If I ingest a grain of sand size piece of the Chernobyl Reactor No.4 core

[henearkr]

I'm baffled at the fact that the answer is entirely about radioactivity. Rather than that, uranium in itself is highly toxic (I mean, chemically).

[atemerev]

This is purely hypothetical, as like he noticed, the fuel particle is not soluble in gastric acid. The damage would be much less than that.

Inhaling the similar amount of finely powdered radioactive dust is another story, though.

[zaroth]

What movie was that?

[remarkEon]

>Me, riding the whole body counter in SP1430, Chernobyl Nuclear Power Plant, after being inside the Unit 4 “Sarcophagus”

What do people do who actually go inside the Sarcophagus these days? I assume there’s monitoring that needs to be done, but I also assume that you can monitor a lot of this remotely. Also, how much longer until Chernobyl is considered “safe”?

[guitarbill]

The Chernobyl New Safe Confinement has two cranes inside, and a lot of sensors. Incidentally, it's a great engineering project. The only downside is that if you visit now, you can't see the sarcophagus.

[philjackson]

I think I heard 20,000 years before it's safe.

[beaner]

Couple naive questions:

1. How does a piece of spent fuel end up in a "grassy bit of ground" outside the reactor? Thought it would have all melted in one big clump in the same spot?

2. Why is Chernobyl still so dangerous if literally ingesting the spent fuel isn't super bad? Or is Chernobyl no longer dangerous?

[DuskStar]

For #1, about 5% of the reactor core was spread outside the building through a series of explosions. (which is a large part of why reactors in the western world all have containment structures) So while most of the core is in a couple of mounds within the reactor building, quite a bit got spread around.

Regarding #2, this is a very small fragment, and there are a lot of them around. Eating this wouldn't do much to you, but 10x a day for a year? Hello cancer.

[AaronFriel]

1. There was an explosion (edit: two explosions) that began the incident which destroyed the reactor and ejected matter a significant distance.

2. Chernobyl, IIRC, isn't really so dangerous to visit but you should avoid eating or drinking anything in the exclusion zone. Cesium-137 and Strontium-90 will poison you from the inside out. The latter ends up bio-accumulating in bone.

[i_am_proteus]

If a biological process concentrates a radioisotope in something humans consume (let's say a deer), and you eat that deer, you might get a much higher committed dose and a resultant materially higher probability of developing cancer.

[codeduck]

1. There were two explosions - the second of which destroyed the reactor core and distributed parts of the reactor structure (including fuel) over the area.

2. That speck of spent fuel is still radioactive enough after 30 years to push most nuclear industry workers over their annual permissable dosage. Chernobyl itself is still phenomenally radioactive - but is far less so than it was immediately after the accident.

[amluto]

I assume the answer to #2 is that there is quite a lot of waste around. Gamma and beta sources are dangerous just being near you — you don’t need to eat them to have a problem.

[ris]

> How does a piece of spent fuel end up in a "grassy bit of ground" outside the reactor?

There was a pretty huge steam-based explosion, blowing the top off the reactor building and scattering fuel and various debris quite far & wide.

[NikkiA]

There was an explosion.

[akvadrako]

It's not that dangerous. There are people living nearby, it just increases the risk of cancer and other random mutations.

[ribalda]

Good to know. I was worried for this girl :) : https://www.youtube.com/watch?v=ejZyDvtX85Y

[userbinator]

I had a feeling it was a bionerd23 video before I clicked that link... she has some pretty scary radioactivity videos.

[dkersten]

I recently watched her videos for the first time (the one where she visited the reactor 4 control room and a few others). A very interesting channel indeed.

[roenxi]

It is worth noting that there is almost literally no mention of potential health impacts; almost all the outcomes listed in the answer are regulatory.

On the one hand, that might be good regulation - we don't want workers getting harmed. On the other hand, it serves as ongoing evidence that getting worried because a situation exceeds regulatory standards is foolish.

Given how little attention he gives it the "marginally higher theoretical likelihood of later detriment such as cancer" turns out to be something trivial like less damage than done by drinking sugar water or not exercising.

[Retric]

Heath impacts are literally the first thing mentioned. “probably nothing; certainly nothing obvious and immediate“

A grain of sand is extremely tiny and solid so it’s also got a very low surface area. Further, if it was suck in your lung you would get significant radiation to the same tissue, but in your digestive system food would act as a barrier while also pushing things along.

From a regulatory framework it’s enough to detect and be concerned about which is interesting.

[kochikame]

https://xkcd.com/radiation/

This masterfully illustrates the relative risks of various sources of radiation, something that the typical person on the street knows almost nothing about but thinks they do

I live in Japan and read up on this topic after the Fukushima disaster

[Creationer]

Which one is 3.6 roentgen, which is not great, not terrible?

[JadeNB]

I had a really hard time with the title displayed here, which is a truncated version of an already-confusing title on Quora. The actual title, with, I think, desireable punctuation included, is "If I ingest[ed] a grain-of-sand-size piece of the Chernobyl Reactor No. 4 core, what would happen to my body?"

[altmind]

There are things much scarier and devastating than uranium. It took 10 micro-grams(10^-5 g) of Pu-210 to poison(ARS) Litvinenko. You cannot see that amount - so tiny it is. And the damage is almost 100% gamma rays - so its hard to detect and the damage is lowered when handling and maximal when ingested.

[ianai]

A discussion about the everyday occurrence of radioactive sources may be more productive.

[godelski]

Here or in the Quora post? There's plenty of people here that know quite a bit about reactors and radiation. Ask away.

[exabrial]

I left with more questions than answers...

[kahoon]

As it is usual when reading Quora "answers".

[jhallenworld]

I've watched this interesting (but long) talk by Brian Sheron, retired director of Nuclear Regulatory Research:

https://www.youtube.com/watch?v=ryI4TTaA7qM

It gives me a better understanding of the risk of nuclear power, particularly for current US reactors, and what our regulatory agencies actually focus on: really it's on preventing direct radiation induced deaths, and not so much on property damage. So: It's not so much that accidents directly kill people, instead they kill the land. The idea is that loss of cooling incidents are contained for a significant amount of time- at least 8 hours. I'm dubious, but this is thought to be enough time to evacuate people from the land that will eventually become contaminated. Only when people move back do people die, and then only from increased cancer risk (Brian says this becomes an EPA problem). So now the land is lost, because who would move back? [of course this focuses only on deaths from radiation, and not for example, deaths caused by stress to elderly people forcibly relocated].

I did not remember when people were evacuated after the Fukushima accident, but it was pretty quick, here is a timeline:

https://www.oecd-nea.org/news/2011/NEWS-04.html

There is another question I'm still trying to answer. If the final heat sink is lost (someone blows up a dam), can the reactor be shut down without incident, assuming no blackout? This would require that the decay heat is spread across a large enough surface area. I'm not sure if the containment building provides such an area (a 1000 MW reactor generates ~70 MW decay heat after shutdown). It reminds me that this is another area that NRC does not focus on: "terrorist attacks are a military problem".

Edit: well I answered my own question from wikipedia entry on containment building: "While the containment plays a critical role in the most severe nuclear reactor accidents, it is only designed to contain or condense steam in the short term (for large break accidents) and long term heat removal still must be provided by other systems." So if the heat sink is a man-made lake held by dam, it's a big risk (of course dam loss would cause direct loss of life anyway). I was wondering about this because my inlaws live near Duke Energy's Oconee Nuclear Station, on man made Lake Keowee https://en.wikipedia.org/wiki/Lake_Keowee

[lisper]

Gotta love the conclusion:

"In summary, it is preferable to not eat spent nuclear fuel."

[DuskStar]

It was interesting to see that it truly was only "preferable" and not "mandatory" or "this will kill you" IMO

[javadocmd]

This is how you know it was written by an engineer. The executive summary is at the bottom.

[ducttape12]

Now you tell me! What are you going to tell me next, that yellowcake isn't made from flour?

[HillaryBriss]

really puts my mind at ease

[soundpuppy]

If we were to make an analogy between radiocative matter entering the body, and toxic information entering the mind, what metrics do we use to measure the dangerous effects of the information? How long it lasts or how deeply it can modify conscious/subconscious brain processes?

[rmdashrfstar]

There's no such thing as dangerous information, only truth and not truth.