The variety of methods for assessment of the radiological impact in different countries often makes it difficult if not impossible to compare them. A detailed study is necessary on to determine an appropriate methodology and calculation tools to evaluate the radiological impact of mill tailings repositories, while respecting the effective dose limit of 1 mSv recommended by the ICRP (International Commission on Radiological Protection), uncertainties related to the natural variation of some phenomena (for example exhalation of radon) and uncertainties related to long term phenomena.  An international reference document, including in particular exposure scenarios to be evaluated in the short, medium and long term, would make it possible to compare radiological impacts more objectively with regard to radiation protection objectives.

The project will consist of two parts:

• the elaboration of an harmonised methodology for assessment of the radiological impact of uranium mill tailings repositories, which would lead to an international reference document,
• the application of the methodology to selected cases.

Working document: French Doctrine Regarding the remediation of repositories for uranium mill tailings. The work is based on the plan of the working document.

1.1 General view of the document : scope, organisation
1.2 Definitions of the main terms 
1.3. The protection of man and the environment

• How to assess the radiological protection
• How to evaluate the effective added dose Remediation options: how to ensure that the installations remain effective

• Information required to assess radiological impact
• Scenarios
• Approach for generating scenarios
• Application to repositories for uranium mill tailings
• Principles of the modelling
• Evaluationof the radiological impact

2.1. Determination of a generic site
2.2. Selection of exposure scenarios
2.3. Validation of parameters for assessment
2.4. Impact calculation

Concerning the programme of the work, we think that the first part of the project will require about three few day's meetings. But as it is a project of harmonisation it can vary according to the number of participants. We would of course save a lot of time if all the participants could have the working document before the first meeting.

The application phase will certainly be longer and will require more individual work.