Objectif THE LITERATURE PROVIDES VARIOUS INDICATIONS THAT CURRENTLY AVAILABLE METHODS AND DATA BASES FOR PREDICTING THE RADIOLOGICAL CONSEQUENCES SUBSEQUENT TO MAJOR RADIOACTIVE RELEASES INTO THE ENVIRONMENT DO NOT ADEQUATELY REFLECT THE SPECIFIC SITUATION OF THE POPULATION AT RISK. ALTHOUGH THIS ASPECT IS CRUCIAL TO PROPERLY PREDICT THE POTENTIAL HAZARD TO THE POPULATION LITTLE EFFORT HAS BEEN DEVOTED TO IMPROVE THE UNDERSTANDING AND ACCURACY OF TOOLS TO PREDICT THE RADIONUCLIDE BEHAVIOUR IN URBAN AREAS. THE RESEARCH WORK PROPOSED IS INTENDED TO EXPLORE THE LITERATURE AND OTHER RELEVANT SOURCES FOR PERTINENT INFORMATION RELATED TO THE DEPOSITION AND POST-DEPOSITION RADIONUCLIDE BEHAVIOUR ON URBAN SURFACES, E.G. PERVIOUS, IMPERVIOUS AND VEGETATIVE SURFACES. THE BASIC DEPOSITION PROCESSES THAT MUST BE EVALUATED AS POTENTIAL SOURCES OF CONTAMINATION OF THESE SURFACES INCLUDE DRY DEPOSITION, WET DEPOSITION, AND RESEDIMENTATION OF SUSPENDED MATERIAL. NOT ALL OF THESE PROCESSES ARE WELL UNDERSTOOD UNDER THE WIDE RANGE OF CONDITION THAT IS EXPECTED TO OCCUR. EMPHASIS WILL BE PLACED ON STUDYING THE DEPOSITION OF RADIONUCLIDES ON SURFACES WHICH TYPICALLY PREVAIL ON URBAN ENVIRONMENTS, I.E. STREET SURFACES, WALKWAYS, ROOFS, ETC... FURTHER ASPECTS REQUIRING ATTENTION INCLUDE THE PHYSICOCHEMICAL FORM OF THE MATERIAL TO BE DEPOSITED AND THE PRINCIPAL MECHANISMS DISPOSING AIRBORNE MATERIAL TO THE GROUND E.G. RAINFALL, SNOW, ETC... SUBSTANCES DEPOSITED ONTO SURFACES ARE SUBJECTED TO A VARIETY OF PHYSICAL AND CHEMICAL PROCESSES, E.G. RADIOACTIVE DECAY, WASHOFF, INFILTRATION, RESUSPENSION, ETC., WITH THE POTENTIAL OF REMOVING THESE DEPOSITS FROM THE SURFACE. WASHOFF OF RADIONUCLIDES BY THE EROSIONAL ACTION OF SURFACE RUNOFF IS GENERALLY BELIEVED TO BE EFFECTIVE IN REMOVING CONTAMINANTS FROM IMPERVIOUS SURFACES AND WILL BE STUDIED IN GREATER DETAIL. THE PRINCIPAL FACTORS CHARACTERIZING THE WASHOFF PHENOMENON UNDER THE VARIETY OF METEOROLOGICAL CONDITIONS AND TYPES OF SURFACES WILL BE FULLY DISCUSSED. THE CONSIDERATIONS EXPLAINED ABOVE ARE INTENDED TO FORM THE BASIS OF A MODELING EFFORT INCLUDING THE MOST RELEVANT DEPOSITION AND POST-DEPOSITION PHENOMENA IN URBAN SURFACES TO ADDRESS THE SPECIFIC NEEDS OF REGIONAL TYPE OF ACCIDENT CONSEQUENCE ANALYSIS PROBLEMS. Champ scientifique natural sciencesphysical sciencesnuclear physicsnuclear decaynatural scienceschemical sciencesnuclear chemistryradiation chemistry Programme(s) FP1-RADPROT 6C - Multiannual research and training programme (Euratom) in the field of radiation protection, 1985-1989 Thème(s) Data not available Appel à propositions Data not available Régime de financement CSC - Cost-sharing contracts Coordinateur Brenk Systemplanung Contribution de l’UE Aucune donnée Adresse Heinrichsallee 38 52062 Aachen Allemagne Voir sur la carte Coût total Aucune donnée
