Aspects of Remediation of Land on Sites Used for Fertiliser Manufacture and Storage

Keywords: NORM, Radioactivity, Regulation, Remediation, Waste management.

Significant changes have occurred in European fertiliser manufacturing in recent years as results of changes in market conditions, feedstocks used and necessary rationalisation. As a result many of the old phosphate-based fertiliser plants are redundant and are being dismantled. The sites of these plants are now being redeveloped. Some of these sites have areas of low-level radioactive contamination as a result of the enhanced levels of naturally occurring radionuclides present in many phosphate ores. Much of this contamination is associated with radionuclides in the ²³⁸U decay series and particularly ²²⁶Ra and its daughters. The sites are also often contaminated with heavy metals from the ores and various acids used in the manufacturing processes. However, it is the radioactive components of the contamination, which tend to dominate the remediation and waste management strategies.

The rehabilitation of radioactively contaminated land is a small but growing field of activity worldwide. To date most of the sites in or associated with the UK have been small in scale and have generally involved natural radionuclides. This paper addresses certain of the key considerations in remediating fertiliser manufacturing and storage sites contaminated with naturally occurring radionuclides. It considers all of the key aspects in any remediation programme, including the regulatory aspects, characterisation of contaminated areas, assessment of the risks posed by any contamination and potential clean-up criteria. It then considers remediation approaches with the technologies used in their application and also waste management. Finally, it illustrates the key aspects of one remediation approach through an example from a UK site. This relates to a former waste storage and processing area.

Lorimer R Fellingham, B.Sc.(Eng), PhD, C. Eng, M.I.Chem.E., M.I.Nuc.E., RWE Nukem Ltd., Harwell, UK.

35 Pages, 2 Tables, 36 Refs.