New scenario for the accumulation and release of radiation damage in rock salt and related materials

Abstract

Take-down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.Downloaded from the University of Groningen/UMCG research database (Pure): http://www.rug.nl/research/portal. For technical reasons the number of authors shown on this cover page is limited to 10 maximum. AbstractRock salt might be a promising geological medium for a radioactive waste repository. However, we have observed that even a basically stable compound such as NaCl may become unstable after heavy irradiation. As a result of the irradiation, dislocations, Na and Cl 2 precipitates and large voids are produced followed ultimately by sudden explosiondriven fracture of the material. We present a new concept of the radiation-induced micro-structural evolution, which explains the phenomena observed in heavily irradiated NaCl samples. This concept can be a prototype of a more general assessment of radiation effects in crystalline radwaste and repository materials, which is necessary for the evaluation of critical effects and maximization of the safety of repositories. Ó

X‐ray‐induced alteration of specimens as crucial obstacle in XRF spectrometry of fluorine in rocks and soils

“…Apart from a signal increase, the formation of borate salts on the surface was discovered . Numerous publications attest that also chlorine compounds are decomposed by ionising radiation, including X‐rays . Urch detected chloride peak characteristics in L 2,3 ‐M spectra of various oxy‐chloro‐anions previously published by Henke and explained this as a result of sample decomposition because of irradiation.…”

“…Studies linked to underground nuclear waste disposal in rock salt caves focussed on the stability of alkali halides in a radioactive environment. Respective investigations of decomposition mechanisms, of voids, of release, accumulation, and recombination of radiolysis products () suggest that, depending on the specific compound, irradiation could well be responsible for both opposing trends of either increasing or decreasing concentrations. This could explain the counterexamples cryolite and PTFE.…”

Lattice deformation of blue halite from Zechstein evaporite basin: Kłodawa Salt Mine, Central Poland

“…For example, there are several papers describing radiation damage of halite mainly for the usage of exploited salt mines as waste storages (Groote et al 1991a(Groote et al ,b, 1994Seinen et al 1992Seinen et al , 1994aWeerkamp et al 1994;den Hartog 1999;den Hartog and Vainshtein 1997;den Hartog et al 2002den Hartog et al , 2007. A review article by Sonnenfeld (1995) summarised the state of the art of the colour of rock salt.…”

Melting properties of radiation‐induced Na and Cl 2 precipitates in ultra‐heavily irradiated NaCl

“…This is unfortunate, because chlorine nano-bubbles play a crucial role in advanced stages of radiolysis. Apart from the above-mentioned defects also dislocations and vacancy voids are created [1]. The efforts in the 1970's and 1980's were made to explain the formation of damage in NaCl, but vacancy voids were not taken into account [2,3].…”