Effect of gamma ray irradiation on strontium oxides immobilized by glass materials

Other Title(s)

تأثير التشعيع بأشعة كاما على أوكسيد السترونتيوم المثبت بواسطة المواد الزجاجية

Dissertant

al-Dafai, Thuraya Amir

Thesis advisor

al-Mashhadani, Asya Hamid

University

University of Baghdad

Faculty

College of Science

Department

Department of Physics

University Country

Iraq

Degree

Master

Degree Date

2013

English Abstract

In an attempt to disposal from nuclear waste which needs to storage for long time until loss radiation effect (became safety).

Therefore must found suitable method to immobilize nuclear waste to prevent leaching ions to surrounding and became hazards threatens environment and our health.

In this study the immobilize nuclear waste (Strontium Oxides) with weight percentage (5%) by vitrification methods in tow type of borosilicate glass (c-type) which are glass and glassceramics to investigate the physical, chemical and mechanical properties of gamma ray radiation effect on these properties.

To representation radiation damage result from decay of vitrification real waste, irradiation samples from glass and glass-ceramics with gamma ray by used Co-60 as a radionuclide with dose rate 0.38 kGy/hr for different period of time to study the effect of value of dose on the physical properties (density), chemical properties (leaching rate) and mechanical properties (microhardness and surface strength) and investigate the effect of gamma radiation on the surface of samples by using phase analyses (x-ray diffraction (XRD) and scanning electronic microscope (SEM)).

It was found that the effect of gamma radiation on physical properties (density) for glass decreases after irradiation but the density of glass-ceramic increases with increases the gamma doses after then these densities remain constant with increasing radiation dose.

Although we found the effect of radiation on the leaching rate for all samples smaller than 0.25 (where 0.25 is a sensitive of atomic absorption devise) it means that there is a very small percentage of Sr leach rates resulting from solid radiation damage will occur only after damage zones overlap and provide interconnected fluid and/or solid diffusion channel ways between the interiors of the samples and the surface.

If individual damage zones anneal in relatively short times, the damage zones will not overlap and significant increases in leach rates will not be realized.

In laboratory experiments, dose rates may be increased several orders of magnitude above levels that are pertinent to actual waste to accelerate glass damage processes into reasonably short time periods.

Gamma radiation is effected the mechanical properties of glass and glassceramics its increase microhardness and decrease the surface strength as the radiation dose increase From phase analysis by the x-ray diffraction for glass samples proved that the glass was fully amorphous before and after exposure to gamma radiation, no peaks detected.

For the XRD spectra of glass-ceramics some peaks in the spectra establish that crystalline phase was found (phase changing by heat treatment) and the appearance phase of Calcium Aluminum Silicate and at doses 343kGy change the crystalline glass to amorphous glass.

Scanning electronic microscope (SEM) testing for waste glasses observed that glass and glass-ceramics samples are never completely homogeneous materials but contain significant amounts of bubbles, foreign incollusions such as refractory oxides and other immiscible components.

A conclusion from these ionization studies is that the limited magnitude of Strontium ion leaching associated with ionization damage does not appear to pose any direct problems for the safe storage of nuclear waste glass.

Main Subjects

Physics

Topics

• Glass
• Mechanical properties
• Lasers
• Environmental aspects
• Glass waste

No. of Pages

112

Table of Contents

• APA
• MLA
• AMA

Language

English

Data Type

Arab Theses

Record ID

BIM-607163