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OPTIMIZATION OF AIR FILTERING SYSTEMS FOR VARIOUS CONCRETE DECONTAMINATION TECHNIQUES

Objective

THE EFFECTIVENESS OF MECHANICAL AND THERMAL METHODS FOR THE DECONTAMINATION OF CONCRETE SURFACES HAS ALREADY BEEN DEMONSTRATED. HOWEVER, THE COLLECTION AND CONDITIONING OF THE IMPORTANT AMOUNT OF GENERATED DUST, AEROSOLS AND TOXIC GASES NEEDS FURTHER DEVELOPMENT.
AS CONCERNS THE FILTRATION DURING THERMAL DECONTAMINATION, MULTI-STAGE STORING FILTERS, AS CURRENTLY USED IN THE NUCLEAR INDUSTRY, HAVE SHOWN ADEQUATE EFFICIENCY, BUT THEIR LIMITED STORAGE CAPACITY PRECLUDES AN ECONOMIC OPERATION. CONCERNING THE EFFECTIVENESS OF FILTRATION SYSTEMS FOR MECHANICAL DECONTAMINATION, NO EXTENSIVE INVESTIGATIONS HAVE BEEN UNDERTAKEN, SO FAR.
THE AIM OF THIS RESEARCH PROGRAMME IS TO INVESTIGATE VARIOUS FILTER SYSTEMS, SUCH AS STORING FILTERS, REGENERATIVE MECHANICAL FILTERS, ELECTROSTATIC FILTERS, CONCERNING THEIR SEPARATION EFFICIENCY, THEIR STORAGE CAPACITY AND SERVICE LIFE, INCLUDING AN ANALYSIS OF THE AMOUNT AND SIZE DISTRIBUTION OF DUST AVAILABLE AT EACH FILTERING STAGE. THE EXPERIMENTS WILL USE DUST GENERATED BY THE ABOVE DECONTAMINATION METHODS ON NON-RADIOACTIVE CONCRETE SAMPLES.
BASED ON EXISTING DATA ON RADIOACTIVE CONCRETE SURFACES, A THEORETICAL ASSESSMENT ON POSSIBLE RADIOACTIVITY INVENTORIES IN THE INVESTIGATED FILTER SYSTEMS WILL BE MADE, WITH A VIEW TO THEIR OPTIMIZATION FOR REAL APPLICATIONS.
When decommissioned nuclear power installations are demolished, the contaminated surface layers must be removed, if it is not intended to dismantle and store the entire structure.

Filter systems have been studied to enable economic separation of this dust. 3 cleanable filters were investigated during the course of the research work in tests using inactive concrete samples. Separation levels of over 99.9% could be achieved with all tested filters. Furthermore the effectiveness of 1 filter could be demonstrated in decontamination operations.
1. MODIFICATION AND ADAPTATION OF THE EXISTING TEST FACILITY FOR AIR FILTERING SYSTEMS.
2. ACQUISITION OF COMPONENTS FOR TESTING AND CONCRETE SAMPLES.
3. SELECTION AND MOUNTING OF VARIOUS AIR FILTER SYSTEMS.
4. IMPLEMENTATION OF VARIOUS THERMAL AND MECHANICAL CONCRETE DECONTAMINATION PROCEDURES (FLAME SPALLING, GRINDING, CHIPPING HAMMER, SCARIFIER).
5. MEASUREMENT OF AIRBORN DUST AND AEROSOLS BY VARIOUS METHODS.
6. ANALYSIS OF THE MEASUREMENT RECORDS AND EVALUATION OF THE TESTED FILTERS WITH RESPECT TO SEPARATION EFFICIENCY, RETENTION CAPACITY, RADIOACTIVITY AND COSTS.

Funding Scheme

CSC - Cost-sharing contracts

Coordinator

Salzgitter AG
Address

38201 Salzgitter
Germany