Nuclear reactor technical discussion (split form War Games: Russia Takes Ukraine)

[MigL]

Hopefully Ukrainian nuclear power plants of recent years have built-in redundant safeguards against fires like Western power plants.
I'd hate to see another Chernobyl.

[geordief]

They say the fire  had been contained at the nuclear site now.

 

Apparently a melt down at that site would/could be worse than  at Chernobyl. 

 

How bad could it be if it was deliberately or accidentally bombed by the Russians (or anyone)?

 

Would it stop the war in its tracks,for example?

 

Edited March 4, 2022 by geordief

[geordief]

49 minutes ago, iNow said:

I prefer using my powers of clairvoyance on cashing in on the lottery and picking winners in horse racing. 

https://edition.cnn.com/europe/live-news/ukraine-russia-putin-news-03-03-22/index.html

 

Think they are there  attributing this quote to Zelensky

But the very fact Russia launched an attack at the plant is itself an extremely dangerous act and could cause a potential catastrophe, he said. "There are 15 nuclear reactors in Ukraine. If one of them blows, that’s the end for everyone, that’s the end of Europe," he added (my bold)

 

Does that sound like hyperbole ?

 

Edited March 4, 2022 by geordief

[iNow]

26 minutes ago, geordief said:

Does that sound like hyperbole ?

A little, yes, but not far off from the truth

[J.C.MacSwell]

53 minutes ago, geordief said:

Does that sound like hyperbole ?

 

Probably just a few "Chernobyls" with contamination limited if the weather is favourable, and with only slightly raised radiation levels beyond countries bordering Ukraine...nothing much to worry about.

[LaurieAG]

1 hour ago, geordief said:

They say the fire  had been contained at the nuclear site now.

Apparently it was a training building and not the sky falling in.

[geordief]

6 hours ago, J.C.MacSwell said:

Probably just a few "Chernobyls" with contamination limited if the weather is favourable, and with only slightly raised radiation levels beyond countries bordering Ukraine...nothing much to worry about.

How much would it cost to repair the damage and how long would it take?

Could Russia be charged out of war reparations?

[J.C.MacSwell]

12 minutes ago, geordief said:

How much would it cost to repair the damage and how long would it take?

Could Russia be charged out of war reparations?

The damage in Chernobyl will outlive us all.

[TheVat]

1 hour ago, J.C.MacSwell said:

The damage in Chernobyl will outlive us all.

Last Spring they were detecting a rise in neutron emissions, and there were concerns as to whether or not it would subside on its own...

https://www.science.org/content/article/nuclear-reactions-reawaken-chernobyl-reactor

We really need to move to the smaller,  modular generation of reactors.

[SergUpstart]

3 hours ago, TheVat said:

We really need to move to the smaller,  modular generation of reactors.

Or maybe it's better to take a closer look at the technology proposed by Russian physicist Igor Ostretsov. He suggests dividing heavy elements on proton accelerators up to 10 MEV. In addition, spent nuclear fuel ceases to be radioactive after processing on accelerators.

11 hours ago, iNow said:

Yeah. My initial reply there probably didn’t offer this situation the seriousness it deserves. The speed and solidarity of the sanctions seem to have surprised Putin and now he’s likely feeling backed into a corner. 

No. He felt trapped earlier and therefore rushed in desperation.

The day before yesterday, the Russian general staff warned in a couple of hours about a missile strike on a TV tower in Kiev. The Ukrainian authorities did not transmit this warning to their civilians. The Ukrainian authorities also do not inform the civilian population about humanitarian corridors from Mariupol, Kiev, Kharkiv. They explain this by saying that they do not want to humanize the image of the enemy. So what is more important for them, to save the lives of their civilians or not to allow the image of the aggressor to be humanized?

According to the representative of the People's Militia of the LPR Ivan Filimonenko, the Ukrainian military mined warehouses with ammonia in the Kiev-controlled city of Severodonetsk, Luhansk region. This was announced by the official representative of the People's Militia of the LPR Ivan Filimonenko.

[swansont]

14 hours ago, geordief said:

https://edition.cnn.com/europe/live-news/ukraine-russia-putin-news-03-03-22/index.html

 

Think they are there  attributing this quote to Zelensky

But the very fact Russia launched an attack at the plant is itself an extremely dangerous act and could cause a potential catastrophe, he said. "There are 15 nuclear reactors in Ukraine. If one of them blows, that’s the end for everyone, that’s the end of Europe," he added (my bold)

 

Does that sound like hyperbole ?

 

Yes. Nuclear reactors don't undergo nuclear explosions.

AFAIK the reactor in question is not the same design as the Chernobyl reactor (which underwent a steam explosion and did not have a containment vessel), so comparisons to it are limited

This is not to say that bad results won't happen from bombing a nuclear plant, but "the end of Europe" is hyperbole. Chernobyl didn't end Europe, just as Fukushima didn't end Japan.

[exchemist]

15 hours ago, geordief said:

https://edition.cnn.com/europe/live-news/ukraine-russia-putin-news-03-03-22/index.html

 

Think they are there  attributing this quote to Zelensky

But the very fact Russia launched an attack at the plant is itself an extremely dangerous act and could cause a potential catastrophe, he said. "There are 15 nuclear reactors in Ukraine. If one of them blows, that’s the end for everyone, that’s the end of Europe," he added (my bold)

 

Does that sound like hyperbole ?

 

Yes, it's hyperbole. One has to understand Zelensky has an agenda, which is to bind the fate of Western Europe, and the EU in particular, as tightly to Ukraine as he can. His (wholly unrealistic) request that Ukraine be allowed to join the EU on an emergency basis is part of the same thing. The guy has his back to the wall and is pressing all the buttons he can. He's been calling everyone, including the pope, to drum up support, and trying everything he can think of. I take my hat off to him for his astounding energy and bravery - he knows he's dead when the Russians get hold of him - but one has to aim off a bit when evaluating some of what he says. 

[StringJunky]

24 minutes ago, exchemist said:

Yes, it's hyperbole. One has to understand Zelensky has an agenda, which is to bind the fate of Western Europe, and the EU in particular, as tightly to Ukraine as he can. His (wholly unrealistic) request that Ukraine be allowed to join the EU on an emergency basis is part of the same thing. The guy has his back to the wall and is pressing all the buttons he can. He's been calling everyone, including the pope, to drum up support, and trying everything he can think of. I take my hat off to him for his astounding energy and bravery - he knows he's dead when the Russians get hold of him - but one has to aim off a bit when evaluating some of what he says. 

If the Russians kill Zelensky, it will be a great career move for him in terms of his posthumous stature. Sometimes a person's untimely death makes them historically notable figures. Shame one can't enjoy it though in person.

Edited March 4, 2022 by StringJunky

[exchemist]

12 minutes ago, StringJunky said:

If the Russians kill Zelensky, it will be a great career move for him in terms of his posthumous stature. Sometimes a person's untimely death makes them historically notable figures. Shame one can't enjoy it though in person.

Yes I've been thinking about that, and I'm sure he as as well. In the information age, and as an actor, he will I'm sure be well aware of the impact that a dramatic public confrontation with his potential executioners could have - a bit like Yeltsin with the tanks. If they gun him down in cold blood, that will put Putin and the Red Army beyond the pale permanently and will ensure a rolling resistance movement against the occupiers for years to come. If they are wise they won't do that. But he may not want to be taken alive, for fear they may torture him, to or use his captured family against him to get him to surrender. A grisly choice. Putin wants him dead, I have no doubt, more than ever now that he has thwarted the original plan. 

Zelensky has his place in history already, though.  

[ScienceNostalgia101]

So I was recently thinking about how people are afraid direct western involvement in this war could provoke a nuclear war. But with the Russians theoretically being able to access the radioactive contaminants at Chernobyl anyway. Wasn't the point of the missile defense system to be able to intercept missiles? What is the risk of that system failing vs. the risk that the Russians could, whether deliberately or by accident, release radioactive fallout into the sky that could spread throughout the world?

[Dropship]

On 3/4/2022 at 2:42 AM, MigL said:

Hopefully Ukrainian nuclear power plants of recent years have built-in redundant safeguards against fires like Western power plants.
I'd hate to see another Chernobyl.

 

Yes hopefully modern reactors are better designed and foolproof.

The 1986 Chernobyl disaster happened because they used cheap graphite rods to save money, and when the operators hit the AZ-5 emergency shutdown button, the rods jammed up and triggered the explosion-

 

[swansont]

11 hours ago, Dropship said:

The 1986 Chernobyl disaster happened because they used cheap graphite rods to save money, and when the operators hit the AZ-5 emergency shutdown button, the rods jammed up and triggered the explosion-

No, that's not accurate.

The control rods had graphite tips, but were made of boron, which readily absorbs neutrons (graphite, not so much). One of several issues was that a bunch of the rods were completely withdrawn from the core. When the control rods were inserted, the first part in was the graphite tip. Graphite is a moderator, so it improved the efficiency of slowing neutrons down, making for an increased fission rate, which is exactly the opposite of what you want to happen when you are trying to shut the plant down. It was a design flaw, and was exacerbated by not following safety protocols - they pulled more rods out of the core than they were supposed to. The system also had a positive void coefficient, so when excess steam started forming inside the core, it increased the fission rate. Again, the opposite of what you want when trying to shut down.

It's not about the rods being cheap. There were design shortfalls and procedures were circumvented; multiple issues which all acted together to cause the accident.

https://www.vice.com/en/article/597k9x/why-the-chernobyl-nuclear-reactor-exploded

https://world-nuclear.org/information-library/safety-and-security/safety-of-plants/chernobyl-accident.aspx

[Dropship]

Yes the control rod tips were cheapskate to save money like the guy sums up in this vid from 1:00,

also the operators were slap-happy in pushing the reactor to it's limits thinking that in an emergency they could simply hit the AZ-5 shutdown button to get out of trouble..:)

 

 

[Dropship]

That video is a clip from the 2019 5-part 'Chernobyl' TV miniseries, and although the show was generally praised for accuracy, the producers did nevertheless say some scenes had been enhanced for dramatic effect.

For example in the top scene below, a firemans hand turns to a painful bloody mush soon after he picks up a lump of highly-radioactive graphite. Would those symptoms happen so quickly in real life?

And the bottom scene is a view from somebody's window when the reactor blows its top, followed by an eerie glowing "radioactive pillar of light" shooting up into the night sky, did that pillar really happen?

 

Edited March 18, 2022 by Dropship

[iNow]

It was a tv show.  Not relevant in a technical discussion of reactors 

[StringJunky]

The operators were not slap-happy, they were inexperienced. The blue light may have been Cherenkov radiation reflecting from the reactor in to the air through the blown off top of the reactor housing.

https://videos.dailymail.co.uk/video/mol/2019/08/19/6360617742329267503/1024x576_MP4_6360617742329267503.mp4

Edited March 18, 2022 by StringJunky

[Dropship]

The operators were no doubt lulled into a false sense of security thinking that the AZ-5 emergency shutdown button would do its job, whereas because of a reactor design flaw it triggered the explosion.

 

[swansont]

On 3/17/2022 at 9:10 PM, Dropship said:

That video is a clip from the 2019 5-part 'Chernobyl' TV miniseries, and although the show was generally praised for accuracy, the producers did nevertheless say some scenes had been enhanced for dramatic effect.

Meaning it has no place in a technical discussion based on fact.

On 3/18/2022 at 10:23 AM, Dropship said:

The operators were no doubt lulled into a false sense of security thinking that the AZ-5 emergency shutdown button would do its job, whereas because of a reactor design flaw it triggered the explosion.

As I pointed out, they pulled more rods out of the core than they were supposed to, As I recall, this was because of a buildup of Xe-135. Had they waited for it to decay, the situation would have been quite different.

[TheVat]

As power was cut to the Chernobyl plant this month, nuclear engineers explained the importance of the electricity grid — even for plants that have been out of operation for decades. Chernobyl’s molten radioactive lava self-heats inside the belly of the blown reactor. Without ventilation, which requires electricity, hot air forms condensation that rains down inside the building, corroding and damaging equipment. With no electricity, the operators, who are working at gunpoint, have no idea of radiation levels inside the shelter. All anyone knows is that monitoring devices across the Chernobyl zone showed a spike in radioactivity a few days after the invasion. Then the monitors were hacked and went radio silent.

Chernobyl’s spent fuel is another danger. Left to its own devices, it can heat up to 1,000 degrees Celsius. At high temperatures, the zirconium sleeves covering the fuel can ignite. After the Chernobyl accident in 1986, Soviet liquidators hastily built huge basins to store highly radioactive spent fuel rods. Water pumped into the basins cools the fuel and blocks radioactive gamma rays that emanate from the irradiated uranium. Now 20,000 fuel rods are stored in Chernobyl basins designed for 17,000. Officials at the IAEA stated March 9 that there is little risk the fuel will catch fire, since the rods are no longer very hot. Yet a U.S. Nuclear Regulatory Commission study from 2000 found that “the possibility of a zirconium fire cannot be dismissed even many years after a final reactor shutdown.”

https://www.washingtonpost.com/outlook/2022/03/18/chernobyl-zaporizhzhia-nuclear-plant-ukraine/

Some of the problems with cutting power to either long dormant reactors or to recently shut down ones. 

[TheVat]

Just thinking back to April 26, 1986 today.  A son was a few weeks away from being born - I recall the wife and I had a conversation about where our cheese was coming from, but no big concern given that she was scarfing only domestic cheese and downwind countries like Sweden had been pretty proactive about rejecting milk from cows who grazed inside the plume.  IIRC, even UK did some bannings of grazing animals in Scotland and other northern stretches.  

Cesium 137 has a half life of 30 years, so more than half of what rained down in Europe has turned to barium.  (probably a cleanup pun in there somewhere). Similar story with strontium 90.

When you read about all the accidents and leaking containments around the world (Rocky Flats, Sellafield, Hanford, Ozersk, that salt dome in Germany whose name I can't recall, et al), it seems like Reactor 4 at Chernobyl is nowhere near the top of the list of potential nastiness.  What always amazes me is the apparent ecological health in most of the Exclusion Zone, in spite of beaucoup curies in soil and trees and marshes.  (sorry to not use the SI unit, but those becquerels are just so tiny that curies makes more sense when you're talking about massive releases of radionuclides)

What I find jaw-dropping is places like Rocky Flats, where our DOE has signed off on having a wildlife preserve and allowing families to hike around it.  And this in spite of flood events, like 2013, where leach from buried containers has come to the surface and oozed across the land.