Developments in Radiological Characterization and Remediation of Non-Nuclear Industrial Sites in the Netherlands

Abstract

In the Netherlands, like in other countries, many industries process ores that contain small amounts of natural radioactivity e.g. phosphate ore for the production of phosphate-acid and fertilizers. These non-nuclear industries have often started their activities many years ago, sometimes 50 to 60 years ago, and cases are known for even longer periods. In these periods no governmental regulations concerning naturally occurring radioactive materials (NORM) existed and it was generally accepted that remaining materials of the industrial process were used for road construction, site improvement, send to household waste belts etc. In the eighties of the last century one became aware that due to industrial processes enhanced concentrations of NORM (TENORM; Technical Enhanced NORM) could occur and employees could receive doses that had to be observed and regulated. Due to this regulations and R&D new processes were set-up and existing factories were closed and successfully decommissioned and dismantled. What remains is that at these sites, due to actions and disposals in the past, enhanced NORM material can still be present that now will fall under the new established regulations. The radiological characterization is a necessarily action for the official ending of the site license in the case that no activities remain that use NORM or produce TENORM. Radiological characterization is also recommended in the case that the property changes of ownership. The characterization gives the new owner the security that there are no spots left with NORM or TENORM above existing governmental limits. While the advantage for the former owner is that no financial funds have to be reserved for an eventual contamination of a non localized spot with NORM or TENORM that supersedes existing governmental limits. In The Netherlands experience has been gained with the radiological characterization, decommissioning and remediation of non-nuclear industrial sites. Used methods will be presented and especially the process of radiological characterization and the definitions of selection and action criteria including motivations.