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I've had friends that served on nuke subs. It still blows my mind that a sub only needs to refuel once every 15 years. I never understood the argument nuclear

• chihuahua 4y ago
  I agree in principle, but I am not aware of any nuclear powered battleships. Iowa class BBs have steam turbines running on fuel oil.
  • frozenport 4y ago
    aircraft carriers?
    • MichaelCollins 4y ago
      All of America's supercarriers have been nuclear powered since the USS Kitty Hawk was decommissioned in 2009. But if you include "amphibious assault ships" like the Wasp class, which can carry a lot of helicopters and STOVL airplanes like the F-35B and Harrier, then US Navy still has a lot of conventional powered carriers.
  • squidlogic 4y ago
    Correct me if I’m wrong haven’t Iowa class battleships all been decommissioned sometime in the early 1990s?
    • jasonwatkinspdx 4y ago
      Yes, and it was a colossal waste of money keeping them running even that long. Realistically they should have been scrapped in the period after the Korean war.
      • ncmncm 4y ago
        It has been proposed that the reason the battleships were in Pearl Harbor was so they would be the ships sunk when the Japanese attacked. The aircraft carriers were all far out to sea. Whether this is true, it shows that the obsolescence of battleships (since aircraft carriers came on line) was recognized well before WWII.
        • pfdietz 4y ago
          Pearl Harbor converted the US in the Pacific from a 17 knot navy to a 25 knot navy. We did get five of the eight battleships back (although some were basically cored out like a rotten tooth and rebuilt almost from scratch.) Two ships were left there (Utah and Arizona). Oklahoma was raised mostly to free up its slot in the harbor, but sank in 1947 while being towed to San Francisco Bay to be scrapped. The BB's role in the Pacific War was as AA platforms and for shore bombardment.
  • shawabawa3 4y ago
    He's technically correct. All zero of the US navy's battleships are nuclear powered
    • chihuahua 4y ago
      The best kind of correct!
  • MichaelCollins 4y ago
    Not battleships, but America did have several nuclear powered cruisers which lasted around 15-30 years (but all were decommissioned in the 90s.) They weren't battleships, but that term is sometimes used colloquially to refer to any surface warship other than carriers. https://en.wikipedia.org/wiki/Nuclear-powered_cruisers_of_the_United_States_Navy https://en.wikipedia.org/wiki/Nuclear-powered_cruisers_of_th...
    • mLuby 4y ago
      > but that term [battleships] is sometimes used colloquially to refer to any surface warship other than carriers Really? I wouldn't be surprised to hear someone call a frigate a cruiser or a littoral combat ship a destroyer or an amphibious assault ship a carrier but everyone knows battleships are the biggest big-gun ships out there.
      • MichaelCollins 4y ago
        I think so, at least for some people who don't have an interest in military stuff or machines generally. Similar to the way any armored but unarmed truck may sometimes be called "a tank." (https://duckduckgo.com/?t=ffab&q=police+tank&iax=images&ia=images https://duckduckgo.com/?t=ffab&q=police+tank&iax=images&ia=i...) I try not to judge, I'm probably equally wrong without knowing it about things as far outside my area of interest.
      • kelnos 4y ago
        I would not be surprised if many people who don't have knowledge of naval vessels would use "battleship" as a generic term for "surface naval vessel". A possible driver of this could be the "Battleship" game. I would also not be surprised if there were many people who'd never heard the terms "destroyer" or "cruiser".
        • josephcsible 4y ago
          But the "Battleship" game has five different kinds of ships, only one of which it calls a battleship, and it does include cruisers and destroyers.
  • deleted 4y ago
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• hutrdvnj 4y ago
  I think if Chernobyl happens on the open sea, then it's not very dangerous, but if you imagine nuke aircraft crashes in dense populated areas.
• nradov 4y ago
  Only a small fraction of the US Navy's fleet is nuclear powered, specifically just the submarines and carriers. Their last battleships were decommissioned many years ago, and those were all conventionally powered. The Navy did build a few nuclear powered surface warships decades ago, but that was largely a failure due to high costs and operational limitations; they don't plan to build any more.
  • indymike 4y ago
    What really killed the CGNs (nuclear powered destroyers) was VLS (vertical launch system) and AEGIS - the sensor suite that newer Navy destroyers and cruisers are built around. CGNs were all built around magazine fed rail-style missile launchers, and sensors were all designed when state of the art was a transistor. Refitting ships to modern sensors like AEGIS and modern VLS was almost a complete rebuild. Even early Ticonderoga class conventionally powered cruisers (CGs) that had rail launchers were retired early because of the cost of refit to VLS. Incidentally, VLS allows for much faster deployment of missiles, and doesn't require deck space for different launchers for different missiles, and a ship with a modern VLS have a huge rate-of-fire advantage on older rail launcher equipped ships.
    • DougWebb 4y ago
      That may have been the reason for mothballing the old ship designs, but why weren't the new ones nuclear powered? That seems to be independent of the missile launcher design.
      • nradov 4y ago
        Mainly for cost reasons, plus nuclear reactors also take up more space and can't accelerate quite as rapidly compared to modern gas turbines. If the Navy ever decides to build a new cruiser class to replace the old Ticonderogas then it might be worth considering nuclear propulsion, but realistically the budget just isn't there to make it happen. The Navy can barely afford to provide enough qualified crew for their existing few nuclear vessels.
      • 4y ago
• oceanplexian 4y ago
  The fact is we could be doing a heck of a lot of cool things, if it weren’t for the anti-nuke crowd that set the technology back 20-30 years. Imagine a world where economies of scale bring nuclear power down to the cost of fuel and maintenance. EVs would be a no brainer Natural gas would be obsolete. Nuclear desalination would completely solve the water crisis in the US West. I’m confident that with advances in material science we would figure out how to build safe nuclear aircraft and nuclear rockets, ushering in a new space age. Really the possibilities are incredible. It would be the equivalent of humanity going from horse and buggy to using fossil fuels, but another order of magnitude.
  • runarberg 4y ago
    This is wishful thinking. France for example never had a Three mile island type of disaster which tilted the public opinion of nuclear power, like the USA did. They continued building up their nuclear power plants well into the 1990s but failed to bring construction costs and delays down like your comment suggests. In fact if we take Germany as a counter-example, when they stopped building nuclear power plants due to popular demand, they significantly increased renewable energy to a point where they are currently replacing coal power at a greater rate then France, despite Germany actively shutting down nuclear plants that still had years of life left. This shows that Nuclear power might actually be a hindrance towards an electrified future, as governments have historically put to much faith in it, which was ultimately unwarranted, instead of investing in renewables. EDIT: I feel like people are focusing on the wrong point here. I was apparently—and unintentionally—disingenuous by touting Germany’s success in replacing coal power with renewables, as compared to France. However, my main point still stands, that investing in nuclear well into the 1990s did not bring costs and delays of new plants down.
    • jjoonathan 4y ago
      > governments have historically put to much faith in it If we (US) hadn't stopped building nuclear in the 80s and had instead merely key up the pace, our grid wouldn't be 20% nuclear like it is today, it would be 100% nuclear. Instead, we made the choice to pump 20 gigatons of carbon into the atmosphere while we waited for solar and wind to become viable. I'm glad they finally are -- they just broke into double digits, in a few years they will pass the nuclear buildout we stopped in the 80s -- but that was one helluva waiting cost.
• deleted 4y ago
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• bobthepanda 4y ago
  The military has a much lower bar for safety though, given all the incidents around chemical poisonings and pollution like soldiers getting exposed to Agent Orange in Vietnam or burn pits in Iraq and Afghanistan.
  • Manuel_D 4y ago
    And yet despite they lower bar, there have been no nuclear accidents. Perhaps the NRC's bar for nuclear safety is needlessly high. A realistic safety regime needs to weight the risk of accidents with the immense risks of continued carbon emissions.
  • tragictrash 4y ago
    The military has a lower bar for taking responsibility for those it views as disposable.
  • kylemh 4y ago
    does that not simply further the point of the post you responded to? despite lower standards, they've had no incidents
  • mwattsun 4y ago
    The Nuclear Navy has an extremely high bar for safety, hence no nuclear accidents. Unlike the Air Force apparently, which sometimes loses hydrogen bombs. Go Navy! https://www.google.com/search?q=air+force+lost+hydrogen+bombs https://www.google.com/search?q=air+force+lost+hydrogen+bomb...
    • MichaelCollins 4y ago
      The US Navy has fumbled a few nuclear bombs too (from airplanes and also submarines), their impeccable safety record is for nuclear reactors specifically. They've lost two nuclear powered submarines, but neither of those was due to reactor problems.
      • formerkrogemp 4y ago
• andbberger 4y ago
  we really oughta let the navy run the power grid
  • NavinF 4y ago
    My libertarian knee jerk reaction was “fuck that”. But then again, it can’t possibly be worse than PG&E so... sure why not.
  • collinmanderson 4y ago
    Yeah, they should get vehicle-to-grid capability.
• runarberg 4y ago
  I don’t think the US military is a positive example of safe usage of nuclear. First the Hanford nuclear site in Washington is one of the most polluted site in the entire state. The cleanup effort is the regions biggest employer and is costing the local communities, the state, and the federal government millions of dollars every year. The Bikini Atoll in the Marshall islands is one of the most polluted places in the pacific ocean. The US military conducted nuclear testing around there and simply swept the pollution in one place. There are dozens of reports of cancer from both former military personnel an nearby local population. And concerns are rising with elevated sea level that pollution will be leaking at greater pace then currently. These are just two examples of the US military neglecting safety concerns with their nuclear technology. There is no single spectacular event like the Chernobyl disaster. But rather decades of neglect and disregard to public safety which polluted many areas leaving potentially an overall damage on par—and potentially greater—then the Chernobyl disaster.
  • titzer 4y ago
    You're saying that nuclear testing produces a lot of radioactive fallout? Yeah, it does. This is absolutely not the same thing as operating a nuclear reactor.
    • runarberg 4y ago
      Hanford had nuclear reactors. But that is despite the point. Their safety record with nuclear is horrendous. Full of examples of neglect and pollution. I’m not an expert in the nuclear history of the US military, but I wouldn’t be surprised that many of their smaller reactors have similar stories as Hanford. It is just not as spectacular—and therefor not as much in the public consciousness—as Chernobyl.
      • smegger001 4y ago
        yes they had reactors that were shutdown clear back in the 70s for being to old of design.
  • smegger001 4y ago
• mikewarot 4y ago
  >I never understood the argument nuclear power is so "dangerous". Oil companies paid to form that opinion in the public. >no Chernobyl Chernobyl was the result of a HIGHLY unauthorized, and stupid experiment... phenomenally stupid. So many red flags were driven past at high speed.
  • czstar 4y ago
    I believe you are wrong about the causes of the Chernobyl disaster. The consensus these days is that it was due to poor reactor design.
    • baobabKoodaa 4y ago
      Many causes can be attributed to the disaster.
    • XorNot 4y ago
      That's taking a blameless post-mortem approach which is a valid tool, but not the entire answer. The reality is to cause the issue, the operators had to drive the reactor well into a dangerous and hard to control regime which it would not get into under any normal operation circumstance. So while yes, it shouldn't have been physically possible to do it, even with that design it took substantial, deliberate malfeasance to get that result (you can also only get that result with that design - a meltdown is not normally an explosion).
      • czstar 4y ago
        From what I’ve read some of the safety systems did not give real-time feedback and the critical error occurred because the operators didn’t know they were in trouble due to lack of real-time feedback. I’m not an engineer and know nothing of these things but the test was not unauthorized and it wasn’t an experiment. As far as I read about the accident.
    • ComputerGuru 4y ago
      It was poor reactor design combined with downright stupid actions by management. But a nuclear plant should be somewhat stupid-proof.
• inejge 4y ago
  It still blows my mind that a sub only needs to refuel once every 15 years. One of the things making this possible is 90+ percent enrichment of U235 in the fuel. That's weapons grade and won't fly in a civilian reactor. I haven't read NuScale's application in great detail but I'd be surprised if they used anything above 5 percent.
  • schrodinger 4y ago
    Can you explain more about what that means or suggest what to Google to learn more?
    • gautamcgoel 4y ago
      There are two uranium isotopes present on earth, U-235 and U-238. U-235 is the fissile material which powers nuclear reactions in both nuclear bombs and nuclear power plants. The 5% number represents the fraction of uranium in the fuel which is U-235 instead of U-238. Anything above 20% or so is considered "highly enriched", and nuclear bombs often have fuel which is 80-90% U-235.
      • gambiting 4y ago
        And the reason why bombs have more of the U-235 is because is splits easier than U-238, so it's easier to end up with a self sustaining chain reaction, where every U-235 that splits produces enough neutrons to split off two more U-235 atoms, which in turn splits 4, then 8, then 16 and so on - the chain reaction splits the whole lot all at once and you've got a bomb.
    • WatchDog 4y ago
      To add to what other commenters have said, apart from the weapons proliferation issues, enriching uranium is very expensive. U-235 only makes up about 0.72% of natural uranium, the rest of it being U-238. Running a reactor on low enriched uranium is much more cost effective, although reactor designs that can run on LEU can be less safe, like Chernobyls RBMK design.
• m463 4y ago
  exactly, especially when you read wikipedia's article on energy density: material specific energy w*h/kg ----------- ---------------------- uranium 22,394,000,000 ... diesel fuel 12,666
  • Gibbon1 4y ago
    Solar panel is like 800,000 wh/kg
• c3534l 4y ago
  Same reason people are afraid of getting robbed at night when they're more common during the day when everyone is at work, or why we're scared of heights and planes, but cars and horseback riding don't phase us. Fear is an emotional reaction, not a rational one.
• deleted 4y ago
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• justinclift 4y ago
  https://en.wikipedia.org/wiki/Nuclear_submarine#Accidents https://en.wikipedia.org/wiki/Nuclear_submarine#Accidents
• jmyeet 4y ago
  > I never understood the argument nuclear power is so "dangerous". The Chernobyl absolute exclusion zone is quite literally 1000 square miles. Nuclear advocates try to treat Chernobyl (and Fukushima and [insert nuclear disaster here]) as an irrelevant outlier rather than what it is: tangible evidence of the impact of inevitable human failure. A plant has to be well-maintained and competently run. Waste products have to be safely stored and transported. As soon as you add corporations to the mix, you've now created a profit motive to neglect safety and maintenance because the risk of disaster is low but the failure modes are incredibly large. Humans have shown themselves to consistently be incredibly bad at managing low-probability high-impact failures. > The US navy has fielded nuclear reactors in warzones since 1954 and no Chernobyl. Military use of nuclear reactors is quite limited, being largely limited to a handful of submarines and aircraft carriers using highly enriched fuel. It's not done out of economic merit either. Having a nuclear missile submarine that can stay deployed for months can literally be done no other way. All that has very little to do with commercial power generation.
  • spookie 4y ago
    I agree, but it's not like nation states do a better job than private entities... I mean, you gave an example yourself.
  • wskinner 4y ago
    Nuclear power has the lowest deaths per unit of power of all commercial power generation methods [1]. The externalities of nuclear power are highly visible and concentrated in a small physical and temporal range. This makes them obvious and scary. The externalities of other power generation methods are diffused through time and space, to the point that they appear mundane if they are noticed at all. Coal power kills 1000x as many people per unit as nuclear. Natural gas kills 40x as many. Solar kills 4x as many. Humans have shown themselves to consistently be incredibly bad at comparing chronic and acute risks at scale. 1: https://www.engineering.com/DesignSoftware/DesignSoftwareArticles/ArticleID/21308/Whats-the-Death-Toll-of-Nuclear-vs-Other-Energy-Sources.aspx https://www.engineering.com/DesignSoftware/DesignSoftwareArt...
    • 4y ago
• Spooky23 4y ago
  The Navy also fostered a strong safety culture with top down controls to get there, and they did so before anti-nuclear sentiment was a thing.
  • ncmncm 4y ago
    Civil nukes have never had any strong safety culture. The emphasis has always been on cost-cutting, because nukes have always been too expensive to compete fairly in an open market. Every nuke, ever, has been massively subsidized. NuScale has been and is still being massively subsidized by the USDoE. It would be wholly uncompetitive with renewables if not so propped up.
    • spopejoy 4y ago
      > NuScale has been and is still being massively subsidized by the USDoE Given the longstanding cozy relationship between the NRC, the DOE and industry it's hard to feel confident in this approval being sufficiently stringent, e.g. on worst-case scenarios, waste disposal and the like.
• dirkt 4y ago
  There is a difference between a nuclear reactor blowing up in a country with low overall population density (e.g. the US; in Chernobyl also it wasn't that taxing to designate an exclusion zone for a few centuries), it happening in a very densely populate country (where it would be a desaster), or it happening in a military sub where the owning state doesn't care about collateral damage [1] [1] https://www.theguardian.com/world/2014/jun/19/us-depleted-uranium-weapons-civilian-areas-iraq https://www.theguardian.com/world/2014/jun/19/us-depleted-ur...
• idontwantthis 4y ago
  I’m not sure what you mean by “battleships”, but the US navy is definitely not mostly nuclear. Super carriers and most subs yes. Everything else (many, many vessels) are not.