What, the nuclear waste handling, long term storage and disposal, as well as disposal of old nuclear plants? It is not really included in any of the price calculations I've seen around Germany, when it comes to what either the plant operators put out (in their business reports), the nuclear lobby is publishing or the politicians are quoting.
One of the most used metrics is the so called Levelized Cost of Electricity (LCOE). The LCOE includes investment, maintenance and operation, fuel and "carbon" costs, as well as waste costs. However, the waste costs are only calculated for the years of operation, so it's not really a great number to look at in terms of actual total cost.
Regardless, the LCOE the German federal government uses is 4-8 cents/kWh for onshore wind, 2-6 for photovoltaic, 14-19 for nuclear.
The (former) nuclear plant operators in Germany are required to pay into a fund that is meant to be used for covering the costs of decommissioning and disposal of the plants, as well as long term storage (except not everything is covered[0]). This is not included in the LCOE. Anyway, operators are required to pay a total of 47 billion EUR into that fund[1].
The old East German plants that got shut down right after the German reunification and are in the process of slowly being deconstructed and disposed of[2] are now estimated to cost 3-7 billion EUR a piece for full disposal (but not storage). If that's any indication, even when considering "lessons learned" will lower costs for future decommissioning and deconstruction, those 47 billion EUR is very unlikely to cover the eventual costs of deconstructing those 20-odd decommissioned German nuclear facilities and store spent fuel and contaminated materials for the first few decades. Some economists from the DIW (the private German Institute of Economic Research, not exactly tree huggers) calculated the eventual cost until 2100 will be closer to 169 billion EUR in 2019s money.
There are some eco lobbying organizations - obviously not without their own bias - that make claims such as "the true cost of nuclear is 42.2 cents/kWh while wind is 8.1 cents/kWH"[3]. I have previously looked through their numbers and argument in more detail, and it sounded mostly very sound to me, however I am a layperson.
Regardless, the fact is: we do not actually know yet the total cost of nuclear power.
[0] E.g. German tax payers have spent 1.5 billion EUR just on exploring potential long term storage sites so far. Just exploring.
[1] This is still litigated a bit, as the German legislature only really had the great idea to make a law about that in 2016. That's another reason nobody historically included it or now includes it in the LCOE.
[2] E.g. the old Greifswald plant. When it operated, it employed 10,000 people. Now 32 years after it officially ceased operation in 1990, it still employs around 1,000 people. Full deconstruction and disposal is now expected to happen by 2028 and will eventually have accumulated costs of a total of 6.5 billion EUR according to the company in charge of the disposal. Not including long term storage costs. Since the operator of those things used to the East Germany, it's now the Federal Republic of Germany's full responsibility to pay for that.
[3] https://www.bund-sh.de/energie/atomkraft/hintergrund/die-wah...