The application of nano silica extracted from kaolinite, bentonite and rice straw is proposed as treatment material for the purification of primary coolant water of pressurized water reactor. Three elements are used to simulate some radionuclides that can be released in the primary coolant water; strontium, nickel and cobalt. Various batch experiments are performed; selection of efficient sorption nanomaterial, Optimum operational weight ratio (element/nano material, selectivity of the nano silica for elements used, determination of the equilibrium curve of sorption process, and desorption behavior of nanomaterial with pH and temperature variation. The samples are analyzed by using the inductively coupled plasma emission spectrometer. Silica of kaolinite, bentonite and rice straw show the same results to remove the three elements used. Silica form of rice straw has been selected as nano-treated materials for economic reasons and avoiding problem of pollution. The sorption process is reached equilibrium after 30 min approximately. The experiments demonstrate that the sorption reaction of element by the nano-silica is irreversible reaction with the change of temperature and pH. Objectively, these findings from experiments using the nano silica increase the safety margin of the treatment stage in the multi barrier concept.