Objective AS PART OF THE DISMANTLING OF A NUCLEAR INSTALLATION, IT IS NECESSARY TO DISPOSE OF RAPID AND EFFICIENT DECONTAMINATION PROCEDURES (HIGH DECONTAMINATION FACTOR), WHICH ARE SIMPLE TO APPLY AND LEAD TO A LOW VOLUME OF WASTES EASY TO TREAT. THE AIM OF THIS RESEARCH IS TO STUDY THE FOLLOWING NEW DECONTAMINATION TECHNIQUES WITH A VIEW TO THEIR APPLICATION IN THE DISMANTLING OF NUCLEAR INSTALLATIONS: - SPRAYING OF GELS, - ELECTROLYTICAL SWAB AND JET, - ABRASIVE WATER BLASTING. THESE TECHNIQUES ARE EXPECTED TO USEFULLY COMPLEMENT THE ESTABLISHED METHODS (IMMERSION IN CHEMICAL BATH, ELECTROLYTICAL BATH, HIGH-PRESSURE JET) DEVELOPED IN A PREVIOUS STUDY (REF.: EUR 10043). The decommissioning of nuclear installations requires decontamination techniques that are efficient, simple to apply and which produce a small amounts of waste, which is easy to process. With a view to this, 3 decontamination methods, which appear to be particularly suited to decommissioning, have been studied.These 3 methods are:spraying of gels carrying chemical decontaminating agents; electropolishing with a swab device;abrasive blasting.Tests were performed in order to check the effectiveness of direct chemical decontamination on small and complex components, usually considered for storage without decontamination because of the small amount of radioactive material involved. 4 small stainless steel valves from the primary system of the Garigliano boiling water reactor (BWR) were decontaminated using mainly aggressive chemicals. On 2 valves, before the treatment with aggressive chemicals, a step with soft chemicals was performed in order to see whether a softening action enhances the following aggressive decontamination. Moreover, in order to increase as much as possible the decontamination effectiveness, a decontamination process using ultrasound jointly with aggressive chemicals was investigated.1. OPTIMIZATION OF THE DECONTAMINATION PROCESSES, I.E. CHEMICAL GELS, ELECTROLYTICAL SWAB AND JET AND ABRASIVE WATER BLASTING, ON NON-RADIOACTIVE SAMPLES OF STAINLESS STEEL, MILD STEEL AND ALUMINIUM. 2. APPLICATION ON CONTAMINATED SAMPLES FROM VARIOUS TYPES OF PLANT (GRAPHITE-GAS REACTOR, PWR, LMFBR, FUEL FABRICATION PLANT AND REPROCESSING PLANT). 3. IMPLEMENTATION OF THESE TECHNIQUES WITH REMOTE CONTROL AND IN THE NUCLEAR FACILITIES BEFORE DISMANTLING. 4. ASSESSMENT OF QUANTITY OF SECONDARY WASTE AND ITS TREATMENT. 5. COST EVALUATION AND ASSESSMENT OF RADIOLOGICAL CONSEQUENCES OF EACH PROCESS, INCLUDING THE TREATMENT OF SECONDARY WASTE. Fields of science natural scienceschemical sciencesinorganic chemistrypost-transition metalsengineering and technologyenvironmental engineeringenergy and fuelsnatural sciencesphysical sciencesacousticsultrasound Programme(s) FP1-DECOM 2C - Research programme (Euratom) concerning the decommissioning of nuclear installations, 1984-1988 Topic(s) Data not available Call for proposal Data not available Funding Scheme CSC - Cost-sharing contracts Coordinator Commissariat à l'Energie Atomique (CEA) EU contribution No data Address Centre d'Études de Cadarache Sere-Ders 13113 SAINT-PAUL-LEZ-DURANCE France See on map Total cost No data
