LeadDev - 2018-03-21
On March 28, 1979, at exactly 4 o’clock in the morning, control rods slammed into the reactor core of Three Mile Island Unit #2, halting the nuclear reaction because of a fault in the reactor cooling system. At 4:02, the automated emergency cooling system activated as the reactor core temperature continued to rise. At 4:04, one of the plant operators made the befuddling decision to switch off the emergency cooling system, dooming the reactor to partial meltdown. Why? When something bad happens, it’s easy to just blame someone and move on. Taking the time to find the systemic causes, though, will not only help keep the problem from repeating, it will enable you to build the psychological safety necessary for your team to truly collaborate. Let’s let the story of Three Mile Island teach us how to make our teams stronger through systems thinking and just culture.
Another problem was that although the same valve had gotten stuck 18 months earlier at another reactor of the same design, resulting in the same problem (but discovered by the operators in time) Babcock & Wilcox had failed to notify other users of this reactor design of the flaw.
@Plate O'shrimp Jay, you need to realize that good author switch topics on the fly to make the read better. My comment about "sinister" was not aimed at you in particular. It was aimed at all the anti-nook-kooks who look for a sinister motive in anything we do. I meant no condescension and I'm sorry you interpreted my writing as such. As for being wrong, please point out to me where I am wrong and we'll see about what is the truth. I still have all my TMI papers - 4 full size file drawer's worth, so I can consult accurate and (in the era) contemporaneous reports and procedures. As we discovered new things, we engineers wrote TDRs - technical data reports. I have the whole set. So please, and this is not being sarcastic, point out to me where I'm wrong.
Total side note, but you'd think there might be a flow or pressure gauge on the relief valve so you have some idea of the quantity of material vented...
Granted this was 1974 state of the art, which was anything but... and looking at it now as an electrical engineer, I'm utterly amazed any of these plants survived with 10% of the computing power of the average microwave oven today... If we had started nuclear power now, today, with the calculation power we have and the relative ease of gathering data, we'd be much better off in 50 years compared to where we are today 50 years after the start of civilian nuclear power use.
I believe that that "other reactor" you talk about was the reactor at the Peach Bottom facility. I read about that in a book entitled "Final Warning" which described the accident at Three Mile Island. In the account given in that book, Peach Bottom and Three Mile Island had identical reactor equipment. When the valve at Peach Bottom got stuck, it was simply, and negligently, assumed that it wouldn't happen anywhere else --- and then it happened at Three Mile Island with much more catastrophic results.
It's my understanding that valve had failed at 11 power plants previously (it was caught by staff each time). NRC knew and didnt issue an alert.
Came to the video interested in nuclear accidents, left it with a new way of looking at mistakes. Awesome talk!
@Michel Roy I thought the system did have coolant pump redundancy, specifically when Nickolas mentions the coolant scrubber system he mentions that there were 8 scrubber tanks but the leak managed to knock all 8 of them out in unison. There were also 2 separate sets of pumps that were turned off so there was def some redundancy in the coolant system. The biggest stopping point in my eyes would be that all the sensors were located within the pressure management tank. Yes, that is cheaper, but it also left you without redundant sensors to be able to properly manage the other redundant systems (remember that the operators could only infer the water level in the reactor, they had no actual measure).
@Cryptic Oh, no redundant sensors then. Still.
@Folterknecht no, not incompetence, lousy protocols, defective human factors design (seriously, a critical indicator in the accident was on the back of a primary console), complacency.
He goes into the weeds when discussing decay heat, after a SCRAM. The TMI reactor would produce 11% of its normal heat output from decay heat, the amount of decay heat from a submarine nuclear reactor is pretty close to that, but he dismisses it with a handwave, which is BS.
But then, he admitted at the beginning of the last ten minutes admitting he knows nothing about nuclear reactors. And thus, tars Rickover, who had his faults and frankly, reactor theory and advanced practices should've also been included, rather than engineering exclusive approaches in building the damned things. But, we lost two nuclear submarines before Rickover took over, we've lost precisely zero nuclear submarines since.
Had the exchanger went solid and a steamhammer occurred, the coolant loop would've ruptured, which is ignored.
After all, he's willing to ignore 780 megawatts. That's essentially sitting on a stick of dynamite, ignoring its detonation, while sitting on top of it (figure around 3/4 stick of dynamite for a rough equivalent in joules per minute equivalent units) for a rough measure, being "easily ignored" for a submarine.
"A loss of power and a disabled ship", no, it'd result in destruction of coolant assemblies, probable puncturing of the pressure hull and that whole dead thing for vessel and crew, still, not a biggie. Kruger-Dunning is strong in this one.
He goes into the pilot valve outlet temperature, on the right path, again, human factors.
Still, on the right path, loses his way through ignorance. The pilot relief valve could have been visually confirmed and 200 degrees F is not boiling and normal observation, 228 is above 212 degrees F, which is boiling, so there is a problem. Again, human factors error.
I'll conditionally agree, 300 baud is slow - save for an alert printer, which showed 40 - 50 alerts, hell, in a second, that's still quite fast, given printer speeds back then and I owned a three head dot matrix printer that nearly shook my printer stand apart.
I've slowed down with age, I can't read at 2400 baud speeds any longer, I'm closer to 1200 baud speed. Trust me, I've read modem buffers many times over the years.
I've also read megabit log reports, via an SIEM, which wasn't available then, to organize, prioritize and categorize alert events.
The reported printer rate depends upon the printer model, which is undisclosed, but likely a slight bit faster - by a fair margin and the events weren't that quickly proceeding.
The entire disaster was a slow motion catastrophe, discovered by an incoming shift operator, who checked the far side, aka, back of the operator on duty's console and noticed the "aw shit" indicator that resolved the mess.
I'll fundamentally disagree that human errors are a fundamental cause of any major problem, save if human factors are considered, such as putting an important indicator outside of the view of someone attempting to resolve a major problem.
Human errors are a significant cause of many problems, see any highway crash for evidence of that, a 50 car pile-up on I-80 recently comes to mind, obviously some engineer should've slowed all traffic driving on ice, covered by snow, or something.
Further flawed is seeking forward, rather than all directions, thereby addressing all failures.
Such failures are addressed via training, not discipline, save in rare cases of intentional malfeasance, which he'd miss and is, thankfully, rare enough to nearly be discarded - nearly.
Or should we disregard a shooting incident in a Florida military installation recently?
I also agree, a non-confrontational review is required. Been in my share of titsup situations, everyone involved was beating themselves up and we can do a far better job than any outsider. Hence, a full, extensive investigation is required - from a neutral approach.
Come in with an opinion, the report is going to be fiction, supporting the opinion.
In one incident, I missed a single event out of around 100k events, which suggested something askance. Subsequent additions to the platform allowed that to become revealing and I wrote a well accepted incident response report, once we had that previously hidden visibility into events that previously was invisible. That, added due to corporate leadership could be criminally charged, due to malfeasance by ignoring an ongoing breach.
My report included reconstructed malware samples, as well as specifics on the attack tactics, techniques and practices of the attacker. The FBI was quite thankful.
How he arrived at the correct conclusion, despite his explanation getting lost in the weeds at multiple points is astounding, suggesting he excessively Goobered it down, wrongfully so.
Such doesn't do the subject proper justice.
There were major management problems, perhaps TEPCO might've avoided them, if such was discussed in depth globally. Add in human factors engineering, because nobody wants to think everything just turned into shit on their shift, key indicators of yes, it has, are critical within the view of anyone operating in any critical position.
Full disclosure, not former Navy, I'm retired Army, worked in nuclear missiles, but know quite a bit about fission fueled power systems and am less than three miles from Two and a Quarter Mile Island.
Which had its remaining unit shut down in September. I somewhat miss that plume visible out of my home's window, alas, the cost was twice the cost of Natural Gas for power generation.
@Stephen Villano And you are the biggest Human Error
Oh, dear. 6.5% of 12MW is not, unsurprisingly, 750MW as you state. It’s 750Kw. So as he says, negligible in relative terms.
Superb account of both technical and human factors in this incident, but Nickolas's greatest achievement in this presentation was to make the "lessons to learn" process and the attribution of blame issue applicable to a vastly greater range of technical and human endeavours. Thank you.
This has been the most amazing explanation of 3 Mile Island I have heard to date. Thank you for this!!!
I live and work in the shadow of this plant, and I can tell you, that as neighbors of Three Mile Island, we have never, in 40 years, been give such a clear and detailed accounting of what happened inside that plant.
@macgto It is one of those thing where, if things can be hidden, things will be hidden, and we (the general public) will never really know what goes on with things like this in full. While this video is by far the best explanation of what happened I have seen to date, I still think we will never know the full truth.
I'm sure you are correct. My father is a retired engineer who worked at the Calvert Cliffs Nuclear Plant in Maryland, I forwarded this video to him to watch. I'm interested on hearing his take.
Car, you may not have noticed this, but normally it takes decades on most any high-level screw-up like this before the ~truth will come out,,, Usually most or all the people in question are dead,,
@macgto howdy, neighbor!
I rather miss seeing the plume from the remaining unit, but alas, its cost was double natural gas electrical production.
The major part of the entire hot mess was human factors engineering.
Seriously, whoinhell looks on the far side of their console for a critical indicator?
I'll not go into ignoring a submarine reactor SCRAM decay heat being trivial, it's close to a stick of TNT going off, nobody in their right mind ignores that!
Per scale, both were equally important, the sub having a lot simpler number of systems.
And of course, more technical geared indicators, of every part of the operational components of the system, some Rickover SOB insisting on them, as well as precise engineering documentation and methods for nuclear submarines.
as someone who was involved in the TMI recovery effort, I think this is an excellent summary. we all thought the operators were screwups until we looked at things from their perspective. don't blame the operators - they did what their training and experience told them to do.
I think Mr Means could've talked more about "setting people up to fail" - the very design of the BW Nuclear Steam Supply System with once thru steam generators that contain very little water set operators up for failure - the PORV is designed to open with loss of condensate. the other PWR designs (Westinghouse and CE at the time) do not.
BW did this to try to distinguish themselves from the other vendor (the one thrus can superheat steam slightly, others cannot) which was driven by their desire for economic success. so should we revamp capitalism also.
well beyond my pay grade.
Reminds me of the Challenger disaster. The O-rings were never supposed to leak as failure could result in the loss of the spacecraft, but since the spacecraft managed to survive (somehow) multiple launches, leaks were ignored, until a particularly cold day arrived. A culture of deviance set in. Likewise, at TMI the valve wasn't supposed to leak but was ignored because things continued to run even though the water temp exceeded 200 degrees. If the valve problem had been addressed at the start, the reactor wouldn't have been subsequently lost.
@Gary Hoffmann Over weight
As far as the challenger goes, if they would have noticed the fire coming out of the side of the booster rocket, the boosters could have been jettisoned early to save the challenger.
@fred garvin Assuming Challenger would have survived the jettison of the SRB's operating at full power (questionable), it would still have to gain enough altitude with its main engines to reach the Azores for a safe landing, else it would have made one giant splashdown in the Atlantic.
Fineman has discovered the cause of a spaceshuttle which id is the deformation of a o riing. he is a excellent genius even if doesn't work at the Nasa. 🌻
In the hearing of the Rogers Commision Lawrence Mulloy and George Hardy referred to the secondary o-ring as being redundant although it was known that the primary o-rings had shown signs of blow-by on several launches. They were relying on the secondary o-rings to be in position to seal but at that point they weren't redundant anymore, they were necessary and essential. Blow-bys of the primary o-rings had to be considered critical failures but they decided to overlook it because they got away with it on 24 previous launches.
Wow, wow. Thumbs up. I have never seen any nuclear "experts" explain the whole saga so clearly, let alone by an outsider.
@Naw Dawg I came here from HBO🤔 I've been on a 5 day binge 🤪🤪.
@MINNESOTA Youtube: Hey kid, I've got some more of that Nuclear Reactor
@MINNESOTA That's how I started too, that show was too good.
That is because UNLIKE Nickolas Means, the "experts" are responsible for proprietary information both for the protection of their employer's trade secrets as well as the public in general from allowing dangerous people obtaining their specialized information and using it to compromise the safety of the plant.
Wow, what an incredible video! Very educational from a nuclear standpoint (what exactly happened) but was rewarded with a management and engineering and life lesson. Thank you for this!
Very good. As a life long control systems engineer I can confirm this presentation is accurate and is in complete alignment with my own experience. TMI had a big impact not just on the nuclear industry, but industrial systems everywhere. President Carter's Commission did a fantastic job and much credit is owed to them.
It so clear you dont evne know what causes the explosions in the first place ... or how physics work .. you dont even know how the old reacotrs work . how new reactors are suppoised to be save .. why molten salt reactors cant explode and what did go worn in any accident .. you never even looked clearly at the topic 🤦♀️🤦♀️🤦♀️
@karma Chernobyl was the result of a 1-in-a-billion beyond-lottery-winning sequence of events on top of a rushed and poorly designed reactor. Fukushima was down to corruption at Tepco who had been warned countless times about the vulnerabilities at Fukushima Daichi. Not to mention that both were second generation reactors, today's third generation reactors have so many built-in redundancies (many of which thanks to Chernobyl) that it is actually tricky to keep them running because even the slightest discrepancy in any of the reactor's systems will cause it to shut down. For the first time it genuinely IS impossible for a reactor to melt or explode.
And that is just the third generation reactors we are building now, the fourth generation reactors projected to be ready for construction by the 2040's will not only have all of these safety mechanisms but they will also be capable of running on spent fuel meaning that we can process some of the nuclear waste we have scattered around.
@Rob Fraser Completely agree that it is a very rare event. Nevertheless, Chernobyl did happen. Until then RBMK reactors were similarly claimed to be meltdown/explosion proof. MSRs operate at even higher temperatures so definitely, they have much more potential for damage, if something goes wrong. Of course there will be redundancies and safeguards in place, but it is just a matter of time before 'the lottery is won' and another such event happens. Above all, the human factor can't be discounted. Human errors can happen. Reactors are prime targets for terrorists or enemy nations in case of war to attack. And explosion is not the sole risk. MSRs use near weapon-grade enrichment levels for fuel, which needs to be handled extremely safely. Any leak can be deadly. Fukushima has over 1000000 tons of contaminated water. They are running out of space to store it safely and are contemplating releasing it into the ocean. How many such Fukushimas does the Earth have space for?
Why doesn't humanity learn from all that has happened? Why take unnecessary risks playing with something that has the potential for such mass destruction, when much more superior and infinitely safer alternatives are available today?
Wonderful presentation. So much to reflect on about system design, monitoring and control systems, the importance of checklists and protocols.
This is an excellent description of what happened at TMI-2. Thanks for sharing.
I would add only a small comment, pertaining to why steam is condensed before being pumped back to the primary loop instead of just piping it there as steam, or more likely pumping it there as steam.
Typically gases do not "pump" very well, thus it takes much larger equipment to deal with the huge volumes of gases involved - certainly much, much more than it would with liquid water. When the steam is condensed back to water, the volume of materials becomes a small percentage of what would have been required as steam. So, economics and several other considerations require conversion back to something that is manageable to handle and transport.
Again, thanks.
That was such an exceptional presentation on so many levels, I think I'll be revisiting this over time. Thanks!
As a PA local there's a stark and humbling reminder of what happened that day. This one set of HV Towers in and around the North East Substation is actually missing one set of lines. This is because the lower-than-expected power output rendered the additional miles and miles of HV lines worthless, and they were removed likely to be recycled or used elsewhere. Even miles from the plant itself you can find full-sized towers oddly missing half of their lines.
You can see this on Google Street View.
I found this to be an informative talk. I'm not getting into the controversy around nuclear power plants ... save to mention I am intrigued by the thorium cycle/molten salt technologies being developed recently. I just like the clear summary of the chain of events. And your discussion of the second story. I have a new entry on my reading list thanks to this presentation. Good job.
Thanks for clearing that up. I've been wondering what caused it since it happened. I was a welding inspector on the Waterford 3 plant at the time and only heard rumors of incompetence which I now feel were untrue. My brother made a bundle helping to clean it up. They needed men who were knowledgeable and hadn't been exposed too much and he was a superintendent at the Fulton power plant who seldom was exposed to radiation. The men had only a very short time to work in the environment before they needed to get out. Less than ten years later my brother died of leukemia.
Absolutely fascinating and well presented talk. Incredible to know that they were ex sub engineers which explains some of the decisions they took. So easy to blame and criticise when we have hindsight. The fact is they did their best and at least it didn't turn into a Chernobyl.
Amazing talk! I work in DevOps and I have already been applying some of this during outages. But there is a lot I haven’t thought of before. I am passing this around to my team because I hope it improves our incident response.
Absolutely incredible talk, Nikolas. I came to the video wondering what about TMI could be learned and used in software development (and indeed, everything else, too), and left inspired.
I never really knew much about TMI, and I learned tons about that.
Never really thought about "first stories" and "second stories", but that's eye-opening, too.
I've heard/thought of the concept of not focusing on punishment, but rather focusing on information gathering and processing, but hadn't really ever heard of it used in a non-textbook way.
Seriously good stuff here!
Arguably one of the most important videos I've seen in a long time. Studying engineering failures is like that. And then there's the important character lessons for organizations...
This was an amazing talk and the generalized lesson at the end is beautifully stated. I've often seen a quote attributed to Eleanor Roosevelt (I've researched it and while there is no one claiming she didn't say it or even any notable claims that it came from someone else, no one who has tried has been able to substantiate that she definitely said it): 'Smart people talk about ideas. Mediocre people talk about events. Stupid people talk about people.' I've seen it rendered with different verbiage and sometimes different order, but the core is the same. While I imagine many people interpret that as just an admonition against gossip, I've always thought it was much more meaningful than that. If you talk about people (specific individuals, not people in general), any observations or information gained is necessarily limited to being applicable to only those people.
If John cheated on Susan, then this fact doesn't carry any real meaning further than that. If you talk about cheating in general, the conversation is lifted and you might learn interesting and new perspectives that help in many situations. Similarly, if you look for someone to blame and seek out the human story of what persons X, Y, and Z did and what occurred, any blame apportioned doesn't help anybody. But if you can look at the situation more generally and extract from it things to change so that persons A, B, and C put in the same situation are less likely to encounter the same challenges, or be likely to make the same decisions, you can help the whole of humanity. Even if blame, shame, and punishment DID work... it would only work for persons X, Y, and Z. Persons A, B, and C would see no benefit and would remain at the same level of risk of repeating the same errors.
A LITTLE KNOWN TMI STORY: My father was one of the B&W Engineers on the first (and subsequent) conference phone calls. Unlike today these were a big deal, relatively expensive and it took some time to setup. On the first conference call an AT&T operator breaks into the call and asks, "Who's paying for this call?". Everyone at the table in three locations looks at each other dumbfounded and there is absolute silence. When there is no response the operator hangs up disconnecting the conference call. And in three places all there is to hear is the hum of the dialtone.
My father was one of the B&W engineers who knew immediately what the problem was. . . albeit too late.
What the current generations born after TMI need to know is that this was the END of nuclear power in the US. Old plants continue to run but many new plants under construction at the time (some actually complete) were abandoned and no new plants were approved since that time. Nuclear power has many problems (such as waste transportation and disposal), that have not been solved technically OR politically. The technical is always possible, but the political?
I would have immediately yelled -- regardless of which end I was on, and who was more senior -- "WE ARE, OPERATOR; HERE'S OUR NUMBER!"
It's how I act all day long anyway, and at least this time it would have been hard for the people above me to have me fired.
@amorag59 Not "too far apart"; the distance does not change if the pressure increases rather than volume. The effect of thermal translational kinetic energy is that the typical combined velocity of the neutron and nucleus impact is higher. There is too much energy, so the neutron just keeps going through rather than being captured.
The "cross section" of the reaction is very sensitive to the collision energy. Raising the temperature -- making the nucleus dart around and high speed too -- reduces the cross-section by orders of magnitude.
The overarching idea is to build reactors that are "fail safe".
The biggest flaw was to go with the technology developed for ships, excluding any other design.
@John Długosz Thanks for the info
The French seem to have solved the waste problem, with vitrification(waste sealed in molten glass), and design(no problems AFAIK)
What is your dad's name? I probably know him. The problems of transport and "disposal" HAVE been solved. There is a version of the molten salt reactor specifically designed to burn light water reactor spent fuel. Another reactor design is designed to transmute and/or burn the Actinides (the bad stuff) into either inert elements or short-lived isotopes.
Remember that when the novice tries to talk about nuclear safety, he is talking about 50s and 60s designs and that the high pressure water reactors were forced on the industry by Adm Rickover. I had the unfortunate "pleasure" of having to share part of my office at TMI-1 with the little bastard. GPU had hired him as a "consultant" during the restart licensing negotiations. We did not get along.
the predicament of the operators at TMI reminds me of the time that I had hot water coming out of my cold faucets and no water at all coming out of the hot ones - afterwards it seemed entirely obvious that my boiler had a faulty vacuum-breaker causing water in the boiler to flow back out of the cold water inlet pipe and into the cold water pipes throughout the house. But until a plumber came and found the fault, it was a total mystery, despite the cause having proved to be extremely obvious on the face of it.
This was a good talk. So.. 1st story is told by someone who was around for the event but not actually there. 2nd story is told from a first person point of view by actual participants during an event. 3rd story is how we choose to document history. 4th story is an evaluation, analysis and interpretation of the history that we had chose to document.
Not only did I find an excellent summary on the TMI accident, I also found a new perspective for analyzing problems in the future. Thanks for the video.
Been working at the gas station all your life? Glad you are finding out something useful,, The point he failed to bring to the forefront is, AUTOMATION,, IFF (if and only if) the software is written correctly, you can remove human-faults that screwed things up here,,
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It's really no different than automated cars driving up around,, Automation removes the human-errors that were injected into the process as shown here
Sounds like a way to also deal with personal relationships that have soured from unaddressed ressentiments. Compassion for the "what" caused them to make that choice as opposed to waiting for them to own their mistake. Great talk!
Great points. I enjoy watching every post-incident animation the USCSB makes, looking back I see all of the points you made in those videos. Even when it comes to mistakes, often companies have poor practices that frequently stray from procedure or pressure from management to ignore safety recommendations.
This is made of 100% solid awesome. I was 13 at the time, and my dad was a physicist in a completely different field, but understood enough about nuclear power to know that events like this didn't represent a problem with the safety of nuclear power. The point he kept hammering on is that taken as a whole, the system worked. No leak occurred. They experienced an unpredictable series of corner-case events and still did not exceed the overall inherent design safety. The series of events is one that in a conference room talking about design, someone would say "but that's absurd. Next you'll say that we have to safeguard against aliens coming in and sabotaging the system."
Among other things I learned from my dad is that Murphy's Law is not simply a cynical joke about how unlucky human beings are. It is a design principle that is baked into the way a federal government should design things that must not fail. From the Apollo missions to nuclear power to the $500 hammer in the toolkit on FMC's Bradley Fighting Vehicle. It only looks like waste when someone with an agenda wants to make someone else look bad in hindsight.
> corner case
You should read about the Davis Besse incident. They experienced essentially the same scenario: secondary loop problem, stuck PORV, high water level in the pressurizer, manual override of the injection pumps, the primary coolant even began to boil in the pumps and reactor vessel.
The only major difference in the scenario was theirs happened during startup and the core had much less decay power. Davis Besse was 18 months before Three-Mile Island.
B&W didn't fully understand that their procedures and training were not preparing operators for a leak from the pressurizer, and that's the second story I take from this presentation and a little more reading. Mike Derivan was the shift supervisor at Davis Besse and has written a deeply fascinating (but more technically detailed) presentation.
http://ansnuclearcafe.org/2014/04/23/tmi-operators-did-what-they-were-trained-to-do/
(One of the systems he mentions which was missing from this talk is the volume control system. Some water is drained from the primary loop - "letdown flow" - then cooled, filtered, demineralized. This cool water is injected at the coolant pump seals so that they don't overheat and so that the small amount of water that weeps through the seals is relatively clean. Water can also be returned to the loop through a heat-exchanger which reheats it. You can read an overview of all the systems on Gen II BWRs in the US here : https://www.nrc.gov/reading-rm/basic-ref/students/for-educators/04.pdf)
@Jordan Rodrigues The pdf link from nrc.gov leads to a "page not found" error. Apparantly the NRC doesn't want us to see that info. jerks
never mind, there was a right parentheses that auto. showed up after clicking the link. it works.
Excellent conference! Thank you! As an engineer, I appreciate a little learning like this.
This is a great presentation, and does a very good job of simplifying the TMI issues for common understanding. Regrettably, TMI U1 ended power operation yesterday. If the public understood just how much changed after TMI, it might still be producing carbon free electricity.
Pretty amazing that despite so many human errors, the safety measures in the plant kept the citizens protected. Incredible.
Really glad to have stumbled across this excellent talk ✌️
TMI is often viewed as a way of increasing accuracy. I have seen this over and over in many different places. The people who design a system frequently do not understand the mental implications of constant data overload on operators.
@- When you state that "Nuclear Energy is really complicated", are you referring to the principles of nuclear physics or the actual operation of a nuclear reactor (as a part of electrical energy production)?!? Regardless, "Nuclear Energy" is not particularly complicated, although individuals of average intellect (or lower) will likely fail to adequately comprehend much of the science involved.
This has to be one of the best talks i've ever watched! Kudos!
I take it you haven't come across Yuri Bezmenov's video presentations on YT?
That was an excellent presentation! Not only a detailed, second by second account of what happened, but how the "blame" should be handled and what should be accounted for, and not who!
As a nuclear engineer with 20 years of experience, I can say that this was a very well done and accurate description of the TMI accident. The crux of the (pathologically wrong) operator responses is that their training (which came from the Navy) was (1) to never, never, never let a pressurizer go solid (i.e. all water and no steam), under any circumstances, and (2) the only reliable indication of water inventory in the reactor vessel is pressurizer level. The accident unfortunately had low pressure, low water inventory, and a high pressurizer level, which made them think that there was ::too much:: water in the primary circuit (exactly the opposite of what the actual situation was). The operators followed their training, but their training was very deficient. The regulatory agency (the Nuclear Regulatory Commission) and the vendor (Babcock & Wilcox) deserve as much or more blame than the operators.
Fortunately, the nuclear industry had a revolution after this accident, forcing enormous changes in the regulatory, training, and safety analysis in the industry. Recognition of cognitive errors became a huge emphasis on training.
Sadly we now see corporations like Boeing, Wall Street, and Big Banks that similarly engage in deficient business practices and whom have "captured" their regulatory agencies, and absolutely nothing is being done about it.
Wow, what an excellent, EXCELLENT presentation. I have just two minor comments: First, there is another bias that can come into play, and that's normalcy bias. When things go outside our experience and training, we have difficulty recognizing the actual problem as serious. Second, I was very happy when the accident occurred, that President Carter was himself a former Navy nuclear engineer. I'm sure he asked some very pointed questions during his visit, and would have seen through any B.S.
now the US has trump. His biggest bias seems to be ego.
Carter knew his shit!
https://www.youtube.com/watch?v=-68iTvhWNB0
@Jason Honingford Yes he did and still does. Still sharp as a tack at age 94 with what is going on in our world today and often speaks out about it. An amazing man.
When I took a Health & Safety course at work about 8 years ago, this same point was made over and over: look deeper for the true causes of an accident, which are most likely in the way a system works, or more importantly, the way a system fails. Thank you, Mr. Means, for a deeper lesson in life!
This is a fundamentally brilliant talk, how have I only just seen this! This will be being shared around my organisation!
Listening to this reminds me of working environments I've been in and seen people shamed, blamed or fired for their mistakes. It's often been a systemic issue that caused their fault, lax safety, following of guidelines or laws etc...
No one goes to work to actively screw up, as a manager or supervisor you need to monitor your employee ecosystem, unless you enjoy a high turn over of staff (aka more work for you).
I've been part of a team where several people received warnings, some quit, some were fired and the actual culprit for all the issues stayed employed, allowing their poison to spread but always take down others.
Thank you Nickolas. I worked at a place where chronic communication issues plagued the office and nobody ever took the time to address the underlying problems behind them.
This is exactly the talk I needed to hear. It isn't about not talking responsibility and growing, it is understanding that you can try your best and still mess up. We are human and it happens.
This is an excellent talk, easily in my top 5. It's interesting throughout with an eye-opening lesson at the end.
Water hammer in the primary is way scarier on a sub than just "loss of propulsion and disabled [boat]." You're talking about the potential for a steam explosion in a very confined space, possibly under the surface of the ocean.
@Tim Avery 😮wow I was on the 626 in prototype 😅
@nunya Or a carrier, where do you think catapult steam comes from anyway...
@MM 27 That was a torpedo that exploded. ;)
@Tim Avery There was that one submarine that may have been lost after a scram while doing an emergency dive... maybe...
@Tim Avery would we really know if they had a nuclear accident though?
Great presentation!
I head the word "infer" twice at critical moments in the description of the mechanical nature of this highly complex feat of engineering.
Infer the water level inside the reactor and infer the position of the pilot operated relief valve. With all the controls and indicators that are already present on the system, why in the world would you leave ANYTHING to inference!? Yea, I get that physics and machine design can make for extremely reliable inference data, but the fact that this accident could have been prevented if the operators just had a tiny bit more information to guide their decisions, makes it seem like the redundancy would have been worth it......but, that's just hindsight rearing its head.
So , would you volunteer to fix the water level sensor in the reactor core when it breaks?
There's a reason beyond "cost savings" for not putting a sensor in there.
Any sensor you put inside the containment vessel would require routine maintenance and testing.
The danger this posed to personnel was the main reason they decided to rely on level sensors in the pressurizers.
Another reason was to minimize penetrations into the reactor vessel (wiring) to reduce the risk of leaks.
The only two issues I had with this excellent presentation ( and both are "nit picking")
1. Skipped over the reasons for not having a level sensor in the core.
2.Never mentioned that President Carter was a Nuclear Engineer who was also trained by Admiral Rickover.
President Carter knew EXACTLY what went wrong.
Wow! The ending was so unexpected but so eye opening. Thank so much for this! It has labelled and put words to something I had been thinking for a while but could not express, that if people make bad decisions, we should try to find out what was at the root cause of that rather than letting the blame rest on them. Apply this second story principle to criminal cases for example like a serial killer: Yes, the killer killed people and should be punished, but if we don't look beyond that and remain happy with their execution or life imrisonment without looking at why they became the terrible person that would do that in an effort to lower risk factors for creating more killers in society, then all we've done is stopped one killer but ignored the root cause and what we could have learned to prevent 10 more from being products of similar environmental risk factors in the future and that makes the truly bad decision that of a public that is happy just to see the offender punished, but not to learn why a James what's his name would shoot up a movie theatre full of people.. It's not enough to find out who sold him the guns and punih them too. We don't get the core cause and so the core cause, unidentified continues to fester or exist in other families or communities and later creates more mass murderers which could have been stopped earlier if the really key why and what quetions at root cause had been asked and answered with truthfulness. What bad incidents in the past happened to them, things that could have been prevented or foerseen that would destroy or destabilize that person's psychology that weren't foreseen or were noticed but overlooked as unimportant or not identified as key risk factors for harming a person's mental health that weren't dealt with and why.. IT's the why behind the why that is often overlooked yet is more central going forward to the prevention of similar future incidents. This getting at the root cause, the why behind the why is a philosophy that can have such broad applications and bitter implications for why some issues never seem to get solves why its more of the same, because we're focused just on the blame (of people) and not looking at the broader systemic issues. When I think how many sectors this idea can be applied to, its staggering the opportunities we're missing in society where we could be righting the boat instead of going down with the ship time and time again.I wonder, if a real reinvetigation of the Titanic disaster along these lines would reveal a drastically different picture of why the ship sank (it was never about an iceberg, that's just a tool of destruction enabled by bad decisions which were caused by ?WHAT? ?????
I've viewed all of Nick's vids, and I must say that Nick has an uncanny ability to zero in on the human element. That part of a system that is the most likely to fail. As Nick stated, had the system been left to govern itself, it would have resolved the problem without crisis. The solution to the problem was already programed.
Great presentation, really explained the reactor, systems, events, and people that were involved.
Okay it’s the end and I am crying.
Thank you!
What an interesting talk!
As a victim of corporate blaming I can assert that it’s the worst feeling and really does put an employee on the defensive.
Terrible manager where I worked. The worst!
As a mechanical engineer, specializing in monitoring and control systems, I can see first some design faults in the monitoring system, thus the operating faults caused.
outcome bias how are you doing ?
This was a phenomenal presentation that could be condensed into a killer TED talk.
Xefe - 2019-06-10
Came in for a nuclear dissaster story and came out with a life and management lesson.
DAMN YOU NICKOLAAAAAAAAAS
Trace Sonny - 2021-08-22
Sorry to be so off topic but does anyone know of a method to get back into an Instagram account?
I was stupid lost my password. I love any tips you can offer me.
Darren Idris - 2021-08-22
@Trace Sonny Instablaster :)
Trace Sonny - 2021-08-22
@Darren Idris it did the trick and I now got access to my account again. I am so happy:D
Thanks so much you saved my ass !
Darren Idris - 2021-08-22
@Trace Sonny Happy to help :D