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.