And you don't want to the complication of loading fuel on site - it immediately negates several of the advantages of the SMR.
And what "hot side" are you thinking of ? As something of an over-simplification, it'll come as a "box" with two pipe connections - coolant in through one, hot coolant out through the other. Easy to pressure test after you've lowered (I was going to write "dropped" but some might take that the wrong way !) the unit into it's concrete hole.
And these will be designed such that loss of coolant does not result in release of radiative material - things like high-temperature fuel encapsulation (e.g. ceramic pellets), passive cooling sufficient to keep the temperature below the melting point of said encapsulation, and so on. Even simple things like placing both connection at the top, so in teh even of a total loss of the external systems, simple gravity keeps coolant in the box.
Biting the hand that feeds IT
