Comment by sophacles | Hacker News Reader

Comment by sophacles | Hacker News Reader

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This is an overly simplistic argument:

1) are the raw materials the same raw materials? (Iron is easier to get than tungsten for instance). Are the materials used in either type of generation actually hard to find or in danger of becoming scarce?

2) How much extra energy is spent on processing the raw materials to the finished product? The vast majority of weight in a turbine is the tower, which is relatively simple to build compared to the thousands of miles of piping welded together in a nuke plant. Even if weight of resources/watt of generation was a good measure, you are not factoring the weight of a) fuel to create energy consumed in manufacture, and b) weight of wasted resources in the refining and manufacture processes.

3) How reusable is the material base? How much of a nuke plant can be used to create the next plant? Presumably a wind down can have it's turbine or airfoils replaced independently of the tower structure itself, reducing tco. (and total resource consumption).

4) Your analysis is not including weight of energy production fuel put in, nor the weight of all resources needed for dealing with post energy production waste (not insignificant in nuclear waste storage).

1:

Most of a nuclear plant is concrete (the containment building) and iron (the reactor body). And both those materials are easy to get. The pipes are minor in comparison (in terms of materials, not in terms of construction). There isn't much if any tungsten used in a reactor, it's all ordinary iron, copper, concrete, etc.

In contrast a wind turbine uses hard to get neodymium rare earth magnets.

Nuclear plants don't require exotic materials.

2:

It's about the same for nuclear plants and wind turbines - you make a mold and pour the concrete. You might have thousands of miles of pipe, but you also produce a thousand times as much energy.

Not much waste in either during manufacturing - any extra metals are reused, and the concrete is poured in place. So it's about the same for turbines/nuclear plants.

> weight of resources/watt of generation was a good measure

It's an approximation of how much resources are needed (mining, energy, etc). We are worried about CO2, but mining also causes pollution, and uses energy.

3:

In a turbine it's the tower and blades both that need to be replaced due to material fatigue. The generator can be reused. The tower is wasted (it's poured concrete). The blades can be melted down, but they are light, and it's not a lot of metal - making them is the hard part.

We've never reused a nuclear plant (that I know of), so it's hard to say what would happen there.

They last a lot longer than wind turbines though, in the range of a 100 years vs 20.

Most likely the nuclear core would be removed, and the building reused for the next power plant. The building itself doesn't wear out, but they might redo the control equipment (pipes, wires, all very recyclable stuff).

4:

The weight of the fuel is tiny - less than 100 tons of fuel for a 1GW reactor, and it lasts around 10 years. That's equivalent to a couple of bolts on a wind turbine (which produces 1/1000 of the energy).

Waste is troublesome, but doesn't use a lot of materials. It's about one semi trailer load - every 10 years, for a plant that produces 1000 times as much as a turbine (which also fits on a semi).

> Nuclear plants don't require exotic materials.

Yeah, I bought 1 kilo of Uranium in the supermarket last week. Was pretty cheap.

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