1. Working Group 1 Reference and Graded Approaches for Assessing the Impact of Radioactive Discharges

2. Aims Methodologies for setup of reference models for assessing radiological impacts – Planned releases – Existing situations – Discharges from HLW to the environment Find consensus on – Reference principles – Procedures – Data sets for defined situations Standardization and harmonization of models for assessing radiological – Humans – Biota

3. Relevant situations Impact of planned discharges – Nuclear industry, NORM, uranium industry, hospitals, laboratories, small enterprises, shallow land burial Compliance of discharges during operation Monitoring strategies – Locations, frequency, environmental media Use of monitoring data in impact assessment Existing contaminations – Past contaminations – NORM, etc.

4. Integrated assessment Aim: Model validation Test and compare assessment model predictions of the transfer of radionuclides in real environments Analysis of radionuclide transfer subsequent to environmental contaminations Releases to atmosphere Releases to water (fresh)water bodies Output Activity in environmental media Exposures via all relevant pathways Internal/external exposure Humans and biota Sensitivity: pathways / processes / parameters

5. 6 proposed issues discussed Prospective assessments of radioactive discharges Prospective assessments of the long-term impact of radioactive waste repositories Prospective assessment of the impact of NORM releases Assessment of radiological impact of legacy sites Integrated assessment Regulatory approach for humans and biota (to be discussed today)

6. Response Interests for all topics Some participants are interested in more than one topic Preliminary ranking: Waste disposal > NORM/Existing situations > Reference models for releases

7. Possible Groups Reference methodologies and models for planned releases – Planning – Operation Reference models for waste disposal – Reference cases Climate Interface geosphere/biosphere Environmental changes Reference models for existing situations – NORM (U, coal, oil gas) – Legacy sites (Russia, Central Asia, USA, UK, etc)

8. How to go on Discussion of a regulatory approach on protection of humans and biota (with WG 2) Agreement on subgroups Continue to work in sub-groups