WP2

Task 2.1 Reducing uncertainties in radon measurements

Leader: BFS, partners: GIG, HES-SO, STUK, ISS, DSA

Task 2.1 is focused on improvement of measurement techniques, protocols, and quality assurance systems leading to more accurate evaluation of both, radon and thoron derived dose. Sources of uncertainties will be identified in relation to temporal and spatial variability, radon-radon progeny equilibrium, aerosols size distribution and currently underestimated thoron presence as well as overall interaction with external condition. Special attention is paid on both, radon and thoron progeny measurements including the necessary calibration resources. Task 2.1 is split into 4 Sub-tasks:

Subtask 2.1.1 Uncertainty of measurements with passive/ active detectors – temporal and spatial variability

Subtask 2.1.2 Metrological, structural and organizational capabilities for a thoron decay product calibration – Support to the establishment of a reference calibration chamber

Subtask 2.1.3: Collection of characteristic data of radon-progeny activity concentration and aerosol characteristics at selected workplaces

Subtask 2.1.4 Promotion of quality assurance and proficiency testing

Task 2.2: Transport of radon in the environment

Leader: DSA, partners: IRSN, SCK-CEN, NMBU, AGES

Radon gas has a potential for long-range atmospheric transport and it is crucial to study its sources and fate in the atmosphere. Due to the much shorter half-life of thoron, additional information on the underlying processes will be obtained by including data on thoron progeny. The aim of this task is to improve the understanding spatial and temporal variability of outdoor radon and thoron and their decay products: exhalation, atmospheric transport, as well as wet and dry deposition. These processes determine outdoor exposure to radon and thoron, and accumulation of long-lived radon decay products in plants. Task 2.2 is split into 3 Subtasks:

Subtask 2.2.1 Radon and thoron exhalation from the ground

Subtask 2.2.2. Radon outdoor concentrations assessment at European scale

Subtask 2.2.3 Wet and dry deposition of radon and thoron decay products. Field studies and development of combined model for forest environments

Task 2.3: Exposure to radon in buildings

Leader: IRSN, other partners: AGES, CIEMAT, CSTB, DSA, ISS, IST-ID, STUK

In the case of dwellings built with building materials containing NORM, workers and inhabitants are exposed to radon and to gamma radiation. By a modelling approach associated with ad hoc measurements radon exhalation and gamma irradiation from building materials will be analysed to better estimate the contribution of such materials to the exposure of the public and the workers to radon. With regard to radon exposure types of workplaces are very different in various aspects. The task aims to (i) identify typologies of workplaces where radon concentration behaviour is significantly different from that in dwellings, (ii) set up workplace- type specific measurement protocols for realistic assessment of the exposure and dose of the workers. In addition the task aims to assess the contribution of local geology versus other sources on radon exposure in dwellings by improving the modelling the radon transport from soils to indoor air. The task is split in 3 subtasks:

Subtask 2.3.1. Building materials as a source of indoor radon exposure

Subtask 2.3.2. Radon exposure in workplaces

Subtask 2.3.3. Contribution of other sources than local geology on radon exposure in buildings

Task 2.4: Improvement of methods to identify high indoor radon levels (radon mapping and other methods)

Leader: ISS, other partners: IRSN, HES-SO, AGES, SURO

This action will improve and upgrade statistical methods to identify both, buildings and areas with high indoor radon levels. The methods will be applied to existing data-sets – focusing on those containing measurements of indoor radon levels or geogenic radon potential, and parameters such as dwelling and soil characteristics – in order to evaluate which parameters show stronger correlation with high radon levels as those parameters may differ from the parameters correlated with the average levels. Some studies have showed high radon levels in some karstic areas. To confirm those results other karstic areas, particularly in France, Switzerland, Italy, and Austria will be analysed. Measurements in soils and in dwellings will be carried out.

This task is split into 2 subtasks:

Subtask 2.4.1. Methods for improving the identification of buildings and areas with high indoor radon levels

Subtask 2.4.2. Studying the influence of local underground voids, both of karstic and anthropic (e.g., caves and catacombs) origins, on radon levels

Task 2.5: Overview of NORM sites and exposure scenarios in Europe and their characteristics

Leader: DSA, other partners: BfS, CIEMAT, CNRS, GIG, IRSN, ISS, NMBU, SCK CEN, STUK, SURO, UPorto, UAV, UGOT

The main objective of this task is to provide a comprehensive overview of existing NORM sites and their characteristics at the European level and to evaluate the most relevant NORM exposure scenarios and scientific and regulatory questions related to these. An overview of NORM sites will contribute to better understanding of to which extent NORM currently is present in Europe and which issues may pose a challenge for regulatory control. This task will also provide compiled scientific data needed for further NORM exposure characterization, development of an integrated risk impact assessment and modelling. Improved understanding of a process from source via transport to human and environmental dose/risks at NORM exposure situations would facilitate regulatory decision-making and contribute to development of holistic and integrated management of NORM.

This task is split into 5 subtasks:

Subtask 2.5.1. Making a national list of NORM exposure sites

Subtask 2.5.2. Radiological characterization of identified national NORM exposure situations.

Subtask 2.5.3. Characterization of NORM exposure situations with respect to other present contaminants

Subtask 2.5.4. Describing relevant processes and environmental parameters of concern

Subtask 2.5.5. Identification of challenges and main issues related to NORM exposure scenarios

Task 2.6: Identifying biological and chemical parameters controlling the transfer of NORM to plants to derive more robust transfer factors (TF)

Leader: CEA, other partners: HZDR, IRSN, UEF, UGR, SCK•CEN, STUK, NMBU

The main goal of this task is to understand the impact of bacteria, fungi and earthworm in NORM transfer to plants and to refine smart Transfer Factors (TF). Different soil and forest systems will be analysed in situ as well as in laboratory experiments. NORM bioavailability will be assessed in situ and a complete picture of U distribution and speciation in the tripartite system soil/plant/bacteria will be obtained.

This task is split into 2 subtasks:

Subtask 2.6.1: Transfer of NORM relevant radionuclides to annual plants

Subtask 2.6.2: Improving transfer parameters to plants

Task 2.7: Identification of geochemical and biological processes controlling NORM mobility to derive more robust solid/liquid distribution coefficient (Kd)

Leader: HZDR, other partners: IRSN, BfS, UB, CNRS, UGR, NMBU

The objectives of task 2.7 are to: (i) elucidate the effect of NORM speciation, including the speciation changes induced by microbial processes, on NORM mobility in the environment, (ii) identify the key soil properties that govern the mobility of NORM in soils, (iii) consider the dynamics of sorption-desorption reactions on soils, and (iv) develop prediction models for Kd from either site-specific data or laboratory experiments.

This task is split into 4 subtasks:

Subtask 2.7.1 Effect of microorganisms on NORM mobility in U mine waters

Subtask 2.7.2 Acquisition of new datasets of sorption and desorption parameters for NORM

Subtask 2.7.3 Development of a methodology of “site-specific Kd” useful for modelling

Subtask 2.7.4 Development of models able to predict Kd for NORM in relevant scenarios

Task 2.8: Updating approaches for modelling long-term prediction of NORM transfer in the environment

Leader: BfS, other partners: CIEMAT, ISS, IRSN, HZDR, DSA, ARPA-VENETO

The task will review radioecological models available for NORM site characterization, relevance of leachate pathway for human dose (drinking water contaminated by NORM residues) and of long-term processes (like erosion, human intrusion, etc.) at landfill sites involving NORM linked to industrial activities, as well as the impact of incineration of residues or/and use in agriculture of sludge from liquid effluent depuration will be assessed. Goal is to support revision of RP 122 and RP 135 in consideration of new types of industries, processes, environmental standards (EURATOM BSS 2013) and types of releases.

This task is split into 2 subtasks:

Subtask 2.8.1 Critical review of exposure pathways considered in radioecological models applicable for dose assessments for the public and biota at industrial/legacy sites involving NORM.

Subtask 2.8.2 Application of the most suitable models sites affected by NORM by accounting for improved understanding of biological and geo-chemical processes.