RE: How Does an RBMK Reactor Explode
09-05-2019, 02:34 PM (This post was last modified: 09-05-2019, 03:13 PM by Dartz.)
09-05-2019, 02:34 PM (This post was last modified: 09-05-2019, 03:13 PM by Dartz.)
I don't have the creativity to write Science-Fiction at the moment - so some Science-Fact will have to do. Even though a little bit of creativity tends to be required - I had to go back and correct a few things I misremembered. There're a dozen shifting accounts of what happened - even from those in the room that night.
With Chernobyl the truth is churned up and spat out in a thousand different versions - of which I'm just churning up and spitting out the least dramatic one I can think of . There're so many competing agendas, quite a few in power who'd like to remain that way, and so many convenient scapegoats.
Akimov and Toptunov gave statements before their deaths. Their testimony is still classified, as is the entire subsequent trial proceeding. Tregub and Stolyarchuk survived to speak publically - which they do from time to time. Bryukhanov is still alive, and living in Ukraine. Fomin went back to working in the nuclear industry after serving a prison sentence. Radiation finally caught up with Dyatlov in the early 90s - but not before he wrote a book that very much disagrees with the official account in many places.
There is a need for those in the room to be responsible - it's far easier to point the finger at the engineer who pushed the button. It was known within a month what had caused the explosion - however the Scientist who discovered the flaw was quietly fired for his troubles years before. Not by Gorbachev, or the KGB - but by his own boss and his colleagues who had every interest in their designs for the RBMK not being found to be responsible for disaster.
The KGB of course, knew this, and knew how utterly necessary it was to figure out what really happened to make sure it never happened again. This is why Valery Legasov was appointed to head the commission - he was a radiochemist, a specialist in how monatomic gasses behaved in ionising radiation - and was most definitely not an expert on RBMK reactors. He was unconnected with the reactor's designers, didn't move in their circles and was most likely to give an honest response. That he did - and more. While the effectiveness of some of his decisions during the managment of the disaster are debatable - Legasov and his team of scientists also faced something which had never occurred in human history and had to make it up as they went along. That most of Europe is still habitable suggests something was done right.
He still toed the party line when faced with the world's glare at Vienna - to avoid a massive international outcry - but at home he knew the truth and pushed for reform of the scientific community that had created the disaster. His 'secret' memoirs were widely circulated and were printed in extract in the newspapers. He was villified not by the Soviet state, but by his own colleagues, who had nothing but their prestige to lose.
Legasov ultimately blamed the disaster on the ability of the operators to override the automatic safety systems - and on the simple fact that the reactor was never equipped with a fully enclosed containment system.
Nevertheless, the reactors were still rapidly modified after the disaster to reduced the void coefficient, and eliminate the tip-effect from the rods. Because reality always wins - and it's one thing to have an annoying power increase, and quite another to have an explosion occuring with no warning. It seems nobody believed Chernobyl was possible until it actually happened. It would take a certain level of insanity to run a reactor knowing that kind of explosion was possible.
It was far easier to rewrite the documentation after the fact. The reactivity margin limit at 15 did exist, and it was violated - but the consequences of violating the limit were never made clear to anyone involved. What consequences were known - were vaguely defined. It was like the speed limit on a wide road.
Ignalina - a similar reactor, but more powerful - in Lithuania was modified heavily after Lithuania joined the EU to the point where it was mostly compliant with European norms. The modern RBMK is a very different beast - it now runs on partially enriched fuel, enabling enough fixed absorbers to be used in the core to force a negative reactivity coefficient in all circumstances. The control rod channels were modified - either with redisigned tips, or replacing liquid water with gas. Their speed was increased, and some of the computer control systems were changed. Ignalina was modified, so that the lid will not lift until fifteen channels are burst. A second shutdown system was added, given control over a specific group of control rods seperate from AZ-5, and was designe to be non-overridable. The a third shutdown system was added after this - injecting liquid boron into the cooling shutdown circuit to kill the reaction dead.
Lithuania was happy with it. Ignalina's two reactors produced enough power to send two Deloreans back to 1955 every operating second, with enough to spare to keep the local town's lights on.
The EU still noped the fuck out and paid them to shut it down.
With Chernobyl the truth is churned up and spat out in a thousand different versions - of which I'm just churning up and spitting out the least dramatic one I can think of . There're so many competing agendas, quite a few in power who'd like to remain that way, and so many convenient scapegoats.
Akimov and Toptunov gave statements before their deaths. Their testimony is still classified, as is the entire subsequent trial proceeding. Tregub and Stolyarchuk survived to speak publically - which they do from time to time. Bryukhanov is still alive, and living in Ukraine. Fomin went back to working in the nuclear industry after serving a prison sentence. Radiation finally caught up with Dyatlov in the early 90s - but not before he wrote a book that very much disagrees with the official account in many places.
There is a need for those in the room to be responsible - it's far easier to point the finger at the engineer who pushed the button. It was known within a month what had caused the explosion - however the Scientist who discovered the flaw was quietly fired for his troubles years before. Not by Gorbachev, or the KGB - but by his own boss and his colleagues who had every interest in their designs for the RBMK not being found to be responsible for disaster.
The KGB of course, knew this, and knew how utterly necessary it was to figure out what really happened to make sure it never happened again. This is why Valery Legasov was appointed to head the commission - he was a radiochemist, a specialist in how monatomic gasses behaved in ionising radiation - and was most definitely not an expert on RBMK reactors. He was unconnected with the reactor's designers, didn't move in their circles and was most likely to give an honest response. That he did - and more. While the effectiveness of some of his decisions during the managment of the disaster are debatable - Legasov and his team of scientists also faced something which had never occurred in human history and had to make it up as they went along. That most of Europe is still habitable suggests something was done right.
He still toed the party line when faced with the world's glare at Vienna - to avoid a massive international outcry - but at home he knew the truth and pushed for reform of the scientific community that had created the disaster. His 'secret' memoirs were widely circulated and were printed in extract in the newspapers. He was villified not by the Soviet state, but by his own colleagues, who had nothing but their prestige to lose.
Legasov ultimately blamed the disaster on the ability of the operators to override the automatic safety systems - and on the simple fact that the reactor was never equipped with a fully enclosed containment system.
Nevertheless, the reactors were still rapidly modified after the disaster to reduced the void coefficient, and eliminate the tip-effect from the rods. Because reality always wins - and it's one thing to have an annoying power increase, and quite another to have an explosion occuring with no warning. It seems nobody believed Chernobyl was possible until it actually happened. It would take a certain level of insanity to run a reactor knowing that kind of explosion was possible.
It was far easier to rewrite the documentation after the fact. The reactivity margin limit at 15 did exist, and it was violated - but the consequences of violating the limit were never made clear to anyone involved. What consequences were known - were vaguely defined. It was like the speed limit on a wide road.
Ignalina - a similar reactor, but more powerful - in Lithuania was modified heavily after Lithuania joined the EU to the point where it was mostly compliant with European norms. The modern RBMK is a very different beast - it now runs on partially enriched fuel, enabling enough fixed absorbers to be used in the core to force a negative reactivity coefficient in all circumstances. The control rod channels were modified - either with redisigned tips, or replacing liquid water with gas. Their speed was increased, and some of the computer control systems were changed. Ignalina was modified, so that the lid will not lift until fifteen channels are burst. A second shutdown system was added, given control over a specific group of control rods seperate from AZ-5, and was designe to be non-overridable. The a third shutdown system was added after this - injecting liquid boron into the cooling shutdown circuit to kill the reaction dead.
Lithuania was happy with it. Ignalina's two reactors produced enough power to send two Deloreans back to 1955 every operating second, with enough to spare to keep the local town's lights on.
The EU still noped the fuck out and paid them to shut it down.
I love the smell of rotaries in the morning. You know one time, I got to work early, before the rush hour. I walked through the empty carpark, I didn't see one bloody Prius or Golf. And that smell, you know that gasoline smell, the whole carpark, smelled like.... ....speed.
One day they're going to ban them.