How Hot is Ukraine Gonna Get?

[DesertFox]

Just now, Bulletpoint said:

but just to be fair, I'm ready to also believe that it was a Russian falling asleep on the red button.

LOL! 

[Grossman]

1 hour ago, Bulletpoint said:

While I'm not a dam engineer either, I am pretty sure such structures are engineered to be strong enough that they won't break even if the dam is at full capacity.

It seems bizarre that it would have been in operation for so many years and then suddenly collapse just as the Ukrainian counteroffensive is imminent.

Ukraine would have no incentive to blow up the dam either, so the arrow clearly points to Russian sabotage on this one.

The Ukrainian's say the explosion happen in the power station, and presumably under the dam. So must have been packed with explosives

[cesmonkey]

Quote

However, our current assessment is that there is no immediate risk to the safety of the plant.

 

[FancyCat]

Any bridgehead across the flooded region needs to contend with crap logistics, wouldn't make sense for Ukraine to do that.

[Kraft]

1 hour ago, Butschi said:

That's not evidence, though, and absolutely doesn't rule out catastrophic failure, right?

On the probability scale I'd weight it about as likely as the Moskva having sunk from stormy weather though. 

Edited June 6, 2023 by Kraft

[Beleg85]

Late to the discussion... damn, it were jokes about this "1812 protcol", but it seems they really starting to fire it up.

Given timing alone, I find accidental collapse of the dam as plausible as Stremousov death in accident the night before Russian withdrawal from Kherson.

With Nuclear PP out of order, Ukraine will loose what...15% of entire energetical grid? Catastrophy.

2 hours ago, panzermartin said:

If the Russians had planned to blow up the dam, there must have been a months long preparation to secure water supply in Crimea, especially since summer is here?

Not if one wants to have a political reason to actually leave it...Also, Russian sloppisness is a factor here.

Here VDV soldier cheering this event:

Edited June 6, 2023 by Beleg85

[DesertFox]

Plausible timeline for me. Sources within the thread.

 

 

[Seedorf81]

The Ukrainian Army-offensive-planners surely must have considered the possibility of this terrible damdestruction-scenario, and are (hopefully) not as surprised as we are..

 

 

 

[Centurian52]

Apologies if this has already been posted (I'm still a few pages behind), but I was excited to see this as the first sentence in this morning's ISW report:

Quote

Russian and Ukrainian officials are signaling the start of the Ukrainian counteroffensive.

https://www.understandingwar.org/backgrounder/russian-offensive-campaign-assessment-june-5-2023

[Ultradave]

8 hours ago, kluge said:

The plant has been more or less shut down for some time now, so I imagine the risk of a full scale disaster is off the table in the immediate future.

However, the plant will eventually need a water supply to keep its reactor and fuel cooled, as a shut down reactor still generates heat that requires active cooling. Previous reports suggested that the plant will be unable to source water if the reservoir drops another 1-2 meters, and judging from the early footage of the breach, that threshold will be crossed very soon.

So while there will be no immediate disaster, the clock has started ticking.

Something will need to be done to get water to the plant. And the obvious backup options- such as trucking in water, or building additional infrastructure to draw water from the river itself- are made much more complicated by the fact that the plant sits directly on the frontline* of an active war.

* Sidenote: The plant is located at a relatively narrow part of the reservoir, which just so happens to be more or less adjacent to the Nikopol bridgehead used during WW2.

 

 

The head of the IAEA said that the cooling water in the separate pond/lake, which is pumped from the reservoir, is sufficient for many months at least, since all the reactors are in cold shutdown. They have the ability to pump more water from the river until the river level gets TO ~12.7m. That's much more than dropping 2m.

The media can stop their breathless reporting of imminent nuclear disaster, another Fukushima, etc. Might have been a good idea for the various media to actually ask some experts first, specifically the IAEA which has been keeping a very close eye on the power plant status since the beginning of the conflict.

Not sure how many people know the intricate workings of a nuclear plant but that pond water does not go in and out of the reactor. In 2 sentences, it's used for the secondary side of heat exchangers that cool the water that is in a closed circuit circulating through the core. It's "clean" water, and not exposed to radioactive contamination.

Dave

[edited] I listened to his statement and thought he said 2.7m. The written statement says 12.7m. In any case, that refers to directly pumping water for cooling, and the cooling pond is still there and good for months of cooling.

Edited June 6, 2023 by Ultradave

[Seedorf81]

3 minutes ago, Ultradave said:

The head of the IAEA said that the cooling water in the separate pond/lake, which is pumped from the reservoir, is sufficient for many months at least, since all the reactors are in cold shutdown. They have the ability to pump more water from the river until the river level gets TO ~2.7m. That's much more than dropping 2m, i.e., almost empty.

The media can stop their breathless reporting of imminent nuclear disaster, another Fukushima, etc. Might have been a good idea for the various media to actually ask some experts first, specifically the IAEA which has been keeping a very close eye on the power plant status since the beginning of the conflict.

Not sure how many people know the intricate workings of a nuclear plant but that pond water does not go in and out of the reactor. In 2 sentences, it's used for the secondary side of heat exchangers that cool the water that is in a closed circuit circulating through the core. It's "clean" water, and not exposed to radioactive contamination.

Dave

Nice to have a forummember that knows how to be cool at the right time.

Edited June 6, 2023 by Seedorf81

[TheVulture]

54 minutes ago, Beleg85 said:

With Nuclear PP out of order, Ukraine will loose what...15% of entire energetical grid? Catastrophy.

 

The plant in question is already shut down and not producing any electricity for Ukraine's grid, so no major change

[kraze]

3 hours ago, panzermartin said:

Oh my, they are all leading themselves to a wider self annihilation each passing day. I hope at least the nuclear plant stays safe. 

If the Russians had planned to blow up the dam, there must have been a months long preparation to secure water supply in Crimea, especially since summer is here?

 

Crimea is an occupied Ukrainian territory. Why would russians suddenly care if local population has drinking water?

[TheVulture]

7 minutes ago, kraze said:

Crimea is an occupied Ukrainian territory. Why would russians suddenly care if local population has drinking water?

Lets be honest - the Russian's would cheerfully do this to any actual Russians inside Russia too (except maybe in Moscow).

[kraze]

13 minutes ago, TheVulture said:

Lets be honest - the Russian's would cheerfully do this to any actual Russians inside Russia too (except maybe in Moscow).

And indeed they are. They are shelling their own territories using rocket arty and dropping bombs from planes in Belgorod oblast like it's nothing. Heck russian soldiers are looting russian shops and apartments there. What a twist.

It's just back to the question of what "russian" is. It's neither ethnicity nor nationality. Because Russia is an old empire, meaning it did a lot of ethnicity mixing over centuries like empires do to delete identities - there's no dominant ethnicity or nationality they would consider their own. So, of course, people from freshly occupied territories are even less human beings to them then people that were always part of the empire.

Hence their brutality towards their "own" Novaya Tavolzhanka and Shebekino. And if need be they would level Moscow too, don't have any doubt about that. In fact they already did that once in history.

Edited June 6, 2023 by kraze

[photon]

I don't understand blowing up the dam now, unless they thought it was now or never? It seems like blowing it now buys the Russians some operational annoyance having to evacuate Kherson for a week, and possibly a week's worth of operational delay for a potential crossing. Unless the AFU was mid-stream (literally) and has maintained good opsec on that?

If the AFU isn't launching an amphibious crossing, keep your dam powder dry for when they are. What am I missing?

[Centurian52]

On 6/5/2023 at 5:32 AM, kevinkin said:

Great points. But has NATO lost it's advantage in night combat or is that advantage difficult to press home in this large and long war? So special ops going into a terrorist nest at night is almost irrelevant when we are talking ground warfare on the scale we are observing? And on a static front. Perhaps the advantage will shine once a war of movement arises. I kind of sort of hope so.

I don't think NATO has lost its advantage in night combat. But Ukraine is not NATO (yet). I have no idea how much night fighting equipment has been sent to Ukraine (more than zero). They clearly have some night fighting equipment, but they also clearly do not have NVGs or thermals on the same scale as a NATO army would. NVGs don't seem to be something that every last Ukrainian soldier can take for granted just yet.

[Butschi]

1 hour ago, Ultradave said:

Might have been a good idea for the various media to actually ask some experts first

A statement that is almost universally true.

But then noone will give you those sweet, sweet clicks...

[pintere]

7 hours ago, kluge said:

The plant has been more or less shut down for some time now, so I imagine the risk of a full scale disaster is off the table in the immediate future.

However, the plant will eventually need a water supply to keep its reactor and fuel cooled, as a shut down reactor still generates heat that requires active cooling. Previous reports suggested that the plant will be unable to source water if the reservoir drops another 1-2 meters, and judging from the early footage of the breach, that threshold will be crossed very soon.

So while there will be no immediate disaster, the clock has started ticking.

Something will need to be done to get water to the plant. And the obvious backup options- such as trucking in water, or building additional infrastructure to draw water from the river itself- are made much more complicated by the fact that the plant sits directly on the frontline* of an active war.

* Sidenote: The plant is located at a relatively narrow part of the reservoir, which just so happens to be more or less adjacent to the Nikopol bridgehead used during WW2.

 

 

From the BBC

"The head of the UN nuclear watchdog has said a lack of cooling water at the Zaporizhzia nuclear plant could disrupt its emergency diesel generator. 

The area around the nuclear plant - near the breached dam - is in a Russian-controlled part of Ukraine.

“Absence of cooling water in the essential cooling water systems for an extended period of time would cause fuel melt and inoperability of the emergency diesel generators," Rafael Grossi of the International Atomic Energy Agency said in a statement. 

But he added that there was "no immediate risk to the safety of the plant" and pointed out there are a number of alternative water sources, including a large cooling pond next to the site."

[billbindc]

4 hours ago, kraze said:

russians are sending dozens of missiles to strike apartment blocks in Kyiv almost every night now.

Are we really arguing if them blowing up the dam was a natural disaster?

The timing and the cui bono are so strongly in one direction it's going to take quite a bit for me to believe it wasn't an intentional act by Russia. Benefit of the doubt simply doesn't apply here.

[Butschi]

1 hour ago, Ultradave said:

Not sure how many people know the intricate workings of a nuclear plant but that pond water does not go in and out of the reactor. In 2 sentences, it's used for the secondary side of heat exchangers that cool the water that is in a closed circuit circulating through the core. It's "clean" water, and not exposed to radioactive contamination.

True. Although lack of cooling can lead to a nuclear meltdown. It's been 20 years since I last studied Soviet style reactors but I seem to remember that the (direct translation from German) steam bubble coefficient is an issue here. Depending on this coefficient, the reaction rate either increases or decreases with temperature where Soviet style reactors being to the former type. Oh well, I guess someone here knows/remembers better.

[Beleg85]

1 hour ago, TheVulture said:

The plant in question is already shut down and not producing any electricity for Ukraine's grid, so no major change

True, but in longer term (when war will end) this will be a problem. Add probable grids which may likely be damaged too sooner or later. And bulding dam of this size will probably take years even if territory is well-governed and at peace.

Plus of course catastrophy for agriculture, both in Crimea and Zaporizhia region. Dniepr is traditionally viewed as "great feeder" of the region for centuries, for a reason.

 

Also remember about environmental catastrophy, there are reports of oil being leaked into river already. Oh, and beaver is coming back to this thread like boomerang. Bloody big one (mutated already?):

Edited June 6, 2023 by Beleg85

[akd]

I don’t see how breach on far right here could be dam failure.

[Joe982]

Ukraine cut the water supply to Crimea way back in 2014, so water to Crimea is not the issue.

Blowing the dam benefits Ukraine more than the Russians as a number of Russian defensive positions will be flooded.

If the Ukrainians advanced and then, sometime later, the Russians blew the dam it could cause unknown problems for the Ukrainian forces. Therefore I think the Ukrainians blew the dam to eliminate the unknown.

 

 

[Ultradave]

29 minutes ago, Butschi said:

True. Although lack of cooling can lead to a nuclear meltdown. It's been 20 years since I last studied Soviet style reactors but I seem to remember that the (direct translation from German) steam bubble coefficient is an issue here. Depending on this coefficient, the reaction rate either increases or decreases with temperature where Soviet style reactors being to the former type. Oh well, I guess someone here knows/remembers better.

Sure I remember. That was the RBMK reactors like at Chernobyl. They had a "positive temperature coefficient"  or  "positive reactivity coefficient" (those mean the same thing) meaning that as temperatures in the coolant increase, the nuclear reaction rate increases, which increases temperature, which increases nuclear reaction rate.....  you can see where that leads. HOWEVER, this is not the design of these reactors. These are more "typical" reactors that have a "negative temperature coefficient".  Reaction rate decreases as water temperature increases. Should be obvious that that is beneficial and is how most reactors are designed. I believe RBMK reactors were the way they were for weapons materials production, for one thing. They also had no containment, which the Russians justified by their strict operating procedures preventing accidents. Ironically, Chernobyl's root cause was a) the violation of multiple operating procedures and parameters, b) running an unapproved test procedure, c) lack of understanding by the operators of the physics of the plant and the indications they were receiving (those are related). 

It's nothing to do with steam by the way. (probably the translation or lack of accurate knowledge by the original writer). It's water. Steam is transparent to neutrons so really has no effect on reaction rate, other than if you've got steam in the core you've got NO cooling, which is of course, very bad. Steam flow is an incredibly poor heat transfer mechanism. Steam is the RESULT of efficient heat transfer.

In my qualification training (18 months) to be licensed for start up testing of US Navy reactor plants one things was drilled into us (well, many things, but) That was "Believe your indications and act on them".  If you have an indication of something going wrong and you take all the steps to shutdown and "put the plant is a safe condition" (that's the key words), you can't go wrong. You may waste time if it turns out to be faulty indicators, but you won't break the plant or kill someone. Our motto in the shipyard nuclear test organization - "When in doubt, shut it down"   An operating sub doesn't necessarily have that option, but many times they do, and that's the reason why we build and test them so well, so that it doesn't come up.

I have had to argue that point a few times with my upper management. "I was there. I had the watch. My decision."    I mean, it's the entire reason they spend 18 months and who knows how many $$ to license us!

Dave

 

Edited June 6, 2023 by Ultradave