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Interesting. Conjecture or researched fact?

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Well armpits constantly sweat providing higher moisture. While crotch does not always sweat constantly.

Every time I read the events that led up to this I want to yell 'don't do it'. Even though I know the outcome I just feels if I yell loud enough they will hear me.

There were so many steps that led up to this. Had they stopped at any of them, this could have been averted. That design was just a disaster to happen all the same.

thank you for your response, sounds like I need to rethink my summer vacation next year 😁

So there are a few different things that we use water for.

Water is a great coolant.

It also makes a good moderator in many designs.

It is an effective shield for radiation sources. About 7 feet of water will reduce the lethal radiation levels in nuclear fuel down to levels we can work under. The spent fuel is typically under 23 feet of water to act as a buffer in case a fuel rod leaks or splits open to act as a dissolving agent for radioisotopes that leak out.

The last part though, is the water can have radioactive material dissolved in it. So yeah it would shield you from the radiation from fuel rods 23 feet deep. But if there are dissolved fission products in the fuel, when you jump in the water those products are now coated on your skin, causing direct radiation impact. If you ingest it or your body absorbs it, you can have internal effects.

So while it’s not going to be lethal like hugging a fuel rod, it’s still harmful and we need to decontaminate you to not only protect you, but keep it from getting out of the plant.

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We do that in a boiling water reactor. But in that case the water is the coolant and the moderator, so as you boil, you get less moderation, which protects the upper portion of the core. We also “shape” the flux profile by adjusting enrichment and gadolinium content (burnable poisons) in the fuel.

Normally in a BWR, power leaks in the bottom 1/4 of the core, and as you deplete the fuel in the bottom later in the cycle, the water is able to “climb” further up the core before boiling, which improves the moderator in the upper portion of the core. By the end of core life, the power peak is in the top 1/3rd of the core.

So it can work when designed right.

But yeah in nearly all other cases, you want to keep your coolant and moderator in a single phase (for the most part)

If you look at the quantum energy levels, the proton and the antineutron, being distinct fermions, can occupy the same energy level (in this case the 1s orbital) and so would be literally in the same place as opposed to far away.

Secondly, the nuclear interaction inside nuclei essentially consists of nucleons swapping quarks with eachother (and creating virtual antiquarks so overall a meson is the exchange particle). So if the proton and the antineutron were bound then an up quark would move from the proton to the antineutron but interact with the antiup quark there and annihilate.

They disabled the reactor trip system. But still typically with actual reactivity controls you have some other interlocks.

>Why there weren’t mechanical limits on the control rods equipped with followers or other system interlocks is beyond me.

I believe the answer to that is in the book "Atomic accidents" By James Mahaffey. Apparently there actually were safety systems like that, but in preparation for the safety test they had a special switch installed which disabled them.

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That sounds fairly Soviet… “Let’s keep the reactor operators as in the dark as possible”

What a comprehensive answer, thank you.
One thing I remember hearing, and I’ve always wondered if it was true, is that water is such a good ‘insulator’ for radiation that you could actually swim around in the water at the top of a modern reactor and not be harmed?

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What a superb and informative comment. I thought I knew a fair bit about RBMK reactors and the accident but there was a lot of interesting new information here.

Boiling coolant inside of the vessel seems like a Bad Idea when one of the effects is to vary the amount of moderation at different depths in the core.

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The control rod modifications and additional absorbers reduced the positive void coefficient from +4.5 (far higher than any architecture other than RMBK) to +0.7, hence the need for enriching the uranium a bit more.

To me it’s more like the jungle is different than the woodland.

Rival bacteria is precisely the point. Clearly a specific bacteria can come to dominate an armpit that never has a chance elsewhere.

I want to know why. What makes the armpit better suited than the crotch for that particular BO smell.