[HN Gopher] Nuclear SMR welding breakthrough: A year's work now ...
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Nuclear SMR welding breakthrough: A year's work now takes a day
Author : geox
Score : 143 points
Date : 2024-02-21 16:31 UTC (6 hours ago)
(HTM) web link (newatlas.com)
(TXT) w3m dump (newatlas.com)
| V__ wrote:
| I'm really rooting for SMRs, but are there realistic projections
| on what the energy production costs will be?
| camel_gopher wrote:
| Latest on NuScale was 189/MW ($0.189/kW). More expensive than
| solar but here in CA 20 cents a kilowatt would be welcome
| bryanlarsen wrote:
| 77% of the cost of a kWh in California are fixed costs. So if
| production cost 19 cents, then your cost would be 19 cents +
| 77% of your current price + a few more cents for the profit
| on the production costs. IOW, it would increase your
| electricity bills.
| Twirrim wrote:
| While also getting you more reliable and consistent power
| generation than anything you'd get from Solar or Wind.
| bryanlarsen wrote:
| The unreliability of the California grid is almost
| entirely due to transmission, not generation.
|
| And nuclear is not a reliability panacea. Nuclear only
| has a 90% uptime, whereas the goal for power delivery is
| 99.99%.
| exe34 wrote:
| > The unreliability of the California grid is almost
| entirely due to transmission, not generation.
|
| I think describing night time as a problem of
| transmission is technically correct, but probably not the
| issue here.
| imtringued wrote:
| Since when does the wind stop blowing at night? You can
| play dishonest games and win dishonest responses.
| BenjiWiebe wrote:
| Not arguing the earlier points or saying this is relevant
| - but - here in Kansas, kinda known for it's wind, it
| usually dies down around sunset. We do get wind at night
| sometimes but we get a _lot_ more during the day.
| AnthonyMouse wrote:
| > Nuclear only has a 90% uptime, whereas the goal for
| power delivery is 99.99%.
|
| Nuclear in the US has a more than 90% uptime, and the
| downtime is scheduled maintenance, which is done at times
| chosen specifically because the load on the grid is known
| to be lower then, rather than being chosen by nature at
| random.
| cwmma wrote:
| I think one of the issues is just that for thermal power plants
| in general, there are big economies of scale, one big
| boiler/turbine/etc is better then multiple small ones)
| earthnail wrote:
| The one thing I still wonder is whether SMRs could create a
| security nightmare.
|
| Every nuclear power plant is a fantastic target for terrorists.
| Transports of nuclear waste are a fantastic target, too.
|
| I read once that the UK has many nuclear waste trains driving all
| the time, most of them empty, just to make it hard to guess which
| one to hit. (I assume other western countries have the same
| system). That kind of security doesn't scale well.
|
| How do you protect infrastructure with many SMRs?
| naasking wrote:
| Switch to a thorium fuel cycle so virtually all of the
| fissionable material is spent, rather than 90+% of it remaining
| in the waste.
| perlgeek wrote:
| Somehow, Thorium has been the future of nuclear reactors
| about as long as fusion has been. It's almost a running gag.
|
| (And yes, I know that there are concrete plans for commercial
| Thorium fission reactors, in a way that aren't for fusion,
| but still no fully-operating, commercial reactor, afaict).
| AnthonyMouse wrote:
| That's not really saying much given the number of new
| nuclear reactors of any fuel source the west has built in
| the current century. You have to build something in order
| to build something that runs on Thorium.
| LorenPechtel wrote:
| Just use breeder reactors.
|
| Somebody repurposing the plutonium? No. Plutonium is not
| plutonium. For a bomb you need Pu-239. The more Pu-240 in
| your material the harder it is to slam the pieces together
| fast enough to avoid a premature chain reaction from robbing
| your bomb of most of it's power.
|
| For both bomb-making and fuel breeding the desired reaction
| is U-238 + n => U-239, decays to Np-239, decays to Pu-239.
| There is also the reaction Pu-239 + n => Pu-240. The power
| guys don't care, Pu-240 works fine. The bomb guys do care.
| Thus the power guys leave the fuel in the reactor until too
| much neutron poison builds up. The bomb guys leave the fuel
| in the reactor only a short time.
| gadders wrote:
| Hire more of these people?
|
| https://www.gov.uk/government/organisations/civil-nuclear-co...
|
| "The Civil Nuclear Constabulary (CNC) is the armed police force
| in charge of protecting civil nuclear sites and nuclear
| materials in England and Scotland."
| credit_guy wrote:
| > Every nuclear power plant is a fantastic target for
| terrorists.
|
| It is not. Let's say you are a terrorist, and you and your team
| have taken hold of a nuclear power plant. Then what? It's a
| problem for the world, but not different from you taking over a
| hotel or a city hall. You might threaten or even kill hostages,
| but there's no way you can create a significant nuclear threat.
| Let's say you force an operator, at gunpoint, to remove some
| rods from the reactor, or otherwise you get possession of some
| nuclear material. So what? How are you going to get away? You
| will be surrounded by hundreds or thousands of SWAT officers.
| What is the scenario where it will make a difference if they
| take over the nuclear power plant vs a different building?
| naasking wrote:
| The point is that they could potentially abscond with nuclear
| material before being surrounded, obviously.
| inglor_cz wrote:
| Handling nuclear material straight out of the reactor is a
| good way to kill yourself very painfully.
| naasking wrote:
| Sure, but if we're talking about terrorists that a
| documented history of being willing to blow themselves
| up, I don't see why they wouldn't do this too. To avoid
| the painful death, blow yourself up after absconding but
| before radiation poisoning really takes its toll.
| throwway120385 wrote:
| We're talking about people with EG civil engineering
| degrees masterminding these plots. The middle-eastern
| terrorists of yesteryear are not necessarily uneducated.
| Osama Bin Laden was educated as an engineer in the US and
| likely would have thought through the endgame and
| implications of such a plot well before executing it.
|
| These people are not stupid and would likely know what
| they are getting in to. I'd be more worried about a
| single unhinged person, but that's why we have security
| guards, and the problem would likely solve itself in
| short order in that case.
| vlowther wrote:
| Terrorists willing to blow themselves up at a time of
| their choosing is the key there. With nuclear waste hot
| enough to be a menace, the window between getting the
| material and being painfully incapacitated and/or dead by
| the material is pretty damn small. Especially since
| nuclear plants tend to have things like lots of
| checkpoints and security.
| inglor_cz wrote:
| If you receive around 1 Gy in five minutes, you won't
| abscond very far. And you would likely receive a lot
| more. Not to mention that you would leave a trail of
| radioactivity from the reactor to your lair/hiding place.
|
| But it is well possible that some people could still
| _try_. The Four Lions, only in the real world.
| LorenPechtel wrote:
| Would it even be painful? Wouldn't the stuff from the
| reactor just kill you promptly?
| inglor_cz wrote:
| IDK how many real-world casuistics we actually have, but
| Wikipedia says that absorbed dose over 30 Gy results in
| severe headache, severe fever, nausea, vomiting and
| seizures, with death taking up to two days.
| hunter-gatherer wrote:
| Obviously. Good luck with that.
| andrewflnr wrote:
| Terrorists don't need to take over, they just need to plant a
| big enough bomb or hit it with a big enough plane that it
| causes a radioactive disaster. Not only do they not
| necessarily care about their survival, they might actively
| crave death.
| credit_guy wrote:
| > In the United States, the design and thickness of the
| containment and the missile shield are governed by federal
| regulations (10 CFR 50.55a), and must be strong enough to
| withstand the impact of a fully loaded passenger airliner
| without rupture.
|
| [1] https://en.wikipedia.org/wiki/Containment_building
| tuukkah wrote:
| Will this apply to SMRs?
| 3D30497420 wrote:
| My issue with thinking like this is that there are plenty of
| targets for terrorists: packed trains, stealing a big truck,
| etc. The fact that these events are pretty rare suggests that
| there aren't nearly as many terrorists as people seem to be
| worried about.
|
| Every power generation method has its plusses and negatives. I
| don't know if the risk from an SMR incident outweighs other
| methods, but it sounds promising. We certainly need an
| alternative to sources we know are bad (coal, oil, etc).
| psunavy03 wrote:
| Western society in general is a bunch of future cancer and
| heart disease victims all freaking out that they're going to
| die in a nuclear meltdown, or by the hand of a terrorist, or
| by a lone gunman "mass shooter," or in a plane crash, or any
| number of other threats that are scary but statistically
| highly unlikely.
|
| Human beings are just utter crap at intuitively estimating
| risk.
| throw0101c wrote:
| > _Western society in general is a bunch of future cancer
| and heart disease victims all freaking out that they 're
| going to die in a nuclear meltdown_ [...]
|
| Also, COVID (to round out the top three in many places).
| crowcroft wrote:
| I agree that people are bad at estimating risk, but I would
| also argue that the reason many people live long enough to
| become cancer victims is because of this freaking out.
| andrewflnr wrote:
| Cancer is the dominant risk of a nuclear meltdown or dirty
| bomb/explosion, yes.
| AnthonyMouse wrote:
| Compare the relative probability of dying of cancer as a
| result of a nuclear meltdown to dying of cancer as a
| result of cigarettes or chemical carcinogens.
| VyseofArcadia wrote:
| > there are plenty of targets for terrorists: packed trains,
| stealing a big truck, etc.
|
| The counterargument is that blowing up a train or stealing a
| truck usually doesn't poison the local area for generations.
| Higher risks means some consideration is due. If the stakes
| are higher but the probability is the same, the expected
| value is still higher.
|
| I for one don't want to live in a hellscape pockmarked by
| miniature exclusion zones.
| consumer451 wrote:
| If you look at it strictly from an economic POV, real
| estate is devalued near sources of fission. (and other
| power plants as well)
|
| The market has spoken on that matter.
| bigbillheck wrote:
| That sounds like a state actor thinking, not a terrorist.
| T_MacThrowFace wrote:
| what if they are actually one and the same
| chasil wrote:
| Ideally, the reactor is designed in such a way that a
| catastrophic failure is not possible.
|
| Something along the lines of the salt plug in a molten salt
| reactor, that melts when cooling fails and dumps the liquid
| into a boron bath, halting fission.
| areoform wrote:
| Getting to the material is mechanically difficult. It's also
| the type of problem that neatly solves itself.
|
| A fuel rod toting terrorist is a dead terrorist.
| > The acceptance criteria in DSRS Section 12.3-12.4 state that
| accessible portions of the facility that are capable of having
| radiation levels greater than 1 Gy/h (100 rads/h) should be
| shielded and clearly marked with a sign stating that
| potentially lethal radiation fields are possible. DCA Part 2,
| Tier 2, Revision 3, identifies a number of areas (e.g., resin
| demineralizers, filters, SRSTs) that may contain quantities of
| radioactive material resulting in radiation dose rates
| exceeding 100 rads/h (1 Gy/h).
|
| Now what I'm about to say changes with the fuel being used, but
| from LLNL's report, > Even for fuel that has
| cooled for 15 years, a lethal dose (LD50) of 450 rem can be
| received at 1m from the fuel assembly after several minutes.
|
| https://www.osti.gov/servlets/purl/10137382
|
| Good luck trying to carry that stuff out. They'll be the
| walking dead in a few minutes. They'll be unable to walk and
| will be just dead in ~100 minutes. Give or take 10 to 20
| minutes depending on how they're holding the item etc.
|
| https://en.wikipedia.org/wiki/Acute_radiation_syndrome#Dose_...
|
| And no, they can't just "put it in [a] lead [box]" to run away
| with it, because then they'll die to bremsstrahlung radiation
| or braking radiation. It'll take longer, but the end result
| will be the same.
|
| If it's fuel that hasn't gone into the reactor yet/hasn't
| undergone neutron activation, then it's not radioactive enough
| to be a concern unless consumed.
|
| Terrorists are rare and they're usually not that capable. It's
| easier for them to buy a gun or a lorry and mow down a crowd
| than it is to plan a fiendishly complicated radiation heist.
| giva wrote:
| I just want to point out that a terrorist that drives a plane
| into a skyscraper is a dead terrorist too.
|
| You need one terrorist to extract the material and put some
| quantities in a somewhat shielded container before being
| incapacitated, and then others to spread it on the subway.
| areoform wrote:
| Radiation isn't magic. Several feet/meters of water are
| used as shielding for the fuel for a good reason.
|
| If you put an activated fuel rod inside of a lead lunch
| box, you will still die. You will now die from a lethal
| dose of bremsstrahlung.
| https://en.wikipedia.org/wiki/Bremsstrahlung
|
| If you interact with this material as an amateur without
| processes, robotics and safety, you will die. Period. You
| will also suffer from intense nausea and be unable to move
| before you die.
|
| Sharks with lasers are more realistic than this concern.
|
| The more plausible scenario is a "dirty bomb" that spreads
| depleted uranium particles everywhere and gives people
| cancer long-term. But there's an element of impracticality
| to this and there's a reason why it hasn't happened yet.
| ViewTrick1002 wrote:
| Even tiny amounts of radioactive waste are dangerous over
| time.
|
| https://en.wikipedia.org/wiki/Goi%C3%A2nia_accident
|
| https://en.wikipedia.org/wiki/Kramatorsk_radiological_acc
| ide...
| lazide wrote:
| The issue they're pointing out is that no one seriously
| considered terrorists flying airplanes into skyscrapers
| either, for similar reasons.
|
| Until they did it.
|
| After all, it's very impractical getting a bunch of
| random terrorists training in flying well enough to do
| this without being caught.
|
| Let alone co-ordinating everything, getting through
| multiple layers of airport security, etc.
|
| And everyone 'successful' is going to die too. Who would
| do that?
|
| Historically, terrorists would just hijack a plane for
| attention and/or money and then let everyone go except
| for those stupid enough to fight them.
|
| Which is why the reaction onboard to the terrorists
| taking the planes was so muted, until a passenger on one
| of the planes heard the news of the first impact, and
| they realized they were in a very different situation
| than a hijacking for money.
|
| Not considering dirty bomb type issues a threat would
| likely be a mistake.
|
| Having a bunch of disposable idiots throw hot fuel rods
| into a water tanker truck, then driving to manhattan,
| seeding the water with cobalt-59, and letting the mess
| 'sort itself out' (or blowing the the truck up) certainly
| wouldn't be hard compared to 9/11 in these scenarios, or
| likely kill more than a handful of terrorists. Depending
| on how well secured the fuel was anyway.
|
| It would create an absolutely terrific mess though.
|
| The only hard part here would be getting the hot fuel
| (and the idiots), everything else would be 'COTS'.
|
| Which, like 9/11, would not be seen as 'expensive'.
|
| This isn't sharks with lasers territory.
| pas wrote:
| SMRs don't mean they would be scattered around
| carelessly. They still need the whole steam boiler
| turbine toybox. And with security requirements they will
| most likely be put on a site like current NPPs.
| lazide wrote:
| A big selling point in the SMR space is they can be
| placed almost anywhere. It's literally on the 'brochure'.
| hcknwscommenter wrote:
| the words "some" and "somewhat" are doing an impractical
| degree of heavy lifting. Pre-activation material is just
| not very radioactive and is thus not a terrorist risk.
| Post-activation material is basically impossible for a non-
| nation state actor to store and transport. If you just want
| to dirty up an area by, e.g., spreading radioactive
| material on a subway, just buy a lot of smoke detectors or
| do a midnight raid on a hospital or factory radiation
| source (not advice!). The point is, these are not going to
| be practical targets.
| LorenPechtel wrote:
| But even if the guy will die to steal it that doesn't mean
| he will live long enough to accomplish anything. And note
| that he's trying to tote around a gamma source--that's
| something that can be detected from some distance away. As
| soon as said terrorist gets it out from behind whatever
| shields it normally lives behind the alarms start blaring.
| I remember reading about one, anti-nuke guy kept showing up
| at meetings at a nuclear facility. Then one day the alarms
| go off--traced to the old radium-dial watch he was wearing.
| Rather silenced him.
| mytailorisrich wrote:
| I expect SMRs would be protected as standard nuclear plants
| are.
|
| Therefore, these are not easy targets and we've seen that they
| are very easy targets everywhere that will have the desired
| effect.
| ElectronCharge wrote:
| I like the idea of siting them underground, which completely
| addresses the aircraft strike vulnerability. Physical security
| is also easy when they're underground.
|
| Thorcon was pursuing this, but has switched to a ship-based
| approach.
|
| Searching today, I found a new (to me at least) company that's
| working on a truly small reactor, 3-15 MW electricity, and is
| planning on underground siting: https://www.usnc.com/mmr/
|
| It also supplies 10-45 MW of thermal, so great for poleward
| climes.
|
| Fission will be a critical technology going forward, until
| fusion generation can compete on power to size/weight
| ratio...and cost. And until aneutronic fusion power is
| practical, there's no large benefit to fusion regarding waste.
| jszymborski wrote:
| SMRs feel like a much worse target from what I understand.
|
| I'm no expert, but my understanding
|
| 1) SMRs are typically designed to be walk-away safe. Their
| smaller capacity means its harder for them to go critical in a
| spectacular way. [0]
|
| 2) Distributed targets are hard to respond to, but they're also
| hard to hit in an impactful way. Instead of having to hit one
| giant nuclear plant which supplies an entire regions energy,
| you have to hit many much smaller targets which supply much
| less energy.
|
| [0] https://www.forbes.com/sites/jamesconca/2018/01/24/can-we-
| ma...
| Retric wrote:
| Getting it critical is a long way from the worst thing you
| can do with access to one or more SMR.
|
| However, nobody is going to be using these things
| individually. You still need a steam turbine, and cooling
| tower etc. So the general assumption is people will be using
| 10+ of these things and the added complexity would be offset
| by economies of scale.
| AnthonyMouse wrote:
| > The one thing I still wonder is whether SMRs could create a
| security nightmare.
|
| People are going to tell you why this isn't a major concern,
| but the main reason it doesn't matter is that it doesn't
| matter. There are chemical poisons every bit as nasty as
| anything in a nuclear reactor which have a half-life of
| ~forever and aren't that hard to make or obtain. You can't
| prevent this because they're simple compounds made of common
| elements.
|
| People are afraid of nuclear because of its association with
| nuclear weapons, not because there is anything uniquely
| dangerous inside the reactor worse than things in chemical
| plants all over the place that nobody pays any attention to.
| lazide wrote:
| Eh, kinda.
|
| The chemical 'poison' equivalent to a hot fuel rod (if spread
| around) is probably roughly equivalent to a couple hundred
| liters of VX nerve gas or Sarin..
|
| Which, if not near anyone, isn't very dangerous! It will lose
| that strength pretty quickly, and the longer lived elements
| are more like a ton of PCBs, or several tons of organic lead
| compounds.
|
| Not great, don't live there, but with proper PPE it wouldn't
| kill you anytime soon.
|
| But if moved to a place where people are at and can't escape
| from, or smeared on something worth a lot of money, is a
| really big problem.
|
| If magnified (with say cobalt powder), it could be an even
| bigger mess.
|
| Hot fuel rods are very strictly controlled for a reason.
| AnthonyMouse wrote:
| It depends on what kind of damage you're trying to cause.
| Someone would use different chemicals for trying to kill a
| lot of people in one place immediately than trying to cause
| a large economic impact by filling the area with something
| expensive to eliminate that causes health problems. But the
| same is true of radioisotopes. The most immediately fatal
| ones have a short half-life and are only effective at that
| when concentrated rather than dispersed over a large area.
|
| If you have physical access to something with a high
| monetary value and you want to mess it up, chemical
| explosives do just fine and can be made from ordinary
| household substances.
|
| > Hot fuel rods are very strictly controlled for a reason.
|
| The main legitimate reason is that some existing reactors
| were purposely designed _not_ to poison the fuel with
| heavier Plutonium isotopes in a way that makes it
| unsuitable for producing weapons, because the countries
| wanted to use them for that, but that can be solved in
| newer designs by doing the opposite. The main political
| reason is media fear mongering and decades of Russian
| propaganda designed to keep people buying Russian gas.
| Which you can kill as many people with as you can with a
| fuel rod, but half the population has it piped into their
| homes.
| mlsu wrote:
| Nuclear material has the fantastic property that you can
| precisely measure the danger. Regardless of the specifics of
| the material, regardless of the geometry, size, surface
| coating, chemical composition -- a geiger counter will tell
| you exactly how dangerous the material is.
|
| There is this kind of weird thing that people do where they
| assume nuclear waste is uniquely dangerous. It isn't! We can
| just measure it, so the danger is perfectly legible. _This is
| a good thing!_ The rest of industrial waste is NOT like this.
| You can see studies of people who live in areas near oil
| refineries and chemical plants in Texas and Louisiana --
| population level cancer and birth defect rates are very high.
| It 's exactly as you say, bog standard "dangerous chemicals"
| are just as dangerous as nuclear radiation is. Only we can't
| measure them, so I guess what can ya do if a whole city gets
| birth defects or cancer?
|
| The double standard is actually wild. I would prefer to live
| next to a nuclear plant, thank you very much. I can get a
| geiger counter and know if I'm being poisoned.
| rich_sasha wrote:
| You can still put them on a small few sites, with heavy
| security. You will still reap the yet-to-be-demonstrated
| benefit of cheaper per-MW power (personally I'm hopeful).
| Cthulhu_ wrote:
| Why does it take 12 months to weld these things in the first
| place? The article doesn't say anything about that, and I can't
| intuit why it would take that long in the first place.
| BryanLegend wrote:
| Might have be a foot thick wedge that was filled one bead weld
| at a time.
| 3D30497420 wrote:
| That's my issue with articles like this. It sounds pretty
| great, but it provides barely any context. The quote at the end
| is a quote from the company's project lead, which sounds like
| it was taken from a company press release. So, yay?
|
| Edit: The quote actually was taken from a news release. See:
| https://www.sheffieldforgemasters.com/news-and-insights/news...
| practicemaths wrote:
| I'm not a welding engineer.
|
| I imagine half of it is checking the welds are to code and
| certifying it.
| djaychela wrote:
| My (albeit short and 30+ years ago) experience in the nuclear
| industry as an apprentice would lead me to believe that it's
| about quality control and inspection as well as it probably
| being a long-winded task if the pressure vessel is 8 inches
| thick. I'd think it would need to be entirely welded at that
| depth, with each weld pass being X-ray inspected.
|
| Everything I did when briefly working in a reactor (3 months of
| my 4 years) took a LOT of time because of safety checks and
| routine.
| magicalhippo wrote:
| Sounds like my buddy who's a programmer for our social
| services. He said they spend about one day per week coding
| and the rest doing code reviews.
| godelski wrote:
| That sounds better than what my buddy who worked at
| Microsoft did, where he said he programed probably <10hrs a
| week and spent more time in meetings.
| asdff wrote:
| The luxury of having 10 hours a week to code
| lifeisstillgood wrote:
| You call that luxury! When I was a lad we were put into a
| cardboard box on the middle of t'motorway, made to code
| an entire distributed database in our lunch hour, and if
| we had less than 100% coverage the project manager would
| cut us into little pieces and dance on our graves.
| T_MacThrowFace wrote:
| you had graves?! in my day management would sell our
| organs on the black market and feed the rest of our
| corpses to the HQ lobby piranha aquarium, though they'd
| still charge our estates for the tombstone retainer of
| course.
| godelski wrote:
| You had piranha tanks? Back in my day our managers just
| threw us in a empty concrete room with no windows and no
| outlets, tossed a computer at us and said "fix it". If we
| were lucky they'd say what "it" was. If we were extra
| lucky, they'd throw us a keyboard. Not that that mattered
| anyways.
| tommiegannert wrote:
| It's good that machine learning is taking over the coding
| part, so we can focus all our engineering efforts on
| meetings...
|
| Personally, I'd love to use machine learning to automate
| the meetings instead.
| godelski wrote:
| And then all the meetings are about how you make time for
| resolving all the bugs introduced by copilot. But you
| can't cancel any meetings, so you need to create a new
| meeting because it is a new issue. And copilot is cheap
| so why not just buy more compute time? Surely that's
| cheaper because humans and machine solve problems in the
| amount of time and to the same degree of satisfaction,
| right? We should probably schedule a meeting so we can
| make a project to find out. We can probably find out if
| we measure the number of lines of code each can write.
| It'll be easy.
| gumby wrote:
| I once worked with a guy who had his nuclear ticket, on a team
| of welders working on high pressure steam and pressure vessels.
| Even many of the steam welds had to be x-rayed and he said the
| nuclear process was more intense, not just testing but
| technology and performance.
| solardev wrote:
| What's a "nuclear ticket"?
| gumby wrote:
| Means he had a certificate that showed he was considered
| (by the US navy in this case) competent in making welds
| suitable for building or repairing a nuclear reactor or
| related devices.
|
| We didn't need that, of course, but because high pressure
| steam is so dangerous we used only union welders who were
| rated master and who already had experience in steam
| plumbing. I don't remember if there was a special ticket
| for that, but everybody we hired was interviewed and had to
| do some welding as a part of it (the equivalent of a
| leetcode test on the whiteboard I suppose). If it isn't
| obvious: I was not qualified to usefully interview any of
| them.
|
| These guys were great to hang around with. go have a beer,
| horse around, etc with but wow, when they were on the clock
| all of them (machinists, etc too) were deadly serious. No
| fucking around.
| lukan wrote:
| "when they were on the clock all of them (machinists, etc
| too) were deadly serious. No fucking around."
|
| Sounds like true professionals. There is no fucking
| around with serious work, when real lifes depend on it. I
| wish, more people had that attitude, then there would be
| less mess everywhere.
| Baeocystin wrote:
| I used to work at a shipyard as a welder. The zero-
| bullshit professionalism when it was go time was
| genuinely satisfying to be working in: there was no way
| someone could fake their skill- literally everyone I
| worked with was competent.
|
| If it weren't for the _literal_ toxic working
| environment, I 'd be tempted to quit tech and return!
| saltcured wrote:
| Hah, an old family friend related a welding interview
| story on the other end of the spectrum.
|
| He had been working as a machinist and welder for BART,
| on a mixture of road and rail car maintenance as well as
| other fixed infrastructure work. He interviewed for a job
| at Lawrence Berkeley Laboratory, but was intimidated when
| they asked him to "weld some gold tissue paper".
| saintfire wrote:
| I'm not in this field, but in trades tickets are technical
| certifications (e.g. journeyman ticket, fall arrest ticket)
|
| Presumably its a certification to weld on or around nuclear
| equipment.
| araes wrote:
| In America, they're all based on the American Society of
| Mechanical Engineers (ASME) Boiler and Pressure Vessel Code
| (BPVC). It covers all the different types of nuclear
| certifications for organizations, because normal welding
| certs don't cover the nuclear industry.
|
| The "nuclear ticket" for most is probably:
|
| > NPT - Fabrication of parts, appurtenances, welded tubular
| products and piping subassemblies
|
| From ToughNickel [2]:
|
| > BPVC Section IX outlines the brazing and welding
| qualification procedures for nuclear pressure vessels.
| Section IX also gives the welding and brazing
| qualifications required to work on equipment for use around
| nuclear reactors. Welders must be qualified per the
| procedures listed in paragraph NCA-5250.
|
| Also, appurtenances up above, not actually a typo.
|
| [1] https://www.asme.org/getmedia/eaacef3f-e8b5-44a4-b0c6-4
| 51e1e...
|
| [2] https://toughnickel.com/business/Nuclear-Welding-
| Certificati...
| sandworm101 wrote:
| Welding stuff at this scale/depth takes time. It isn't just
| inspections either. There is lots of prep work. Sometimes the
| material itself has to be pre-heated/cooled in order to prevent
| warps/cracks in huge blocks of metal. But, for the same
| reasons, that preheating itself cannot be done too quickly.
| Multiply this by hundreds or thousands of weld lines and 12
| months doesn't sound so long.
| MichaelZuo wrote:
| Why does there need to be 'hundreds or thousands of weld
| lines'?
| lazide wrote:
| Typical welding can only safely deposit a certain volume of
| metal at a time due to physics constraints.
|
| Either the puddle gets too large and sags, or flux needs to
| be removed between passes, or the work piece needs to be
| moved with a certain speed/force that doesn't scale, or the
| heat can only be deposited on a single surface at a limited
| rate, which causes problematic distortion and limits
| penetration.
|
| Welding a 6" thick piece of anything with stick/tig/mig may
| take dozens or even hundreds of passes depending on
| geometry, material, available welding positions, etc.
|
| Welding the same thing with stir welding may take 100+ or
| even 1000+ tons of pressure in a moving weld fixture.
|
| And because of that, will also cause major distortion to
| the part unless done very carefully.
|
| Electron beam welding doesn't have many of these issues
| because the electron beam doesn't get absorbed in a point
| at the surface (and the beam can be very narrow), allowing
| very deep penetration compared to something like an
| electrical arc, also allowing a lot less total heat input
| to get the welded spots to fuse, and that also means weld
| joint shapes can be used that won't need filler metal being
| added, or movement, it doesn't have puddle size issues or
| flux removal problems (necessarily). Due to the lower total
| heat input, it also wouldn't have as significant distortion
| effects.
|
| The internal tension/distortion created from welding heat
| can be really mind blowing - we're talking enough to twist
| automobile frames into pretzels if not done correctly, or
| rip apart armor plating and heavy machinery joints just
| from the act of cooling.
|
| It also doesn't have force scaling issues like stir welding
| (generally).
|
| It would require completely, perfectly clean surfaces and a
| non-reactive environment, and clearance for the beam
| emission equipment though.
|
| Pretty neat overall!
| kstrauser wrote:
| I would like to subscribe to your newsletter.
|
| Thanks for that fascinating explanation!
| agumonkey wrote:
| Not sure if this applies, but IIRC some welds are embedded in
| complex structures that require only very skilled workers...
| and sometimes only a left handed guy can access the surface.
| CamperBob2 wrote:
| Talk about ambiguous headlines. I thought this was going to be
| about using nuclear energy for welding.
| opwieurposiu wrote:
| There are more details and a video of the welder here:
|
| https://camvaceng.com/electron-beam/ebflow/
|
| It has a mini-vacuum chamber on the welding head so you can
| e-beam weld large workpieces without needing a large vacuum
| chamber.
| senectus1 wrote:
| thats some pretty cool engineering
| m3kw9 wrote:
| Can someone help visualize what is being welded?
| waldothedog wrote:
| Someone else might have more detail, but I believe these are
| "basically" massive metal tubes that are created by building up
| welds, one on top of the other, to achieve extremely high
| integrity structures for containing nuclear fission.
| mikece wrote:
| One of the benefits often cited (and it is again in this article)
| is that SMRs allow for electrical generation to be located
| extremely close to where it will be consumed, avoiding line
| losses on the transmission grid. How significant are the line
| losses for a plant that is 100 miles from where the electricity
| is being consumed?
| ahmedfromtunis wrote:
| I did a paper on this back at engineering school around 10
| years ago.
|
| I forgot most of the details, but iirc the losses can be up to
| 33% in certain conditions (mostly cold weather).
| mikece wrote:
| Worse in cold weather? I thought conductors get more
| efficient the colder they get (or is cold relative to humans
| insignificant to high voltage lines)?
| ahmedfromtunis wrote:
| I forgot the details but I remember it's something about
| humidity in the air.
|
| I recall however that I read about a blue halo forming
| around some cables in snowy nights as electricity charges
| the air surrounding said cables.
|
| This phenomenon was a huge source of losses in transport
| cables.
| tnorgaard wrote:
| Viking Link, the 765 km HVDC (VSC-based) link rated at 1400 MW
| between England and Denmark has a rated loss at 3.7% [0].
|
| [0] https://www.viking-link.com/auction-faqs
| LorenPechtel wrote:
| Can't address it overall but some while back I did some
| calculation on shipping power around the world from wherever
| the sun was shining. I took the real-world numbers for the
| biggest transmission lines--and found the only question being
| how many nines on the loss percentage.
|
| You are fighting two separate forces. Some of the energy is
| lost to heat in the wires, this is minimized by making the
| voltage as high as possible--but the higher the voltage the
| more corona loss there will be.
| apendleton wrote:
| At least in a US context, the proximity advantage is often less
| about line losses than about the political realities of
| building transmission. We have way less transmission in the US
| than we're expected to need as we electrify, and the right-of-
| way acquisition, permitting, etc., to build new high-voltage
| transmission are really daunting. NIMBYs tend to hate it
| (somewhat understandably -- it's ugly), and every jurisdiction
| along the path of the proposed new line typically has its own
| permitting process which effectively grants it veto power
| (unlike gas pipelines, interestingly, where the federal
| government has permitting authority that supersedes local
| authority).
|
| A big potential advantage of these kinds of solutions is that
| you can just site the plant such that you can avoid building
| the transmission at all. Of course, nuclear obviously has its
| own NIMBY concerns, permitting issues, etc., so it's not a
| panacea.
| boxed wrote:
| Seems like this tech could be very relevant to SpaceX too...
| SubiculumCode wrote:
| Security against malevolent actors? Having reactors everywhere
| seems like an invitation for disaster...
|
| edit: i am pro clean power and i believe nuclear waste can be
| stored safely; I just don't want to put town's at risk via under
| secured nuclear facilities.
| XzAeRosho wrote:
| One could argue that large reactor plants make for easier
| targets since the surface area of attack vectors is much
| larger.
| SubiculumCode wrote:
| One might also argue that 1000 units versus 1 (guessing)
| would be harder to keep track of.
| temp0826 wrote:
| >> potentially taking high-cost welding processes out of the
| equation
|
| I wonder what kind of cost they're talking if a high-powered
| electron gun and vacuum chamber are cheaper
| ActionHank wrote:
| 12 months of labour I'm assuming
| ajcp wrote:
| The vacuum chamber *is* part of the electron gun; it's
| essentially on the end of the "barrel" to create a vacuum just
| at the spot of the weld.
| peter_d_sherman wrote:
| >"Using conventional techniques, this can take over a year, but
| Sheffield Forgemasters have reduced this to under a day using
| what is called Local Electron-Beam Welding (LEBW) to complete
| four thick, nuclear-grade welds.
|
| LEBW is a revolutionary method to weld two pieces of metal
| together using a high-energy density fusion process centered on a
| high-powered electron gun operating in a local vacuum. This melts
| and fuses components to one another and allows for an efficiency
| of 95%, deep penetration, and a high depth-to-width ratio."
|
| Never heard about this before... let's learn more about it!:
|
| https://en.wikipedia.org/wiki/Electron-beam_welding
|
| Apparently you first need a vaccuum chamber to prevent energy
| dissipation... that sounds about right...
|
| But then we find this interesting quote:
|
| _> "Magnetic lenses can shape the beam into a narrow cone and
| focus to a small diameter. This allows for a high power density
| on the surface to be welded."_
|
| Now that's super-cool!
|
| (Or, well, _super-hot_ -- as the case may be! :-) )
|
| Then there's this:
|
| _> "The beam can then be redirected to meet the needs of
| applications beyond welding such as surface hardening, annealing,
| exact beam positioning, imaging, and engraving. Resolution of 0.1
| mm can be achieved."_
|
| Now that is truly useful!
|
| It seems like this would be an excellent technology for creating
| future space stations, spaceships and other deep-space vehicles,
| of one form or another...
|
| Anyway, great article!
| LorenPechtel wrote:
| And it sounds like something that would be practical to use in
| space.
|
| Normally you either burn fuel (and lifting said fuel is very
| pricey!) or you use an electric arc--but your arc won't work in
| vacuum.
| datadrivenangel wrote:
| The Soviet Union and USA have used electron beam and laser
| welding in space [1].
|
| 1. https://ntrs.nasa.gov/api/citations/20200002259/downloads/
| 20...
| codersfocus wrote:
| How high powered? This sounds like a CRT display.
| lchengify wrote:
| If you're interested in a visual of how different welds interact
| with the metal, I watched this video on SpaceX's Starship welding
| that was helpful [1].
|
| Something I try to remember is that most non-organic materials
| gain their properties from a precise lattice structure. This
| often doesn't come across when looking straight at the chemistry
| equations. Welding both disrupts and rebuilds this lattice
| structure, which is why it requires so much skill to do at
| volume.
|
| [1] https://www.youtube.com/watch?v=CP8Hbr2jL_c
| demaga wrote:
| I jumped to 3:16 and was very confused for a moment.
| barryrandall wrote:
| 1 reactor per day would double the number of reactors in the
| world in less than 18 months. Can we generate enough people
| qualified to run them without compromising safety?
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