GLAVNI TIPOVI STIJENA ZA ODLAGALIŠTE RADIOAKTIVNOG OTPADA

Underground geological storage of high- and intermediate/low radioactive waste is aimed to represent a barrier between the surface environment and potentially hazardous radioactive elements. Permeability, behavior against external stresses, chemical reacatibility and absorption are the key geological parameters for the geological storage of radioactive waste. Three principal rock types were discussed and applied to the Dinarides: (1) evaporites in general, (2) shale, and (3) crystalline basement rocks. (1) Within the Dinarides, evaporite formations are located within the central part of a Carbonate platform and are inappropriate for storage. Offshore evaporites are located within diapiric structures of the central and southern part of the Adriatic Sea and are covered by thick Mesozoic to Cenozoic clastic sediment. Under very specific circumstances they can be considered as potential site locations for further investigation for the storage of low/intermediate level radioactive wast e. (2) Thick flysch type formation of shale to phyllite rocks are exposed at the basement units of the Petrova and Trgovska gora regions whereas (3) crystalline magmatic to metamorphic basement is exposed at the Moslavačka Gora and Slavonian Mts. regions. For high-level radioactive waste, basement phyllites and granites may represent the only realistic potential option in the NW Dinarides.Podzemno odlaganje visoko i srednje do nisko radioaktivnog otpada predstavlja barijeru između površinskog okoliša i potencijalno opasnih radioaktivnih elemenata. Neki od ključnih geoloških parametara za odlaganje radioaktivnog otpada su permeabilnost, ponašanje prilikom opterećenja, intenzitet kemijskih reakcija i apsorpcija. U članku diskutiramo tri pogodna tipa stijena za odlagališta: (1) evaporiti, (2) šejl, i (3) stijene kristalinske podloge, čije predstavnike pronalazimo i u Dinaridima. (1) Evaporitne formacije smještene su na kopnu duž centralnog dijela Karbonatne platforme i u podmorju unutar dijapirskih struktura centralnog i južnog dijela Jadranskog mora. Evaporiti na kopnu sastoje se od gipsa i anhidrita i nepogodni su za odlagališta. Evaporiti u podmorju sastoje se od anhidrita i soli i mogli bi biti pogodni su za odlaganje nisko do srednje radioaktivnog otpada. (2) Debele formacije šejla i filita nalaze su u području Petrove i Trgovske gore, dok su (3) magmatsko-metamorfne stijene kristalinske podloge izložene u području Moslavačke gore i Slavonskih planina. Za odlagališta visoko radioaktivnog otpada, kristalinska podloga i filiti predstavljaju jedine moguće lokacije unutar Dinarida

Dinaride evaporite mélange: Diagenesis of the Kosovo polje evaporites

Permian to Triassic age and floored by the various Adriatic carbonate platform units. The tectonic history of the Dinaridic evaporite mélange is related to long term burial and Palaeogene to Neogene exhumation processes. Evaporiterocks of the Kosovo polje deposits are associated with carbonates, clastic and minor albitized, subvolcanic, neutralto basic rocks. They are capped by a clayey Quaternary cover of variable thickness, and a several metres thick cavernouscarbonate breccia – rauhwacke. Evaporite rocks show two distinct facies: laminated evaporite-carbonate, composed of evaporite and dolomicrite (± organic matter, pyrite, halite) intercalations, and evaporite-carbonate breccia, composed of fragments of laminated evaporites, carbonate and siltite, cemented by massive gypsum ± sulfur, occurringat the shallower levels and related to the emplacement. The Quaternary cover is composed of 47-88% clayey material, comprising illite, kaolinite and most likely vermiculite, 9-49 % carbonate and 3-4% evaporite minerals. The thickness of the evaporite rehydration zone correlates negatively with the thickness of the overlying Quater nary cover and with the amount of clayey material within it. Rauhwacke are composed of partly dedolomitized dolostone and leachedgypsum fragments, cemented with late stage calcite. Diagenetic processes are related to early diagenesis and the burialphase began with the formation of diagenetic halite from an oversaturated subsurface or surface (lagoon) brine, and was followed by the biochemical reduction of evaporite sulphate to sulfide and formation of pyrite within organic-richcarbonate laminae. These processes triggered early dolomitization (in a shallow burial realm), and the formation of idiomorphic planar-e type of dolomite crystals at temperatures below 50-60°C. Planar dolomite suppressed diagenetichalite. With an increase in burial depth, gypsum dehydrates to anhydrite and when temperatures exceed ~50 °C, precipitation of fine grained non-planar –a type of dolomite began. Halite molds are partly replaced with non-planar-atype of dolomite. During regional uplift and exhumation, anhydrite rehydrated to gypsum under the influence of low-temperature undersaturated fluid (meteoric water), whereas hydrogen-sulfide oxi dized to elementary sulfur, observed as cement in the evaporite-carbonate breccia. Rauhwacke at the uppermost part of the deposit are formed by severe tectonic movements associated with the gypsum-driven dedolomitization process.</p

PRINCIPLE ROCK TYPES FOR RADIOACTIVE WASTE REPOSITORIES

Underground geological storage of high- and intermediate/low radioactive waste is aimed to represent a barrier between the surface environment and potentially hazardous radioactive elements. Permeability, behavior against external stresses, chemical reacatibility and absorption are the key geological parameters for the geological storage of radioactive waste. Three principal rock types were discussed and applied to the Dinarides: (1) evaporites in general, (2) shale, and (3) crystalline basement rocks. (1) Within the Dinarides, evaporite formations are located within the central part of a Carbonate platform and are inappropriate for storage. Offshore evaporites are located within diapiric structures of the central and southern part of the Adriatic Sea and are covered by thick Mesozoic to Cenozoic clastic sediment. Under very specific circumstances they can be considered as potential site locations for further investigation for the storage of low/intermediate level radioactive wast e. (2) Thick flysch type formation of shale to phyllite rocks are exposed at the basement units of the Petrova and Trgovska gora regions whereas (3) crystalline magmatic to metamorphic basement is exposed at the Moslavačka Gora and Slavonian Mts. regions. For high-level radioactive waste, basement phyllites and granites may represent the only realistic potential option in the NW Dinarides