If something is Nuclear enough it can generate heat

That's an extreme oversimplification. RTGs don't use nuclear waste. Spent reactor fuel still emits a large amount of gamma and neutron radiation, but not with enough intensity to be useful in a reactor. The amount of shielding required makes any kind of non-terrestrial application impossible.

The most common RTG fuel is plutonium (^238^Pu, usually as PuO~2~), which emits mostly alpha and beta particles, and can be used with minimal shielding. It can't be produced by reprocessing spent reactor fuel. In 2024, only Russia is manufacturing it. Polonium (^210^Po) is also an excellent fuel with a very high energy density, but it has a prohibitively short half-life of just over a hundred days. It also has to be manufactured and can't be extracted.

^90^Sr (strontium) can be extracted from nuclear fuel, and was used by early Soviet RTGs, but only terrestrially because the gamma emission requires heavy shielding. Strontium is also a very reactive alkaline metal. It isn't used as RTG fuel today.

Nature catastrophes are the top 1 danger to nuclear energy. See Fukushima.

And the real question here would be a comparison between risk of a nuclear accident event and a renewables-impacting climate event.

Yeah let me imagine a supervolcano explosion of that scale to effect global weather patterns. What do you think will happen to your reactors? No, they are not indestructable just because they can handle an earthquake of normally expected proportion.

Uptime is calculated by kWh, I.E How many kilowatts of power you can produce for how many hours.

So it's flexible. If you have 4kw of battery, you can produce 1kw for 4hrs, or 2kw for 2hrs, 4kw for 1hr, etc.

Nuclear is steady state. If the reactor can generate 1gw, it can only generate 1gw, but for 24hrs.

So to match a 1gw nuclear plant, you need around 12gw of of storage, and ~~13gw~~ 2gw of production.

This has come up before. See this comment where I break down the most recent utility scale nuclear and solar deployments in the US. The comentor above is right, and that doesn't take into account huge strides in solar and battery tech we are currently making.

The 2 most recent reactors built in the US, the Vogtle reactors 3 and 4 in Georgia, took 14 years at 34 billion dollars. They produce 2.4GW of power together.

For comparison, a 1 GW solar/battery plant opened in nevada this year. It took 2 years from funding to finished construction, and cost 2 billion dollars.

So each 1.2GW reactor works out to be 17bil. Time to build still looks like 14 years, as both were started on the same time frame, and only one is fully online now, but we will give it a pass. You could argue it took 18 years, as that's when the first proposals for the plants were formally submitted, but I only took into account financing/build time, so let's sick with 14.

For 17bil in nuclear, you get 1.2GW production and 1.2GW "storage" for 24hrs.

So for 17bil in solar/battery, you get 4.8GW production, and 2.85gw storage for 4hrs. Having that huge storage in batteries is more flexible than nuclear, so you can provide that 2.85gw for 4 hr, or 1.425 for 8hrs, or 712MW for 16hrs. If we are kind to solar and say the sun is down for 12hrs out of every 24, that means the storage lines up with nuclear.

The solar also goes up much, much faster. I don't think a 7.5x larger solar array will take 7.5x longer to build, as it's mostly parallel action. I would expect maybe 6 years instead of 2.

So, worst case, instead of nuclear, for the same cost you can build solar+ battery farms that produces 4x the power, have the same steady baseline power as nuclear, that will take 1/2 as long to build.

This is old news now! Here's a link from 5 years ago. https://www.forbes.com/sites/jeffmcmahon/2019/07/01/new-solar--battery-price-crushes-fossil-fuels-buries-nuclear/

This is from last year: https://www.lazard.com/research-insights/2023-levelized-cost-of-energyplus/

As to uptime, they have the same legal requirements as all utilities.

I was pro nuke until finding out solar plus grid battery was cheaper.

you know that grid storage does not always mean "a huge battery", you can also just pump water in a higher basin oder push carts up a hill and release the potential energy when you need it...

You don't need lithium. That's just the story told to have an argument why renewables are allegedly bad for the environment.

Lithium is fine for handhelds or cars (everywhere where you need the maximum energy density). Grid level storage however doesn't care if the building houising the batteries weighs 15% more. On the contrary there are a lot of other battery materials better suited because lithium batteries also come with a lot of drawback (heat and quicker degradation being the main ones here).

PS: And the materials can also be recycled. Funnily there's always the pro-nuclear argument coming up then you can recycle waste to create new fuel rod (although it's never actually done), yet with battery tech the exact same argument is then ignored.

They're currently bringing sodium batteries to market (as in "the first vendor is selling them right now"). They're bulky but fairly robust IIRC and they don't need lithium.

Yeah, lithium mining and processing is extremely toxic and destructive to the environment. On one hand, it's primarily limited to a smaller area, but on the other hand, is it sustainable long-term unless a highly efficient lithium recycling technology emerges? And yes, I know there are some startups that are trying to solve the recycling problem, some that are promising.