13 ms·

Massachusetts gas fires: Another technological tragedy

216 points by greeneggs 8y ago

acidburnNSA 8y ago
"All of these events feel like unnecessary disasters—if we were just a little smarter, we could have avoided them—but the fires in Lawrence are particularly tormenting in this respect. With an aircraft 35,000 feet over the ocean, you can’t simply press Pause when things don’t go right. Likewise a nuclear reactor has no safe-harbor state; even after you shut down the fission chain reaction, the core of the reactor generates enough heat to destroy itself. But Columbia Gas faced no such constraints in Lawrence. " Pretty interesting comparison. Arguably airplanes can coast down and nuclear reactors (especially Gen-IV low-pressure ones like sodium metal or molten salt) can passively cool their nuclear decay heat post shutdown without external power. But it is true that TMI and Fukushima were not chain reacting, they were both decay heat cooling problems. For those unfamiliar with this, a chain reactor immediately drops to about 7% of full power after shutdown and then exponentially decays to 1% after a day and half a percent after weeks. Turns out 1% of a gigawatt is still a lot. On the nuclear topic, I'm annoyed that natural gas accidents that cause deaths get way lighter media treatment than nuclear accidents like TMI that cause no deaths.
- PhantomGremlin 8y ago
  Turns out 1% of a gigawatt is still a lot. Just to be pedantic, nuclear plants generate electricity at about 33% efficiency. So to get 1000 MW of electricity, you start with about 3000 MW thermal. Turns out 1% of three gigawatts is even more. :)
  - acidburnNSA 8y ago
    Truth. The ones I'm designing are generally like 38% efficient and 300 MWe scale so pardon my slightly unconventional sizing. It's definitely a lot. But nothing naturally-circulating sodium metal through 4 redundant NaK-air dump heat exchangers can't handle.
    - blattimwind 8y ago
      HN, the place where an article using an analogy of nuclear reactors probably means that an actual nuclear reactor designer will comment on state-of-the-art nuclear reactors.
      - deleted 8y ago
        [deleted]
      - ericb 8y ago
        And still get pedantically corrected on a minor point! What a place this is!
        village-idiot 8y ago
        Is that a positive or negative statement?
        deleted 8y ago
        [deleted]
    - xvf22 8y ago
      I've spent a few years in the CANDU world so it's interesting to hear opinions from elsewhere. I've grown to appreciate the lag time the design gives you.
    - mcguire 8y ago
      NaK-air? Doesn't NaK catch fire in the presence of air?
      - wmoser 8y ago
        Probably a giant radiator. Lots of equipment that is “air cooled” has an intermediary coolant that is actually cooled by air over a heat exchanger (radiator).
        8y ago
- Jach 8y ago
  > On the nuclear topic, I'm annoyed that natural gas accidents that cause deaths get way lighter media treatment than nuclear accidents like TMI that cause no deaths. Why this annoyance? I'd prefer the media for the most part shut up about energy accidents in general, considering how damaging their outcries have been for nuclear power. A few sober reports are fine. It's probably a minor miracle the natural gas industry hasn't suffered like the nuclear one.
  - acidburnNSA 8y ago
    Heh, I guess you're right: I'd prefer both nuclear and natural gas to get sober reports. I think natural gas has a better name (it's natural! As if uranium is not), no ties to superweapons, and no The Simpsons. Regular fire is just easier to understand to most folks than radioisotopes.
    - nicoburns 8y ago
      With natural gas incidents, the entire surrounding area doesn't become unusable for hundreds of years...
      - URSpider94 8y ago
        No, but over the past 50 years, we’ve had two severe nuclear incidents resulting in any kind of long-term environmental damage (Fukuhima and Chernobyl), and Fukushima will be remediated within a decade. In the mean time, we’ve had Exxon Valdez, Deepwater Horizon, Andover, San Carlos, CA, plus oil trains burning down entire towns, coal mine explosions, two Gulf Wars, and sea level rise due to global warming. Pick your poison.
        Pfhreak 8y ago
        I find this to be an interesting comparison: https://en.wikipedia.org/wiki/List_of_pipeline_accidents https://en.wikipedia.org/wiki/List_of_pipeline_accidents The list of accidents is so large that the US has to create separate wikipedia pages for every 25 year span.
- skybrian 8y ago
  Number of deaths isn't the only metric of severity. For example, there is also the number of people who lost their homes (evacuated and not able to return for many years), which for Fukashima was apparently 150,000. [1] Since nuclear power plants are so expensive to build, even just the loss of plant itself is in the billions. https://www.forbes.com/sites/jamesconca/2016/03/10/after-five-years-what-is-the-cost-of-fukushima/ https://www.forbes.com/sites/jamesconca/2016/03/10/after-fiv...
  - yongjik 8y ago
    > ... which for Fukashima was apparently 150,000 To put it in perspective, the prediction for the number of climate refugees vary, but papers seem to put the number somewhere between 150 and 300 million by 2050.[1] That's about one Fukushima every five to eleven days, starting from now and continuing until 2050. Think about it. [1] https://orbi.uliege.be//bitstream/2268/136972/1/11-1188-mr7-why-the-numbers-dont-add-up-estimates-of-people-displaced.pdf https://orbi.uliege.be//bitstream/2268/136972/1/11-1188-mr7-... (Table 1, page 5) - Disclaimer: this was the first link from Googling "climate refugee prediction".
    - chmod775 8y ago
      To put that into perspective, about 120,000 people are displaced every day in the middle east because of a mess ultimately created in the pursuit of oil interests. That's one Fukoshima every day. Apparently the US felt that hundreds of thousands dead, millions displaced, and democratic governments overthrown was an acceptable price for slightly cheaper oil. I fully expect that calculation to come out the same when climate refugees are considered. The lengths we'll go to for cheap energy and car culture, right?
      - jplayer01 8y ago
        Not sure why you were downvoted. You're entirely right. Oil is incredibly destructive for the environment and society, yet it's accepted because that's just how things are.
- anovikov 8y ago
  Other kinds of consequences like cost of mitigation, value of lost property (and lost value of property what wasn't destroyed by itself - you can easily see thousands of homes near, but not in evacuation zone deprecating severely), costs of health checks for hundreds of thousands of people etc. - are worse in nuclear accidents.
  - antidesitter 8y ago
    > are worse in nuclear accidents Do you have numbers for this comparison?
  - 8bitsrule 8y ago
    Fans of the nuclear industry doesn't like to columnize the costs of 'externalities'. For one, they rarely mention the amount of US government subsidies ($hundreds of billions) poured into getting the early plants up and running. For another, the unwillingness of insurers to take an interest in those operations. When Rocky Flats spilled a little Pu dust into the Denver suburbs, they just raised the 'safe' exposure by a factor of 10. Easy peasy.
- masklinn 8y ago
  > Turns out 1% of a gigawatt is still a lot. Reactors are circa gigawatt electrical. Nukes usually have a thermodynamic efficiency around 1/3rd, so a 1GWe reactor will produce 3GWt at the core. That's the heat they have to deal with when uncooled.
- t0mas88 8y ago
  Airplanes coast down fine after a (double) engine failure, but they don't coast nicely when your primary instruments aren't working. The Air France flight didn't just loose airspeed indication, they got invalid readings and all associated warnings. Unfortunately that is the common failure mode for flight instruments, they don't just show nothing, they show wrong values. Fortunately pilots are trained to know how instruments work on the inside and what the most likely wrong indications and their causes are. The problem the author points out is that you cannot "pause" to think about what information may be correct and which instruments to follow. You have to react immediately, which is much harder than considering the same decisions sitting at a desk reading the NTSB report. If the low speed indication/alert is correct you need to push the nose forward immediately to keep the aircraft out of a stall, if the high speed indication/alert is correct you need to pull power to flight-idle and nose up carefully but immediately to avoid overspeeding the aircraft and risk structural failure.
  - Gravityloss 8y ago
    AFAIK the Air France flight would have been ok if they had not even touched the controls. They had a lot of altitude. Of course easy to say from the arm chair. I'm not sure how easily a regular airline overspeeds or stalls if the controls are close to a middle position. They should be aerodynamically stable (if loaded correctly). For a fighter jet it's a different situation.
    - kpil 8y ago
      They were initially close to a high altitude stall, the margins are not that large at that altitude, so just dropping everything isn't really an option. The report highlighted training, which I guess is always possible to point out, but looking at the event I think they could have made more conclusions regarding how the control system performed counterintuitive by emitting stall warnings at the time they actually did the right thing, and provides little feedback when it drops into alternate law making a standard full pullback into a potentially dangerous move.
  - quietbritishjim 8y ago
    What I remember reading of the Air France flight was that both people flying understood perfectly well the situation, and had plenty of time to get out of it, but one panicked and tried to pull up even though that was exactly the wrong thing to do. The other problem was that no one else realised that one of them was trying to pull up and the plane averaged the actions of the two sticks (pull up and dive) causing effectively zero net action. (Other planes feedback each stick's action to the other so the other person would soon have realised what was going on.) They had so long to fix the problem that the captain (who had been sleeping) had time to wake up and enter the cockpit, and he finally managed to coax out the information that one of the copilots was trying to pull up, and for them to stop. By that point they were only seconds from the water and it actually was too late.
- EamonnMR 8y ago
  Regionally this was covered extensively with pictures of devastated houses and graphic detail about the fatality.
taliesinb 8y ago
The Chemical Safety Board produces some pretty fascinating videos that reconstruct the chains of events that led to large industrial accidents in chemical plants. The videos normally conclude with recommendations for voluntary actions industry can take to prevent similar incidents in future. They basically summarize the results of detailed investigations by CSB agents. The videos are well produced and, apart from those accidents that involve injury or death, they are quite entertaining if you happen to be in a forensic frame of mind. Here’s an example of one of their videos: https://youtu.be/_icf-5uoZbc https://youtu.be/_icf-5uoZbc
- jayd16 8y ago
  These are produced like one of those Air Crash Investigation type shows.
- Scoundreller 8y ago
  I like their videos. Unfortunately, this incident will be investigated by the Transportation Safety Board. The report will be thorough, but we may not get a great video out of it :(
  - hexane360 8y ago
    The TSB does do videos, but you're right that they're not as polished as the CSB's.
- btown 8y ago
  Why are these actions voluntary? Shouldn’t there be regulations that at least ensure we don’t make the same mistake twice?
  - akiselev 8y ago
    In some cases it allows the agency to operate freely regardless of the political environment and in others, there are historical reasons for the way they operate (ala NTSB and FAA). It also allows the market to decide what risks justify the cost and which ones don't via the insurance market. These advisories are front and center in lawsuits when dealing with repeat occurrences so the pressure comes from economic forces. Thankfully, there are limitations to what the market is allowed to decide so this may eventually become a regulation through public pressure or agency review.
jrjrjrjr 8y ago
Even my air compressors have blow off valves, did something get lost in the advancement of technology from the boiler days ???? it seems to be a pretty stupid design that doesn't have relief valves.
- wyattpeak 8y ago
  I don't know much about the specifics of gas distribution, but I came across a comment on an entirely different discussion recently which I think is apropos: > you should be very suspicious of any conclusion that requires you to assume that all the world’s experts have missed something extremely basic. It seems to me most likely that the answer is simply that releasing natural gas into the air is an even more dangerous failure mode than overpressure - natgas is not air in a compressor. But regardless I'd bet you dollars to doughnuts that, for one reason or another, blow-off valves are a bad idea in the context.
  - enjeyw 8y ago
    I see your logic, but the fact that overpressure demonstrably caused a catastrophic failure sets the bar pretty high for blow-off having worse consequences.
  - captain_perl 8y ago
    > you should be very suspicious of any conclusion that requires you to assume that all the world’s experts have missed something extremely basic. This is hugely mistaken. If you're an expert in compliance in one field, often your insights are valid in another field. For example, anybody who has certified a data center knows that Fukushima was both in the wrong location and had wonky power distribution. Anybody in aviation knows the Tyndall F-22s were in the wrong location after Kermit Weeks' collection was destroyed in Florida in 1990. Expertise and common sense are always in short supply. It's 2018 - we've collected enough hindsight for the next 100 years.
  - drb91 8y ago
    I’m not sure I agree with the statement—humans overlook basic details all the time. Most computer bugs are “extremely basic”. Multiply times possible failure points and it’s easy to see how basic flaws can easily cause systemic failure. Experts DO miss extremely basic things daily. You have to actively build proccesses to avoid this. Expertise is not enough!
jacknews 8y ago
I realise this is beside the point of the article, but gas distribution seems like an obsolete and dangerous technology to me. For cooking, induction, for heating, heat pumps.
- deleted 8y ago
  [deleted]
- jzwinck 8y ago
  Induction stoves are unpleasant and ineffective to cook on, not to mention inefficient. And if you want to use a wok, well, you can't. They are definitely better in appealing to first time buyers who may not know or care about their shortcomings. They look great and are easy to clean. But if you are into cooking, gas wins.
  - toomuchtodo 8y ago
    > Induction stoves are unpleasant and ineffective to cook on, not to mention inefficient. And if you want to use a wok, well, you can't. With induction, ~90% of the energy from the electricity is used for cooking while only 40% of energy is used using a gas cooktop. Induction is more efficient, and you can use a wok if one is purchased that is designed for use with induction. Induction units can also regulate themselves based on feedback from the cooking device on the receiving end. Induction is arguably superior to cooking with gas. https://www.consumerreports.org/electric-induction-ranges/pros-and-cons-of-induction-cooktops-and-ranges/ https://www.consumerreports.org/electric-induction-ranges/pr... https://www.reviewed.com/ovens/features/induction-101-better-cooking-through-science https://www.reviewed.com/ovens/features/induction-101-better... > On almost all counts, induction is faster, safer, cleaner, and more efficient than either gas or electric. And yes, we've done exhaustive oven testing in our labs to support that claim.
    - jzwinck 8y ago
      What about the 45% efficiency of a natural gas power plant? Yes induction is efficient if you only look at the part inside your house. But most of the losses are outside your house. If you live in a place with advanced wind or solar power like South Korea then electric probably is more efficient.
jt2190 8y ago
While they were replacing an old system with a new system, they had inadvertently created an interim (hybrid?) system that wasn't as safe as either the old or new: > The cause of the accident was not a leak or an equipment failure or a design flaw or a worker turning the wrong valve. The pressure didn’t just creep up beyond safe limits while no one was paying attention; the pressure was driven up by the automatic control system meant to keep it in bounds. The pressure regulators were "trying" to do the right thing. Sensor readings told them the pressure was falling, and so the controllers took corrective action to keep the gas flowing to customers. But the feedback loop the regulators relied on was not in fact a loop. They were measuring pressure in one pipe and pumping gas into another.
Animats 8y ago
There are modern controllers which will detect this situation: "When Open Loop Detection is enabled L.dE, the controller will look for the power output to be at 100%. Once there, the control will then begin to monitor the Open Loop Detect Deviation L.dd as it relates to the value entered for the Open Loop Detect Time L.dt. If the specified time period expires and the deviation does not occur, an Open Loop Error will be triggered. Once the Open Loop Error condition exists the control mode will go off and an Open Loop message will be display. If the process value goes in the opposite direction, a Reversed Loop message is display. The sensor is likely wired in reverse polarity." If this crew was replacing an old cast iron gas main, it probably predated such controllers. That's not necessarily a bad thing. A mechanical controller can work for many decades. It's hard to get that level of uptime from microprocessors. The real problem here is "maintenance induced failure". Especially on a system which is not fully shut down. [1] https://www.watlow.com/-/media/documents/user-manuals/pm-pid-1.ashx https://www.watlow.com/-/media/documents/user-manuals/pm-pid...
joe_the_user 8y ago
I had believed such a catastrophe was all but impossible. The natural gas industry has many troubles, including chronic leaks that release millions of tons of methane into the atmosphere, but I had thought that pressure regulation was a solved problem. Yeah, natural gas tech is old and over time has been worked into a multi-layer system that is close to "inherently safe". I remember years ago trying to light an old heater the most stupid way possible and only singeing my eyebrows in the resulting explosion. But these events just show that if a company skimps enough on needed maintenance, ignoring constant smaller leaks and the similar despicable maneuvers done by this gas company, then the overall potential of piping an explosive gas into a city can be realized and people die and are injured, building are destroyed and so-forth. In this context, it seems pretty obvious this isn't a "technological tragedy" but a "people doing bad things tragedy" and I hope it's obvious people deserve to go to jail for this and if they don't then other problematic aspect of this society are then to blame.
- edejong 8y ago
  I wish we could just separate technology and human factors like this. In reality, each system is designed to prevent neither technological malfunction nor miscommunication or errors in process. Unfortunately, programmers seem often to be isolated from this really complex part of engineering, so this interplay might not be appreciated properly.
  - specialist 8y ago
    Donald Norman's Design of Everyday Things helped cure my technophilia, maybe even turning me into a humanist. http://a.co/d/dSsOfxJ http://a.co/d/dSsOfxJ Aha, looks like there's a new version (dated 2013).
    - glogla 8y ago
      Ah, referal link. How sneaky.
      - specialist 8y ago
userbinator 8y ago
I suspect the remote-sensing aspect of their regulation system was not well known, and thus the consequences of possibly opening the control loop weren't taken into consideration. It's a subtle but important point --- and I remember a friend telling me a story of destroying some very expensive electronics because the sense line of the power supply came loose.
hyperion2010 8y ago
Oh man. My PhD work is focused on helping people communicate clearly about the measurements they are making and how to interpret them and where the pitfalls are in a research setting. Every time I read about something like this I wonder if I can use what I am working on to help people automatically detect when the assumptions of their measurement model could be violated. For example, if you can explicitly model the fact that the measurement is not the actual value and that they can become decoupled (and can thus brainstorm and model potential reasons), then you can start to help people realize that the map (measurements) are not the territory (reality), in ways that aren't just cute phrases without guidance for practical implementation.
- spongo 8y ago
  I'm curious: within which field are you doing this PhD? I could see you as a computer scientist, systems designer, political theorist, perhaps an economist or philosopher. Is any of your work available to read online?
  - hyperion2010 8y ago
    I'm technically in neuroscience, neuroinformatics more specifically, but was raised by a political theorist. Unfortunately I have a bad habit of writing code rather than prose, and don't keep a blog or similar, so the first thing that I could point you to would be my thesis, which is still months away.
    - YeGoblynQueenne 8y ago
      Well, hurry up then :) Seriously, this sounds like a very interesting subject. Best of luck with your thesis writing and submission (mine's still a couple of years away).
    - dotancohen 8y ago
      Post the thesis to HN when you're done, or PM me (my Gmail username is the same as my HN username) and I'll host it and post it. Better communication tools for statistics and technical subjects is seriously something that the HN community could use and promote.
patcheudor 8y ago
What I still don't understand is why the pressure regulators and over pressure valves on the house gas meters didn't kick in? Were the homes involved so old that the meter protections failed or weren't there in the first place? It seems that ultimately you've got to have failsafes at the homes themselves. Without such failsafes, what would stop a bad actor from purposely over pressurizing a residential branch?
- mikestew 8y ago
  It does seem odd, and I’m guessing that such protections simply do not exist or the article might have mentioned it. Kinda like running a network with no firewall if you ask me. “I’ll accept whatever comes down the pipe” is a bad idea whether it’s a literal pipe or Ethernet.
- lutorm 8y ago
  What would those devices do? A pressure regulator is designed to handle a range of input pressures. If the pressure really got 75x higher than the design pressure, the regulators probably just failed.
  - sschueller 8y ago
    Are there really no pressure release valves that will blow out at a certain over pressure? Like a spring release that will give way and release all of the gas outside the house.
- jacquesm 8y ago
  Those regulators work within a set range of input pressures, and need a certain delta to work properly. Over-pressure them severely and they will simply fail, and most such failures will lead to gas escaping from the regulator body. That is why you will usually find them outside of the premises they protect so they vent into the outdoors rather than into some enclosed space. As for your bad actor: what would he pressurize your lines with? An air compressor? He'd have to dig up the lines or disconnect them first and gas from the line would likely escape in quantities large enough to discourage such tricks. Just like in theory you could disconnect the mains from a house and then send a high voltage pulse down the feed lines, in practice pranksters and miscreants tend to avoid doing stuff that might get them killed instead.
chb 8y ago
"I admit to a morbid fascination with stories of technological disaster. I read NTSB accident reports the way some people consume murder mysteries. The narratives belong to the genre of tragedy." The author is not alone. Over a decade ago, there was a theater piece called "Charlie Victor Romeo" that consisted solely of actors re-enacting cockpit voice recordings of aircraft that crashed. http://charlievictorromeo.com/ http://charlievictorromeo.com/
scotty79 8y ago
What I see in those incidents is severe lack of backup sensors. Why after switching to new pipe nobody checked/could check the pressure in it? Why there were no other kind of speed sensors on a plane, simpler, less accurate, slower but not that vulnerable to icing? Why in Three Miles Island incident why people couldn't double check if reactor has water in it or not?
amluto 8y ago
I find it bizarre that it’s not required by code for a pressure regulation station to have a sensor in that station. I also wonder if the utiliy’s connection between the sensor and controller is on the internet.
dsfyu404ed 8y ago
Properly installed residential gas piping should be able to handle triple digit pressures. Appliances should be able to handle double digit pressures because almost all appliances that can run on NG also can be equipped to run on propane which outputs at up to 30psi depending on the regulator. Manufacturers slap a safety factor on top because it's a consumer product and you don't want someone to blow up their house and sue you because they used the wrong regulator. There's a reason some houses went bang and some houses didn't. I know it's fashionable to blame the megacorp (and it sure looks like they have plenty of blame in this case) but there's plenty of blame to go around here. There's a reason some houses went bang and others didn't. I've worked residential construction in MA and plumbers as a group have a pretty bad reputation (well earned, at least based on my experience, you should see some of the corners these guys will cut). I would wager that the houses that went bang weren't the ones that had their gas pipes done by the apprentice who still does everything by the book but the "seasoned professional" who knows exactly what you can get away with when your work only needs to hold 1/2psi. Like any large accident there are many dominoes that need to be lined up before they can all be knocked down at once. I think it's foolish to act like some contractor dutifully carrying out Colombia Gas's faulty work order is the only cause of this.
ekke 8y ago
This is fascinating. For anyone interested in a slightly odd but unique and in-depth view of Systems design and failure, would like to recommend "The Systems Bible: The Beginner's Guide to Systems Large and Small" by John Gall. https://www.amazon.com/Systems-Bible-Beginners-Guide-Large/dp/0961825170 https://www.amazon.com/Systems-Bible-Beginners-Guide-Large/d...
LawfulRewrite 8y ago
Next year we may see the first models without a steering wheel or a brake pedal—there goes the option of asking the driver (passenger?) to take over. This is bad news for everyone. This is the network effect exploitatively writ large, such that, surely you can prevent yourself from being inside such a thing, but as a lone individual, without laws in place to ban such a thing, you, your children, your family, your friends are all endangered by a blameless force that everyone can simply shrug at, and point to statistics claiming that there is even just an incremental improvement over ordinary human performance. You can stop yourself from posting selfies on social media, under your real name. You cannot stop other people from taking pictures, which your acquaintances discover and tag with your real name. This is kind of horrific. At least as horrific, or moreso than, current traffic statistics, because the moral hazard in play is abysmally worse. There was an effective arms race that took shape with SUVs and road rage in the late 1990's. I think something similar will take shape, as self driving cars ramp up. It may surprise some, to find that a self driving incident won't be accepted as blameless, glitchy software errors. Owners may see themselves villified directly, for things a car they chose to own, had subsequently carried out. I think there are three turns of consequence to a botched self driving car deployment. One: some will choose harm the legal owner as an individual, lawfully or lawlessly. Two: others will harm dealerships, mostly through sabotage. Three: overt action against the manufacturers. At all levels, and not limited to ordinary civil disobedience. These consequences are nothing to be sniffed at. Aviation shows us that spotty disasters don't result in civil unrest, but with a human in the loop survival was incentivized. Automotive deployments like this will be a fire and forget scenario, and the corporations loosing the reigns, have a demostrable history of neglect. I wonder if they anticipate, in the rush to market, just how severely the general public might react to finding their roads on the receiving end of software glitches that kill their firends and relatives like deer?

216 points by greeneggs 8y ago

"All of these events feel like unnecessary disasters—if we were just a little smarter, we could have avoided them—but the fires in Lawrence are particularly tormenting in this respect. With an aircraft 35,000 feet over the ocean, you can’t simply press Pause when things don’t go right. Likewise a nuclear reactor has no safe-harbor state; even after you shut down the fission chain reaction, the core of the reactor generates enough heat to destroy itself. But Columbia Gas faced no such constraints in Lawrence. " Pretty interesting comparison. Arguably airplanes can coast down and nuclear reactors (especially Gen-IV low-pressure ones like sodium metal or molten salt) can passively cool their nuclear decay heat post shutdown without external power. But it is true that TMI and Fukushima were not chain reacting, they were both decay heat cooling problems. For those unfamiliar with this, a chain reactor immediately drops to about 7% of full power after shutdown and then exponentially decays to 1% after a day and half a percent after weeks. Turns out 1% of a gigawatt is still a lot. On the nuclear topic, I'm annoyed that natural gas accidents that cause deaths get way lighter media treatment than nuclear accidents like TMI that cause no deaths.

PhantomGremlin 8y ago
Turns out 1% of a gigawatt is still a lot. Just to be pedantic, nuclear plants generate electricity at about 33% efficiency. So to get 1000 MW of electricity, you start with about 3000 MW thermal. Turns out 1% of three gigawatts is even more. :)
- acidburnNSA 8y ago
  Truth. The ones I'm designing are generally like 38% efficient and 300 MWe scale so pardon my slightly unconventional sizing. It's definitely a lot. But nothing naturally-circulating sodium metal through 4 redundant NaK-air dump heat exchangers can't handle.
  - blattimwind 8y ago
    HN, the place where an article using an analogy of nuclear reactors probably means that an actual nuclear reactor designer will comment on state-of-the-art nuclear reactors.
    - deleted 8y ago
      [deleted]
    - ericb 8y ago
      And still get pedantically corrected on a minor point! What a place this is!
      - village-idiot 8y ago
        Is that a positive or negative statement?
        deleted 8y ago
        [deleted]
  - xvf22 8y ago
    I've spent a few years in the CANDU world so it's interesting to hear opinions from elsewhere. I've grown to appreciate the lag time the design gives you.
  - mcguire 8y ago
    NaK-air? Doesn't NaK catch fire in the presence of air?
    - wmoser 8y ago
      Probably a giant radiator. Lots of equipment that is “air cooled” has an intermediary coolant that is actually cooled by air over a heat exchanger (radiator).
      - 8y ago
Jach 8y ago
> On the nuclear topic, I'm annoyed that natural gas accidents that cause deaths get way lighter media treatment than nuclear accidents like TMI that cause no deaths. Why this annoyance? I'd prefer the media for the most part shut up about energy accidents in general, considering how damaging their outcries have been for nuclear power. A few sober reports are fine. It's probably a minor miracle the natural gas industry hasn't suffered like the nuclear one.
- acidburnNSA 8y ago
  Heh, I guess you're right: I'd prefer both nuclear and natural gas to get sober reports. I think natural gas has a better name (it's natural! As if uranium is not), no ties to superweapons, and no The Simpsons. Regular fire is just easier to understand to most folks than radioisotopes.
  - nicoburns 8y ago
    With natural gas incidents, the entire surrounding area doesn't become unusable for hundreds of years...
    - URSpider94 8y ago
      No, but over the past 50 years, we’ve had two severe nuclear incidents resulting in any kind of long-term environmental damage (Fukuhima and Chernobyl), and Fukushima will be remediated within a decade. In the mean time, we’ve had Exxon Valdez, Deepwater Horizon, Andover, San Carlos, CA, plus oil trains burning down entire towns, coal mine explosions, two Gulf Wars, and sea level rise due to global warming. Pick your poison.
      - Pfhreak 8y ago
        I find this to be an interesting comparison: https://en.wikipedia.org/wiki/List_of_pipeline_accidents https://en.wikipedia.org/wiki/List_of_pipeline_accidents The list of accidents is so large that the US has to create separate wikipedia pages for every 25 year span.
skybrian 8y ago
Number of deaths isn't the only metric of severity. For example, there is also the number of people who lost their homes (evacuated and not able to return for many years), which for Fukashima was apparently 150,000. [1] Since nuclear power plants are so expensive to build, even just the loss of plant itself is in the billions. https://www.forbes.com/sites/jamesconca/2016/03/10/after-five-years-what-is-the-cost-of-fukushima/ https://www.forbes.com/sites/jamesconca/2016/03/10/after-fiv...
- yongjik 8y ago
  > ... which for Fukashima was apparently 150,000 To put it in perspective, the prediction for the number of climate refugees vary, but papers seem to put the number somewhere between 150 and 300 million by 2050.[1] That's about one Fukushima every five to eleven days, starting from now and continuing until 2050. Think about it. [1] https://orbi.uliege.be//bitstream/2268/136972/1/11-1188-mr7-why-the-numbers-dont-add-up-estimates-of-people-displaced.pdf https://orbi.uliege.be//bitstream/2268/136972/1/11-1188-mr7-... (Table 1, page 5) - Disclaimer: this was the first link from Googling "climate refugee prediction".
  - chmod775 8y ago
    To put that into perspective, about 120,000 people are displaced every day in the middle east because of a mess ultimately created in the pursuit of oil interests. That's one Fukoshima every day. Apparently the US felt that hundreds of thousands dead, millions displaced, and democratic governments overthrown was an acceptable price for slightly cheaper oil. I fully expect that calculation to come out the same when climate refugees are considered. The lengths we'll go to for cheap energy and car culture, right?
    - jplayer01 8y ago
      Not sure why you were downvoted. You're entirely right. Oil is incredibly destructive for the environment and society, yet it's accepted because that's just how things are.
anovikov 8y ago
Other kinds of consequences like cost of mitigation, value of lost property (and lost value of property what wasn't destroyed by itself - you can easily see thousands of homes near, but not in evacuation zone deprecating severely), costs of health checks for hundreds of thousands of people etc. - are worse in nuclear accidents.
- antidesitter 8y ago
  > are worse in nuclear accidents Do you have numbers for this comparison?
- 8bitsrule 8y ago
  Fans of the nuclear industry doesn't like to columnize the costs of 'externalities'. For one, they rarely mention the amount of US government subsidies ($hundreds of billions) poured into getting the early plants up and running. For another, the unwillingness of insurers to take an interest in those operations. When Rocky Flats spilled a little Pu dust into the Denver suburbs, they just raised the 'safe' exposure by a factor of 10. Easy peasy.
masklinn 8y ago
> Turns out 1% of a gigawatt is still a lot. Reactors are circa gigawatt electrical. Nukes usually have a thermodynamic efficiency around 1/3rd, so a 1GWe reactor will produce 3GWt at the core. That's the heat they have to deal with when uncooled.
t0mas88 8y ago
Airplanes coast down fine after a (double) engine failure, but they don't coast nicely when your primary instruments aren't working. The Air France flight didn't just loose airspeed indication, they got invalid readings and all associated warnings. Unfortunately that is the common failure mode for flight instruments, they don't just show nothing, they show wrong values. Fortunately pilots are trained to know how instruments work on the inside and what the most likely wrong indications and their causes are. The problem the author points out is that you cannot "pause" to think about what information may be correct and which instruments to follow. You have to react immediately, which is much harder than considering the same decisions sitting at a desk reading the NTSB report. If the low speed indication/alert is correct you need to push the nose forward immediately to keep the aircraft out of a stall, if the high speed indication/alert is correct you need to pull power to flight-idle and nose up carefully but immediately to avoid overspeeding the aircraft and risk structural failure.
- Gravityloss 8y ago
  AFAIK the Air France flight would have been ok if they had not even touched the controls. They had a lot of altitude. Of course easy to say from the arm chair. I'm not sure how easily a regular airline overspeeds or stalls if the controls are close to a middle position. They should be aerodynamically stable (if loaded correctly). For a fighter jet it's a different situation.
  - kpil 8y ago
    They were initially close to a high altitude stall, the margins are not that large at that altitude, so just dropping everything isn't really an option. The report highlighted training, which I guess is always possible to point out, but looking at the event I think they could have made more conclusions regarding how the control system performed counterintuitive by emitting stall warnings at the time they actually did the right thing, and provides little feedback when it drops into alternate law making a standard full pullback into a potentially dangerous move.
- quietbritishjim 8y ago
  What I remember reading of the Air France flight was that both people flying understood perfectly well the situation, and had plenty of time to get out of it, but one panicked and tried to pull up even though that was exactly the wrong thing to do. The other problem was that no one else realised that one of them was trying to pull up and the plane averaged the actions of the two sticks (pull up and dive) causing effectively zero net action. (Other planes feedback each stick's action to the other so the other person would soon have realised what was going on.) They had so long to fix the problem that the captain (who had been sleeping) had time to wake up and enter the cockpit, and he finally managed to coax out the information that one of the copilots was trying to pull up, and for them to stop. By that point they were only seconds from the water and it actually was too late.
EamonnMR 8y ago
Regionally this was covered extensively with pictures of devastated houses and graphic detail about the fatality.

taliesinb 8y ago

The Chemical Safety Board produces some pretty fascinating videos that reconstruct the chains of events that led to large industrial accidents in chemical plants. The videos normally conclude with recommendations for voluntary actions industry can take to prevent similar incidents in future. They basically summarize the results of detailed investigations by CSB agents. The videos are well produced and, apart from those accidents that involve injury or death, they are quite entertaining if you happen to be in a forensic frame of mind. Here’s an example of one of their videos: https://youtu.be/_icf-5uoZbc https://youtu.be/_icf-5uoZbc

jayd16 8y ago
These are produced like one of those Air Crash Investigation type shows.
Scoundreller 8y ago
I like their videos. Unfortunately, this incident will be investigated by the Transportation Safety Board. The report will be thorough, but we may not get a great video out of it :(
- hexane360 8y ago
  The TSB does do videos, but you're right that they're not as polished as the CSB's.
btown 8y ago
Why are these actions voluntary? Shouldn’t there be regulations that at least ensure we don’t make the same mistake twice?
- akiselev 8y ago
  In some cases it allows the agency to operate freely regardless of the political environment and in others, there are historical reasons for the way they operate (ala NTSB and FAA). It also allows the market to decide what risks justify the cost and which ones don't via the insurance market. These advisories are front and center in lawsuits when dealing with repeat occurrences so the pressure comes from economic forces. Thankfully, there are limitations to what the market is allowed to decide so this may eventually become a regulation through public pressure or agency review.

jrjrjrjr 8y ago

Even my air compressors have blow off valves, did something get lost in the advancement of technology from the boiler days ???? it seems to be a pretty stupid design that doesn't have relief valves.

wyattpeak 8y ago
I don't know much about the specifics of gas distribution, but I came across a comment on an entirely different discussion recently which I think is apropos: > you should be very suspicious of any conclusion that requires you to assume that all the world’s experts have missed something extremely basic. It seems to me most likely that the answer is simply that releasing natural gas into the air is an even more dangerous failure mode than overpressure - natgas is not air in a compressor. But regardless I'd bet you dollars to doughnuts that, for one reason or another, blow-off valves are a bad idea in the context.
- enjeyw 8y ago
  I see your logic, but the fact that overpressure demonstrably caused a catastrophic failure sets the bar pretty high for blow-off having worse consequences.
- captain_perl 8y ago
  > you should be very suspicious of any conclusion that requires you to assume that all the world’s experts have missed something extremely basic. This is hugely mistaken. If you're an expert in compliance in one field, often your insights are valid in another field. For example, anybody who has certified a data center knows that Fukushima was both in the wrong location and had wonky power distribution. Anybody in aviation knows the Tyndall F-22s were in the wrong location after Kermit Weeks' collection was destroyed in Florida in 1990. Expertise and common sense are always in short supply. It's 2018 - we've collected enough hindsight for the next 100 years.
- drb91 8y ago
  I’m not sure I agree with the statement—humans overlook basic details all the time. Most computer bugs are “extremely basic”. Multiply times possible failure points and it’s easy to see how basic flaws can easily cause systemic failure. Experts DO miss extremely basic things daily. You have to actively build proccesses to avoid this. Expertise is not enough!

jacknews 8y ago

I realise this is beside the point of the article, but gas distribution seems like an obsolete and dangerous technology to me. For cooking, induction, for heating, heat pumps.

deleted 8y ago
[deleted]
jzwinck 8y ago
Induction stoves are unpleasant and ineffective to cook on, not to mention inefficient. And if you want to use a wok, well, you can't. They are definitely better in appealing to first time buyers who may not know or care about their shortcomings. They look great and are easy to clean. But if you are into cooking, gas wins.
- toomuchtodo 8y ago
  > Induction stoves are unpleasant and ineffective to cook on, not to mention inefficient. And if you want to use a wok, well, you can't. With induction, ~90% of the energy from the electricity is used for cooking while only 40% of energy is used using a gas cooktop. Induction is more efficient, and you can use a wok if one is purchased that is designed for use with induction. Induction units can also regulate themselves based on feedback from the cooking device on the receiving end. Induction is arguably superior to cooking with gas. https://www.consumerreports.org/electric-induction-ranges/pros-and-cons-of-induction-cooktops-and-ranges/ https://www.consumerreports.org/electric-induction-ranges/pr... https://www.reviewed.com/ovens/features/induction-101-better-cooking-through-science https://www.reviewed.com/ovens/features/induction-101-better... > On almost all counts, induction is faster, safer, cleaner, and more efficient than either gas or electric. And yes, we've done exhaustive oven testing in our labs to support that claim.
  - jzwinck 8y ago
    What about the 45% efficiency of a natural gas power plant? Yes induction is efficient if you only look at the part inside your house. But most of the losses are outside your house. If you live in a place with advanced wind or solar power like South Korea then electric probably is more efficient.

jt2190 8y ago

While they were replacing an old system with a new system, they had inadvertently created an interim (hybrid?) system that wasn't as safe as either the old or new: > The cause of the accident was not a leak or an equipment failure or a design flaw or a worker turning the wrong valve. The pressure didn’t just creep up beyond safe limits while no one was paying attention; the pressure was driven up by the automatic control system meant to keep it in bounds. The pressure regulators were "trying" to do the right thing. Sensor readings told them the pressure was falling, and so the controllers took corrective action to keep the gas flowing to customers. But the feedback loop the regulators relied on was not in fact a loop. They were measuring pressure in one pipe and pumping gas into another.

Animats 8y ago

There are modern controllers which will detect this situation: "When Open Loop Detection is enabled L.dE, the controller will look for the power output to be at 100%. Once there, the control will then begin to monitor the Open Loop Detect Deviation L.dd as it relates to the value entered for the Open Loop Detect Time L.dt. If the specified time period expires and the deviation does not occur, an Open Loop Error will be triggered. Once the Open Loop Error condition exists the control mode will go off and an Open Loop message will be display. If the process value goes in the opposite direction, a Reversed Loop message is display. The sensor is likely wired in reverse polarity." If this crew was replacing an old cast iron gas main, it probably predated such controllers. That's not necessarily a bad thing. A mechanical controller can work for many decades. It's hard to get that level of uptime from microprocessors. The real problem here is "maintenance induced failure". Especially on a system which is not fully shut down. [1] https://www.watlow.com/-/media/documents/user-manuals/pm-pid-1.ashx https://www.watlow.com/-/media/documents/user-manuals/pm-pid...

joe_the_user 8y ago

I had believed such a catastrophe was all but impossible. The natural gas industry has many troubles, including chronic leaks that release millions of tons of methane into the atmosphere, but I had thought that pressure regulation was a solved problem. Yeah, natural gas tech is old and over time has been worked into a multi-layer system that is close to "inherently safe". I remember years ago trying to light an old heater the most stupid way possible and only singeing my eyebrows in the resulting explosion. But these events just show that if a company skimps enough on needed maintenance, ignoring constant smaller leaks and the similar despicable maneuvers done by this gas company, then the overall potential of piping an explosive gas into a city can be realized and people die and are injured, building are destroyed and so-forth. In this context, it seems pretty obvious this isn't a "technological tragedy" but a "people doing bad things tragedy" and I hope it's obvious people deserve to go to jail for this and if they don't then other problematic aspect of this society are then to blame.

edejong 8y ago
I wish we could just separate technology and human factors like this. In reality, each system is designed to prevent neither technological malfunction nor miscommunication or errors in process. Unfortunately, programmers seem often to be isolated from this really complex part of engineering, so this interplay might not be appreciated properly.
- specialist 8y ago
  Donald Norman's Design of Everyday Things helped cure my technophilia, maybe even turning me into a humanist. http://a.co/d/dSsOfxJ http://a.co/d/dSsOfxJ Aha, looks like there's a new version (dated 2013).
  - glogla 8y ago
    Ah, referal link. How sneaky.
    - specialist 8y ago

userbinator 8y ago

I suspect the remote-sensing aspect of their regulation system was not well known, and thus the consequences of possibly opening the control loop weren't taken into consideration. It's a subtle but important point --- and I remember a friend telling me a story of destroying some very expensive electronics because the sense line of the power supply came loose.

hyperion2010 8y ago

Oh man. My PhD work is focused on helping people communicate clearly about the measurements they are making and how to interpret them and where the pitfalls are in a research setting. Every time I read about something like this I wonder if I can use what I am working on to help people automatically detect when the assumptions of their measurement model could be violated. For example, if you can explicitly model the fact that the measurement is not the actual value and that they can become decoupled (and can thus brainstorm and model potential reasons), then you can start to help people realize that the map (measurements) are not the territory (reality), in ways that aren't just cute phrases without guidance for practical implementation.

spongo 8y ago
I'm curious: within which field are you doing this PhD? I could see you as a computer scientist, systems designer, political theorist, perhaps an economist or philosopher. Is any of your work available to read online?
- hyperion2010 8y ago
  I'm technically in neuroscience, neuroinformatics more specifically, but was raised by a political theorist. Unfortunately I have a bad habit of writing code rather than prose, and don't keep a blog or similar, so the first thing that I could point you to would be my thesis, which is still months away.
  - YeGoblynQueenne 8y ago
    Well, hurry up then :) Seriously, this sounds like a very interesting subject. Best of luck with your thesis writing and submission (mine's still a couple of years away).
  - dotancohen 8y ago
    Post the thesis to HN when you're done, or PM me (my Gmail username is the same as my HN username) and I'll host it and post it. Better communication tools for statistics and technical subjects is seriously something that the HN community could use and promote.

patcheudor 8y ago

What I still don't understand is why the pressure regulators and over pressure valves on the house gas meters didn't kick in? Were the homes involved so old that the meter protections failed or weren't there in the first place? It seems that ultimately you've got to have failsafes at the homes themselves. Without such failsafes, what would stop a bad actor from purposely over pressurizing a residential branch?

mikestew 8y ago
It does seem odd, and I’m guessing that such protections simply do not exist or the article might have mentioned it. Kinda like running a network with no firewall if you ask me. “I’ll accept whatever comes down the pipe” is a bad idea whether it’s a literal pipe or Ethernet.
lutorm 8y ago
What would those devices do? A pressure regulator is designed to handle a range of input pressures. If the pressure really got 75x higher than the design pressure, the regulators probably just failed.
- sschueller 8y ago
  Are there really no pressure release valves that will blow out at a certain over pressure? Like a spring release that will give way and release all of the gas outside the house.
jacquesm 8y ago
Those regulators work within a set range of input pressures, and need a certain delta to work properly. Over-pressure them severely and they will simply fail, and most such failures will lead to gas escaping from the regulator body. That is why you will usually find them outside of the premises they protect so they vent into the outdoors rather than into some enclosed space. As for your bad actor: what would he pressurize your lines with? An air compressor? He'd have to dig up the lines or disconnect them first and gas from the line would likely escape in quantities large enough to discourage such tricks. Just like in theory you could disconnect the mains from a house and then send a high voltage pulse down the feed lines, in practice pranksters and miscreants tend to avoid doing stuff that might get them killed instead.

chb 8y ago

"I admit to a morbid fascination with stories of technological disaster. I read NTSB accident reports the way some people consume murder mysteries. The narratives belong to the genre of tragedy." The author is not alone. Over a decade ago, there was a theater piece called "Charlie Victor Romeo" that consisted solely of actors re-enacting cockpit voice recordings of aircraft that crashed. http://charlievictorromeo.com/ http://charlievictorromeo.com/

scotty79 8y ago

What I see in those incidents is severe lack of backup sensors. Why after switching to new pipe nobody checked/could check the pressure in it? Why there were no other kind of speed sensors on a plane, simpler, less accurate, slower but not that vulnerable to icing? Why in Three Miles Island incident why people couldn't double check if reactor has water in it or not?

amluto 8y ago

I find it bizarre that it’s not required by code for a pressure regulation station to have a sensor in that station. I also wonder if the utiliy’s connection between the sensor and controller is on the internet.

dsfyu404ed 8y ago

Properly installed residential gas piping should be able to handle triple digit pressures. Appliances should be able to handle double digit pressures because almost all appliances that can run on NG also can be equipped to run on propane which outputs at up to 30psi depending on the regulator. Manufacturers slap a safety factor on top because it's a consumer product and you don't want someone to blow up their house and sue you because they used the wrong regulator. There's a reason some houses went bang and some houses didn't. I know it's fashionable to blame the megacorp (and it sure looks like they have plenty of blame in this case) but there's plenty of blame to go around here. There's a reason some houses went bang and others didn't. I've worked residential construction in MA and plumbers as a group have a pretty bad reputation (well earned, at least based on my experience, you should see some of the corners these guys will cut). I would wager that the houses that went bang weren't the ones that had their gas pipes done by the apprentice who still does everything by the book but the "seasoned professional" who knows exactly what you can get away with when your work only needs to hold 1/2psi. Like any large accident there are many dominoes that need to be lined up before they can all be knocked down at once. I think it's foolish to act like some contractor dutifully carrying out Colombia Gas's faulty work order is the only cause of this.

ekke 8y ago

This is fascinating. For anyone interested in a slightly odd but unique and in-depth view of Systems design and failure, would like to recommend "The Systems Bible: The Beginner's Guide to Systems Large and Small" by John Gall. https://www.amazon.com/Systems-Bible-Beginners-Guide-Large/dp/0961825170 https://www.amazon.com/Systems-Bible-Beginners-Guide-Large/d...

LawfulRewrite 8y ago

Next year we may see the first models without a steering wheel or a brake pedal—there goes the option of asking the driver (passenger?) to take over. This is bad news for everyone. This is the network effect exploitatively writ large, such that, surely you can prevent yourself from being inside such a thing, but as a lone individual, without laws in place to ban such a thing, you, your children, your family, your friends are all endangered by a blameless force that everyone can simply shrug at, and point to statistics claiming that there is even just an incremental improvement over ordinary human performance. You can stop yourself from posting selfies on social media, under your real name. You cannot stop other people from taking pictures, which your acquaintances discover and tag with your real name. This is kind of horrific. At least as horrific, or moreso than, current traffic statistics, because the moral hazard in play is abysmally worse. There was an effective arms race that took shape with SUVs and road rage in the late 1990's. I think something similar will take shape, as self driving cars ramp up. It may surprise some, to find that a self driving incident won't be accepted as blameless, glitchy software errors. Owners may see themselves villified directly, for things a car they chose to own, had subsequently carried out. I think there are three turns of consequence to a botched self driving car deployment. One: some will choose harm the legal owner as an individual, lawfully or lawlessly. Two: others will harm dealerships, mostly through sabotage. Three: overt action against the manufacturers. At all levels, and not limited to ordinary civil disobedience. These consequences are nothing to be sniffed at. Aviation shows us that spotty disasters don't result in civil unrest, but with a human in the loop survival was incentivized. Automotive deployments like this will be a fire and forget scenario, and the corporations loosing the reigns, have a demostrable history of neglect. I wonder if they anticipate, in the rush to market, just how severely the general public might react to finding their roads on the receiving end of software glitches that kill their firends and relatives like deer?