Fusion?

Do you mean "per year"?

This page suggests 40 kg of 2H and 60 kg of 3H per year, but seems to leave out any consideration of the conversion efficiency of thermal steam plants. Assuming a 40% efficiency, in the ballpark for common steam plants (excluding the nukes that have an extra loop for safety) makes its numbers match yours.

https://physics.stackexchange.com/questions/234379/so-how-much-fuel-does-a-hypothetical-fusion-plant-need

 

Seawater ought to average a slightly higher concentration than fresh water, as it evaporates slightly less easily. Online sources show significant variations in fresh water, from well below to some overlap compared to seawater.

I understand that deuterium can also be made by nuclear irradiation. But it isn't done on commercial scale because separation from natural water is cheaper. If water supply is scarce, one can potentially change methods.

Is that much new water flow really needed for a steam power plant? Or is that just because we keep using open cycle water cooling because it is cheaper than closed cycles? That may be an issue that can be addressed separately, to reduce water needs and allow greater freedom of placement.

Fusion plants ought not be as earthquake intolerant as fission plants, so near-ocean placements (high enough to avoid tsunamis) ought not carry the same risks, while providing access to an essentially unlimited water supply. It just needs to be desalinated.

 

⋅years!

On a few hundred kg of stuff.

Not too shabby.

 

Is it inconvenient to observe there is a natural fusion reactor 93 million miles from earth?

That natural, fusion reactor intermittently drives planet earth air and water that can provide power via wind mills, water turbines, and photocells. Coupling these intermittent sources with energy storage technology like batteries, pumped water, and even heavy weights suspended from cables can provide predictable, controlled power. But I am not totally against fusion and fission power.

A common problem with fusion and fission power is irradiation of their working containment vessels ... what allows them to work. The known mitigation is to surround fusion and fission with materials that when irradiated behave less hazardous than others. For example, lithium to become tritium. Just don't drink tritium water!

My reading (an actual nuclear engineering book,) suggests that fission of thorium salts can generate a less bad, irradiated material. This material can be chemically treated on site to remove the very small volume of longer lasting and biologically hazardous isotopes. The non-irradiate material returns to the on-site, fuel cycle, already in progress. Eventually the containment hardware will radiation age to the point of no longer being safe to operate. Although difficult and dangerous, even these irradiated materials can be processed to concentrate the small volume of longer lasting and biologically hazardous isotopes. Wild speculation, concentrated hazardous material returned to a dense neutron space, the active fission volume, might transmute them to less bad stuff. But fusion provides an interesting approach.

Assuming the problem of efficient, high power, pulsed laser generation can be solved, confinement fusion in a sphere of liquid lithium would be a clever solution. The lithium would be the working fluid and also source of tritium and possibly deuterium. As for the laser, a free-electron laser might work.

So my priorities would be:

1. Wind, water, and solar generation coupled with energy storage - the low hanging fruit is well within today's manufacturing and technology. It can be mastered by relatively unsophisticated engineers to provide rapid, measured in less than a year, relief. For example, the Hornsdale power storage project.
2. Advanced fission - already demonstrated in the 1960s, research and development could within decades result in safe, affordable, scalable, thermally efficient power plants. Compared to renewables, less land use and controlled power generation (aka., throttle-able.) They could be delivered to other planets and moons to support extended exploration.
3. Fusion - with tens of decades research, our specifies may solve the technical problems. It would provide the ability for significantly faster space travel.

Bob Wilson

 

Ah yes fusion. Where it sounds like each instrument is simultaneously playing a different tune.

.

 

When I was a child, commercial fusion was 20 years away.
When I was in college, commercial fusion was 20 years away.
Now as an elderly professor after a long engineering career, commercial fusion is 20 years away.

Making a prediction that a technology is 20 years away is psychologically safe as the prognosticator will never have to admit error. It basically says that there is no known path to a success and you might as well say that it will never happen.

JeffD

p.s. Hydrogen based cars are 20 years away

 

We have working hydrogen cars. Their lack of success has nothing to do with the technology. It's the economics. Build fuel cells at the levels we are making batteries, and their costs will also drastically drop. It is the refueling structure that is the big hurdle. It will be expensive as is.

Fusion power may never happen, but this is an important step for it to have a chance.

 

Absence of affordable hydrogen is the problem.

Bob Wilson

 

That is one of several problems limiting the viability of Hydrogen cars.

JeffD

 

Hydrogen based cars are 20 years away.​

Didn’t Social Security and Medicare go broke every 20 years?

Bob Wilson

 

Not as long as we continue to increase the money supply

 

I'm not sure about what happened before my time.

But during my adult years, the last substantial Social Security reform, to shore up the funding and keep it from going broke, was in 1983, under President Reagan. That fund is not expected to be depleted until 2033. So roughly 50 years.

Of course, Congress borrowed and spent all that money, which now must be paid back to SSA from general tax revenues. Something that a few congresscritters are balking about.

 

c'mon you fusion sceptics! read how toyota has transformed hydrogen transportation theory into reality!

air-in-water-out-six-interesting-facts-about-fuel-cell-electric-technology

 

My prediction? "19 Years".

Reasoning? With this advance, atop the advance at the UK machine last year, we finally decremented the Nuclear Fusion Countdown Clock by one year. A clock that had been stuck at "20 Years" since ... um ... uh ... before I was born?

I think this Fusion Countdown Clock will generally be ticking somewhat faster in the future, but don't expect it to ever reach the same rate as our everyday civil clocks and calendars.

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Another note: This U.S. device seems to be primarily meant for thermonuclear weapons research and maintenance. Controlled fusion for civilian power production seems to be a side gig for it. I'm not aware of any additional follow-on machines planned to continue this approach. The magnetic confinement path in Tokamaks, as is being explored in the UK and ITER machines, seems to be the only active path towards developing power production.

 

Might also work for space propulsion.

 

That will be essential in the future.

 

It only works with efficient, high power, pulsed lasers. This is a hard problem … or they are using Elon Musk clocks.

Bob Wilson

 

Following @fuzzy1 @21, I intend to make a concise post to clarify power and energy. But, busy elsewhere. Great if someone else does that first.