Spectroscopic Investigations of Radiation Damage in Glasses Used for Immobilization of Radioactive Waste

Abstract

Borosilicate based glass formulations have been found suitable for vitrification of high level nuclear waste (HLW) generated during the reprocessing of spent nuclear fuel from nuclear reactors. These glasses possess desirable properties like high chemical, mechanical, thermal and radiation stability for HLW storage. Also, the amorphous nature of the glass helps accommodate the waste containing a variety of elements easily. Because of the presence of the radioactive components, such as, fission /activation products and minor actinides present in the waste, the glass containment experiences radiation damage that can significantly alter the glass structure which may influence their long term leaching behavior. Spectroscopic techniques provide direct and non-invasive method for investigating this radiation damage in the glasses. The present paper gives a glimpse of the current status and issues regarding the investigation of radiation damage in the glass matrices.

Radiation damage effects on the structure and properties of radioactive waste glasses

“….... Table 6. to fluences of 1x10 15 , 1x10 16 , 5x10 16 and 1x10 17 to fluences of 1x10 15 , 1x10 16 , 5x10 16 and 1x10 17…”

“…the effects of alpha, beta and gamma irradiation over long time scales so that their relationships with long-term stability and dissolution of the waste form can be understood, established and more accurately predicted [16]. This has led to several studies on self-irradiation damage on simpler and more complex surrogate waste loaded glasses to address these issues [17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35].…”

“…These complexities present incredible challenges to accurately simulate and study the effects of radiation damage in HLW glasses and consequently many different approaches, methods and techniques have been employed to simulate and study the effects of self-irradiation damage in HLW glasses [3]. These include ion beams from accelerators or TEM to simulate the electronic energy losses of alpha, beta particles and gamma photons, as well as losses due to elastic collisions or ballistic interactions of alpha recoil nuclei [17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35]. These studies are essentially accelerated studies, meaning that an equivalent integrated dose of longer period is delivered in a short time.…”

“…Whilst there have been a considerable number of studies performed on simple glasses and nuclear waste glasses to study the aqueous corrosion and chemical durability in geological repository or related conditions [16,[46][47][48][49][50][51][52][53][54], self-irradiation damage of nuclear waste glasses has received less attention. Furthermore, selfirradiation -induced paramagnetic defects, structural changes associated with them and their relationships with glass composition, temperature, macroscopic changes, and impact on glass dissolution requires an enhanced understanding to be able to predict the long-term performance of HLW waste forms in geological repository conditions [15,17,37,55].…”

“…Facility (LEIBF) at the Inter-University Accelerator Center, India. NaBaBSi and LiNaBSi glasses were implanted with 650 KeV He 2+ ions to fluences of 1x10 15 , 1x10 16 , 5x10 16 and 1x10 17 ions/cm 2 . The ion-beam parameters are given in Table 4.1 and energy loss in the glass specimens were calculated using SRIM-2013 software (The Stopping and Range of Ions in Matter) [233].…”