Nuclear power

[TimberWolf]

Fusion. We should spend gazillions on it in a sort of Manhattan project just get it done kind of way instead of fannying about with windmills.

It's pitiful the amount we spend on this kind of research into this kind. The ITER project is projected to cost €16billion, which by 2050 is expected to have generated 0J worth of electricity, being just an experimental reactor. What's €16billion, funded globally, compared to fighting oil wars in the Middle East, where a single bomb might cost £1m. Humanity should be investing in this and on reaching the stars, not so much on bombing foreigners. Though having said, wars do spur scientific research and its perhaps no coincidence that fusion was cracked by our ancestors decades ago, but only for use in big bombs.

[wurzel]

Build the reactors on top of a cliff.

Good idea, how about somewhere on the east coast of the UK?

[OwlHoot]

And reactors heavily depend on water, pumping it up a cliff isn't a good idea.

My idea is to have the reactor floating in the sea, but I think the Russian's have already nicked my idea.

I still say it would be safer and more economical in the long run to build them two or three miles underground. But nobody listens to Owly.

(I do see that getting large amounts of cooling water circulating at those depths would be challenging. But you could use multiple interlocking cooling "circuits", e.g. fairly compact reactors with liquid sodium primary cooling, linked to secondary water cooling circuits, and maybe even a third.

The advantages of deep underground reactors are obviously:

(1) No pain-in-the-ass NIMBYs objecting to large reactors near their homes, and minimal surface footprint where land is in short supply (e.g. UK and Japan)

(2) No risk of radiation leaks to the atmosphere, if tunnels properly designed, whatever befalls the reactor

(3) Safe from bombs, whether terrorist or sovereign state (although admittedly bombs could put them out of action by destroying surface infrastructure)

(4) They can be decommissioned by little more than collapsing or blocking a few tunnels and leaving them. (Also these tunnels could first be stuffed full of low, medium, and high grade radioactive waste, reducing the perennial headache of where to store that.)

(5) Basaltic and/or granitic material excavated to form the runnels and chambers could be used for other purposes, such as road building, without having to extract marine shingle or unsightly surface mines

(6) etc ...

[DimPrawn]

Good idea, how about somewhere on the east coast of the UK?

Hartlepool Nuclear Power Station - Wikipedia, the free encyclopedia

[wurzel]

Hartlepool Nuclear Power Station - Wikipedia, the free encyclopedia

I guess they don't lose 30 feet a year through coastal erosion up there then....

[suityou01]

Fusion. We should spend gazillions on it in a sort of Manhattan project just get it done kind of way instead of fannying about with windmills.

The thing I didn't like about the Manhattan project was that they had no idea how far the chain reactions would go. The were "quite confident" that atoms such as oxygen, nitrogen, carbon etc would not be involved but there were still disputes between Feynman and the others as to who was right.

Luckily it was Feynman.

[TimberWolf]

I still say it would be safer and more economical in the long run to build them two or three miles underground. But nobody listens to Owly.

(I do see that getting large amounts of cooling water circulating at those depths would be challenging. But you could use multiple interlocking cooling "circuits", e.g. fairly compact reactors with liquid sodium primary cooling, linked to secondary water cooling circuits, and maybe even a third.

The advantages of deep underground reactors are obviously:

No disadvantages?

What about efficiency, which effects cost.

A 1GW reactor might need say 2GW of thermal energy to remove. I'm not sure how multiple cooling circuits address that, but even if they did, multiple circuits reduce efficiency, since the primary cooling circuit would presumably be warmer than would a single cooling circuit. Efficiency being 1- Temp_Cold/Temp_Hot

It's also hotter underground meaning another efficiency hit and energy needed to cool equipment and humans

The geothermal gradient is the rate at which the Earth's temperature increases with depth, indicating heat flowing from the Earth's warm interior to its cooler surface. Away from tectonic plate boundaries, it is 25-30°C per km of depth in most of the world.

Even if a vertical tunnel chimney were used to vent super hot steam, I imagine a lot of it would fall back down as hot rain before it escaped, unless there were a mega updraught, reducing efficiency.

People disposing of spent fuel rods seem to spend a lot of time figuring out good places to bury spent waste, so I imagine the same headaches will exist for reactor sites.

[DodgyAgent]

You cannot drop buckets of seawater from helicopters onto a reactor to cool it if it is underground

[DimPrawn]

You cannot drop buckets of seawater from helicopters onto a reactor to cool it if it is underground

True, but gravity does work in your favour in that you can open some valves and flood the place.

[doodab]

What happens to underground caverns during an earthquake? Are they safe places to be?