Introduction to Immobilisation

Ojovan, Michael I.; Lee, W.E.

doi:10.1016/b978-008044462-8/50003-x

Cited by 121 publications

(304 citation statements)

References 0 publications

Supporting

Mentioning

301

Contrasting

Order By: Relevance

“…In the UK these are classified according to their nature and level of radioactivity into Very Low Level Waste (VLLW), Low Level Waste (LLW), Intermediate Level Waste (ILW) and High Level Waste (HLW) [1,2]. VLLW has a negligible radiological hazard and is safety disposed of at landfill sites.…”

Section: Introductionmentioning

confidence: 99%

“…For the purpose of this study the corrosion of Al in cementitious samples, cured for more than 6 months, was accelerated by adding 50 mL of deionized water in the plastic containers. The latter was done in order to simulate one of the possible scenario during the interim storage of the packaged wasteforms when water can penetrate and interact with the encapsulating cementitious matrix and waste [1]. In this paper the results from the AE monitoring of a BFS/OPC sample cured for more than 6 months are presented and discussed.…”

Section: Specimensmentioning

confidence: 99%

“…It was shown in [21][22][23] that the AE signals recorded from the reference OPC structure with encapsulated Al can be classified and associated with different micro and macro scale mechanisms leading to damage development within the structure with the time progress of the Al corrosion process. The aim of this study was to extend the work, briefly reported in [21][22][23], on composite cement formulation used for production of real wasteforms for encapsulation of metallic radioactive wastes [1,3,4]. Herein the evaluation of the damage induced within the structures was performed using AE parameter and signal-based analysis.…”

Section: Ae Technique Applied For Structures Immobilising Nuclear Wastesmentioning

confidence: 99%

“…All processes involved in the nuclear energy production are associated with generation of gaseous, liquid and solid wastes with various concentrations of radioactive elements [1]. In the UK these are classified according to their nature and level of radioactivity into Very Low Level Waste (VLLW), Low Level Waste (LLW), Intermediate Level Waste (ILW) and High Level Waste (HLW) [1,2].…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Characterisation of Al corrosion and its impact on the mechanical performance of composite cement wasteforms by the acoustic emission technique

Spasova

Ojovan

2008

Journal of Nuclear Materials

Self Cite

View full text Add to dashboard Cite

Abstract. In this study acoustic emission (AE) non-destructive method was used to evaluate the mechanical performance of cementitious wasteforms with encapsulated Al waste. AE waves generated as a result of Al corrosion in small-size blast furnace slag/ordinary Portland cement wasteforms were recorded and analysed. The basic principles of the conventional parameter-based AE approach and signal-based analysis were combined to establish a relationship between recorded AE signals and different interactions between the Al and the encapsulating cement matrix. The AE technique was shown as a potential and valuable tool for a new area of application related to monitoring and inspection of the mechanical stability of cementitious wasteforms with encapsulated metallic wastes such as Al.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Specimensmentioning

confidence: 99%

Section: Ae Technique Applied For Structures Immobilising Nuclear Wastesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Characterisation of Al corrosion and its impact on the mechanical performance of composite cement wasteforms by the acoustic emission technique

Spasova

Ojovan

2008

Journal of Nuclear Materials

Self Cite

View full text Add to dashboard Cite

show abstract

“…These properties have made them suitable for use in several key applications [3], including as a biomaterial for bone and dental repairs [4], refractory concretes [5,6], specialised mortars for structural applications [1], carbonation resistant geothermal well applications [7], and more recently immobilisation of metallic radioactive wastes [8][9][10][11] and toxic metal solutions [12].…”

Section: Introductionmentioning

confidence: 99%

Identification of the hydrate gel phases present in phosphate-modified calcium aluminate binders

Chavda

Bernal

Apperley

et al. 2015

Cement and Concrete Research

View full text Add to dashboard Cite

The conversion of hexagonal calcium aluminate hydrates to cubic phases in hydrated calcium aluminate cements (CAC) can involve undesirable porosity changes and loss of strength.Modification of CAC by phosphate addition avoids conversion, by altering the nature of the reaction products, yielding a stable amorphous gel instead of the usual crystalline hydrate products. Here, details of the environments of aluminium and phosphorus in this gel were elucidated using solid-state NMR and complementary techniques. Aluminium is identified in both octahedral and tetrahedral coordination states, and phosphorus is present in hydrous environments with varying, but mostly low, degrees of crosslinking. A 31 P/ 27 Al rotational echo adiabatic passage double resonance (REAPDOR) experiment showed the existence of aluminium-phosphorus interactions, confirming the formation of a hydrated calcium aluminophosphate gel as a key component of the binding phase. This resolves previous disagreements in the literature regarding the nature of the disordered products forming in this system.

show abstract

Crystallization of iron‐containing sodium aluminosilicate glasses in the NaAlSiO₄‐NaFeSiO₄ join

2017

View full text Add to dashboard Cite

Although natural materials are the subject of most Earth science articles, fundamental studies on analogous synthetic materials, produced under laboratory‐controlled conditions, can provide significant insight into expected behavior of natural systems. Iron, a common element in natural aluminosilicates as well as high‐level nuclear wastes, plays a crucial role in crystallization behavior. In the present study, effects of Fe‐Al substitution in nepheline‐based aluminosilicate glasses (NaAl(1 − x)FexSiO4, x = 0.0–1.0) were investigated to assess the role of iron in crystallization, employing semiquantitative X‐ray diffraction (XRD), vibrating sample magnetometry (VSM), and electron probe microanalysis (EPMA). Fe promotes nepheline crystallization when substituted for Al in low additions (x < 0.3), yet suppresses it at higher additions (x > 0.5). Since effect of Fe is the subject of the present work and is the most common magnetic element, magnetic techniques were used to further analyze the phase assemblage. VSM measurements revealed that Fe oxides, i.e., hematite and magnetite, are present in cases even when their fractions are below the XRD detection limit, and backscattered electron micrographs confirm their presence. EPMA also shows that Fe incorporation in nepheline increases with increasing Fe‐Al substitution, up to a maximum of x = 0.37 for the nepheline crystals in the sample with starting glass of Na(Al0.3Fe0.7)SiO4. The residual glass, on the other hand, contains approximately constant Fe concentration x ~ 0.54–0.59 for all samples with starting Fe addition 0.4 ≤ x ≤ 0.8, and excess iron is expelled into Fe oxide phases. The significance of these results for geological processes and immobilization of high‐level nuclear waste is discussed.

show abstract

Introduction to Immobilisation

Cited by 121 publications

References 0 publications

Characterisation of Al corrosion and its impact on the mechanical performance of composite cement wasteforms by the acoustic emission technique

Characterisation of Al corrosion and its impact on the mechanical performance of composite cement wasteforms by the acoustic emission technique

Identification of the hydrate gel phases present in phosphate-modified calcium aluminate binders

Crystallization of iron‐containing sodium aluminosilicate glasses in the NaAlSiO₄‐NaFeSiO₄ join

Contact Info

Product

Resources

About

Introduction to Immobilisation

Cited by 121 publications

References 0 publications

Characterisation of Al corrosion and its impact on the mechanical performance of composite cement wasteforms by the acoustic emission technique

Characterisation of Al corrosion and its impact on the mechanical performance of composite cement wasteforms by the acoustic emission technique

Identification of the hydrate gel phases present in phosphate-modified calcium aluminate binders

Crystallization of iron‐containing sodium aluminosilicate glasses in the NaAlSiO4‐NaFeSiO4 join

Contact Info

Product

Resources

About

Crystallization of iron‐containing sodium aluminosilicate glasses in the NaAlSiO₄‐NaFeSiO₄ join