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Power The Military

Offsite Power Supply Destroyed. What Happens Next at Ukraine's Zaporizhzhia Nuclear Plant (france24.com) 124

"A vital offsite electricity supply to the Zaporizhzhia nuclear plant has been destroyed by shelling," the Guardian reported Friday, "and there is little likelihood a reliable supply will be re-established, the United Nations' nuclear watchdog chief has said." Rafael Grossi, the director general of the International Atomic Energy Agency (IAEA), said shelling had destroyed the switchyard of a nearby thermal power plant. The plant has supplied power to the nuclear facility each time its normal supply lines had been cut over the past three weeks.

The thermal plant was also supplying the surrounding area, which was plunged into darkness. Local Ukrainian officials said work was under way to restore the connection, which has been cut multiple times this week....

When the thermal supply has been cut the plant has relied on its only remaining operating reactor for the power needed for cooling and other safety functions. This method is designed to provide power only for a few hours at a time. Diesel generators are used as a last resort. The constant destruction of thermal power supply has led Ukraine to consider shutting down the remaining operating reactor, said Grossi. Ukraine "no longer [has] confidence in the restoration of offsite power", he said.

Grossi said that if Ukraine decided not to restore the offsite supply the entire power plant would be reliant on emergency diesel generators to ensure supplies for the nuclear safety and security functions.

"As a consequence, the operator would not be able to restart the reactors unless offsite power was reliably re-established," he said.

NPR provides some context: Normally, the plant holds a 10-day reserve of diesel fuel, the agency says, and currently has approximately 2,250 tonnes of fuel available. If that fuel is depleted, or the generators are damaged in further fighting, it could trigger a meltdown.

But Steven Nesbit, a nuclear engineer and member of the American Nuclear Society's rapid response taskforce, which is tracking the current crisis, says that doesn't necessarily mean there would be a Chernobyl-like catastrophe. The meltdown at Chernobyl was due to a unique mix of design flaws and operator error that would be essentially impossible to replicate at Zaporizhzhia. And unlike the Fukushima nuclear disaster in 2011, some of the reactors at Zaporizhzhia have already been shut down for a while, allowing the nuclear fuel to cool somewhat, Nesbit says. Even in the worst case scenario, the reactors at Zaporizhzhia are a modern design surrounded by a heavy "containment" building, Nesbit says. "It's reinforced concrete, typically about three to four feet of that; it's designed to withstand very high internal pressures." That could allow it to hold in any radioactive material.

But the world's nuclear agency doesn't want to test any of this.

Meanwhile, the French international news agency AFP reports on what's been happening at the plant since it was captured by Russian troops in March: Russian forces controlling Ukraine's Zaporizhzhia nuclear power plant have killed two staff at the facility and detained and abused dozens of others, the head of Ukraine's nuclear energy agency told AFP on Friday.

"We do not know where about ten people are now," Petro Kotin said. "They were taken (by the Russians) and after that we have no information about their whereabouts," Kotin said, adding about 200 people had been detained. He described the current situation at the plant as "very difficult," citing "torture" of staff and "beatings" of personnel. "The Russians look for pro-Ukrainian people and persecute them. People are psychologically broken," he said in an interview with AFP reporters in his office in Kyiv... "Two people on the territory of the plant were wounded during shelling — a woman and a man — on separate occasions," Kotin, clad in a military-style jacket, said.

"But people understand that the nuclear safety of the plant depends on them, so the employees return to Energodar and continue working at the facility," he added.

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Offsite Power Supply Destroyed. What Happens Next at Ukraine's Zaporizhzhia Nuclear Plant

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  • by Kunedog ( 1033226 ) on Saturday September 10, 2022 @01:50PM (#62870575)
    Diesel is happens.
    • Funny. Of course when it is clear that the Russians are not only going to lose the war but lose the Crimean peninsula as well they will go scorched earth. This will include sabotage of the plants cooling systems to assure that there is a melt down and further guarantee prolonged suffering of the Ukrainian people and Europeans.
      • Of course when it is clear that the Russians are not only going to lose the war but lose the Crimean peninsula as well they will go scorched earth.

        I suspect that this will happen long after it is clear that the Russians will lose the war and Crimea, for the simple reason that they will be unable to acknowledge their impending loss.

    • by ls671 ( 1122017 )

      Indeed, "What's Happens" !

      Came here to post the same, what's a retarded title! :)

    • by rworne ( 538610 )

      Russians have been in control of the plant for a while now, right?
      Anyone want to guess if the diesel fuel for the backup generators has been stolen or not? Forcing the plant to use diesel power would be a very cynical way of finding that out.

    • Turn of the lecce, disrupt the gas, diesel and food supply, then let old man winter have them. It worked against Napoleon, Germany and many others.
  • Basically this is a whole story about if a power plant in a war zone may have to shut down or not.

    There's zero danger of and kind of radiation leak, so it really does not seem like it's that much of a story, even in the context of the larger war.

    I will say I greatly admire the dedication of the workers at the plant who are still coming in despite it being occupied and them being mistreated horribly. It would probably be better for them if the plant is fully shut down, though not good for the surrounding re

    • Basically this is a whole story about if a power plant in a war zone may have to shut down or not.

      There's zero danger of and kind of radiation leak, so it really does not seem like it's that much of a story, even in the context of the larger war.

      You can't just turn off a power plant. It takes years for reactors to cool to the point where they no longer require active cooling (e.g. power) to avert a meltdown.

      I will say I greatly admire the dedication of the workers at the plant who are still coming in despite it being occupied and them being mistreated horribly. It would probably be better for them if the plant is fully shut down, though not good for the surrounding region...

      Two employees of the plant have been murdered by Russians.

      • by Tailhook ( 98486 )

        It takes years for reactors to cool to the point where they no longer require active cooling

        This is not correct. It depends on reactor design and power history (the condition of the fuel, amount of time and power level it had been running,) prior to shutdown, but reaching a core temperature where no coolant circulation is required is at most a few weeks. Often it is considerably less.

        • but reaching a core temperature where no coolant circulation is required is at most a few weeks. That is wrong.

          Often it is considerably less.
          And this is so wrong it is just bullshit.

          Depending on the amount of fuel spent: it is years!! Or why the funk do you think spent fuel rods are stored on site in water pools? Ah, just for fun ato see the blue glowing ...

          • There is a difference between sitting in a small pool of water utilizing natural convection, and active cooling. "Modern" reactors can achieve cold shutdown within 2-3 days, at which point backup power is not critical.

            You wouldn't want to leave a spent rod sitting in open air, but a reactor that's been off for a while and depressurized won't just spontaneously melt. Such a design would never be used by anyone, even the USSR.

            • Modern" reactors can achieve cold shutdown within 2-3 days, at which point backup power is not critical. No one is operating such a reactor.

              You wouldn't want to leave a spent rod sitting in open air, but a reactor that's been off for a while and depressurized won't just spontaneously melt. Such a design would never be used by anyone, even the USSR. Yes it would. Hint: TMI, Fukushima and various other places. Fukushima melted WEEKs after the power failure.

          • by Tailhook ( 98486 )

            it is years!!

            No, sorry, it isn't, no matter how many exclamation points you employ. A reactor running at full power can be stopped, cooled, refueled and restarted in 30 days. With active cooling it takes less than 48 hours to get below 1% operating temperature and a couple weeks to get to 0.1%. Soon after you can stop all active circulation and replace the fuel rods.

            If active cooling were somehow necessary for "years" you couldn't perform that operation in an economically viable time.

            In a full blackout even 0.1%

            • . A reactor running at full power can be stopped, cooled, refueled and restarted in 30 days.
              Yes. And what hs that to do with needing cooling for several years for the waste?

              Obviously you have no clue about what you are taking.

              If active cooling were somehow necessary for "years" you couldn't perform that operation in an economically viable time.

              Perhaps you could check how refueling works, facepalm. Obviously the "spent fuel" gets removed. And were do they put it? Up to you to figure, dumbass.

        • This is not correct. It depends on reactor design and power history (the condition of the fuel, amount of time and power level it had been running,) prior to shutdown, but reaching a core temperature where no coolant circulation is required is at most a few weeks.

          No it isn't.

    • by AmiMoJo ( 196126 )

      Zero risk of a nuclear disaster? They are shelling the area, and aren't renowned for their incredible accuracy. They are getting desperate too, as the war is going badly for them.

      Remember it's not just the reactors, it's the waste storage. Spent fuel pools.

      • Zero risk of a nuclear disaster? They are shelling the area, and aren't renowned for their incredible accuracy.

        Absolutely nothing major has been even damaged, and if you actually read the story you'd realize the containment walls are way too thick to be affected by shelling.

        Remember it's not just the reactors, it's the waste storage. Spent fuel pools.

        Shelling is designed to mostly throw out fragments to hurt people, but they dint really do much to structures, much less thick concrete or pools of water or e

      • by tlhIngan ( 30335 )

        Zero risk of a nuclear disaster? They are shelling the area, and aren't renowned for their incredible accuracy

        The containment domes, if properly designed, are designed to take the full impact of a fully loaded airliner purposefully crashed into them at full speed. Without damage. Shelling isn't a consideration.

        The main problem with a nuclear reactor isn't the strength of the containment dome, it's the fact that all the problems with nuclear power stem from human decisions.

        When "properly run and managed" (no

        • by AmiMoJo ( 196126 )

          Citation needed, Soviet era containment buildings were done on the cheap due to lack of resources and cost.

    • by gweihir ( 88907 ) on Saturday September 10, 2022 @05:17PM (#62870981)

      Only if you are clueless. Nuclear reactors need cooling power for several weeks after shut down. The story, without saying so clearly, is about that energy likely not being available. And then these reactors will have core a melt-down, potentially all six of them. And when that happens, the plant turns into an exceptionally expensive clean-up job in the best case, and a real disaster in the worst case namely if one or several of the containments do not hold. As a second danger, there very likely is also spent fuel stored there that needs cooling for years or it will catch fire. We can only hope that fuel is inside the containment, because burning nuclear waste is about the most dangerous thing known to man. Remember what effort the Japanese went to to keep their fuel from going up in flames in Fukushima. If it had, they may well have lost most of Japan for a long, long time. And they were doing this under much easier conditions with no war going on.

      • A little knowledge is a dangerous thing, and I think that saying applies to many layman's knowledge of nuclear plants. The basic sketch is presented to us as a core with control rods. The implication is that you can simply shut the reactor down by re-inserting all the rods.

        I myself thought this until not too long ago. Turns out there are more details as you mentioned--lower grade heat is produced for a while even when the rods are fully inserted, and spent fuel still produces significant heat.

        Dissipati

        • by gweihir ( 88907 )

          Yes, a little knowledge is often dangerous, especially if the people having it do not know that their knowledge is incomplete. What I find most telling for nuclear is that those most aggressively for it usually know the absolute least about it and are often incapable of accepting that there is a lot more to know before you can arrive at an informed opinion.

          History seems to show that if it's possible, it'll happen to a nuke plant.

          Pretty much. It does happen to all other forms of power-station as well, but with nuclear, the damage is typically excessive. The insane thing with nucle

          • by gweihir ( 88907 )

            Before I forget: Kudos for being willing to learn and to accept your previous knowledge was incomplete.

    • I will say I greatly admire the dedication of the workers at the plant who are still coming in despite it being occupied and them being mistreated horribly.

      Yes, that really seems to be the case in every nuclear disaster we've had. Nuclear engineers seem to be willing to lay down their lives at risk of horrific, agonising deaths from radiation exposure in order to try to stop the worst from happening. Apparently, at the Fukushima disaster, the engineers defied orders from senior management to leave the plant, choosing instead to risk their lives to minimise the impact. These are the true heroes.

    • I don't know the actual risk of a leak in the case of a scram caused by loss of power. It seems unlikely but can you provide sources for your claim that there's zero risk?
    • It is a big deal. Even if a plant is shut down, you still need a reliable outside source of power to keep fuel in the reactor and spent fuel pool cool via pumps and heat exchangers. Turn off that cooling and the decay heat from the fuel assemblies is still hot enough to boil water. Boil off enough water and you expose the fuel to air. And then you really start to have problems.

      Emergency diesel generators (roughly the size and horsepower of locomotive engines - which some are, but modified for stationary

  • The money made off of movies and video games from another nuclear disaster will be enough to build a new power plant somewhere else.

    You folks need to look at the glass half full not half empty.

  • If there is a problem, I hope it looms over Russia.
    • If there is a problem, I hope it looms over Russia.

      I assume you mean Westerly winds, i.e. winds out of the west blowing toward the east?

      They've (we've all) already got a problem. The occupying troops already "dug in" in the Red Forest (where most of the high-level radioactives settled out, turning the pine forest red), throwing the crud back up into the air.

      Although I suppose a new meltdown or six could make things a whole lot worse.

  • china syndrome or Chernobyl 2.0!

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