THE DECOMMISSIONING OF STANDARD-SIZE PLUTONIUM GLOVE BOXES HAS BEEN PERFORMED IN SEVERAL COUNTRIES FOR SEVERAL YEARS. HIWEVER, THE DISMANTLING OF VERY LARGE ALPHA-RADIATING UNITS HAS YET TO BE DEMONSTRATED.
PLUTONIUM RESEARCH LABORATORIES AND MIXED-OXIDE FUEL FABRICATION PLANTS HAVE TO BE PARTIALLY DISMANTLED IN THE NEAR FUTURE. DURING THESE DISMANTLING TEASKS, SEVERE PROBLEMS WILL ARISE WITH THE DECOMMISSIONING OF HUGE GLOVE BOXES CONTAINING VERY LARGE AND HEAVY EQUIPMENT.THESE UNITS HAVE TO BE CONDITIONED AND TRANSPORTED TO AN AD-HOC INSTALLATION FOR DISMANTLING AND FINAL DISPOSAL. THE TECHNIQUES USED UNTIL NOW FOR THE CONDITIONING AND THE TRANSPORT OF SMALL UNITS ARE NOT APPLICABLE IN THIS FIELD. INDEED, NEW TECHNIQUES HAVE TO BE DEVELOPED FOR ASSURING AT ANY TIME THE LEAK-TIGHTNESS OF SUCH UNITS UP TO THE MOMENT OF THEIR DISMANTLING.
THE AIM OF THE RESEARCH IS TO DEVELOP CONCEPTS NEEDED AND TO EXECUTE AND DEMONSTRATE DECOMMISSIONING OPERATIONS ON FIVE LARGE GLOVE BOXES OF THE DESSEL MIXED-OXIDE FUEL FABRICATION PLANT.
THESE OPERATIONS INCLUDE CONDITIONING, TRANSPORTATION ON PUBLIC ROADS TO AN EXTERNAL DISMANTLING CELL, DISMANTLING AND ASSESSMENT OF APPLIED TECHNIQUES.
Work performed on decommissioning a very large glove box and and on decommissioning a complex glove box structure to be dismounted partially in place is described. Some research was carried out on the freon cleaning of glove boxes and some preliminary research on the effect of frozen carbon dioxide particles on nonradioactive samples was conducted. The solution presented to the problem of the transportation of the glove boxes to a specialised dismantling plant is justified. The problems of manipulating large gloves are detailed and the method of building a so called stiffening frame around each glove box is described.
B.1. CONDITIONING FOR ALLOWING SAFE TRANSPORTATION OF FIVE LARGE PLUTONIUM GLOVE BOXES, FORMERLY USED FOR MIXED-OXIDE FUEL FABRICATION.
B.2. PREPARATION AND SAFE AND LEAK-TIGHT TRANSPORTATION OF FIVE LARGE GLOVE BOXES TO A SPECIAL DISMANTLING INSTALLATION.
B.3. ADAPTATION FOR AIR-TIGHT INTRODUCTION OF THE GLOVE BOXES INTO THE DISMANTLING CELL, EXECUTION OF THE DISMANTLING BY A SELECTED APPROPRIATE PROCEDURE AND FINAL ASSESSMENT OF THE APPLIED TECHNIQUES WITH RECOMMENDATIONS FOR FURTHER APPLICATIONS.