Can a nuclear power station produce nuclear warheads?

Sort of. It can produce plutonium, but normally it doesn't produce a pure enough sample of the desired isotope. Nuclear weapons require isotopes with odd mass numbers (really). So for uranium, U-233 or U235 can be used. read more

No. It can produce plutonium which, when separated from the uranium by a chemical process, can be used to make nuclear warheads. But the material in and generated by a nuclear power plant does not make nuclear warheads. A comparison might be made with an iron mine. read more

That is why uranium enrichment technology is inherently dual-use. Any civilian enrichment facility can be used to produce nuclear weapons material. Because of this danger, all nuclear material in civilian enrichment facilities owned by non-nuclear weapons states is under International Atomic Energy Agency (IAEA) safeguards. read more