Objective AIMS AND SCIENTIFIC FACTORS. UNDER AN EARLIER CONTRACT(FI1W/0152-F),A METHOD WAS DEVELOPED OF DETECTING VARIATIONS IN THE MECHANICAL BEHAVIOUR OF SOLID ROCK SUBMITTED TO STRESSING (THERMAL,HYDRAULIC OR SIMPLY MECHANICAL)SUCH THAT IT WOULD THEN SUFFER DEFORMATION.THE SITE SELECTED WAS THE UNDERGROUND CEN/SCK LABORATORY IN THE CLAY STRETCHING FROM BOOM TO MOL(B). THE BASIC PRINCIPLE IS THAT IN ANY STRESS PROPAGATION FIELD THE FREQUENTIAL CONTENT OF THE WAVE GENERATED IS FILTERED DIFFERENTIALLY BY THE CRACKS AND MICRO-CRACKS EXISTING IN THE SOLID ROCK.ITS APPLICATION TO THE MONITORING OF A WASTE STORE IS IMMEDIATE:IT IS POSSIBLE TO ENVISAGE USE OF THIS METHOD AROUND A HEAT SOURCE THAT IS HEATING UP THE SURROUNDING SOLID ROCK. IN ORDER TO APPLY THIS PRINCIPLE IT WAS FIRST OF ALL NECESSARY TO PRODUCE A "MARGOT" SHOCK GENERATING PROBE ENABLING SHOCKS TO BE PRODUCED IN OBLIQUE BOREHOLES,SINCE THE EXISTING VERTICAL BOREHOLES ARE FINALLY ALL FULL AT MOL.IF THE WAY MAKE A COMPARISON THIS FAIRLY COMPLEX ITEM OF EQUIPMENT COULD BE LIKENED TO A BAZOOKA WHICH ON EACH OCCASION RECOVERED ITS MISSILE,ONLY TO FIRE IT ONCE MORE AGAINST THE SOLID EARTHEN ANVIL. THE REMAINDER OF THE PROGRAMME WAS USED TO CONDUCT THREE TESTS ON SITE,AND TO DEVELOP A COMPLETE ANALYSIS AND INTERPRETATION SOFTWARE FOR TWO INITIAL MEASURING SEQUENCES AT AMBIENT TEMPERATURE. THE SOUNDWAVE GENERATOR AND RECEIVER MAY THUS BE LOCATED CLOSE TO A BOREHOLE WHERE VARIOUS OF THE STRUCTURAL MATERIALS WHICH COULD CONCEIVABLY BE DEPOSITED IN THE CLAY HAVE BEEN IMPLANTED CLOSE TO A "HOT SPOT"(THIS DEVICE IS KNOWN AS A "CORROSION LOOP").THE HEATING ELEMENT WAS PLACED IN SERVICE IN LATE 1989.THE AIM OF THE CURRENT PROGRAMME IS TO PLOT MECHANICAL CHANGES TO THE CLAY UNDER THE EFFECT OF HEATING BY MEANS OF THE EQUIPMENT DEVELOPED PREVIOUSLY. IN 1990 ME2I STAFF WILL MAKE SEVERAL TRIPS TO THE MOL SITE IN ORDER TO INSTALL THE EQUIPMENT,WHICH CONSIST OF: -THE MARGOT EMITTER PROBE, -THE RECEIVER PROBE,TOGETHER WITH ACCELEROMETERS, -THE ACCELEROMETER SYSTEM, -THE 4-TRACK SPECTRUM ANALYSER, -THE 8-TRACK MAGNETIC RECORDER. BEFORE EACH TRIP THE MARGOT PROBE WILL BE REVISED AND POSSIBLY MODIFIED. AFTER EACH TRIP THE DATA COLLECTED BY THE SPECTRUM ANALYSER WILL THEMSELVES BE ANALYSED,PROCESSED AND INTERPRETED BY THE COMPETENT STAFF,USING APPROPRIATE SOFTWARE. ANY CHANGES DUE TO HEATING WITHIN THE CLAY (E.G. WATER FLOW,LOCAL CRACKING)COULD BE IDENTIFIED VIA SOUNDING AND LINKED TO OVERALL BEHAVIOUR MODELS OF THE SOLID ROCK.THE MODELS COULD THUS BE VALIDATED IN THIS WAY. THE WORK WILL FINALLY LEAD TO PROPOSED IMPROVEMENTS TO THE ACQUISITION AND PROCESSING EQUIPMENT. Fields of science natural sciencescomputer and information sciencessoftware Programme(s) FP1-RADWASTOM 3C - Research and development programme (Euratom) on the management and storage of radioactive waste, 1985-1989 Topic(s) Data not available Call for proposal Data not available Funding Scheme CSC - Cost-sharing contracts Coordinator ME2I SARL EU contribution No data Address 8 rue Eugène Oudiné 75013 Paris France See on map Total cost No data Participants (2) Sort alphabetically Sort by EU Contribution Expand all Collapse all CEN/SCK Belgium EU contribution No data Address MOL See on map Total cost No data Commissariat à l'Energie Atomique (CEA) France EU contribution No data Address Route du Panorama Robert Schuman 92266 Fontenay-aux-Roses See on map Total cost No data
