Fusion breakthrough?

[Loren Pechtel]

Fusion power has been technically feasible since the 1950s.

All you need to do is drill a deep hole, lob in an H-bomb, and then use geothermal power gear to extract the energy from the hot rocks. When they cool down, lob in another H-bomb.

Of course, such a power plant would break a number of nuclear weapons limitation treaties.

And would scare the living crap out of the "Greens".

I don't think you can contain the boom adequately. You also have the problem of your water being radioactive. H-bomb fusion plants don't scale down to a practical scale well.

 

[lpetrich]

I'll believe it when I see it. Controlled nuclear fusion is VERY difficult.

Controlled nuclear fusion is so easy, a kid built a working fusion reactor for a science fair, and came in second! The technology has been around since the 60s. There's a company building them commercially; they're used for manufacturing radioactive medical isotopes. What's very difficult is getting a fusion reactor to generate more power than it takes to run the thing. That's what the clowns at Lawrence Livermore claimed to have done -- the binding asterisks are they're comparing the energy generated by fusing the hydrogen in a pellet with the energy delivered to the pellet by the lasers they fired at it to make it fuse. I.e., their breakthrough is they would hypothetically have a net gain reaction if they hypothetically had used 100% efficiency lasers.

But what is (energy out) / (energy in)? EROEI or EROI = energy returned on (energy) invested

I concede that nuclear fusion with a teeny tiny EROEI is very feasible - one can easily do that with a particle accelerator that accelerates nuclei with more than a few MeV of energy.

But what one wants to do is get EROEI > 1, and that has been VERY difficult.

 

[Shadowy Man]

Previous attempts to do a thing have failed, therefore all future attempts to do that thing will also fail.

Ah, logic.

What’s the saying: “doing the same thing over and over and expecting different results is the definition of insanity.”

 

[steve_bank]

energy out/energy in is efficiency.

The total energy is energy in, energy in the system, and energy out. Same with mass. Conservation.

Entropy represents energy lost that can not be used t do work in the system.

 

[steve_bank]

I have a relative who word n the Brookhaven Relativistic Heavy Ion Collider. He wored on the cryogenic cooling system. I got to see it.

It dependss on where you draw the thermodynamic boundary and determine efficiency.

For the collider that includes the coollinig system, computers, sensors and so on.

In power supplies boot strapping once the supply is running means using part of the output to run the supply. It can improve efficiency.

It does not take a lot of energy to start a fission reactor. Pull out control rods and heat is generated. Electricity out of the plant can be tapped off to run the rector once it is running. Backup generators are needed for an orderly shutdown in an emergency.

Fussiaon takes a lot of energy to start. I don't know how much energy it takes to maintain containment and transfer power to turbines. That woud be part of efficncy.

Do you need a small fission plantt next to a fusion reactor? Depending on how the numbers go that might be a solution.

 

[Cheerful Charlie]

Cold fusion refuses to die.

Italian company to sell portable cold fusion plant deliverable next year

(Phys.org) —Italian company Energy Catalyzer (shortened to ECAT) has announced that it is right now taking preorders for its ECAT 1MW portable cold fusion plant. Founded by Italian scientist Andrea Rossi, the plant has the scientific community shaking its collective head—it's never been peer...

phys.org

 

[barbos]

Fusion power has been technically feasible since the 1950s.

All you need to do is drill a deep hole, lob in an H-bomb, and then use geothermal power gear to extract the energy from the hot rocks. When they cool down, lob in another H-bomb.

Of course, such a power plant would break a number of nuclear weapons limitation treaties.

And would scare the living crap out of the "Greens".

I don't think you can contain the boom adequately. You also have the problem of your water being radioactive. H-bomb fusion plants don't scale down to a practical scale well.

Actually, particular experiment we are discussing here is basically an attempt at making tiny H-bomb explode.

 

[bilby]

I have a relative who word n the Brookhaven Relativistic Heavy Ion Collider. He wored on the cryogenic cooling system. I got to see it.

It dependss on where you draw the thermodynamic boundary and determine efficiency.

For the collider that includes the coollinig system, computers, sensors and so on.

In power supplies boot strapping once the supply is running means using part of the output to run the supply. It can improve efficiency.

It does not take a lot of energy to start a fission reactor. Pull out control rods and heat is generated. Electricity out of the plant can be tapped off to run the rector once it is running. Backup generators are needed for an orderly shutdown in an emergency.

Fussiaon takes a lot of energy to start. I don't know how much energy it takes to maintain containment and transfer power to turbines. That woud be part of efficncy.

Do you need a small fission plantt next to a fusion reactor? Depending on how the numbers go that might be a solution.

Seems like a totally pointless exercise to me. Just build the fission plant bigger, and sell the electricity from it.

 

[steve_bank]

We all know cold fusion works. It was suppressed by the fossil fuel companies.

 

[Loren Pechtel]

Fusion power has been technically feasible since the 1950s.

All you need to do is drill a deep hole, lob in an H-bomb, and then use geothermal power gear to extract the energy from the hot rocks. When they cool down, lob in another H-bomb.

Of course, such a power plant would break a number of nuclear weapons limitation treaties.

And would scare the living crap out of the "Greens".

I don't think you can contain the boom adequately. You also have the problem of your water being radioactive. H-bomb fusion plants don't scale down to a practical scale well.

Actually, particular experiment we are discussing here is basically an attempt at making tiny H-bomb explode.

He's talking about the drop-an-h-bomb-in-a-hole type system. It would work pretty well on a large enough scale--but we don't have a large enough scale to keep the bomb from breaching the cavern it's in. Thus we are left with trying to make small fusion booms without using a couple of critical masses worth of fissionables.

 

[Loren Pechtel]

We all know cold fusion works. It was suppressed by the fossil fuel companies.

Sure it works--just not at a useful pace. There are plenty of ways of getting a trickle of fusion to happen, but they're useless for power production because they don't get hot enough to matter.

 

[steve_bank]

Foreffciency it starts with fuel, just like a gas car.

Fission or fusion has energy in Joules/kg.

Efficiency is [energy out + losses]/[fuel energy]

Cost is based in dollars per kg of fuel. Coal and natural gas are cheap. Little or no processing required.

Losses, all measured in Joules or watts in Joules per second.

1. Start energy, subtracted from the output.
2. Conversion losses from fuel to heat to steam.
3. System losses like energy needed for the reaction confinement.
4/ Constrol system electronics.

In the 60s the power industry thought all they had to do was scale up Navy submarine reactors to industrial scale. Top promote nuclear energy it was claimed it would be so cheap it would not be metered, you wouldpay a flat monthly fee.

 

[bilby]

Top promote nuclear energy it was claimed it would be so cheap it would not be metered, you wouldpay a flat monthly fee.

Not quite. The suggestion was made by the AEC chairman, Lewis L. Strauss, in a 1954 speech in which he raised the prospect of the benefits that nuclear engineering could potentially provide. At the time of his speech, there was no nuclear energy to promote; He was trying to talk up the potential of a near future set of endeavours.

Our children will enjoy in their homes electrical energy too cheap to meter…Transmutation of the elements, unlimited power, ability to investigate the working of living cells by tracer atoms, the secret of photosynthesis about to be uncovered, these and a host of other results, all in about fifteen short years. It is not too much to expect that our children will know of great periodic famines in the world only as matters of history, will travel effortlessly over the seas and under the ground and through the air with a minimum of danger and at great speeds, and will experience a life span far longer than ours, as disease yields and man comes to understand what causes him to age.

He got pretty much all of this right; We now have all the things he predicted, apart from ultra-cheap electricity.

And of course, "too cheap to meter" meant something rather different in 1954, when metering meant paying a person to walk around to every property at least four times a year, writing meter readings on bits of card that were then collated by a small army of clerks (all of whom needed paying), converted to dollar amounts owed, typed up by typists (all of whom needed paying), and then mailed out to the customers. Metering was expensive in the 1950s. These days, a smart meter can send the amounts used to the utility's computer, which automatically sends out bills (often electronically), and can even directly debit the amount charged from the customers' accounts. It's much more cost effective to meter anything today, than it was back then.

"The nuclear power industry promised us electricity too cheap to meter, and they lied" is a gross canard, and factually incorrect on many levels.

Like so much of the received wisdom about nuclear power.

Such is the effectiveness of a seventy year propaganda campaign against the industry (which has been massively funded by fossil fuel companies).

 

[Bomb#20]

Saw that tritium was used for the reaction. Using tritium as a fuel would be terribly expensive. Like using tritium as a fuel.

You can breed tritium.

Line either a fission or fusion reactor with deuterium.

I.e.,

n + D -> T
D + T -> He + n
-------------------
n + 2D -> He + n

And that can work provided the efficiency of capturing neutrons in the deuterium lining is 100%. Which is about as likely as 100% efficiency lasers. If you capture only 90% you still need Steve's little fission reactor next to the big fusion reactor.

Of course the folks planning our future fusion economy have schemes in mind that might let us get around this problem, involving various further nuclear reactions of the general form n + X -> Y + 2n, where X is something we can mine. None of them are proven technology, but maybe they'll make a go of one or another candidate reaction. The folks at ITER plan to run tests on various proposals over the next few decades. But it looks to me like even if they make one of them work it will be more expensive and more polluting than just doing the obvious and putting a little fission reactor next to the big fusion reactor. The cynic in me suspects this issue isn't being taken more seriously because putting a little fission reactor next to the big fusion reactor has been the unspoken plan all along. I.e., everything bilby said in post #4 was right on the money.

Funny story -- the type of existing fission reactor that's best suited for making tritium is the CANDU; consequently nearly the entire world tritium supply comes from Canada. The CANDU reactors are aging and Canada doesn't intend to replace them when they reach end-of-life, so tritium is going to get quite a bit rarer and more expensive in a few decades.

 

[lpetrich]

The original press release: National Ignition Facility achieves fusion ignition | Lawrence Livermore National Laboratory - "LLNL’s experiment surpassed the fusion threshold by delivering 2.05 megajoules (MJ) of energy to the target, resulting in 3.15 MJ of fusion energy output, demonstrating for the first time a most fundamental science basis for inertial fusion energy (IFE)."

That's an energy ratio of 1.54 - energy return on investment (EROI). But as far as I can tell from that press release, that is only for the energy of the laser light that reaches the pellets.

NIF sets new laser energy record | Lawrence Livermore National Laboratory - "The NIF laser uses tens of thousands of large precision optical components, including lenses, laser glass slabs, mirrors and frequency conversion crystals to amplify and guide 192 laser beams to a small target in the 10-meter target chamber."

I haven't been able to find the efficiency of the superlasers that the National Ignition Facility uses, but I've found efficiency numbers for plenty of smaller - and more common - lasers.

Wall-plug efficiency, explained by RP Photonics Encyclopedia; electrical-to-optical, all-solid-state lasers - relative to the total energy consumption of the laser, including the lasing material itself, the light pumping for light-pumped systems, and the coolant system of high-powered lasers.

Laser efficiency - online book

Laser type	Wavelength	Efficiency
CO2	0.6 um	15%
He-Ne	0.6328 um	0.1%
He-Cd	0.442, 0.325 um	0.01-0.02%
Nd-YAG	1.06	0.1-2.0%
FEL	(wide range)	30%
Diode laser	0.7-1.5 um	20%

um = microns, YAG = yttrium aluminum garnet, FEL = free-electron laser

Wall-plug efficiency, explained by RP Photonics Encyclopedia; electrical-to-optical, all-solid-state lasers

Using the term in that common way, values of the order of 25% result for many diode-pumped laser systems (→ all-solid-state lasers), e.g. Nd:YAG lasers. Even values above 30% are possible, e.g. with thin-disk lasers based on Yb:YAG and efficient laser diodes. It is to be expected that within the next few years laser diodes could become even more efficient, further raising the wall-plug efficiency of such systems. Pure laser diode systems (→ direct-diode lasers) can reach the highest efficiencies, sometimes well above 60%, but they can not always be used, e.g. because of their poor beam quality and their inability to generate intense pulses. When using a high-power fiber laser as a brightness converter, one can obtain high output beam quality and (to some extent) intense light pulses, while the overall wall-plug efficiency can in the best cases be of the order of 50%. On the other hand, argon ion lasers, and even more so titanium–sapphire lasers and the like when they are pumped with argon ion lasers, generally have wall-plug efficiencies around or below 0.1%.

 

[Elixir]

Is there a theoretical lower limit to the mass of the pellet?

 

[Bomb#20]

Is there a theoretical lower limit to the mass of the pellet?

8.3 x 10^-27 kg.

 

[Elixir]

Is there a theoretical lower limit to the mass of the pellet?

8.3 x 10^-27 kg.

Seriously? less than the mass of a hydrogen atom?

 

[Bomb#20]

I haven't been able to find the efficiency of the superlasers that the National Ignition Facility uses, but I've found efficiency numbers for plenty of smaller - and more common - lasers.

They're about 0.7% efficient.

https://physicsworld.com/a/national...trates-net-fusion-energy-gain-in-world-first/

 

[Bomb#20]

Is there a theoretical lower limit to the mass of the pellet?

8.3 x 10^-27 kg.

Seriously? less than the mass of a hydrogen atom?

A deuterium atom and a tritium atom weigh 8.3 x 10^-27 kg. You must have found the hydrogen atom mass in grams, not kilograms.