Vol. 8, No 1, 2010 pp. 39 - 43
DOI 10.2298/FUPCT1001039P
UDC 546.36 : 615.463 + 666.32
CURING TIME EFFECT ON THE FRACTION OF 137CS FROM CEMENT-ION EXCHANGE RESINS-BENTONITE CLAY COMPOSITION
Ilija Plećaš, Slavko Dimović
Vinča Institute of Nuclear Sciences, P.O.BOX 522, 11001 Belgrade, Serbia
Abstract. To assess the safety of disposal of radioactive waste material in cement, curing conditions and time of leaching radionuclides 137Cs have been studied. Leaching tests in cement-ion exchange resins-bentonite matrix, were carried out in accordance with a method recommended by IAEA. Curing conditions and curing time prior to commencing the leaching test are critically important in leach studies since the extent of hydration of the cement materials determines how much hydration product develops and whether it is available to block the pore network, thereby reducing leaching. Incremental leaching rates Rn[cm/d] of 137Cs from cement-ion exchange resins-bentonite matrix after 240 days were measured. The results presented in this paper are examples of results obtained in a 30-year concrete testing project which will influence the design of the engineer trenches system for future central Serbian radioactive waste storing centre.
Key words: cement, radioactive waste, radionuclide, leaching, concrete
EFEKAT VREMENA OČVRŠĆAVANJA NA FAKTOR IZLUŽIVANJA 137CS IZ KOMPOZICIJE CEMENT-JONOIZMENJIVAČKA SMOLA-BENTONIT
U cilju procene bezbednosti konačnog odlagališta radioaktivnih otpadnih materijala cementnim postupkom, ispitivano je vreme očvršćavanja uzoraka i vreme izluživanja 137Cs iz uzoraka cement-jonoizmenjivačke smole Bentonit, u skladu sa metodom preporučenom od strane IAEA. Uslovi očvršćavanja i vreme očvršćavanja pre ispitivanja brzine izluživanja su od izuzetne važnosti za proučavanje izluživosti uzoraka i hidrataciju cementnih materijala, kao i mogućnost ispitivanja hidratacije na zapušavanje pora cementnih uzoraka, čime se smanjuje brzina izluživanja radionuklida. Merenje je trajalo 240 dana i izračunat je prirast vrednosti izluživanja Rn[cm/d] radionuklida 137Cs. Rezultati ovih istraživanja su deo 30-godišnjeg rada na pripremi projekta izgradnje trajnog odlagališta radioaktivnog otpada tipa plitko ukopanih betonskih inženjerskih tranšeja.
Ključne reči: cement, radioaktivni otpad, radionuklid, izluživanje, beton
