Then social unrest came. Spare parts became rare parts. And one morning Harold's unblowable reactor, blew up, ending the neighborhood. We know from digs and the elephants foot, we're Harold last rested for good.
Why would a nuclear reactor blow up? There's nothing explosive in them.
Hydrogen generated by hydrolised cooling water, ignited by irradiated zirkonuium giving off sparks. But this is technical details of the interior reactor failing, distracting from the exterior reactor "society failing. If you proposed the catholic church running the reactor, that would have been a better gotcha..