Ecology, Environment and Conservation Paper

THE PERFORMANCE OF CLAY AT DIFFERENT MOISTURE CONTENTS FOR ENVIRONMENTAL PROTECTION AGAINST GAMMA RAY

Hajar Share Isfahani, Sayyed Mahdi Abtahi, Mohammad Ali Roshanzamir and Sayyed Mahdi Hejazi

Abstract

Nowadays, by the process of industrial growth, environmental conservation becomes one of the most important issues. Nuclear energy is considered as anew technology that recently brings application in various fields. However, radiation more than standard limit may impose significant defects on human and environment health. As a result, radiation shielding becomes an important concept. Clay soil is natural, eco-friendly and inexpensive material. In this research, the performance of bentonite clay soil with different moisture contents were investigated in radiation shielding against Gamma ray at three levels of energy (661.6, 1173.2 and 1332.5 keV). At first, plastic and liquid limit of soil were obtained by means of Atterberg limits test. Then, samples at three states (dry, plastic and liquid limit of moisture contents) were prepared. Gamma-ray intensity transmitted through a certain thickness of the sample and gamma-ray intensity without absorber were measured by HPGe detector. Then radiation shielding parameters such as, linear attenuation coefficient (µ), HVl, and TVL were calculated. The micro structure of the bentonite was characterized by scanning electron microscope (SEM) with Energy Dispersive X-ray (EDX). Results of bentonite samples were compared with concrete linear attenuation coefficient. Results indicated that bentonite clay at plastic limit moisture content has a satisfactory performance in radiation shielding. So it can be used for radiation shielding in many cases such as, capping and surrounding the low level radioactive waste disposal landfills.