A SYSTEM FOR SPRAY-BASED CONSTRUCTION OF HIGH-DENSITY LAYERS WITH LOW PERMEABILITY FOR RADIOACTIVE WASTE DISPOSAL FACILITIES

Abstract

 High-density, low-permeability uniform layers of bentonite are required in radioactive waste disposal facilities to prevent the migration of such waste into the biosphere via ground water. Against such a background, the applicability of high-density compacted bentonite for the construction of low-permeability layers has become a subject of international consideration. However, the construction of these layers involves major technical challenges because the limited space available means that heavy machinery cannot be used.
 The authors developed a method for the construction of high-density low-permeability layers using a wet spraying approach that enables work to be performed in restricted spaces. This paper reports on research performed to verify the method, to investigate a water content adjustment technique for the bentonite used, and to study a measurement technique for bulk density, and also outlines construction quality control criteria.