The European Spallation Source (ESS) is under construction in the outskirts of Lund. When in operation, ESS will produce an intense beam of high-energy protons which will generate the desired spallation neutrons in a large target of tungsten. A small part of the radioactive by-products produced will be released to the environment during normal operation. The radionuclides generated in the ESS target will differ from that of e.g. nuclear power plants. The future environmental monitoring of ESS need to be able to quantify these ESS-specific radionuclides in environmental samples to ensure that dose limits to the public are not exceeded.

This project (SSM2018-1636), financed by the Swedish Radiation Safety Authority (SSM) and performed in cooperation between the BAR group and researchers at Medical Radiation Physics, Malmö, aimed to strengthen competence at Lund University for measurement and analysis of ESS-specific radionuclides. The project included:

• An extensive literature review, with modelling as well as experimental analyses, of ESS-relevant radionuclides.
• An independent simplified model of the ESS target sector for calculating radionuclide production in the ESS tungsten target using the code FLUKA (link).
• A literature review of known environmental measurement technologies for various ESS-relevant radionuclides, focussing on pure difficult-to-measure alpha- and beta-emitters.
• Three experimental parts: i) related to initiation of radioactivity measurements of aerosols at Lund University; ii) mapping of environmental tritium in the Lund area; iii) a study of tritium in persons presently living or working in Lund (link).

The full report of the project is available at SSM's website.