DEVELOPMENT OF CEMENT SOLIDIFICATION PROCESS FOR SODIUM BORATE WASTE GENERATED FROM PWR PLANTS

摘要

A cement solidification process for treating sodium borate waste produced in pressurized water reactor (PWR) plants was studied. To obtain high volume reduction and high mechanical strength of the waste, simulated concentrated borate liquid waste with a sodium / boron (Na/B) mole ratio of 0.27 was dehydrated and powdered by using a wiped film evaporator. To investigate the effect of the Na/B mole ratio on the solidification process, a sodium tetraborate decahydrate reagent with a Na/B mole ratio of 0.5 was also used. Ordinary portland cement (OPC) and some additives were used for the solidificaiton. Solidified cement prepared from powdered waste with a Na/B mole ratio 0.24 and having a high sillica sand content (silica sand/cement＞2) showed to improved uniaxial compressive strength.