MPN11

Surely constantly replenished by the Dnipro?

Lucifer Morningstar

It depends how deep the lake is, and whether it has a constant slope to the deepest point on both sides (very unlikely). As the water level lowers, it may well form multiple individual lakes, with islands of 'higher ground', and whilst it will empty to the lowest level of the breach, it may be far deeper than that in places so it is possible that a sizeable reservoir will remain. As I say, all of this is dependant on the depth at any given place in relation to the bottom of the breach.

Regardless of the inflowing Dnipro, it can only ever 'fill' to the lowest level of the breach as pure physics dictates.

As others have indicated, this was indeed the use of a weapon of mass distruction by Russia, just not the one we thought. For me at least, the fact no individual nations are coming to Ukraines direct aid (boots on the ground) after this, shows Putin he can indeed act with impunity. I hear the Poles are at least discussing internally the possibility of direct intervention, and they are formidable to say the least, but until and unless that happens I suspect Putin will be taking away from this the fact that the West will not act directly against him regardless of his actions.

I very much look forward to being proven wrong.

Winemaker

When you try filling a tub with the drain open, it will never fill.

ORAC

With the Ukrainian counter-offensive now clearly underway and heavy fighting reported south of Orikhiv, I'm re-upping @ian_matveev's analysis from April of the challenges that the Ukrainians will be facing. Worth noting that the fighting is happening exactly where Ian predicted.

Part 1

https://threadreaderapp.com/thread/1...814857216.html

​​​​​​​Part 2

https://threadreaderapp.com/thread/1...857718278.html

albatross

Unless the amount of water entering the tub is greater than the amount of water exiting via the drain. Of course a bit “Apples and Oranges” when compared to this damn dam as the size and capacity of the tub’s drain and associated plumbing is fixed and not subject to expansion due to erosion.

ORAC

https://euromaidanpress.com/2023/06/...ense-minister/

A missile program has been approved in Ukraine with “good prospects” for the country to have domestic missiles with a range of more than 1,000 kilometers, according to Defense Minister Oleksii Reznikov, who said it at a Kyiv forum on the restoration of Ukraine, an Ukrinform reports.

“We have very good prospects of having Ukrainian missiles with a range of more than 1,000 kilometers,” Reznikov said.

According to the minister, the missile program has been officially approved, and funds have already been allocated from the budget to this end. The actors involved in the program are Ukrainian producers, according to Reznikov.

The minister did not mention the particular types of missiles which are going to be produced under the program. The closest Ukrainian project is the HRIM-2 which targeted the 500-kilometer range and was nearing its testing stage before the war.

Russia’s Defense Ministry claimed several times, providing no evidence, to have shot down HRIM-2 missiles.

Another possibility is extending the range of the R-360 Neptune anti-ship missiles, known for sinkingthe Russian Black Sea Fleet’s flagship Moskva.

soarbum

Nobody is quite sure yet. If the base and walls of the concrete channel have been breached and the flow is eroding an earthern portion, it could be very bad. If the concrete base underneath the now demolished gates and HPP is still OK and the water is being confined within a concrete spillway, then the water level will reduce from 16m to 12.7m but should hold there.

PS: Purely speculative thinking here and I'm not a civil engineer. If the concrete spillway is relatively intact, then when the artillery stops flying, it might be possible to build a set of gates across the entire portion that previously had gates and the HPP. It wouldn't generate any power but maybe it could be done within a year to control the flow and get the Crimean water, agriculture and ZNPP back to normal. A new HPP will take a lot longer but perhaps this could be done separately behind a coffer on the Western side of the dam.

ORAC

The Kakhovka reservoir has reached 'dead pool' only two days after its dam was breached, and is no longer able to supply settlements or the Zaporizhia nuclear power plant. It's expected to stabilise at a drastically lower depth and to shrink the Dnipro's width by kilometers.

The head of Ukraine's hydroelecticity provider, Ukrhydroenergo, has said that as of the evening of Thursday 8 June, the reservoir has reached a depth of 12.5 metres (41 ft). This is 20 cm below the point known as 'dead pool', when water can no longer flow from the reservoir.

Ihor Syrota says that water can now no longer flow to settlements and the Russian-held Zaporizhzhia nuclear power plant. The water level is likely to stabilise at around 3 m (9 ft). It's dropping around 1 m daily, so the outflow will continue for another 7-8 days.

When it reaches 11 m it will no longer be able to supply the North Crimean Canal and other irrigation channels serving southern Ukraine. At the current outflow rate, the canals' water supply will be cut off by Sunday.

https://threadreaderapp.com/thread/1...311224325.html
​​​​​​​

Beamr

On a lighter note, tiktok-Kadyrov is convinced the Chechen forces will take Poland and France and then reach Germany.
A routing I'd never have thought of.

ORAC

Russian imports of electronics are back to pre-war level - Jim O’Brien, sanctions coordinator at the U.S. State Department.

This means Russia gets the chips, processors and integrated circuits it needs to make weapons.

The US have identified five countries who do the most sanctions circumvention to get the electronics to Russia: Turkey, Kazakhstan, Georgia, UAE and Armenia….

https://www.politico.eu/article/russ...s-war-ukraine/

Russia is getting better at evading Western sanctions on electronics, US official says

FUMR

Which is why sanctions just don't work!

Mr Mac

Lonewolf
If the blast was under the spill way or Locks, as it appears to be, and the concrete core does not go to the base of the dam from the cross section, then the sheer bulk of water will erode down to the river level at that point. If you think of Lake Eire draining into Northern New York, or for Brits Lock Ness going for a walk in the Thames Valley you get the idea of the volume and mass involved.

Cheers
Mr Mac

ORAC

They work in that the enemy ends up paying 10 to 100 times as much per chip at a substantial cost to their funds for other munitions….

Mr Mac

ORAC
I agree that the seller will make a handy turn, but would it not be worth the West, as let’s be clear, it us who are supporting Ukraine, as I can tell you from listening to people outside the lottery bubble of North America, Wester Europe, Japan ,Australasia and a few smaller areas the rest are a little ambivalent.

Time to use our buying power with certain countries like India , Brazil , China, UAE and others. If not then what is the use, as Russia will buy its away round sanctions as others have done in the past. Take away the support, and it will fall apart, let these quasi supporters, or shall we say greengrocers, know where their market is, and that the market is not happy. Perhaps if our govt publicly called out these quasi supporters?

Cheers
MrMac

NutLoose

Tenders assessment of the on going situation which seems very good and fair.

​​​​​​​

Winemaker

The outflow through the break is likely an order of magnitude greater than the previous spillway flow, so the lake will empty to some unknown level. Let's hope there is concrete structure left; the California Oroville dam spillway concrete erosion a few years ago was amazing, with the dam coming close to a collapse situation.

NutLoose

Something is burning in Berdyansk

tdracer

I read somewhere (I can't seem to find it now - if I do I'll link it) that the breach only goes down to the bottom of the spillway - which is something like 12 meters from the bottom (i.e. roughly half the height of the dam).
Further, as that portion is all concrete, it should be reasonably immune to erosion.
I hope the writer knows what they are talking about...

fdr

The loss of pool water replacement at ZNPP is a high risk issue. The fuel rods that are removed and are in cooling ponds will continue to heat the water and without refreshing the water through heat exchangers the pool water will increase in temperature, and volume will be lost. Without heat dissipation, the fuel rods will initially lose the radiation absorption barrier of the water mass, and will become a local hazard which will complicate handling, and sometime thereafter, the fuel rods can overheat to the point of breaking down the cladding exposing the fuel pellets to atmosphere, and potentially becoming an unstructured mass of enriched fuel pellets, which is not good. The fuel rods reduce their activity rapidly in the first few hours following coming off criticality, but they are still energetic, and will remain so for years. Overheating that may result in loss of fuel rod integrity risks a criticality event at some point in the future. The pool cooling would normally be used to dissipate heat prior to any dry storage being used, and dry storage must ensure that criticality is avoided by physical minimum distance management.

ZNPP is a nuclear disaster unfolding at a slow pace for now, and the IAEA and other parties including China need to demand, and get, immediate access and control of the ZNPP to sort out reliability of cooling and to start mitigating the incompetence and negligence of Russia, should it be worthwhile to circumvent a radiological disaster unfolding due to the actions of Russia. No one wins from a ZNPP corium event. (This is more of a concern than Tokaimura's Level 4 event, it would be at least the level of Windscale, or potentially up to Kyshtym, hopefully less than Chernobyl or Fukushima Daiichi, those both involved H2 explosions, which is not going to occur if there is no containment at all, and no H2O.... )

Zircaloy normal limit temps are 394-400C with a maximum fire event limit of 570C according to NRC risk analysis of dry storage of spent fuel rods. Accelerated oxidation occurs around 1100C, and melting of zircaloy-4 occurs around 1850C. These are fairly high values, but then the heat buildup of a failure of relatively fresh fuel rods in a cooling pond that is dry appears to be outside of the normal risk analysis, it is a condition that is designed to never occur; the risk analysis does not appear to cover a criminal incursion into a NPP that manages to destroy the cooling pond integrity. If there is any studies on such an event, I'm all ears, I cannot find it following public data searches. The concerns have been raised before, a 1997 study by the Brookhaven National Laboratory on Long Island described a worst-case disaster from uncovered spent fuel in a reactor cooling pool. It estimated 100 quick deaths would occur within a range of 500 miles and 138,000 eventual deaths. The study also found that land over 2,170 miles would be contaminated and damages would hit $546 billion.
"Once most of the fuel is exposed, he said, it can catch fire. If the spent fuel is a few months old, most of the iodine 131 — one of the most dangerous radioactive byproducts in spent fuel — will have decayed into harmless forms. But the cesium 137 in the spent fuel has a half-life of 30 years, meaning it would take about two centuries to diminish its levels of radioactivity down to 1 percent. It is cesium 137 that still contaminates much land in Ukraine around the Chernobyl reactor, which suffered a meltdown in 1986."

The quote above is related to the analysis at BNL, and arose from the concerns of the Fukushima disaster. ZNPP is unique as there has never before been a NPP event that was due to and under the "care" of criminal terrorists. The BNL analysis doesn't suppose having criminal damage and interference by Russia to efforts to mitigate the damage that has been wrought.

The fuel rods (pins) even after cooling for years provide so much residual heat from nuclear decay that the dry storage casks can have temperatures well above 100C in areas, (the NRC has studies on the risks of dry casks) so a loss of recirculating cooling water to the pools for the next many years will risk a boiling of the pool water (happened at Fukushima) and a high probability of fire, failure of the cladding and then a mess of unseparated nuclear fuel melting into a blob, until physics takes over to separate that all. Russia needs to be removed from ZNPP and emergency measures taken to avoid the potential of contamination of the whole area, including the black sea, NATO states, Russia, the Stans, Western China, the Mediterranean, etc.... As non trivial goes, ZNPP and the irresponsible, criminal actions of Russia are of global impact, far outside of just Russia or Ukraine.

C. Little.

soarbum

A few more images to ponder...

The first shows the dam before the collapse. The hydro is off and most of the sluice gates are closed despite the swelling levels in the Dnipro.
The red lines that I put in are where I think that the limits of the concrete section are. This is a huge slab up to a height of 12.7m above base on which is built the sluice gates, the road bridge and the HPP station.
Left and right of the red lines, the dam is earthen and not designed to have any water flowing over it.



Next, we have the after shot with two distinct flows. Flow A is going over the 12.7m concrete dam through where half of the sluice gates would have been and through the ruins of the HPP.
I suspect that when the level drops below 12.7m (and it may already have), Flow A will dry up.
Flow B is going through what was previously earthen and will erode a much deeper channel. If the concrete base of A is still intact then soon, all of the water will go through Flow B.



Finally, I add the streetview showing the area that Flow B now occupies. If the gates had gone first, the resevoir level would have dropped so I can't see why water would have afterwards flowed through B.
I think it more likely that the reservoir got so high that the water washed down the grass bank in the pic below around the left side of the HPP first. Perhaps it eroded under foundations causing the building to collapse and lots of pre-laid munitions to go boom.



As for rebuilding, if the underlying slab has survied intact, the water is already diverted through Flow B so the site at A should dry up. If new sluice gates and road bridge can be built on the slab, then a coffer dam could be built from the end of the canal spit in an arc to the new gates. That would block Flow B and leave the old site of the HPP dry for rebuilting over the next 5-10 years but at least in the meantime, levels could be regulated as before.