ORA, UK
N.J. Pilkington
Affiliation:
AEA Technology, Harwell Laboratory, Oxfordshire, OX 1I ORA, UK
A.J. Smith
Affiliation:
AEA Technology, Harwell Laboratory, Oxfordshire, OX 1I ORA, UK
J.L. Smith-Briggs
Affiliation:
AEA Technology, Harwell Laboratory, Oxfordshire, OX 1I ORA, UK
Get access

Abstract

The Nirex Safety Assessment Research Programme (NSARP) comprises scientific research to support the safety assessment of a deep geological repository for low- and intermediate-level radioactive wastes. The NSARP addresses several areas of research, one of which is a continuing investigation of the behaviour of radioelements in a cementitious environment. This paper draws together recent experimental measurements of solubility and sorption under such conditions, along with the results of interpretive thermochemical and sorption modelling. Under conditions similar to those expected in the repository, the predicted solubility of selenium is about 3xl0−8M. Experimental measurements confirm that at low redox potential the solubility of selenium is substantially less than that previously observed under an air atmosphere, and is closer to the predictions of the thermochemical modelling. The solubility of sodium stannate has been studied after heating solutions at 50, 80 and 200°C. Crystalline tin solids were formed at all temperatures. For solutions heated at 200°C the solids were identified as cassiterite. The solubilities of all of the crystalline solids were 1x10−6M to 1x10−9M which are at least five orders of magnitude lower than that of the original sodium stannate. Distribution ratios (Rd) between 1x103 and 5x103 ml g-1 have been measured for the sorption of tetravalent technetium on to a cementitious material. Preliminary results from an in-diffusion experiment involving americium and an intact cement sample are in good agreement (at 1sx104 ml g-1) with Rd values determined from previously reported batch sorption experiments.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 257: Symposium – Scientific Basis for Nuclear Waste Management XV , 1991 , 641
Copyright
Copyright © Materials Research Society 1992

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. Preliminary Environmental and Radiological Assessment and Preliminary Safety Report, UK Nirex Report No. 71, 1989.Google Scholar
2. Atkinson, A., UKAEA Report AERE-R11777, 1985.Google Scholar
3. Sharland, S.M., Tasker, P.W., and Tweed, C.J., UKAEA Report AERE-R12442, 1986.Google Scholar
4. Thomason, H.P. and Williams, S.J., Nirex Report NSS R128, 1991.Google Scholar
5. Bayliss, S., Howse, R.M., McCrohon, R, Oliver, P, Smith-Briggs, J.L. and Thomason, H.P., Nirex Report NSS R124, 1991.Google Scholar
6. Greenfield, B.F., Moreton, A.D., Spindler, M.W., Williams, S.J. and Woodwark, D.R., presented at the 1991 MRS Fall Meeting, Strasbourg, France, 1991 (unpublished).Google Scholar
7. Atkinson, A., Harris, A.W., Naish, C.C., Sharland, S.M. and Smith, A.C., presented at the 1991 MRS Fall Meeting, Strasbourg, France, 1991 (unpublished).Google Scholar
8. Pilkington, N.J., Shadbolt, P.J. and Wilkins, J.D., Nirex Report NSS/R1 16, 1989.Google Scholar
9. Bayliss, S., Ewart, F.T., Howse, R.M., Lane, S.A., Pilkington, N.J., Smith-Briggs, J.L. and Williams, S.J., in Scientific Basis for Nuclear Waste Management XII, edited by Lutze, W. and Ewing, R.C. (Mater. Res. Soc. Proc. 127, Pittsburgh, 1989) pp.879–885.Google Scholar
10. Parkhurst, D.L., Thorstenson, D.C. and Plummer, L.N., Report USGS/WRI 80-96, NTIS Tech. Rep. PB81-167801, 1980, Revised 1985.Google Scholar
11. Cross, J.E., Ewart, F.T. and Tweed, C.J., UKAEA Report AERE-R12324, 1986.Google Scholar
12. Brown, P.L., Haworth, A., Sharland, S.M., and Tweed, C.J., Nirex Report NSS/R188, 1989.Google Scholar
13. Cross, J.E. and Ewart, F.T., Nirex Report NSS/R212, 1990.Google Scholar
14. Baeyens, B. and McKinley, I., Nagra technical report NTB 88-28, 1989.Google Scholar
15. Meyer, R.E., Arnold, W.D., Case, F.I. and O'Kelly, G.D., US Nuclear Regulatory Commission Report, NUREG/CR-5235, 1989.Google Scholar
16. Schwochau, K., Angewandte Chemie 76, 9–19 (1964).Google Scholar
17. Lever, D.A., UKAEA Report AERE-R12321, 1986.Google Scholar
18. Ewart, F.T. and Tasker, P.W., Proc. Symp. Waste Management 87, Vol. 3, 1987, p. 71 Google Scholar
19. Brown, P.L., Haworth, A., McCrohon, R., Sharland, S.M., and Tweed, C.J., in Scientific Basis for Nuclear Waste Management XIII, (Mater. Res. Soc. Proc. 176, Pittsburgh, 1990) pp. 591–598.Google Scholar