The Interaction of Na-Al-P-Glass (Cs, Sr-Bearing) with Water at Elevated Temperatures (70–250°C)

Abstract

At present Na-Al-P-glass is used in Russia as matrix for high level nuclear waste which include a sufficient portion of 90Sr and 137Cs isotopes. It has been known that this type of glass is characterized by relatively poor hydrothermal stability above 120°C (Krilova et al., 1990 [1], Balukova et al., 1987 [2]). Although careful studies were devoted to the glass, some questions of geochemical behavior of Sr and Cs in the limits of the nearest repository environment have remained undecided. For example, these have been left uncertain: the mechanism of the glass leaching, phenomena limiting the glass dissolution, the detailed composition of newly formed phases, temperature dependence of the glass solubility. The main purpose of the present experimental investigation was to detect factors controlling Sr and Cs concentrations of aquous solutions and to study the possibility of new solid phase formation as a factor slowing down migration of Cs and Sr in water satureted circumstance.

Effects of modifier additions on the thermal properties, chemical durability, oxidation state and structure of iron phosphate glasses

“…• ∼760 cm −1 symmetric stretching of (P-O-P) bonds in Q 1 (P2O7) 4 Additions of modifier cations to the base glass, PFe1 M, result in a number of spectral changes which become more pronounced as the modifier content increases, as illustrated in Fig. 4(a,b).…”

“…Silicate glasses are also the obvious host matrix for the vitrification of toxic incinerator ashes given that these wastes are usually rich in SiO2. Phosphate glasses by comparison have few applications; however, they have received substantial attention over the past 40-50 years as possible host materials for the immobilization of certain specific radioactive wastes [1], [2], [3], [4] and [5]. Some Russian HLW has been immobilized in sodium aluminophosphate glasses at the Mayak facility in Ozersk [4] and [5].…”

“…Phosphate glasses by comparison have few applications; however, they have received substantial attention over the past 40-50 years as possible host materials for the immobilization of certain specific radioactive wastes [1], [2], [3], [4] and [5]. Some Russian HLW has been immobilized in sodium aluminophosphate glasses at the Mayak facility in Ozersk [4] and [5]. The formation of Recently we have studied glass formation and the solubility of SO3 in 60P2O5-40Fe2O3 (mol%) glasses to which have been added oxides of monovalent (Li, Na, and K) and divalent (Mg, Ca, Ba, and Pb) cations.…”

The Role of Replacing CdO by Fe<sub>2</sub>O<sub>3</sub> on the Fast Neutron Removal Cross Sections in Cd-Boro Phosphate Glass Shield

“…The sub bands in the region 810 -920 cm −1 is overlapping the asymmetric stretching vibration of P-O-P linkages and the symmetrical stretching vibrations of BO 4 units [16,17]. The sub band around 1037 cm −1 is attributed to the symmetric stretching vibration of the 3 4 PO  tetrahedral (P-O ionic group) [18] and BO 4 units. The sub band at 1198 cm −1 is assigned to PO 2 asymmetric stretching vibration [17].…”

Immobilization of simulated radioactive fluoride waste in phosphate glass

“…Siemer processed fluoride wastes by volatilization/separation of the bulk of the fluorine, and vitrified its cationic components (mostly alkali metals and fission products (FPs)) to an iron phosphate glass waste form, obtaining a much higher effective waste loading [11,12]. Sodium aluminophosphate (NaAlP) glasses had been selected as the glass matrix in the former Soviet Union [13] and developed at the Institute of Physical Chemistry of the Russian Academy of Sciences [14].…”