Are nuclear reactors safe?

Aqueous homogeneous reactors cores employ water in which soluble nuclear salts (usually uranyl sulfate or uranyl nitrate) have been dissolved. As the water serves as the solvent for the uranium salts, it serves as the fuel. As it is water, it serves to cool the reactor as well- hence the name 'homogeneous' (as coolant and fuel are one homogeneous substance). The water can be either heavy water or ordinary light water.