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- Hacker News
- To rephrase it: nothing happened, and reactor is back online generating clean electricity.
This is the equivalent of a Kubernetes pod restarting.
by stmw - Why they dropped?by high_na_euv
- I was unable to find the NRC filling, if someone finds the link to it, please drop a reply with it.
This is potentially interesting as this reactor recently had its operating license extended earlier in the year.
by toomuchtodo - Perhaps an interruption of power to the field windings of the affected control rods. Could be as simple as a control cabinet fried unexpectedly or some other electrical gremlin.
3 rods inserted into the core out of the many available would have disrupted the neutron flux profile away from what the reactor is intended to operate against in steady-state, so manual shutdown is the right answer until the cause of the control rod being dropped can be figured out, repaired, tested and then the reactor restarted.
But while not typical, this kind of event has happened many times before and will again. Pretty boring IMO, which is why I agree with the non-emergency declaration by NRC.
by mpyne - I have mixed feelings. It seems like nothing serious happened, no one was hurt, and all the systems worked, but on the other hand, this is still an emergency. Why did those rods fall in the first place?by imnotr0b0t
- This is not even in the same realm of reality as an emergency. There really was not even a reason this should've been reported in the news.by mixdup
- Sounds like the Nuclear Regulatory Commission explicitly categorized it as a "non-emergency"by hrldcpr
- This isn't even worthy of a news article. Nothing of consequence happened. It's only news because the media loves to scare people. Does a gas plant breaking or shutting down deserve a big media presence? No? Then this shouldn't either.by briandw
- The rods prevent an emergency. They’re a fail-safe.
It’s possible nothing was wrong and some sort of “blip” triggered them when they weren’t needed. And if so that’s annoying for the operators, but nothing bad was happening. And it confirmed the failsafe works.
If anything was starting to happen and the rods dropped and immediately stopped it that’s a failsafe working perfectly.
Either way this is fine. I know nuclear + unexpected = scary for many (maybe not you), but I don’t think that’s necessary here.
by MBCook - The rod holding mechanisms require active power to hold the rods out of the reactor. It sounds like once in a while, a rod accidentally drops, which is infinitely preferable to the alternative, of once in a while a rod failing to drop. But that unplanned adjustment to reactivity means, you don't want to simply use other means to boost the reactivity back up (like reducing boric acid in the water), because once you get the rod back out, it'll be too reactive. So they insert a couple more rods and call it a shutdown to take a few days or weeks to investigate and perform maintenance. Sounds like this is a highly planned for and fairly routine procedure, if not ideal. I'm sure they'll find a couple reasons why the rod unexpectedly dropped, and make changes to prevent an identical incident in the future.by hnuser123456
- I wonder why so much repetition in the article. Do they have word limit to hit?
I wish it have provided some reasons on this
by ImOssir - From the article: "This story was reported on-air by a journalist and has been converted to this platform with the assistance of AI. [...]"by verytrivial
- This "dropping" activity is not defined well in the context. Was it e.g. a controlled but uncommanded insertion? Or did something or some three things slip, snap, or something else? Can the rods be retrieved using BAU procedures, or is reactor in an annoying state now?
The details divulged seems to have been driven by event reporting regulations, not any specific news gathering or investigation, right?
by verytrivial - This article is just an over length summary of a very short preliminary notice published by NRC. Since it is non-emergency there will not necessarily be much follow up either, plants are just required to report any abnormality to NRC which publishes the reports online. Most of these reports are, like, procedural problems in employee drug testing.
Control rods are designed as fail safe so lots of scenarios can cause them to drop, could be a mechanical failure but probably more likely it was triggered by an electrical fault or intentionally by a safety system due to some condition they haven't quite worked out yet. Since having control rods in puts the reactor out of it's approved operating envelope it will lead to a trip out of an excess of caution. The fact that the trip wasn't triggered automatically suggests to me that the rods probably weren't inserted by a safety system but due to some fault.
by jcrawfordor - Did anyone else see the footer for the article?
Very cool! It probably helps these local TV stations to better monetize their on-air content by making it available in text.> This story was reported on-air by a journalist and has been converted to this platform with the assistance of AI. - What's probably more interesting than the incident itself is that it elicited well over a hundred comments on this site. Explosions happen at natural gas plants semi-frequently, few make the news, and fewer still are likely to get much attention here.by beloch
- It's standard human bias — a plane falling out of the sky with 200 people on it once a year is a major catastrophe we all know about within hours, but 40_000 people dying per year in road accidents is just a statistic. Besides, driving can't be all that unsafe — I do it every day and I'm fine!
Similarly here: something irrelevant happened at a nuclear power plant? PANIC! But 100_000 people died last year from coal plants dumping their waste products into the air we all breathe? Meh, who cares, how boring.
by Mawr - A challenge with news like this is there isn't an easy risk reference to put it into perspective. People only think of Chernobyl, Fukushima, 3-mile island, etc etc. We don't have something personal to relate it to to help us determine 'NBD, why is this a story?' or 'Wow! That was close!'. In everyday life I generally use driving to help me determine how risky something is. Driving is something most people do somewhat regularly and that we recognize as risky so we put controls on like training, regulations, special services, etc etc. Anything more risky than driving makes me really take notice. Anything less and I don't shrug it off, but I also don't get too worried.
I appreciate the factual nature of this story but I think an important aspect of journalism is giving people relatable references that allow them to better understand the information presented. It would be helpful if a story like this gave that context because without it it is hard to understand if this is 'Wow! What a close one!' or 'I guess this is a little interesting?'.
by jmward01 - I'm pretty sure the context here would require college level courses plus industry training on operational procedures to actually understand in any meaningful sense. Not much different than any other time some safety feature triggers at any other highly complex and hazardous industrial facility. Except that in all those other cases the media ignores it and leaves it to the technical experts who do understand the context to sort it out, and everybody goes on with their lives never knowing about it. But since this particular highly complex and hazardous industrial facility is a nuclear power plant what we will get is journalists who know nothing about the subject screaming about it to millions of other people who know nothing about it who will assume it was a near miss on killing half the population of Florida.by consensus1
- This is the equivalent of a Kubernetes pod restarting.by stmw
- You only accept the risks of driving because its normalised in your community. In many communities, public transport is the norm and it would be considered foolish to hand over car keys to a majority of the population.by Gud
- I actually thought they were talking about the island in the Caribbean since Florida is not mentioned in the article. Anyway, in case you did not know, the reactor in question is in Florida: https://en.wikipedia.org/wiki/St._Lucie_Nuclear_Power_Plant
- I can't be the only one to see that location and think "Holy climate change risk, Batman!"
Despite the appearance, is it uniquely prone to flooding or storm surges?
by ashleyn - I came here looking for that information, as I was incredibly surprised to learn of nuclear energy existing in the Caribbean.
It would be a dream to no longer have to rely on fossil fuels, but my native island is at the peak possible cross-section of hurricane, earthquakes, and volcano eruption risks, so I guess we're only missing tsunamis and dry forest fires to complete our bingo for "best place to build nuclear"
- Saint Lucia[^1] vs St. Lucie[^2]:
> The name "St. Lucie" is originally derived from the name of a settlement near Jupiter Inlet, which was founded on St. Lucia's Day in 1566. Due to numerous errors, the name later came to be associated with the present-day town of St. Lucie Village, Florida, north of present-day Port St. Lucie. After La Florida and St. Augustine, it is the oldest still-in-use European place name in the United States.
by js2 - https://www.nuclear-power.com/nuclear-power/reactor-physics/...
Can someone check my understanding: Control rods are suspended above the reactor as a sort of a "deadman's switch" - if a loss of power occurs, they will drop into the reactor core to limit reactivity. As a result, sometimes control rods will drop into the reactor accidentally. In these cases, the automatic system may withdraw other rods in order to maintain power output. However, this may overshoot the target power output or create a localized, dangerous "hot spot" elsewhere in the reactor core. In order to avoid this, in this case, the operators chose to insert other control rods instead of trying to stabilize the reactor under load.
by fwipsy - > sometimes control rods will drop into the reactor accidentally. In these cases, the automatic system may withdraw other rods in order to maintain power output
So this suggests that the dead man's switch has an automated anti-dead-man's switch that may result in more danger?
It'd be an interesting design choice, but defendable, if the "accidental dropping" rate is too high.
Safety wise, it would seem more sensible to try to keep the automatic drops unchallenged and try to prevent the conditions that make it happen.
by solarkraft - Yup. Often one rod fully in is no big deal -- it has been analyzed and you keep operating. But no one has certified to run the reactor with a few rods fully in.
The control systems are designed to err on the side of dropping the rods -- a failure to insert a rod is a lot worse than inserting one accidentally. So now they figure out why this happened while the reactor is in standby.
by mlyle - This happened in 2024 too.
This link (second one down, first event is missing control rods in Texas...) has almost the exact same wording as the article.
https://www.nrc.gov/reading-rm/doc-collections/event-status/...
I found the root cause of the older issue on LinkedIn of all places.
https://www.linkedin.com/posts/robert-meyer-8672ab4a_st-luci...
Root cause of 2024 was apparently a procedural issue combined with electrical failure of the control rod grippers.
by aeonik - Relevant 2024 excerpt from linkedin link:
CEA means Control Element Assembly. A CEA is a group of control rods that can be inserted into or withdrawn from a reactor coredouble hold was placed on Subgroup 4 resulting in the associated control rod lower grippers being engaged prior to removing the upper gripper drawer. After successful replacement of the UG coil CPMD the double hold was removed, per 2-NOP-99.07, and CEAs 43, 45, and 49 fell and fully inserted into the core.by robocat