THE ROLE OF COLLOIDS IN THE TRANSPORT OF RADIONUCLIDES IN GEOLOGICAL FORMATION

Objetivo

RECENT RESEARCH HAS EMPHASISED THE POTENTIAL IMPORTANCE OF COLLOIDS IN THE MIGRATION OF RADIONUCLIDES FROM A WASTE REPOSITORY INTO THE GEOSPHERE /1,2,3/. THUS, IF RADIONUCLIDES ARE ASSOCIATED WITH COLLOIDS THEIR FATE MAY BE DIFFERENT FROM THAT OF SIMPLE IONIC SPECIES IN SOLUTION. IN PARTICULAR, DEPENDING ON THE SIZE AND CHARGE OF COLLOID SPECIES RETENTION EFFECTS MAY OCCUR DUE TO FILTRATION, OR IN CONTRAST THERE MAY BE ENHANCED MIGRATION DUE TO DIFFERENCES IN FLOW MECHANISMS AND A REDUCTION IN THE INTERACTION WITH MINERAL SURFACES.
OUR OBJECTIVE HERE IS TO IMPROVE THE UNDERSTANDING OF THE ROLE OF COLLOIDS IN RADIOACTIVE WASTE DISPOSAL. THIS IS BEING ACHIEVED FIRSTLY BY DETAILED CHARACTERISATION OF NATURAL COLLOIDS DERIVED FROM GROUNDWATERS, TYPICAL OF THOSE IN A GRANITE GEOLOGY PROPOSED FOR WASTE DISPOSAL, AND SECONDLY BY INVESTIGATING THE INTERACTION OF NATURAL AND SYNTHETIC COLLOIDS (AS MODEL SYSTEMS) WITH GRANITE SURFACES WHICH HAVE BEEN CHARACTERISED PETROGRAPHICALLY. THIS SHOULD PROVIDE AN INSIGHT INTO RETENTION MECHANISMS AND WOULD LEAD TO SUBSEQUENT INVESTIGATIONS OF THE TRANSPORT AND HYDRODYNAMIC BEHAVIOUR OF COLLOIDS IN THESE AND OTHER GEOLOGICAL SYSTEMS. HERE EXPERTISE AND TECHNIQUES DEVELOPED AT BOTH HARWELL AND FONTENAY ARE BEING APPLIED IN A COLLABORATIVE INVESTIGATION.

1 PREPARATION AND CHARACTERISATION OF SYNTHETIC COLLOIDS
1.1 PREPARATION OF SILICA, IRON OXIDE, ALUMINA AND HUMIC MATERIALS
1.2 CHARACTERISATION BY LIGHT SCATTERING, ELECTROPHORESIS AND ELECTRON MICROSCOPY
2. CHARACTERISATION OF NATURAL COLLOIDS OCCURING IN GROUNDWATERS
2.1 CHARACTERISATION OF HOST ROCK
2.2 CHARACTERISATION OF GROUNDWATER
2.3 CHARACTERISATION OF NATURAL COLLOIDS BY LIGHT SCATTERING TECHNIQUES, ULTRAFILTRATION AND ELECTRON MICROSCOPY
2.4 ISOLATION OF ORGANIC COLLOIDS
3. STUDIES OF RADIO-COLLOID RETENTION PROCESSES
3.1 ASSOCIATION (INCORPORATION, SORPTION) OF ACTINIDES AND RARE EARTH ELEMENTS WITH NATURAL/SYNTHETIC COLLOIDS
3.2 INTERACTIONS OF COLLOIDS WITH WELL CHARACTERISED MINERAL SURFACES.

Ámbito científico

Programa(s)

FP1-RADWASTOM 3C - Research and development programme (Euratom) on the management and storage of radioactive waste, 1985-1989

Tema(s)

Data not available

Convocatoria de propuestas

Data not available

Régimen de financiación

CSC - Cost-sharing contracts

Coordinador

United Kingdom Atomic Energy Authority

Dirección

353,harwell
OX11 0RA Didcot - oxfordshire
Reino Unido

Aportación de la UE

Sin datos

Participantes (1)

COMMISSARIAT A L'ENERGIE ATOMIQUE (CEA)

Francia