TO REDUCE RADIOACTIVE DISCHARGES IN ENVIRONMENT AT THE MARCOULE REPROCESSING PLANT, THE TREATMENT OF LOW AND MEDIUM LEVEL LIQUID WASTES BY EVAPORATION WILL TAKE THE PLACE OF CHEMICAL PRECIPITATION PROCESS. DUE TO THE HIGH SODIUM NITRATE CONCENTRATION OF LIQUID WASTES, THE BITUMINIZATION OF CONCENTRATE WILL GIVE RISE TO LARGE VOLUMES OF WASTE FORMS FOR DISPOSAL IN GEOLOGICAL FORMATION.
FOR SAFETY OBJECTIVES AND TO REDUCE THE VOLUME OF WASTEFORMS, IT IS IMPORTANT TO DESTROY THE NITRATES; DIFFERENT PROCESSES HAVE BEEN EXAMINED (ELECTRODIALYSIS, BIOLOGICAL DENITRATION, CHEMICAL DENITRATION, CALCINATION) BUT THE FLUIDIZED BED CALCINATION WAS CHOSEN.
THIS PROJECT PRESENTS SIX MAIN POINTS:
- ANALYSIS OF THE LITTERATURE DATA TO SHOW WHAT ADVANTAGES AND DRAWBACKS ARE FOR EACH DENITRATION PROCESS WHICH IS QUOTED BEFORE.
- CONCEPTION AND REALIZATION OF A FLUIDIZED BED CALCINATOR.
- DETERMINATION OF THE WORKING CONDITIONS BY STUDYING IN THIS CONTINUOUS WORKING THE INFLUENCE OF DIFFERENT PARATMETERS.
- TESTS IN CONTINUOUS WORKING.
- EVALUATION OF RESULTS AND STUDY OF A CONDITIONING WAY FOR THE PRODUCT OBTAINED BY CALCINATION.
- ELABORATION OF A PLAN FOR AN INDUSTRIAL PLANT ABLE TO COME UP TO THE EXPECTATIONS OF THE MARCOULE REPROCESSING PLANT.

2.2. DEFINITION OF THE AIMS OF THE TREATMENT; MODIFICATION INVOLVED BY EVAPORATION FOR THE TREATMENT OF LOW AND MEDIUM-LEVEL WASTES WILL BE STUDIED.
2.3. ANALYSIS OF DIFFERENT DENITRATION PROCESSES TO EXPLAIN THE CHOICE WHICH WAS MADE WITH FLUIDIZED BED CALCINATION.
2.4. CONCEPTION AND REALIZATION OF FLUIDIZED BED CALCINATOR THE WORKING OF WHICH WILL BE EXPLAINED. THE TREATEMENT OF GASEOUS WASTES WILL BE ALSO DESCRIBED.
2.5. DETERMINATION OF WORKING CONDITIONS BY STUDYING THE INFLUENCE OF DIFFERENT PARAMETERS.
3.1. BED-TEMPERATURE BETWEEN 500-1000 CELCIUS DEGREES.
3.2. NATURE AND CONCENTRATION OF THE ADDITIVE USED TO PREVENT AGGLOMERATION OF THE PARTICLES.
3.3. NATURE, CONCENTRATION AND GRANULOMETRY OF MATERIAL USED IN THE FLUIDIZED-BED.
3.4. FLOW AND CONCENTRATION OF THE SOLUTION TO DENITRATE.
3.5. FLOW OF THE FLUIDIZING GAS.
3.6. PLACE AND TYPE OF THE ATOMISER (NOZZLE).
3.7. REACTION TIME.
ALL THESE EXPERIMENTS WILL BE CARRIED OUT WITH INACTIVE PRODUCTS, IN DISCONTINUOUS WORKING.
2.6. EXPERIMENTS IN CONTINUOUS WORKING.
2.7. EVALUATION OF THE RESULTS; THE PACKAGING WAY OF CONCENTRATES WILL BE STUDIED.
2.8. ELABORATION OF AN INDUSTRIAL PLAN BY EXTRAPOLATING THE CHARACTERISTICS OF THE PILOT SCALE DENITRATOR TO AN INDUSTRIAL SCALE.