Effect of Gamma Irradiation on Simulated Waste Glass Leaching and on the Leach Vessel

Concern over the low resistance of teflon to radiation-induced damage leads to the requirement that, when teflon leach vessels are used, the exposure limit is 1 × 10⁵ rad of beta or gamma radiation during a leach experiment. This limit is supported for MCC 76–68 simulated waste glass by the present investigation .     

Effect of Gamma Radiation on the Strength of Plate Glass of Varying Arsenic Content

Samples of plate glass containing a small amount of arsenic oxide as well as arsenic-free samples were subjected to gamma radiation from a cobalt-60 source after which modulus of rupture measurements were made. The arsenic-containing glass showed a significant increase in strength upon irradiation while the arsenic-free glass became weaker.     

Outgassing of Glass Caused by Thermal Neutrons and Gamma Radiation

Prebaked evacuated glass bulbs were exposed to gamma radiation and thermal neutrons. The gases initially present in the bulb plus those evolved in a subsequent baking were measured and analyzed with a mass spectrometer. Several glasses were exposed to a gamma dosage of more than 10⁷ rads. Small quantities of hydrogen as well as some CO, CO₂, and water were detected. Several boron-containing glasses were exposed to more than 10 ¹⁷ thermal neutrons/cm². The gas evolved was almost entirely helium, formed as a result of alpha-particle emission in the reaction The total quantity of helium formed can be predicted from the thermal neutron dose and the boron content of the glass. The role of helium permeability is also discussed.     

热辐射对夹层玻璃工艺的影响

随着建筑玻璃幕墙不断的推广使用,对其安全性要求也越来越高。近年来建筑玻璃幕墙使用干法夹层玻璃复合而成的玻璃制品越来越多,但是干法夹层玻璃在生产过程中存在一些影响夹层玻璃寿命的因素,其中最为致命的就是夹层气泡。从玻璃生产受热角度解析干法夹层生产过程中的工艺控制要点,以期对生产企业有所帮助。     

Effect of Gamma Radiation on Spectral Transmission of Some Commercial Glasses

An account is given of the effect of gamma radiation on the spectral transmission of certain commercial glasses. Curves are given showing the rate of fading of the coloration produced in these glasses by doses of gamma radiation in the range 10⁴ to 10⁸ rads. The effect on the optical density of some of these glasses by increasing doses of gamma radiation is discussed.     

Gamma Radiation Effects on the Glass Transition Temperature and Mechanical Properties of PMMA/soot nanocomposites

Summary Poly(methyl methacrylate) (PMMA) was produced via free radical polymerization. Polymer samples were sonicated and melt compounded to form 1%, 0.5%, and 0.25% PMMA/soot samples. Soot containing unpurified carbon nanotubes was provided by NASA Ames Research Center. The composites were compression molded and exposed to ionizing radiation in air from a Cesium-137 source. The PMMA/soot samples were characterized before and after exposure to radiation. Differential Scanning Calorimetry (DSC) was used to determine glass transition temperatures. Mechanical properties of composites were characterized via Dynamic Mechanical Analysis (DMA) and microhardness measurements. The glass transition temperatures from this study, when compared to similar studies conducted by Harmon et. al on purified single-wall and multi-wall carbon nanotube composites indicate that soot composites possess lower radiation resistance.     

Influence of Gamma Irradiation on Leaching of Simulated Nuclear Waste Glass: Temperature and Dose Rate Dependence in Deaerated Water

Elemental leaching rates from a simulated nuclear waste glass undergoing gamma irradiation in deaerated deionized water were evaluated as a function of temperature and gamma dose rate. Deaeration of the water eliminated nitric acid formation via air radiolysis, previously shown to substantially accelerate waste glass corrosion, and thus allowed the effects of water radiolysis alone to be measured. Water radiolysis resulted in enhanced reaction-layer thicknesses on glass samples as well as an approximate factor of three increase in the leach rate at 50°C. At 90°C, leach rates were indistinguishable for irradiated and unirradiated glasses. Most of the increase in glass dissolution occurred up to a gamma dose rate of ∼1 × 10⁵ rad/h. Above this value, only minor further increases were observed. It is concluded that the observed glass corrosion enhancement was due to reaction with short-lived transient species generated by water radiolysis and that the effect is unlikely to significantly contribute to long-term waste isolation.     

温度对模拟高放玻璃固化体显微结构和抗浸出性能的影响

以模拟北山地下水为浸泡剂,采用静态浸出试验法(MCC-1),研究了温度(40～150℃)对模拟高放废液硼硅酸盐玻璃固化体显微结构和抗浸出性能的影响.结果表明:玻璃固化体浸泡42 d后,在90℃及以上温度出现了蜂窝状的页硅酸盐和铝硅酸盐矿物,在150℃还新生成了白色板状BaSO4晶体;Si、B、Cs和U元素的归一化浸出率(LR)在28 d后趋于平稳,且随着温度升高浸出率逐渐升高;基于B元素浸出速率的表观活化能约为27.8 kJ/mol;玻璃固化体在90℃模拟地下水浸泡28 d后的LRSi、LRB、LRCs、LRU分别为1.45×10-1、1.39×10-1、2.48×10-1、1.3×10-1g/(m2·d).     

Effect of Gamma Irradiation on Structural and Optical Investigations of Borosilicate Glass Doped Yttrium Oxide

The structural, physical, and optical properties of prepared glass samples of the composition formula 30SiO₂-(40-x)B₂O₃-20Na₂O-10Al₂O₃-xY₂O₃, where x = 0, 1, 5, 7 (wt%) were studied before and after gamma irradiation using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and UV-visible spectroscopy. The optical absorption spectra of study glasses were recorded in the UV/visible range of 200–900 nm. The optical band gap energies were calculated from absorption data. These results show that E_opt decreases with increasing concentration of Y₂O₃. The changes occurring in the optical parameters obtained from absorption spectra before and after irradiation have been referred to irradiation induced structural defects and compositional changes.     

玻璃成分与酸沥滤关系的探讨

从3种玻璃纤维成分入手,分别分析了3种玻璃酸沥滤过程中SiO_2质量分数的变化和玻璃成分的溶出,分析了该过程中的溶出机理。从微观形态的角度探讨了酸沥滤对高硅氧布力学性能的影响,指出高硅氧纤维性能与酸沥滤的时间、温度、酸度以及纤维本身的成分都有关系,在开拓高硅氧纤维应用领域的时候,应从用途出发筛选酸沥滤因素。     

Radiation Characteristics of Glass Foams

This paper is concerned with the analysis of the radiative heat transfer in glass foams. The closed-form analytical model for the reflectance, transmittance, and absorptance of radiation by a foam layer has been utilized to assess the resistance of radiation heat transfer from the hot combustion gases and refractories to the molten glass in the glassmelting furnace due to glass foaming. The size (radius) and shape (void fraction) of foam bubbles, their size distribution function, the scattering anisotropy, and the reflectance of the foam/glass interface have been identified as major physical parameters governing the problem. Detailed parametric calculations have been performed, and the results are reported and critically discussed with the aim of quantifying the radiation characteristics of glass foams. The findings lead to a fundamental understanding of the radiative transport in the foams, and can be used to improve the design and operation of modern glassmelting furnaces.     

Inhibition of Nuclear Waste Glass Leaching by Chemisorption

The durability of a simulated nuclear waste containment glass was investigated by static leaching tests in six types of leaching containers. Glass corrosion in lead containers was reduced by more than two orders of magnitude from that measured in Teflon, whereas aluminum containers resulted in nearly a one order of magnitude reduction. Relatively minor effects on glass leaching were measured in copper, tin, and titanium containers. The results have strong implications concerning the choice of materials in possible waste package designs.     

Effect of Gamma Radiation on the Direct-Current Resistivity of GeO2

Results of dc resistively measurements on high-purity GeO₂ glasses before and after radiation with ⁶⁰Coure reported. For these glasses, the dc resistivity is increased by irradiation in a stable and reproducible fashion. This effect is attributed to the interaction of radiation-induced defects with the sodium-ion charge carriers.     

γ辐射和高温对放射性废物水泥固化体强度的影响(英文)

为了处理高活性、放热性C级放射性废弃物,在比利时通常采用圆柱体混凝土＂超级容器＂作为基本途径。＂超级容器＂是合成的废弃物包,废弃物由碳钢包裹组成,碳钢被波特兰水泥制成的＂缓冲器＂包裹。自密实混凝土作为一种特殊类型的混凝土,正被考虑用来制备＂缓冲器＂。一旦＂缓冲器＂被浇筑并且硬化程度很高时,放射性废弃物就被包裹在＂缓冲器＂内,存在的缝隙可以采用新拌灌浆料填充（例如自密实砂浆）。用盖子将＂超级容器＂密封后应用于＂超级容器＂的混凝土层,即混凝土缓冲器、灌浆料及盖子在硬化期间（灌浆料）与硬化之后（＂缓冲器＂与盖子）将暴露在废弃物热场与辐射场内。因此,需要解决2个主要的问题：1）γ射线（α与β射线被碳钢包裹层阻断,中子的影响可以忽略）对灌浆料硬化强度的影响;2）温度升高（从20℃升高到105℃）对硬化试件强度的影响。为了证实强度是否损失并确定强度损失后的主要机理,采用荧光显微镜,在砂浆或混凝土薄片的截面上直接分析毛细孔隙率。     

玻璃应力对玻璃强度的影响

介绍了玻璃的应力与玻璃强度之间的关系,并讨论了几种不同类型的应力对玻璃强度的影响。     

Kinetics of Leaching of Lead Glass by Ethylenediaminetetraacetic Acid

Treatment of lead glass with a hot basic solution of the sodium salt of ethylenediaminetetraacetic acid (EDTA) was shown to remove lead from the glass surface. A mechanism is proposed whereby lead is removed by a two-step reaction involving hydroxyl ions and EDTA. The rate constant and the overall heat of activation were estimated for this reaction. Potassium and silicon are also removed from the glass surface and show a dependence similar to that of lead removal. Potassium and silicon, however, do not form complexes with EDTA. Thus, it appears that lead removal weakens the silicate structure of the glass surface, allowing the potassium and silicon to be attacked and removed by hydroxyl ions and/or water. Experimental results indicate that the silicon released from the glass surface is in the form of silica.     

Jute-Reinforced Urethane Polymer Composite Under Gamma Radiation

Some formulations were developed with urethane triacrylate oligomer in combination with monomers of different functionalities. Thick (2 mm) polymer films were prepared with these formulations under Co-60 gamma radiation. The films were reinforced with jute by mixing jute particles in the above formulations at different proportions. These films were characterized and it was observed that both tensile and bending strengths were enhanced by the addition of the jute in the formulation; however, elongation reduced with the increase in jute concentration. However, the presence of trimethylol propane triacrylate (TMPTA) in the formulations slightly reduced the tensile properties of the composites from the already enhanced properties induced by the TMPTA in the films.     

Sodium Diffusion and Leaching of Simulated Nuclear Waste Glass

Oxides such as CaO, ZnO, Fe₂0O₃, and Zr0O₂ were substituted for Si0O₂ into a 14 Na₂0-10 B₂0O₃-76 Si0O₂ (wt%) glass in proportion to their weight percent in PNL-7668 simulated nuclear waste glass. No correlation was found between the Na diffusion coefficient (D_Na) in the bulk glass and sodium leaching in water for any of the iron-containing borosilicate glasses. Effective diffusion coefficients calculated from the sodium leach rates in deionized water were 500 to 2000 times larger than D_Na. The experimental leaching data agreed with a diffusion-convection model where the convective term was a measured "phase-boundary" velocity moving into the glass.