SMR’s for the most point are almost entirely safe. For one they do not deal in the sheer size of current plants (these things will fit on the bed of an 18 wheeler) and there are some under development that would take the “used” power rods (large reactors only extract 10% tops of the power possible out of the rods which is why it is radioactive) and use them to power it while also decreasing the radiation.

Essentially it would take rods that are radio active for thousands or years and turn it into just hundreds which is significant.