
Hot weather cuts French, German nuclear power output - tosh
https://www.reuters.com/article/us-france-electricity-heatwave/hot-weather-cuts-french-german-nuclear-power-output-idUSKCN1UK0HR
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mrb
I think this is a non-problem. At least for France and Germany, peak
electricity consumption is in winter, because electric heating is much more
common (and needed!) than air conditioning. This seasonal surplus is such that
nuclear power plants actually have to reduce their power output in summer.
Here is a chart showing a ±30% seasonal variation in nuclear electricity
production: [https://jancovici.com/wp-content/uploads/2017/10/elec-
mensue...](https://jancovici.com/wp-content/uploads/2017/10/elec-mensuelle-
nuke-France.jpg)

~~~
Arn_Thor
It is a problem, if not a very big one right now. With the climate changing,
expect Europe to build out more air conditioning to cope with hotter summers,
raising power usage. Dismissing this very real operational problem for the
power plants is unwise.

~~~
realusername
Air conditioning is consuming much less electricity than heating, there's no
scenario where it would become greater than the winter usage. And there's only
a few reactors affected by this issue, you have this kind of clickbait article
every year.

~~~
xyzzyz
> Air conditioning is consuming much less electricity than heating, there's no
> scenario where it would become greater than the winter usage.

How about "most people aren't using electricity for heating"? People rarely
heat their houses with electricity in Europe, that would be very expensive.
It's usually gas or oil boiler, sometimes a coal one.

~~~
realusername
You have about 50% share of electricity heating in France, it's far from
nothing.

Edit: And coal heating is probably close to zero to be honest, that sounds
old, even for the countryside. The rest of those 50% would be gas, petrol and
wood.

~~~
noragami
I am so jealous. Here in Kazakhstan we use coal-powered central heating. And
here is the kind of air it gives us:

[https://b.radikal.ru/b12/1902/bd/a6d615dba25b.jpg](https://b.radikal.ru/b12/1902/bd/a6d615dba25b.jpg)

[https://d.radikal.ru/d15/1901/1b/ea0e8c26f8d2.jpg](https://d.radikal.ru/d15/1901/1b/ea0e8c26f8d2.jpg)

It gets much worse in the evening.

These photos were taken in Almaty, but the situation is the same everywhere
(if not worse).

~~~
noragami
At first I wanted to post this particular photo, but couldn't find it, and now
I can't edit the original comment.

[https://d.radikal.ru/d17/1812/fd/ed5cc5dcd4c4.jpg](https://d.radikal.ru/d17/1812/fd/ed5cc5dcd4c4.jpg)

~~~
realusername
Those pictures look awful, I hope it will improve in the future :/

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i_am_proteus
This should also be affecting coal plants, since they also need to exhaust
heat via an identical mechanism. Yet the article only mentions nuclear.

~~~
foepys
That's because you need literally days to get a nuclear plant running again.
Coal plants can start within hours.

But do you have numbers on how it's affecting coal plants? Maybe coal plants
don't need so much cooling?

~~~
ohyes
They don’t necessarily shut the nuclear plants down, they throttle the power
output. It isn’t a strict on/off switch, but a controlled reaction. They said
two were offline but it wasn’t said why they were offline. (Likely usual
maintenance and refueling). You wouldn’t specifically shut down for this
reason.

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shartshooter
How big of a problem is this if nuclear is going to be an option as global
temperatures rise?

Will nuclear be shut down so often in the future that we can't depend on it?
Similar to the argument folks make against solar(it doesn't work at night).

~~~
colechristensen
Power plants are designed are designed to take useful energy by transmitting
heat between something hot and something cold. They can be designed to work
for any condition of "cold" and a few degrees doesn't change the ability to
design.

Problem was these plants were designed for an amount and kind of heat sink
which wasn't there for a while. If it became a frequent problem it would be
fixed by building alternative heat sinks that worked in more situations.

Water cooled reactors run at about 300C, molten salt around 700C or "much
higher", and some designs for gas cooled reactors go over 1000C. The weather
being a few degrees hotter or even tens of degrees hotter isn't really going
to matter if your cooling system is designed to handle it.

The minimum temperature gap up there is > 250 degrees, taking a few away isn't
going to make anything impossible, but it might make some existing plants
increasingly unreliable if there are no investments in new plants or upgrades.

~~~
Maledictus
this is not an engineering problem, it is a "how much are we willing to affect
wild life" problem.

~~~
masklinn
No it's an engineering problem, these plants were designed without cooling
towers because it was assumed the direct cooling using river water would be
sufficient in all but the rarest cases.

~~~
flukus
Presumably it's more of a financial/efficiency problem. Pumping water is
expensive, less reliable and a heap of maintenance nightmare compared to
passive options. You'd avoid it entirely if it was feasible.

~~~
masklinn
> Presumably it's more of a financial/efficiency problem.

It's absolutely a financial decision, but it wasn't a financial _problem_.
Cooling towers are not free but in the grand scheme of building a nuclear
plant they're not expensive either (most power stations — including non-
nuclear — have cooling towers).

And "Direct cooling" is not a passive option, you're still pumping water from
and to the river or body of water in order to condense steam in the secondary
circuit. What you're not doing is semi-closed cycling of that water through a
cooling tower, you're feeding the condenser straight from the body of water,
and sending water back into it more or less directly (possibly having gone
through a radiator of some sort to shed some heat).

~~~
elproxy
Don’t forget the PR aspect, and political cost. A lot of people in France
believe nuclear power is carbon intensive because of the plume coming out of
the towers.

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sunkenvicar
This story omits the most important information. What happens to plant and
animal life if we raise the river temperature? And what happens if we instead
burn more coal in Germany to compensate?

~~~
_ph_
The plants and the fish can die. On the short term, the oxygene content of the
water is the problem. The oxygen content decreases with increasing water
temperature. So beyond a certain temperature, the oxygene levels can go below
the levels required for survival, the animals and plants suffocate. Especially
in lakes it can happen, that in these weather conditions basically all fishes
can die at the same time. Agitating the water helps to maintain higher oxygene
levels.

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batmansmk
"Available nuclear power supply was down 1.4%" and for environmental reasons,
not engineering oens. So much drama for nothing. If you advocate for renewable
in reaction to this article, tell me how much a solar panel drops everyday at
night, or a wind turbine when there is no wind.

~~~
flukus
> Available nuclear power supply was down 1.4 percentage points at 65.3% of
> total capacity compared with Wednesday.

You left out an important part to the point of being intentionally deceptive,
the opening paragraph says it's down 8% overall. If aircon were common that
could mean large scale brown outs. As this becomes more common they'll
probably need more solar to help with the unreliability of nuclear.

> tell me how much a solar panel drops everyday at night

Nighttime is the easiest problem to solve with solar, it correlates with lower
energy use and is an extremely predictable occurrence making it much easier to
plan for than weather events.

> or a wind turbine when there is no wind.

Depends on the location and what it's paired with, but wind is almost always
available in some capacity.

Let's not pretend nuclear is perfect, even without events like this plants go
offline for things like maintenance (TFA mentions 2 that are currently
offline), renewables aren't unique in their need to build excess capacity to
deal with intermittent availability.

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tosh
tl;dr:

> High water temperatures and sluggish flows limit the ability to use river
> water to cool reactors.

> EDF’s use of water from rivers as a coolant is regulated by law to protect
> plant and animal life and it is obliged to cut output in hot weather when
> water temperatures rise, or when river levels and flow rates are low.

~~~
caymanjim
When I started reading this, particularly the first line quoted above, I was
ready to call BS on it, and almost stopped reading. The idea that that the
river being a bit warmer would make it ineffective at cooling the reactor was
too silly. But then I got to the second quote and realized they just don't
want the reactor to make the river any warmer than it already is.

~~~
mrob
The Wikipedia article for Bugey Nuclear Power Plant says "Some of the cooling
comes from direct use of the Rhône water (units 2 and 3) while some is done by
the use of cooling towers (units 4 and 5)." Cooling towers use evaporation to
remove the heat, and water has high enthalpy of vaporization so they'll
probably still work even with warmer input water, but if the direct cooling
system is not designed to boil the water then it might fail if the input water
is too warm.

[https://en.wikipedia.org/wiki/Bugey_Nuclear_Power_Plant](https://en.wikipedia.org/wiki/Bugey_Nuclear_Power_Plant)

~~~
caymanjim
I live near
[https://en.wikipedia.org/wiki/Oyster_Creek_Nuclear_Generatin...](https://en.wikipedia.org/wiki/Oyster_Creek_Nuclear_Generating_Station).
When the plant was running, it would suck in so much water that one river
would run backwards, pulling in brackish water from the bay (near the outlet
of another river), and depositing the outflow into a different river, which
went back into the bay about a mile away. Both the inlet side and outlet side
were rich fishing and crabbing grounds. Now that the plant is shut down, both
the inlet and outlet are nearly stagnant, and all the seafood is gone. The
outlet was a particularly popular fishing spot, because the warmer water both
attracted more fish and greatly extended the fishing season (even through the
winter, when you couldn't catch much elsewhere).

