a nuclear power plant takes a decade or more to build

That's largely due to waste, not the actual process of safe construction. If there's public will, nuclear projects could be fast-tracked without compromising safety, though the costs would probably go up:

But those were far from the only costs. They cite a worker survey that indicated that about a quarter of the unproductive labor time came because the workers were waiting for either tools or materials to become available. In a lot of other cases, construction procedures were changed in the middle of the build, leading to confusion and delays. Finally, there was the general decrease in performance noted above. All told, problems that reduced the construction efficiency contributed nearly 70 percent to the increased costs.

By contrast, R&D-related expenses, which included both regulatory changes and things like the identification of better materials or designs, accounted for the other third of the increases. Often, a single change met several R&D goals, so assigning the full third to regulatory changes is probably an over-estimate.

So, while safety regulations added to the costs, they were far from the primary factor. And deciding whether they were worthwhile costs would require a detailed analysis of every regulatory change in light of accidents like Three Mile Island and Fukushima.

As for the majority of the cost explosion, the obvious question is whether we can do any better. Here, the researchers' answer is very much a "maybe." They consider things like the possibility of using a central facility to produce high-performance concrete parts for the plant, as we have shifted to doing for projects like bridge construction. But this concrete is often more expensive than materials poured on site, meaning the higher efficiency of the off-site production would have to more than offset that difference. The material's performance in the environment of a nuclear plant hasn't been tested, so it's not clear whether it's even a solution.

The above focuses on costs, but there's also some discussion about time as well (e.g. waiting for tools and materials).

nuclear waste

At least in the US, we have plenty of space for that. Most of Nevada is barren, and isn't likely to be used by people for anything important. There's also research into recycling spent nuclear fuel into new fuel:

Spent nuclear fuel from power plants still has 95% of its potential to produce electricity

I don't know much about water use though, so that could absolutely be an issue in many parts of the world. I am interested in looking into efficient ways to desalinize water, which is important for a whole host of reasons.

In conclusion, renewables are by far the best solution, not nuclear energy.

The best solution is a mixture of both. We need an inexpensive baseline energy production. Solar, wind, etc are bursty by nature, so we'd need a large amount of energy storage in order to go full renewable. Until I see a practical, inexpensive way to store energy, I'm going to push for nuclear since it's a clean, stable energy supply.

As far as the waste goes, China is building molten salt reactors that can use the waste to run. The waste that those reactors produce has much shorter half lives, like days, and can be stored almost anywhere.

That being said, agreed that we would be better off investing in renewables, and getting the planet down to two or three reactors total. We can't go completely renewable, as we need the isotopes we create in nuclear reactors for medical reasons.

Yeah I think people don't appreciate how much the cost of renewables has gone down. If we were making a big push on fixing climate change two decodes ago, then nuclear would've been a good route to go. But that didn't happen, and looking at the cost of renewables now and the timelines needed for nuclear, it simply doesn't make sense anymore.

Though what Germany did with shutting down their nuclear plants was stupid. Keep existing nuclear going until all carbon emitting power generation is replaced, then consider replacing existing nuclear with renewables.

Renewables are a solution only in short term. The biggest issue with renewables is the relatively low power output. Our power demands will only grow in the future and eventually we're going to hit a wall with renewables. Long term nuclear is the way to go. Ideally we should be creating solar and wind parks and focus on making thorium reactors viable so we could switch from renewables to thorium.

Nuclear is the future, just not the kind of nuclear we're using right now.

Yeah, just getting nuclear waste disposal and whatnot started up would be very expensive, despite having a ton of space to put said waste, since there are likely all kinds of regulations around moving such waste between states and territories.

That said, Australia surely needs some electric backbone for overnight use, and the goto solution for renewables is batteries, which are quite expensive at scale. So I'd like to see the numbers here.

The other problem Australia has is we have too little need for power. We couldn't build five nuclear plants to allow one at a time to be stopped for maintenance

We could probably use two, but then lose half our baseload supply for maintenance

That 2014 plan was for 100% renewable energy by 2020-something wasn't it?