They definitely have enough capital for nuclear. Their neighbours, Slovakia and Czechia, both have quite significant nuclear installations. Czechia generates 34% [1] of electricity from nuclear and Slovakia 52% [2]. Slovakia is finishing expansion of one of their nuclear power plants (Mochovce), which will add 2 more reactors - each with ability to deliver 13% of total country consumption [3].
Both Slovakia and Czechia are bit more "richer" than Poland (if you look at GDP (PPP) per capita), however Poland is much bigger economy - 5x size of Slovakia.
My guess is that because so far they had so much coal (largest reserves in Europe [4]), it was no brainer for them. However they are now in the process of commissioning nuclear power plant and plan to generate power from nuclear by 2033 [4]
Nuclear may have some of the same issues as coal, in that if its use declines worldwide it becomes more expensive for you to keep using it. Not to mention the historical baggage associated with it.