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The Sorption of Niobium, Tin, Iodine and Chlorine onto Nirex Reference Vault Backfill

Published online by Cambridge University Press:  25 February 2011

S. Baker
Affiliation:
AEA Technology, Harwell, Didcot, Oxfordshire OX11 0RA, United Kingdom
R. McCrohon
Affiliation:
AEA Technology, Harwell, Didcot, Oxfordshire OX11 0RA, United Kingdom
P. Oliver
Affiliation:
AEA Technology, Harwell, Didcot, Oxfordshire OX11 0RA, United Kingdom
N.J. Pilkington
Affiliation:
AEA Technology, Harwell, Didcot, Oxfordshire OX11 0RA, United Kingdom
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Abstract

UK Nirex Ltd is proposing to develop a deep underground repository for the disposal of solid low- and intermediate-level radioactive wastes in the UK, and is currently investigating Sellafield in Cumbria as a possible site. The Nirex Safety Assessment Research Programme (NSARP) comprises scientific research to support the post-closure performance assessment of the repository. One of the investigations carried out by AEA Technology under the NSARP is the study of the sorption of radionuclides onto the backfill. Sorption is one of the key parameters determining the rate of release of radionuclides from the repository. The radionuclides present in the waste include 94Nb, 126Sn, 129I and 36Cl. This paper reports the measurement of the sorption of niobium, tin, iodine and chlorine onto the Nirex reference vault backfill at 20±5°C by the batch sorption method. The temperature dependence of tin sorption was investigated by carrying out additional experiments at 77±5°C. Experiments on niobium solubility and sorption were carried out under saline conditions to reflect the nature of the groundwater at Sellafield. Sorption coefficients (Rd) for niobium are within the range measured in other work, whereas for tin the results are a factor of ten lower than literature values. For iodine and chlorine, the results are consistent with the literature; they also show an increase in Rd with decreasing initial inventory. The Rd values for niobium and tin are significantly higher than those for chlorine and iodine.

Type
Research Article
Copyright
Copyright © Materials Research Society 1994

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References

REFERENCES

1 Nirex adopts new design for waste repository, Atom, No 419, p. 4 (January 1992).Google Scholar
2 Atkinson, A. and Guppy, R.M., UKAEA Report AERE-R12961 (1988).Google Scholar
3 Bradbury, M.H., Jefferies, N.L., UKAEA Report AERE-R11881 (1985).Google Scholar
4 Serne, R. J. and Relyea, J.F., The status of radionuclide sorption-desorption studies performed by the WRIT program, Pacific Northwest Lab., Richland, WA, PNL-3997 UC-70 (1982).Google Scholar
5 Bayliss, S., Howse, R.M., McCrohon, R., Oliver, P., Smith-Briggs, J.L. and Thomason, H.P., UK Nirex Ltd Report NSS/R124, to be published.Google Scholar
6 UK Patent Application 9316995.1. Patent applied for 16 August 1993. Case Vault Backfill UK Nirex Ltd.Google Scholar
7 Sorption: Modelling and Measurement for Nuclear Waste Disposal Studies. Summary of a workshop of the Organisation for Economic Co-operation and Development’s Nuclear Energy Agency, held 6–7 June 1983 in Paris, France, RWM-4 (1983).Google Scholar
8 Pilkington, N.J. and Stone, N.S., UK Nirex Ltd Report NSS/R186 (1990).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., Scientific Basis for Nuclear Waste Management XII, MRS Symp. Proc. 127, 879885 (1989).CrossRefGoogle Scholar
10 Liu, Y. and von Gunten, H.R., Migration chemistry and behaviour of iodine relevant to geological disposal of radioactive wastes, Paul Scherrer Institute Report No. 16, Villigen PSI, Switzerland (1988).Google Scholar
11 Sarott, F.-A., Bradbury, M.H., Pandolfo, P. and Spieler, P., Cement and Concrete Research 22, 439444 (1992).CrossRefGoogle Scholar