a nuclear power plant that will float ~8 miles out to sea

http://phys.org/news/2015-06-nuclear-power-miles-sea.html

it has certain advantages over land-based nuclear power plants. One is safety: the sea water can serve as an infinite source of cooling water in case of emergency—no pumping needed.
The link also implies it should be cheaper but the link gives no indication of by about how much so it is pretty hard to guess how economical this would be from the link. Providing it can be made cost effective and economically competitive with renewables (else what's the point? ) and providing it can be made very safe, I for one would have no objections to this.

Perhaps this idea could be combined with the concept of a thorium particle accelerator reactor which should in theory be much safer than all other types of fission reactors to date; if the two are combined i.e. make it a floating sea-bound thorium particle accelerator reactor, it will have the combination of all the excellent safety features of both and surely could be designed to be extremely safe indeed! Then it wouldn't no longer be a question of safety but rather just its cost effectiveness; will that really be cost effective? If not, might as well just stick too renewables some (if not already most/all ) of which already have a proven track record for cost effectiveness ( including hydroelectric ) and the cost of the rest will eventually come down so that they all will become cost effective from every point of view.

I have now put that idea of mine of a floating sea-bound thorium particle accelerator reactor as a comment at the bottom of that link.
Does any of the physicists here have anything to say about what they think about that idea of combining (for safety reasons ) the two concepts? Is it sound from an engineering point of view? Bad or good idea?

Originally posted by humy
it has certain advantages over land-based nuclear power plants. One is safety: the sea water can serve as an infinite source of cooling water in case of emergency—no pumping needed.

Many nuclear power plants are located by the sea including our Cape Town power plant and the Fukushima one to give ready access to sea water. Presumably clever design could make the sea based version passively cooled which is one advantage.

My concerns would be:
1. In case of leaks, how much sea gets contaminated? This was a public concern with the Fukushima plant as it was reportedly pumping out radioactive water which spread globally. It is likely that the actual levels were negligible, but I see it as a possible political concern.
2. How easy would it be to access for emergency personnel. I believe off shore platforms can be hard to get to especially in bad weather.
3. If it were outside territorial waters there may be political issues.
4. What do undersea power lines cost?
5. Is nuclear cost effective anyway?

I guess one benefit is that you could sell your power stations to other countries when you get tired of them. South Africa is currently badly in need of more power stations, and if Russia said it could deliver an offshore power station tomorrow, I think we would buy it. Instead we are going to go through a 10 year corruption ridden construction process by which time renewables will be far cheaper anyway and we will be sitting with a white elephant.

Surely clever engineering should make it possible to make a seaside reactor that automatically sucks in fresh sea water when it overheats even with loss of electricity?

Originally posted by twhitehead
Surely clever engineering should make it possible to make a seaside reactor that automatically sucks in fresh sea water when it overheats even with loss of electricity?

4th gen nuclear reactors passively shut down in the event of loss of coolant and thus
cannot do a 'fukashima' [or Chernobyl].

They built a liquid sodium [or sodium salt, I forget] cooled nuclear reactor in the USA that
they did exactly that test on.
They just shut down the cooling, and sat there and watched as the reactor passively shut down.

The molten sodium [you can also use lead] acts as a nuclear moderator, and if the reactor gets to
hot the sodium or lead heats up, expands, releases neutrons, and the reaction shuts down.

And MSR reactors do just the same, although in their case the coolant and the reaction fuel
are one and the same thing.

These reactors are also not pressurised and thus don't need the hugely expensive pressure vessels
needed for water or gas reactors. They also use ~99% of the fuel instead of ~1% of the fuel, which
also makes them much cheaper. And most 4th gen reactors can burn high level nuclear waste which
means we don't have to spend the vast sum's of money required to store it and instead make money
by using it and disposing of it at the same time.


Building a reactor in the sea strikes me as a bad move for many of the reasons mentioned.

It's likely to be expensive to build in/on the sea, salt water needs desalinating before being used as a
coolant because it's corrosive, bad weather is a concern, both for access and safety.
It acts as a barrier to using waste hot water to heat homes and businesses which reduces potential efficiency.
And it's unnecessary given modern reactor safety.

The leaking of radioactive waste water into the oceans is much less of an issue.

The oceans are massive, and already contain radioactive materiel. In fact they contain so much that it's
actually a serious proposition to extract this materiel and use it to fuel our civilisation [for a few thousand years].
Any waste water dumped into the oceans will dilute so vastly that it will no longer be a problem.

It can present local issues before that happens, and particulate radioactive materiel is an issue as that
will remain concentrated and could enter the food chain.

Best to have reactors on land if possible.

Originally posted by twhitehead
Surely clever engineering should make it possible to make a seaside reactor that automatically sucks in fresh sea water when it overheats even with loss of electricity?

I thought Thorium reactors were inherently safer, which seems to refute the idea you need to put it in the ocean at all.

Originally posted by sonhouse
I thought Thorium reactors were inherently safer, which seems to refute the idea you need to put it in the ocean at all.

esp the thorium particle accelerator type of thorium reactor;
To shut them down, all you need to do is STOP firing the particles in them that trigger nuclear reactions that turn up the heat; you can think of it as a kind of 'fail safe'. This is the type of thorium reactor I would be most interested in, purely for safety reasons.

In addition, if there was a thorium reactor leak, it is generally thought that, unlike a typical uranium or plutonium reactor leak, it would pose only a relatively miner environmental hazard since the isotope 232Th used is only slightly radioactive and there shouldn't be a huge buildup of hazardous nuclear byproducts from the reaction.

One should note that the average human contains about 100 micrograms of thorium which does us little harm because it is only slightly radioactive, so you could argue that we are already all 'contaminated' (if that is the right word ) with significant amounts of thorium anyway! I doubt that adding a few more micrograms to that from a thorium leak from a reactor will make much difference to our health! It would probability be only the byproducts from the reaction you should worry about, but it is my understanding there wouldn't tend to be much buildup of them.

But, again, it comes down to the question of cost effectiveness; which is its possible stumbling block.

Originally posted by sonhouse
... which seems to refute the idea you need to put it in the ocean at all.

But why not make them even safer by putting them in the ocean?
That is my idea.

Originally posted by humy
But why not make them even safer by putting them in the ocean?
That is my idea.

Because it will not make them safer. And it will make them more expensive.

Originally posted by googlefudge
Because it will not make them safer. .

Why would it not make them safer when it provides them with an unlimited amount of water for cooling in an emergency?
I assume even a thorium particle accelerator reactor might need a lot of cooling if something goes horribly wrong.

And it will make them more expensive

One of the reasons to put them out to sea is to make them cheaper.
Read the link to see why.

The only problematic issue I see here is that nuclear may still not be cost effectiveness despite this.

Originally posted by humy
esp the thorium particle accelerator type of thorium reactor;
To shut them down, all you need to do is STOP firing the particles in them that trigger nuclear reactions that turn up the heat; you can think of it as a kind of 'fail safe'. This is the type of thorium reactor I would be most interested in, purely for safety reasons.

In addition, if there ...[text shortened]... ain, it comes down to the question of cost effectiveness; which is its possible stumbling block.

So a new thuggery industry opens up, 1 million dead people = 100 grams of thorium! Reminds me of Soyent Green🙂

Originally posted by humy
Why would it not make them safer when it provides them with an unlimited amount of water for cooling in an emergency?
I assume even a thorium particle accelerator reactor might need a lot of cooling if something goes horribly wrong.

And it will make them more expensive

One of the reasons to put them out to sea is to make them cheaper. ...[text shortened]... y problematic issue I see here is that nuclear may still not be cost effectiveness despite this.

I assume even a thorium particle accelerator reactor might need a lot of cooling if something goes
horribly wrong.

You assume wrongly. As I have already pointed out, such reactors passive fail to cold shutdown
with no active cooling. That is the whole point.

Pumping untreated seawater through them will make them more dangerous and destroy the reactor core.

One of the reasons to put them out to sea is to make them cheaper.

Yes, because it's so much cheaper to build stuff at sea, that's why the seasteading movement isn't dying
a quiet death because they haven't just realised that they need 50 billion plus to get going...

Their design calls for a pressure vessel so they are not looking at 4th gen reactors which are already safer
and cheaper and don't need all that cooling water in an emergency.

There's all kinds of nuclear carriers and submarines already in service. It is doable.

Originally posted by AThousandYoung
There's all kinds of nuclear carriers and submarines already in service. It is doable.

They generate way less power than a commercial reactor, and cost [for any given amount of power]
way more.

The question is not if it's possible, but if it's practical, economical, and better than just building them
on land.

After just doing a bit more background reading on the subject of thorium reactors, my suspicion is greater than ever that my idea is just pie in the sky anyway for economic reasons. Oh well, no harm just thinking about these alternatives, right?

I think, at least in the very long run, we will almost certainly go all renewable i.e. with no nuclear and with nuclear at best contributing to power generation in the medium run just to help reduce CO2 emissions until we have 100% renewables.
-this is all assuming that nuclear fission doesn't ever come a big thing.