Can you share some sources for this? This sounds both amazing and extremely tragic.

that's amazing and tragic

Don't give the dolphins access to nuclear power. We've been warned about this already!

It's a nuclear reactor on wheels. That is kinda doomed to cause problems. I also do have questions about how it would be economically viable when compared to other available means of mobile power generation. It takes some really well trained people to safely operate this thing, and a natural gas/diesel generator can be used with barley any training and is both safer and cheaper, and on top of this has more capacity. That's not to say that this was a bad thing, the fact that they managed to build this thing, and at least according to the source i found it was also very stable and reliable, it was simply always doomed to not be very useful. But well, nuclear reactors use a lot of water, and well, mobile reactors on ships make a lot more sense, both because of this and because putting shielding on those is a lot easier. Ship based mobile reactors also can handle far higher capacities then land based ones. The only places where something like this might be useful is after natural disasters that destroy large amounts of infrastructure. That is mostly A) Earthquakes B) Tsunamis. Both of which also damage the streets that this thing would drive on, and well, after quakes and further flood waves would block practical operation for both of these. And well, there is diesel. It might not be as eco friendly as a reactor, but that just doesn't really matter here. You can carry a small diesel generator and anyone can use them. They are also a lot cheaper to make. And those are just things seen from the perspective of back then. Today we have mobile solar and wind generators, better batteries, and if you really want that mobile multi-megawatt power plant, use natural gas or hydrogen generators. Mobile nuclear reactors are just to expensive to make sense on a scale you can fit on a car. On a ship? sure. that works, that's why swimming nuclear plants exist. On land? no. It will always loose to other methods of power generation, both because you certainly can't make that thing very efficient power wise, and it will be pretty expensive as well.
There is also the problem that this thing probably, i can't find any non-Russian sources on this and don't speak Russian, this thing needs a lot of water for cooling. At least all other reactors do, and i don't see a way they could have gotten around that. This makes this thing useless in a lot of environments.

You can also simply consider this: The soviets agreed with me, they gave up on it.