8 ms·

SL-1: The only fatal nuclear reactor accident in US history

68 points by herendin 11y ago

retrogradeorbit 11y ago
"...killed by the only fatal reactor accident in US history." Is that really true? '“Nobody died at Three Mile Island” — unless you count babies.' http://www.counterpunch.org/2015/03/27/cancer-and-infant-mortality-at-three-mile-island/ http://www.counterpunch.org/2015/03/27/cancer-and-infant-mor...
- tdicola 11y ago
  TMI's radioactive gas release was nothing compared to the years of above-ground nuclear tests in the 50's and 60's. There are plenty of non-nuclear superfund sites that have done more harm too.
- droiditecH 11y ago
  > Nobody died at Three Mile Island” — unless you count babies Seems consistent with liberals...
- illumen 11y ago
  Can someone change the obviously untrue headline?
- rosser 11y ago
  It's certainly debatable, but as I understand it, there's a distinction made between accidents in which people are killed, and those because of which people are killed. This is one of the former. It's a very small set. Deaths from radiation poisoning, which is the deadly thing most strongly associated with nuclear accidents, tend to number among the latter, because it's the radiation, a consequence of the accident, that kills those victims, not the accident, itself. Again, it's a debatable distinction, but it's the one we've chosen to make. You conflate them either out of ignorance, or because you're fearmongering.
  - illumen 11y ago
    "You conflate them either out of ignorance, or because you're fearmongering." It's a valid argument that people die because of multiple nuclear accidents in the USA. In a car accident if someone dies two days after in hospital as a result because of injuries (a consequence of the accident), people say that they died of a car accident. Radiation poisoning is obtained as a result of a nuclear accident. In exactly the same way as injuries obtained as the result of other accidents. To draw a distinction, and claim there is a difference is being ambiguous. Many people will misunderstand the difference because it makes no sense, and is not the way everyone else uses the language. To claim people understanding the statement in a sound way are fearmongering or being ignorant is silly. The headline is misleading. ps. "only fatal reactor accident in US history" claim, apart from the other deaths within the USA, the recent (and still ongoing) Fukushima accident used a General Electric design from the USA.
    - rosser 11y ago
      In a car accident if someone dies two days after in hospital as a result because of injuries (a consequence of the accident), people say that they died of a car accident. Yes, exactly. We say they died of a car accident. Not in one. See the difference?
    - Spooky23 11y ago
      You're not going to make any headway here, this is a very pro-nuclear crowd. Google some of the Fukishima threads here to really understand it. IMO, nuclear power generation in the U.S. is an overly secretive industry running obsolete on arrival technology that is a public health hazard. Just like coal, the industry enjoys a very cozy relationship with government that enables it to weasel around their pretty obvious risks and problems they bring.
      - alextgordon 11y ago
        Few will dispute any of that. I don't think there's a person here who wouldn't like ubiquitous solar power! But when the alternative is coal, nuclear power is less polluting, less radioactive and less likely to kill you.
- rdl 11y ago
  Somewhat crazy, but: One more level of abstraction, and lots of people die at nuclear plants because they're not built yet (or existing ones were delayed, or in maintenance), due to the coal power which they would displace.
  - rimantas 11y ago
    And coal power plants spread more radioactive material than nuclear ones.
    - spacecowboy_lon 11y ago
      And that's not counting the coal miners that die in accidents or get silicosis aka black lung
      - pgeorgi 11y ago
        Family of mine worked in uranium mines. Lots of people died there as a result of radioactive particles that ended up in their lungs (plus the typical mining accidents).
  - InclinedPlane 11y ago
    Even weirder, the rates of cancer are higher around nuclear power plant locations. Even when the plants haven't been built yet. Turns out, such things tens to get built in old industrial areas that are already heavily contaminated.
    - iwwr 11y ago
      If anything causes people to get medical check-ups more often it's still beneficial, even if the reason for doing it may be irrational (fear of radiation leaked from a nuclear reactor). Such fears may even trigger a statistical increase in cancer rates from increased detection.
    - HCIdivision17 11y ago
      This is going to be my go-to factoid on nuclear plant nimby-ism. My uncle had an interesting experience in this vein. It was well understood that high voltage power lines caused all manner of health issues, from cancer to various degenerative diseases. He understood that EM radiation from the lines really shouldn't be very dangerous, though, and didn't think much of the leg of a line tower in his back yard. Then one day the power company came through to clear out the underbrush growing around the base of the line's tower. In just two days after the spraying all vegitation was thoroughly dead. Turns out they spray an Agent Orange-like chemical to keep the towers maintained from plant overgrowth. You can bet he moved shortly after noticing that. (This was some years ago, and likely has been (hopefully) rectified.)
abecode 11y ago
That part of Idaho is interesting to drive through. It's near craters of the moon national park. The Idaho Nuclear Laboratory is pretty big. I remember it being nearly 50 miles along one side of the road with all barbed wire fences. It's pretty lonely and creepy out there. There was one cliff in Atomic City that was covered with graffiti of large random numbers. It turned out that the numbers were from high school graduating classes but the numbers weren't in order so it seemed like some random code.
Animats 11y ago
The SL-1 story is well known in the industry. The Atomic Energy Commission has a video.[1] SL-1 was an experimental reactor at the National Reactor Testing Station in Idaho, an 8000 square mile AEC reservation. It's an isolated area, and the test reactors were many miles apart, just in case. [1] https://www.youtube.com/watch?v=qOt7xDKxmCM https://www.youtube.com/watch?v=qOt7xDKxmCM
MurMan 11y ago
I was a power plant operator on a nuclear submarine. We were shown a classified film that about the SL-1 incident as part of our training. Recalling that film still gives me chills. A lot was learned about reactor safety as result of that disaster.
- hamiltonkibbe 11y ago
  I'd imagine the feeling is similar to the first day back in the RC after watching K-19.
  - MurMan 11y ago
    The movie came out years after I left the Navy. But yeah, watching it gave me that same sick feeling. The images seem to combine with memories in a way that makes me feel like I'm there. Parts of the film are unrealistic, but I won't watch it again.
- angersock 11y ago
  What else was in the film?
  - MurMan 11y ago
    Nice try! :-)
anabis 11y ago
Does the Demon Core count as a reactor?
- Sanddancer 11y ago
  No. It was designed to go above critical only once, albeit with lots of sound and fury. It's also of note that during its intended trip into criticality, it ended up detonating about a half mile from its target. Core was jinxed till the end.
- tyho 11y ago
  Yes it does: https://en.wiktionary.org/wiki/nuclear_reactor https://en.wiktionary.org/wiki/nuclear_reactor
  - rosser 11y ago
    No, it doesn't. The definition you're citing says, "Any device in which a controlled chain reaction is maintained", emphasis added. First of all, the Demon Core wasn't a "device", but a shaped lump of plutonium, which briefly — and accidentally — went super-critical. (Yes, twice. And, yes, subsequently deliberately.) A "reactor" is the entire assembly, not just the "hot" stuff. Secondly, it wasn't exactly designed for controlled criticality. EDIT: corrections.
    - tyho 11y ago
      It was controlled using a screw driver. What makes a device? For me 2 plutonium spheres and a screw driver rotated to adjust the gap counts.
- david-given 11y ago
  Context: https://en.wikipedia.org/wiki/Demon_core https://en.wikipedia.org/wiki/Demon_core tl;dr: prototype warhead core, on which people were doing very risky experiments, which underwent some criticality events by accident, releasing lots of radiation which killed some of them. It was eventually detonated in a weapons test in 1946.
deleted 11y ago
[deleted]
JohnGB 11y ago
I find the term "accident" a somewhat meaningless distinction. Millions of people have gotten cancer (statistically) from the radiation in the atmosphere as a result of nuclear tests. Does it really matter that the tests were intentional or not?
- pixl97 11y ago
  Well, mostly because it would make discussing anything difficult and meaningless. And, in that case, if we wanted to talk about the about the largest nuclear 'accident' involving the most deaths, we'd discuss coal burning power plants.
- Agathos 11y ago
  The title specifies "reactor accident," which is intentionally narrow. There have been several other fatal accidents involving nuclear material but not involving reactors. For example, the Demon Core experiments.
hudibras 11y ago
For what it's worth, I like the original title on the article better.
infinotize 11y ago
Whoa: > In the split second it took for the rod to travel the remaining 8.3cm, the reactor spiked to 20 GW, 6300 times its safe operating capacity. (Up from that days' configured power output of 3 MW, happened while operator was lifting a control rod)
- gh02t 11y ago
  Yeah, the reactor went prompt-critical, which is pretty much the worst thing that could possibly happen. In the reactor normally there's two classes of neutrons present - "prompt", which are emitted directly from fission, and "delayed", which are secondary neutron emissions from decay of fission byproducts. Prompt neutrons are emitted on a very very short timescale and so if the power were controlled solely by them it'd be impossible to control a reactor because any change in the control rod position would cause an extremely rapid change in the power. Instead, reactors are designed to be subcritical considering only prompt neutrons and then be made critical via the remaining delayed neutrons. This extends the reactor period (time it takes for the power to change by a factor of exp(1)) from milliseconds to minutes. However, if there isn't enough control material in the core that the proportion of prompt neutrons is enough to make the reactor critical by itself then it goes "prompt critical" and exactly what happens in the article occurs. Reactors are supposed to be operated with enough margin that this won't ever happen (which isn't that difficult), but it sounds like they were deliberately operating right on the limit, which scares me.
  - stymaar 11y ago
    Interesting explanation thanks ! However, I think you made a mistake (probably a typo but I think it's worth noting it to avoid confusion of other readers) in that sentence: “However, if there isn't enough control material in the core that the proportion of FAST neutrons is enough to make the reactor critical”. Prompt neutron (short time between fission and neutron emission) should not be mistaken with fast neutron (high kinetic energy, see https://en.wikipedia.org/wiki/Neutron_temperature https://en.wikipedia.org/wiki/Neutron_temperature)
    - gh02t 11y ago
timr 11y ago
Here's another youtube video that goes more extensively into the mechanics of the accident. It's pretty remarkable that they were able to work out the position of the control rods, given that they were blasted around the room during the accident, bent, broken and (in some cases) embedded in the ceiling: https://www.youtube.com/watch?v=phbaE_0LANc https://www.youtube.com/watch?v=phbaE_0LANc
- angersock 11y ago
  Or in the personnel: Fifteen minutes later they found Legg, also dead—he had been impaled to the ceiling by one of the plugs used to seal the unused control rod channels That's pretty metal, I've got to say.
regehr 11y ago
Pretty good book about this incident: http://www.amazon.com/Idaho-Falls-Americas-Nuclear-Accident/dp/1550225626/ http://www.amazon.com/Idaho-Falls-Americas-Nuclear-Accident/...
stymaar 11y ago
Fortunately, this reactor was moderated by water, so after the incident, all the water was gone and the nuclear reaction stopped by itself. I don't want to imagine what would have happened if the moderator was Graphite instead :/

68 points by herendin 11y ago

"...killed by the only fatal reactor accident in US history." Is that really true? '“Nobody died at Three Mile Island” — unless you count babies.' http://www.counterpunch.org/2015/03/27/cancer-and-infant-mortality-at-three-mile-island/ http://www.counterpunch.org/2015/03/27/cancer-and-infant-mor...

tdicola 11y ago
TMI's radioactive gas release was nothing compared to the years of above-ground nuclear tests in the 50's and 60's. There are plenty of non-nuclear superfund sites that have done more harm too.
droiditecH 11y ago
> Nobody died at Three Mile Island” — unless you count babies Seems consistent with liberals...
illumen 11y ago
Can someone change the obviously untrue headline?
rosser 11y ago
It's certainly debatable, but as I understand it, there's a distinction made between accidents in which people are killed, and those because of which people are killed. This is one of the former. It's a very small set. Deaths from radiation poisoning, which is the deadly thing most strongly associated with nuclear accidents, tend to number among the latter, because it's the radiation, a consequence of the accident, that kills those victims, not the accident, itself. Again, it's a debatable distinction, but it's the one we've chosen to make. You conflate them either out of ignorance, or because you're fearmongering.
- illumen 11y ago
  "You conflate them either out of ignorance, or because you're fearmongering." It's a valid argument that people die because of multiple nuclear accidents in the USA. In a car accident if someone dies two days after in hospital as a result because of injuries (a consequence of the accident), people say that they died of a car accident. Radiation poisoning is obtained as a result of a nuclear accident. In exactly the same way as injuries obtained as the result of other accidents. To draw a distinction, and claim there is a difference is being ambiguous. Many people will misunderstand the difference because it makes no sense, and is not the way everyone else uses the language. To claim people understanding the statement in a sound way are fearmongering or being ignorant is silly. The headline is misleading. ps. "only fatal reactor accident in US history" claim, apart from the other deaths within the USA, the recent (and still ongoing) Fukushima accident used a General Electric design from the USA.
  - rosser 11y ago
    In a car accident if someone dies two days after in hospital as a result because of injuries (a consequence of the accident), people say that they died of a car accident. Yes, exactly. We say they died of a car accident. Not in one. See the difference?
  - Spooky23 11y ago
    You're not going to make any headway here, this is a very pro-nuclear crowd. Google some of the Fukishima threads here to really understand it. IMO, nuclear power generation in the U.S. is an overly secretive industry running obsolete on arrival technology that is a public health hazard. Just like coal, the industry enjoys a very cozy relationship with government that enables it to weasel around their pretty obvious risks and problems they bring.
    - alextgordon 11y ago
      Few will dispute any of that. I don't think there's a person here who wouldn't like ubiquitous solar power! But when the alternative is coal, nuclear power is less polluting, less radioactive and less likely to kill you.
rdl 11y ago
Somewhat crazy, but: One more level of abstraction, and lots of people die at nuclear plants because they're not built yet (or existing ones were delayed, or in maintenance), due to the coal power which they would displace.
- rimantas 11y ago
  And coal power plants spread more radioactive material than nuclear ones.
  - spacecowboy_lon 11y ago
    And that's not counting the coal miners that die in accidents or get silicosis aka black lung
    - pgeorgi 11y ago
      Family of mine worked in uranium mines. Lots of people died there as a result of radioactive particles that ended up in their lungs (plus the typical mining accidents).
- InclinedPlane 11y ago
  Even weirder, the rates of cancer are higher around nuclear power plant locations. Even when the plants haven't been built yet. Turns out, such things tens to get built in old industrial areas that are already heavily contaminated.
  - iwwr 11y ago
    If anything causes people to get medical check-ups more often it's still beneficial, even if the reason for doing it may be irrational (fear of radiation leaked from a nuclear reactor). Such fears may even trigger a statistical increase in cancer rates from increased detection.
  - HCIdivision17 11y ago
    This is going to be my go-to factoid on nuclear plant nimby-ism. My uncle had an interesting experience in this vein. It was well understood that high voltage power lines caused all manner of health issues, from cancer to various degenerative diseases. He understood that EM radiation from the lines really shouldn't be very dangerous, though, and didn't think much of the leg of a line tower in his back yard. Then one day the power company came through to clear out the underbrush growing around the base of the line's tower. In just two days after the spraying all vegitation was thoroughly dead. Turns out they spray an Agent Orange-like chemical to keep the towers maintained from plant overgrowth. You can bet he moved shortly after noticing that. (This was some years ago, and likely has been (hopefully) rectified.)

abecode 11y ago

That part of Idaho is interesting to drive through. It's near craters of the moon national park. The Idaho Nuclear Laboratory is pretty big. I remember it being nearly 50 miles along one side of the road with all barbed wire fences. It's pretty lonely and creepy out there. There was one cliff in Atomic City that was covered with graffiti of large random numbers. It turned out that the numbers were from high school graduating classes but the numbers weren't in order so it seemed like some random code.

Animats 11y ago

The SL-1 story is well known in the industry. The Atomic Energy Commission has a video.[1] SL-1 was an experimental reactor at the National Reactor Testing Station in Idaho, an 8000 square mile AEC reservation. It's an isolated area, and the test reactors were many miles apart, just in case. [1] https://www.youtube.com/watch?v=qOt7xDKxmCM https://www.youtube.com/watch?v=qOt7xDKxmCM

MurMan 11y ago

I was a power plant operator on a nuclear submarine. We were shown a classified film that about the SL-1 incident as part of our training. Recalling that film still gives me chills. A lot was learned about reactor safety as result of that disaster.

hamiltonkibbe 11y ago
I'd imagine the feeling is similar to the first day back in the RC after watching K-19.
- MurMan 11y ago
  The movie came out years after I left the Navy. But yeah, watching it gave me that same sick feeling. The images seem to combine with memories in a way that makes me feel like I'm there. Parts of the film are unrealistic, but I won't watch it again.
angersock 11y ago
What else was in the film?
- MurMan 11y ago
  Nice try! :-)

anabis 11y ago

Does the Demon Core count as a reactor?

Sanddancer 11y ago
No. It was designed to go above critical only once, albeit with lots of sound and fury. It's also of note that during its intended trip into criticality, it ended up detonating about a half mile from its target. Core was jinxed till the end.
tyho 11y ago
Yes it does: https://en.wiktionary.org/wiki/nuclear_reactor https://en.wiktionary.org/wiki/nuclear_reactor
- rosser 11y ago
  No, it doesn't. The definition you're citing says, "Any device in which a controlled chain reaction is maintained", emphasis added. First of all, the Demon Core wasn't a "device", but a shaped lump of plutonium, which briefly — and accidentally — went super-critical. (Yes, twice. And, yes, subsequently deliberately.) A "reactor" is the entire assembly, not just the "hot" stuff. Secondly, it wasn't exactly designed for controlled criticality. EDIT: corrections.
  - tyho 11y ago
    It was controlled using a screw driver. What makes a device? For me 2 plutonium spheres and a screw driver rotated to adjust the gap counts.
david-given 11y ago
Context: https://en.wikipedia.org/wiki/Demon_core https://en.wikipedia.org/wiki/Demon_core tl;dr: prototype warhead core, on which people were doing very risky experiments, which underwent some criticality events by accident, releasing lots of radiation which killed some of them. It was eventually detonated in a weapons test in 1946.

deleted 11y ago

[deleted]

JohnGB 11y ago

I find the term "accident" a somewhat meaningless distinction. Millions of people have gotten cancer (statistically) from the radiation in the atmosphere as a result of nuclear tests. Does it really matter that the tests were intentional or not?

pixl97 11y ago
Well, mostly because it would make discussing anything difficult and meaningless. And, in that case, if we wanted to talk about the about the largest nuclear 'accident' involving the most deaths, we'd discuss coal burning power plants.
Agathos 11y ago
The title specifies "reactor accident," which is intentionally narrow. There have been several other fatal accidents involving nuclear material but not involving reactors. For example, the Demon Core experiments.

hudibras 11y ago

For what it's worth, I like the original title on the article better.

infinotize 11y ago

Whoa: > In the split second it took for the rod to travel the remaining 8.3cm, the reactor spiked to 20 GW, 6300 times its safe operating capacity. (Up from that days' configured power output of 3 MW, happened while operator was lifting a control rod)

gh02t 11y ago
Yeah, the reactor went prompt-critical, which is pretty much the worst thing that could possibly happen. In the reactor normally there's two classes of neutrons present - "prompt", which are emitted directly from fission, and "delayed", which are secondary neutron emissions from decay of fission byproducts. Prompt neutrons are emitted on a very very short timescale and so if the power were controlled solely by them it'd be impossible to control a reactor because any change in the control rod position would cause an extremely rapid change in the power. Instead, reactors are designed to be subcritical considering only prompt neutrons and then be made critical via the remaining delayed neutrons. This extends the reactor period (time it takes for the power to change by a factor of exp(1)) from milliseconds to minutes. However, if there isn't enough control material in the core that the proportion of prompt neutrons is enough to make the reactor critical by itself then it goes "prompt critical" and exactly what happens in the article occurs. Reactors are supposed to be operated with enough margin that this won't ever happen (which isn't that difficult), but it sounds like they were deliberately operating right on the limit, which scares me.
- stymaar 11y ago
  Interesting explanation thanks ! However, I think you made a mistake (probably a typo but I think it's worth noting it to avoid confusion of other readers) in that sentence: “However, if there isn't enough control material in the core that the proportion of FAST neutrons is enough to make the reactor critical”. Prompt neutron (short time between fission and neutron emission) should not be mistaken with fast neutron (high kinetic energy, see https://en.wikipedia.org/wiki/Neutron_temperature https://en.wikipedia.org/wiki/Neutron_temperature)
  - gh02t 11y ago

timr 11y ago

Here's another youtube video that goes more extensively into the mechanics of the accident. It's pretty remarkable that they were able to work out the position of the control rods, given that they were blasted around the room during the accident, bent, broken and (in some cases) embedded in the ceiling: https://www.youtube.com/watch?v=phbaE_0LANc https://www.youtube.com/watch?v=phbaE_0LANc

angersock 11y ago
Or in the personnel: Fifteen minutes later they found Legg, also dead—he had been impaled to the ceiling by one of the plugs used to seal the unused control rod channels That's pretty metal, I've got to say.

regehr 11y ago

Pretty good book about this incident: http://www.amazon.com/Idaho-Falls-Americas-Nuclear-Accident/dp/1550225626/ http://www.amazon.com/Idaho-Falls-Americas-Nuclear-Accident/...

stymaar 11y ago

Fortunately, this reactor was moderated by water, so after the incident, all the water was gone and the nuclear reaction stopped by itself. I don't want to imagine what would have happened if the moderator was Graphite instead :/