Hacker News Reader

Comment by cstross | Hacker News Reader

The key point about NIF is buried way down in the article:

But the NIF was never “about” societal energy. Its primary purpose is nuclear weapons research. This pesky thing called the nuclear test ban treaty means we can’t just go around detonating nuclear bombs whenever we feel like it. Surely we did not run out of South Pacific island paradises to blow to smithereens. The NIF allows study of matter at extremely high energy density.

NIF was built by the Lawrence Livermore National Laboratory, a weapons research and development lab established during the Manhattan Project. Talk of laser fusion as a viable path to commercial fusion reactors is propaganda intended to further the budgetary aims of the nuclear weapons industry. The realistic path to fusion power lies through magnetic confinement reactors (eg. ITER, Wendelstein-7X, etc.)

View on HN

I don't know why there is any doubt about that. Maybe it's only because I am older and was DoE-adjacent in the relevant timeframe, but I distinctly recall the pitch for funding NIF was 100% pure weapons. They even wrote it down:

https://www.osti.gov/biblio/50733

""" The National Ignition Facility (NIF) will enable us to produce energy densities (energies per particle) that overlap with the energy densities produced in nuclear weapons, yet the total energy available on NIF will be a minuscule fraction of the total energy from a weapon. This combination of low total energy with weapons-regime energy density will allow us to pursue, besides ignition experiments, many nonignition experiments. These will allow us to improve our understanding of materials and processes in extreme conditions by isolating various fundamental physics processes and phenomena for separate investigation. Such studies will include opacity to radiation, equations of state, and hydrodynamic instability. In addition to these, we will study processes in which two or more such phenomena come into play, such as in radiation transport and in ignition. Weapons physics research on NIF offers a considerable benefit to stockpile stewardship, not only in enabling us to keep abreast of issues associated with an aging stockpile, but also in offering a major resource for training the next generation of scientists who will monitor the stockpile. """

I was looking around for news about the current state of operations at JET when I found this article https://physicsworld.com/a/ignition-pending/ which repeatedly muddles fusion power research and fusion weapons research. (Never mind the several paragraphs about the cold fusion idiocy.) And this is in a publication that is supposed to be for a technical and knowledgable audience. Sigh.

Anyway, in recent years at JET they have been doing a new round of deuterium-tritium experiments. The interior of the reactor has been refurbished with tungsten and beryllium inner surfaces, like ITER will have, and they have been testing longer reaction pulses. Sounds promising https://physicsworld.com/a/fusion-energy-record-smashed-by-j...

I don't know if you've heard much about Tokamak Energy; https://en.m.wikipedia.org/wiki/Tokamak_Energy

I think they have a good shot at commercial fusion by 2030s. The REBCO magnets reduce the size and complexity of the machine massively. Oddly, Brexit is a benefit to them; JET employees can no longer go work for ITER if they want a pay and lifestyle upgrade, but they can go a few hundred meters down the road.

> NIF was built by the Lawrence Livermore National Laboratory, a weapons research and development lab established during the Manhattan Project.

Isn't this wrong? LLNL was an 1952 off-shoot of Lawrence Berkeley National Lab, which in turn was founded in 1931. LLNL was not established during or by the Manhattan project, which ended in 1946.

> [Lawrence Livermore National Laboratory] was originally established as the University of California Radiation Laboratory, Livermore Branch in 1952 in response to the detonation of the Soviet Union's first atomic bomb during the Cold War. It later became autonomous in 1971 and was designated a national laboratory in 1981.

https://en.wikipedia.org/wiki/Lawrence_Livermore_National_La...

> [Lawrence Berkeley National Laboratory] was founded on August 26, 1931, by Ernest Lawrence, as the Radiation Laboratory of the University of California, Berkeley, associated with the Physics Department.

https://en.wikipedia.org/wiki/Lawrence_Berkeley_National_Lab...

> Although the Manhattan Project ceased to exist on 31 December 1946, the Manhattan District was not abolished until 15 August 1947

https://en.wikipedia.org/wiki/Manhattan_Project#After_the_wa...

I don't think ITER will ever be completed.

They have delayed the announcement of the delay, but it's expected to be another 5+ years.

It's the most complicated machine ever built, with each part built by a different firm in a different country for political reasons. The first vacuum vessel sector installed was corroded. Korea used steel that didn't meet the specifications. 8 more sectors from four different nations to go, each one could bring its own 5 year delay. Or maybe they don't find any issues on the inspections but only find a leak after the whole machine has been assembled.

Maybe a dumb question, but what is the point of continuing nuclear weapons research?

Isn't the research basically done, as in "we can build big enough bombs to annihilate whatever we want"?

Good question!

Existing nukes degrade due to various factors such as the natural radioactive decay of the uranium and plutonium they’re made of. Supercomputers are used to simulate this and make predictions about reliability, remaining lifetime, etc…

When it comes time to refurbish old bombs, ideally they should have the cores reprocessed into new, modern designs with better safety, reliability, and less fallout when they go boom (better efficiency).

All of this requires measurements, simulations, tests, etc…

In the past it was done with experiments on complete bombs, now it’s done with experiments on just small subsets that don’t go boom in the desert.

That makes me wonder whether it would be feasible to build a bomb type reactor. Detonate a hydrogen bomb in an underground lake 10km down, then extract the steam over the next few days.

If you've got a 10 KM tunnel bored into the earth you could just build a geothermal power plant and not need the nuclear aspect at all.

They did consider using nukes as a fracking device to aid in geothermal power plants: https://en.wikipedia.org/wiki/Project_Plowshare#Proposed_nuc... (near the bottom of the list)

You have described "Project PACER". It turned out not to be economical.

... and the first net gain result and headline just so happened to coincide with the renewal of their gov grant.

That "net gain" comes with a lot of a caveats. 400MJ to produce a 2.1MJ laser burst that resulted in 3.5MJ of fusion out is pretty far from a total net gain.

What would be the advantage of a bomb built out of this technology as opposed to an H-bomb?

How do you know it's not the other way around:

That they're using the gigantic piggy bank of the military to fund actual fusion research?

I agree that ICF doesn't seem like a winning strategy. But surely it's not complete waste, either, right?

You can't build a bomb using this technology. Period.

But you can achieve plasmas of equivalent density and temperature to those you get in an H-bomb explosion, which is invaluable to weapons researchers if they're not allowed to actually detonate any bombs.

It sounds like you know, so I'm curious...

Why is it so valuable to create those temperatures for researchers?

There's also the angle that it's just something for the researchers at that lab to do, gives them a purpose. And in exchange, the US has a perpetually well staffed nuclear weapons research lab.

Reply on news.ycombinator.com