I would have preferred to make it a pressurized water reactor similar to a CANDU. Or minimize boiling in the fueled region similar to the ESBWR. The issue is you are voiding your coolant in the reactor. If you never let it boil you don’t have the strong positive void coefficient (and you can design around loss of pressure transients like the CANDU design). Then it doesn’t matter as much if rods go in the top or the bottom.

Honestly the CANDU design is a far better answer. You still have some positive void coefficient but you can design around it.

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This is a relevant article on the subject.

https://www.nature.com/articles/nature.2012.11555

>After cell death, enzymes start to break down the bonds between the nucleotides that form the backbone of DNA, and micro-organisms speed the decay. In the long run, however, reactions with water are thought to be responsible for most bond degradation. Groundwater is almost ubiquitous, so DNA in buried bone samples should, in theory, degrade at a set rate.

Basically, unless the sample is preserved under unnaturally dry conditions while also conveniently protected from all other sources of degradation (something that is unlikely to happen naturally), you're looking at best case scenario of ~7 million years, though the most likely would be ~1 million years.

As water is the main contributing factor, it's unlikely salt water would have any significant net positive effect on preservation length of time.

Edit: Here is an article I found that suggests high salt anoxic conditions will have a net protective effect, however the study does have some limitations. Overall, it might suggest that a high salt environment might help skew the half life to the longer end of the spectrum, though I'm unable to suggest it may extend it beyond that to any significant degree.

https://www.nature.com/articles/srep22960

Also I didn't truly answer your question. I would expect that we would be able to extract DNA from the organisms you are looking at in those salt pools, however the success would decrease with time. After about 500 years, about 1/2 the DNA bonds would be broken, and 500 years after that another half would be broken. We can piece together fragments of DNA to make up the whole (sort of like piecing a puzzle back together), but the chance of success would decrease with time. The further back you go, the more samples you'd need to get a complete picture, and after about a million years the task would pretty much become impossible even if you had an abundance of well preserved samples.

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It is like a mini ecosystem. Just like how a jungle is different than a sea. Level of sweat, ingredients in sweat, rival bacteria etc.

I appreciate your taking the time.

Can I ask a follow up? Why makes the armpit environment so different from a crotch environment?

We expect helium rain in the interior of Jupiter.

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Well I know there are species that can be grown artificially but not commercially. For example, the western huckleberry. It thrives in high elevations in very specific conditions. Although you MAY be able to grow a single plant (with great difficulty) as far as I know they are really only naturally growing plants.

This may be a dumb question and not worded properly but are we able to artificially produce different elevation conditions?

Is there any way to recreate high elevations in a low elevated environment? For example, is there any way to grow a high elevation plant at low elevation?

Precipitation can be almost anything depending on the pressures and climates. It can continually rain stone if there is planet wide long term volcanic activity and like others have stated methane rain happens in our own solar system. Also there are clouds of sulfuric acid on venus

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The way it was explained to me, is that the graphite would typically slow the reactivity, but because the tips were in the reactor they were themselves irradiated. When they're inserted they bring it down, but there would be an initial surge from the tips going in. This could be fixed by not having the ends of the rods in, but would be more mechanically complicated.

Not at all. In fact, unlike power plants that use fossil fuels (like coal), fuel costs aren't a huge part of the cost of running a nuclear power plant anywhere, regardless of enrichment. (Caveat: nuclear power plants use relatively low fuel enrichments, like 5% or less. If you had an NPP with a very high enrichment, the cost could change, but NPPs don't need high enrichments.)

Iron rain on Wasp-76b

Exoplanet Wasp-76b orbits so close in to its host star, its dayside temperatures exceed 2,400C - hot enough to vaporise metal.

The planet's nightside, on the other hand, is 1,000 degrees cooler, allowing those metals to condense and rain out.

There aren't been any natural nuclear reactors any more. Over a billion years ago, the natural enrichment of uranium was much higher, because U-235 and U-238 have different half-lives.

The only place a natural reactor was ever thought to have operated was at Oklo, and it can't happen anywhere now.

I don’t think that’s correct as there’s very little difference in surface temperature between the poles and equator on Titan. It probably has more to do with Titan’s long seasons and it’s axial tilt. In any case there are equinoctial storms in Titan’s tropics, but the liquid methane seeps into the dry surface. There is some evidence that it flows back poleward within subsurface aquifers.

What would the fundamentally correct way to design the reactor if the RBMK was backwards?

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