Ukraine Nuclear Power Plants 9

[bones206]

Nuclear power plants are not designed to operate in war zones. What can be done to proactively shore up the safety systems of these plants in Ukraine?

Assuming Russia permitted the international community to bring equipment on-site uncontested, is there anything that could be used in a pinch to augment emergency power systems etc? When I got out of the nuclear industry in 2016, there were a lot of projects in the works for this type of “beyond design basis” scenario in response to Fukushima.

Hopefully IAEA is already being proactive about this and working in a contingency plan, but I’m interested in hearing thoughts from our community here.

 

[RedSnake]

The "red forest" is named after the reddish-brown color of the pines in the area since they died of high levels of radiation after the Chernobyl accident on April 26, 1986.
After the disaster, the forest was cleared and the trees dug down.
The Red Forest is today one of the most polluted areas in the world.

In this image I have put the current measured values on top of the old Curies per km map
The arrow points at the highest measuring station and the value is right now 460 nSv/h

https://remap.jrc.ec.europa.eu/Advanced.aspx

From our guidelines below making this calculation

Take the maximum recommendation for eyes 20mSv/year.
With 0,00046 mSiv/h, one hour would give you 0,00046*24*365 = ca 40mSv/year
And this is not the most contaminated part.
For stirring up dust, I don't know, feels like a exaggeration, it's still quit much winter and wet.
But just being there is not good.
Digging even worse.

Dose limits
The following dose limits apply to external and internal radiation (Radiation Protection Ordinance 2018: 506):

The maximum permissible radiation dose (effective dose) for radiological staff over the age of 18, when the whole body is irradiated, is 20 mSv / year. The corresponding limit for individual years for students / apprentices between the ages of 16 and 18 is 6 mSv / year. For pregnant women, a maximum of 1 mSv applies to the fetus throughout the pregnancy. In addition, the maximum permitted dose equivalent to:

skin, hands and feet are 500 mSv / year
eyes (lens) are 20 mSv / year

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

 

[Alistair_Heaton]

John there were a load of pits dug that they dumped core graphite that was jettisoned when the lid was blown off the core.

The stuff was lying around outside the building everywhere. The stuff that was on the roofs was chucked back into the hole.

The stuff on the ground surrounding along with other material was dumped in the pits. They then covered it with soil and left it.

The intel is coming from the Hospitals in Belarus.

They have been ingesting it, breathing it. And more than likely they will have a guess about the Dose by the symptoms but in reality nobody will have a clue what they got.

Have a watch of the Chernobyl tv series I am told by people that were there that it was pretty accurate. And I know 2 that were flying helicopters dropping sand into it.

The other thing is they have been hunting to get food and eating what they caught in those woods.

 

[Nukeman948]

Is there good intel that this is a true story? What would be the likely source of the radiation that they may have received?

There were confirmed reports of elevated levels of radiation at the plant from when the occupying forces drove in and kicked up contaminated dust. It is likely that they dug positions to secure the area. But we really don't know the extent of the problem. The dust cloud either dispersed before it reached other monitoring sites or the levels were soon too low to measure.

My guess is that they didn't dig up any graphite but it would not be good if they did or to be near it for long. They would need to grind it to dust to breath it in, but they probably didn't have access to showers to scrub contamination from their skin. Proper clothing is to keep the contamination off of you but it doesn't stop radiation.

So what else is there? When it exploded and burned it released huge clouds of fission products including iodine 131, strontium 90, cesium 134 and cesium 137 among other things. The iodine has a half life of around 8 days so there is none of it left. The cesium 134 has a half life around 2.1 years so there isn't much left, if any. The cesium 137 has a half life of 30 years and is most likely the largest concern. The worst part of cesium contamination is that it accumulates in the bones and is very hard to get out of the body once it is there.

I read that some of the doctors in Belarus refused to treat those that came there but they should be able to do a whole body scan to determine exactly what they are contaminated with and to what extent. They can even tell if you eat a lot of bananas (or other high potassium foods)!
The guy in the first truck probably didn't breath in as much dust as the guys that followed. None of them wore respirators that we know of. Our next three best tools to protect ourselves are time, distance and shielding. Did they spend a month there wallowing in the dirt or did they at least have guard duty in shifts and sleep in the plant? I don't know. They also may have been exposed to other sources of radiation in the lab areas of the plant or even around the old reactors.


Some light reading:

https://news.mit.edu/1994/safe-0105

https://en.wikipedia.org/wiki/Whole-body_counting

https://www.epa.gov/radiation/radionuclide-basics-cesium-137

https://www.epa.gov/radiation/radionuclide-basics-iodine

[sub]Edited to add strontium 90 I forgot to the list with similar health concerns as cesium.
[/sub]​

 

[electricpete]

Even if they can safely shut down, decay heat cannot be removed without power. Some kind of cooling loop is required, which is run with pumps, which require power. It is my understanding that these plants cannot simply remain passively safe after a shutdown without heat removal systems running on electricity for an extended period of time (possibly longer than this war lasts).

I agree they need power to remove decay heat. If the local power grid goes down, they will need an ongoing resupply of diesel fuel. In the US, plants are required to have on-site reserve of a 7 day supply for each safety diesel and would require replenishment of diesel fuel from outside the plant before the end of that period (at least that's the simplest way to look at it, in reality they may not need it that soon due to redundancy provided by multiple safety trains, but for conservatism they assume that one of the safety trains in each plant fails in such a way that they cannot take credit for it).

In Fukushima, the diesel fuel storage tanks were unprotected and were washed away by the flood (the same event that took down the power), so they didn't even have the benefit of power for the time afforded by their onsite diesel fuel storage. In the US, diesel fuel storage is protected from flood and heavy winds.

Reliance on on-site diesel fuel storage and replenishment under challenging circumstances has been put to the test in the US when the eye of a category 4 hurricane went directly over Turkey Point nuclear plant (south of Miami Florida) in the 1990's creating widespread disruption of power/transportation infrastructure around the plant. There have been several other extreme weather events around US nuclear plants in that past but I think that was the worst. The hurricanes can be seen well in advance and the plants generally shut down at least 2 hours before any hurricane force winds are projected on-site (to allow a controlled shutdown and get a head start on decay heat removal, I presume). It's obviously a different situation in Ukraine where the threat timing is less predictable and the ability to resupply diesel fuel following loss of grid power is also less predictable.


=====================================
(2B)+(2B)' ?

 

[RedSnake]

Hi! I hope things are better with you, then some parts of the world.

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

 

[electricpete]

Hi RS! I logged myself out of the pub to remove myself from the craziness of the political scene. But the world news is crazier than ever, even for someone like me living on the other side of the planet. I can only imagine what it's like for those that are closer. It's hard to see when/how this war will end. Let's hope it is soon.

=====================================
(2B)+(2B)' ?

 

[RedSnake]

Yes, it's just one thing after the other it seems.
It is soon spring here so that is a little light in the future at least for us.


“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

 

[Alistair_Heaton]

H'mm For some of us Chernobyl is 450 miles away.

On a nice note we have had absolutely stunning weather last month still cold but I produced 1.31 MWh of electricity with my solar plant most of which got fed into the grid. And some days it was over 0.5 euros a kWh

 

[RedSnake]

FYI

Servicemen of the National Guard arrived at the Chornobyl nuclear power plant - they took the object under their protection

https://twitter.com/5channel/status/1511417149864120320

And the radioactivity environmental monitoring is on again.

https://remap.jrc.ec.europa.eu/Advanced.aspx

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

 

[RedSnake]

Does Russians might have been lucky not digging in the worse part of Red forest if they haven't been in other places too.

https://liveuamap.com/en/2022/6-april-drone-video-of-trenches-excavated-by-russians-in

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

 

[electricpete]

I gather that maybe the Russians viewed the Chernobyl area as a protected position for their soldiers to camp, since Ukranians wouldn't attack that area with artillery (out of fear of damaging the plant)

It is rich with irony that soldiers from the country responsible for the Chernobyl incident stumbled back into it, seemingingly unawareness of the danger.

But on the individual soldier level, who knows what they really knew about the plant or their reasons for being at that particular location (or in Ukraine for that matter). Surely if they knew what that big structure was, it would have raised some alarm bells for them to dig trenches within sight of the worst nuclear disaster in history.

There are some reports that Chernobyl plant personnel had to steal fuel to keep power to vital safety / containment / monitoring systems.

I have a feeling the Russians won't be going back to Chernobyl again anytime soon, but who knows about the other nuc plants in Ukraine.

=====================================
(2B)+(2B)' ?

 

[electricpete]

Status update

Fears grow for Ukraine nuke plant ahead of inspector report

In the meantime, the plant’s only remaining operational reactor will “generate the power the plant needs for its safety and other functions,” the IAEA said. The plant needs power to run the cooling systems for its reactors and spent fuel and avoid a meltdown.

Mycle Schneider, an independent analyst in Canada on nuclear energy, said that means the plant was probably functioning in “island mode,” or producing electricity just for its own operations.

“Island mode is a very shaky, unstable and unreliable way to provide continuous power supply to a nuclear plant,” Schneider said.

It was just the latest incident to fuel fears of a nuclear disaster in a country still haunted by the world’s worst nuclear accident, at Chernobyl in 1986. Experts say the reactors at Zaporizhzhia are designed to withstand natural disasters and even plane crashes, but the unpredictable fighting has repeatedly threatened to disrupt critical cooling systems, raising the risk of a meltdown.

Island mode is a step better than relying only on diesel power. But I agree it's tenuous situation the sole remaining plant may easily trip due to unusual configuration (operating in island mode at low power) or war-related challenges. And if it's a war related challenge, it could perhaps challenge the safety systems in the same way that in Fukushima the event that shut down the reactors and the grid also took down some of their emergency diesel power.

I've heard of some articles warning of potential Fukushima-like event. I'm not qualified to judge with absolute certainty but it doesn't ring true to me.

[ol 1]
[li]* The biggest difference, these Zaporizhzhia plants are PWR's. All the Fukushima reactors were old generation BWR's. I'm under the impression PWR's are simply not susceptible to the Fukushima scenario or anything like it (if nothing else, think about the TMI scenario where even even though the reactor melted down, the environmental release was minimal).[/li]
[li]* Fukushima was made quite a bit worse by proximity to the ocean. Stopping water from leaking into the ocean is nigh impossible (the team has gone to great lengths to freeze the ground as a barrier to leakage... a herculean effort). In contrast establishing a barrier area around a landlocked plant would be a lot easier. Of course Chernobyl was landlocked but that's a whole different story... bad reactivity management design, no containment building, and actions of the 3-man crew conducting an idiotic experiment which first disabled multiple safety systems and then challenged the reactor with the very scenario those safety systems were designed to protect[/li]
[li]* Also having most of the reactors shutdown is a safer condition (the worst case accident is with reactors initially operating and at full power, since decay heat decreases with time after shutdown). There is only one remaining and it is indeed the most susceptible (although not as susceptible as if it were operating at 100% power since the decay heat at time of shutdown depends on the power history). Shutting it down at this point in time (without availability of grid power) is not necessarily a great option since the power produced by the operating plant is more important when disconnected from the grid. 20-20 hindsight, one wonders why they didn't preemptively shut down that reactor while it was connected to the grid and the need to keep it running was not as large from a safety standpoint. Most likely any safety concerns were trumped by other considerations. Note I believe the plant was previously disconnected from the grid at least once before during this war.[/li]
[/ol]


=====================================
(2B)+(2B)' ?

 

[RedSnake]

Island mode, what does it mean electricpete?

It only toke an hour or so after the majority of the IAEA left the Zaporizhia NPP before the plant was shelled again by the Russians and the 6th generator was turned of because of the electrical lines where broken again the whole UA grid connection was down.
I think they have repaired the lines to generator 6 and it has been started up again.

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

 

[electricpete]

High R/S!

Island mode means a generator is producing power but it is not connected/synchronized to the grid (in this case the power from the nuc plant is going to supply only the loads on-site at the nuclear plant). I guess in the analogy implied by the terminology is that the grid plays the role of a mainland continent and the plant plays the role of an island, not connected to the continent.

It sounds like a rapidly evolving situation and the news is not reliably reported. Tough to keep up with. It will be interesting to hear the upcoming IAEA report from their visit.

I don't know exactly how the electric grid figures into the war effort for both sides. If Russians have been in control of the plant and didn't shut it down during months past, then I'd think that Russia must believe it is to their advantage to keep the plant producing power (somehow Russia benefits from that power more than Ukraine). Or else it is a common humanitarian interest that leads both sides to prefer the plant continue operating.

There is a parallel situation with grain exports where Russia allowed something on seemingly humanitarian grounds. But I gather it was the threat of NATO warship intervention to enforce open trade that made that happen (Russia doesn't want to give NATO any excuse to intervene directly). I've heard people say optimistically that in a similar way, if NATO demanded Russian concessions toward nuclear safety at the plant under threat of NATO-enforced no-fly zone over the plant, then Russia would likely comply. That's something that NATO wouldn't announce/demand unless NATO was prepared to follow through... it remains to be seen.


=====================================
(2B)+(2B)' ?

 

[Alistair_Heaton]

Ukraine was synced to the EU grid quite early on.

Russia has said that they are its reactors and Ukraine should pay for the power from them.

They were trying to organise things so they could attach them to the Russian grid via Crimea. Ukraine took out the hardware connections to be able to do that.

Ukraine was in the process of life extension and converting to using none Russian fuel.

 

[RedSnake]

If Russians are in control of the plant and didn't shut it down during months past, then I gather Russia must believe it is to their advantage to keep the plant producing power (somehow Russia benefits from that power more than Ukraine).

What they are trying to do is to disconnect it from the Ukrainian grid and connect it to the Crimean one so they can get the power to Russia.
Some partisans in Crimea blew up the transformation point on the grid on the Crimea insula so they couldn't do it.

This would make the energi "crisis" in Europe bigger since Ukraina is connected to the EU grid since the spring.

They also use it as a threat instead of nuclear weapons, "just have to wait until the wind blows in the right direction".
They shelled the ash dumps there too, making radio aktive dust flying around, of course blaming the Ukrainians, and the radio aktive sensors closest to NPP is not working.

I think you can get some more long term data I don't remeber how though.

https://remap.jrc.ec.europa.eu/Advanced.aspx

EDITED: The Russians tried to get a contract with someone to deliver diesel so they could run the cooling even if everything was off grid, that was a month ago, but now when the Ukrainians offensiv have started and the Ukrainians are constantly blowing up supply routes thru out the occupied territories I am not sure that those delivery's can be uphold even if there is some.

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

 

[electricpete]

Thanks Alistair and Redsnake. It sounds like there are Russian incentives to keep the plant making power at least if they can establish connection to Crimea.

Diesel fuel is indeed a critical commodity for the nuclear plant. It never occurred to me before that the same fuel is also valuable to the resupplying Russian war effort. That does seem to give the Russians some leverage to protect their supply lines, especially if they treat the nuclear diesel fuel storage tanks as a resource for military refueling.

=====================================
(2B)+(2B)' ?

 

[Alistair_Heaton]

They can't do that now. And its in a spot that if the logistic lines from Crimea are cut they can't hold it supplying from the east.

It was basically the power house for the heavy industry in the South and East not that there is much of that left. But it would still be a major source of GDP if Ukraine can clear the area.

The Russians along with the other reactors built in soviet times see it as 100% owned by them and paid for by them. Along with any partially built reactors dotted around which there is a vast number of them. EU has basically blocked them all and moves are afoot to prevent the possibility of the others being completed. The one in Belarus was planned to sell power to the Baltic states but nobody has touched it. There is another 2 in Kaliningrad which one is 90% complete which they want to do the same with but the Baltics are due to desync from the Russian grid in 2023.

Mixed in with the conversion of the areas reactors to western fuel sources I can't see them giving it up in a working condition. The big question is how safely they can sabotage it. I think most of them are due a tempering to extend life which can only be done by Russia so there isn;t that much life left in them if that isn't done.

 

[Alistair_Heaton]

Seems the Russians have taken outthe switching yard that was the only one left to hook up the plant to the grid. So it's in island mode or backup gens requiring 500ltrs of diesel a day. Only one reactor critical just now supplying local power for cooling.

There is one other reator which has recently shit down which is still quite active with transnuclided heat production the others are through that now. Also the spent fuel pools need cooling.

The active reactor is at lowest stable thermal power no iodine poisoning just sitting ticking over.

 

[TugboatEng]

500 liters per day? That seems a bit low. We always used the 1 gallon per horsepower per day to plan consumption for voyages. A typical nuclear plant backup generator is going to be in the 2000-5000 horsepower range. I don't know what the load is but they are certainly capable of burning a lot more fuel.