I severely doubt this is any safer from the meltdown problem than other designs.
Since the "primer source" is nothing but some highly radioactive material all that has to happen for a meltdown scenario is that the mechanism regulating the link between it and the reactor to lock up. It's exactly the same problem.
True although stopping active fission is relatively easy. The harder to solve problem is decay heat. Modern reactor designs employ passively safe measures which are designed to keep reactor cool (dissipate decay heat) without the need for pumps and/or electrical power.
My problem is that the people on wikipedia claim that meltdown is impossible, and that is simply not true.
It's the usual thing with some fanatic proponents, especially in nuclear power... claim one thing and once you research it it turns out to be an exaggeration.
This is probably safer than the reactors running in current powerplants, but nowhere as safe as conventional power.
The main problem with any reactor imo is that is has to run as hot as possible in order to archive higher Carnot Efficiency. So they are constructed to the limits of what the material can withstand. With conventional power you have a limit on the temperature you are able to generate in the first place, not so with nuclear power. It needs a technology which is able to withstand such high temperatures to be able to leverage the higher efficiency in the first place. Steam is not it. Thermoacoustic devices might do it for example.