Stability of neat hydrophobic Room-Temperature Ionic Liquids (RTIL) [BuMeIm]X, where [BuMeIm]+ is 1-butyl-3-methylimidazolium and X- is PF6-, and (CF3SO2)2N-, was studied under gamma radiolysis (137Cs) in an argon atmosphere and in air. It was found that the density, surface tension, and refraction index of RTILs are unchanged even by an absorbed dose of approximately 600 kGy. Studied RTILs exhibit considerable darkening when subjected to gamma irradiation. The light absorbance of ionic liquids increases linearly with the irradiation dose. Water has no influence on radiolytic darkening. A comparative study of [BuMeIm]X and [Bu4N][Tf2N] leads to the conclusion that the formation of colored products is related to gamma radiolysis of the [BuMeIm]+ cation. The radiolytic darkening kinetics of RTILs is influenced by the anions as follows: Cl- < (CF3SO2)2N- < PF6-. Electrospray ionization mass spectrometry and NMR analysis reveal the presence of nonvolatile radiolysis products at concentrations below 1 mol% for an absorbed dose exceeding 1200 kGy. Initial step of BuMeIm+ cation radiolysis is the loss of the Bu* group, the H* atom from the 2 position on the imidazolium ring, and the H* atom from the butyl chain. Radiolysis of ionic liquid anions yields F* and CF3* from PF6- and [Tf2N]-, respectively. Recombinations of these primary products of radiolysis lead to various polymeric and acidic species.

International Simple Glass -a six oxide borosilicate glass selected by the international nuclear glass community to improve the understanding of glass corrosion mechanisms and kinetics -was altered at 90°C in a solution initially saturated with respect to amorphous 29 SiO 2 . The pH 90°C , was fixed at 9 at the start of the experiment and raised to 11.5 after 209 d by the addition of KOH. Isotope sensitive analytical techniques were used to analyze the solution and altered glass samples, helping to understand the driving forces and rate limiting processes controlling long-term glass alteration. At pH 9, the corrosion rate continuously drops and the glass slowly transforms into a uniform, homogeneous amorphous alteration layer. The mechanisms responsible for this transformation are water penetration through the growing alteration layer and ion exchange. We demonstrate that this amorphous alteration layer is not a precipitate resulting from the hydrolysis of the silicate network; it is mostly inherited from the glass structure from which the most weakly bonded cations (Na, Ca and B) have been released. At pH 11.5, the alteration process is very different: the high solubility of glass network formers (Si, Al, Zr) triggers the rapid and complete dissolution of the glass (dissolution becomes congruent) and precipitation of amorphous and crystalline phases. Unlike at pH 9 where glass corrosion rate decreased by 3 orders of magnitude likely due to the retroaction of the alteration layer on water dynamics/reactivity at the reaction front, the rate at pH 11.5 is maintained at a value close to the forward rate due to both the hydrolysis of the silicate network promoted by OHand the precipitation of CSH and zeolites. This study provides key information for a unified model for glass dissolution.As a result of the complex suite of corrosion processes listed above (hydration, interdiffusion, hydrolysis, condensation, precipitation), the dissolution of glass is rarely congruent. This means that, in addition to soluble species directly released into the solution, solid products are also formed. The 157 167 SiGlass surface at t = 0