Yet Another Cycling Forum

Off Topic => The Pub => Topic started by: Jaded on 14 January, 2017, 09:01:47 pm

Title: Chernobyl Mega Arch Tomb
Post by: Jaded on 14 January, 2017, 09:01:47 pm
Just watching the BBC Four programme on this.

Rather extraordinary and so far it seems to have worked as hoped for.
Title: Re: Chernobyl Mega Arch Tomb
Post by: woollypigs on 14 January, 2017, 09:51:47 pm
From what I understand they might turn it into a solar panel. Rumour has it that China want to buy land there to panels up too.
Title: Re: Chernobyl Mega Arch Tomb
Post by: Jaded on 14 January, 2017, 11:11:34 pm
The solar panel thing is quite a few sq km of land that is uninhabitable, apparently bought the by the Chinese very cheaply to build a solar farm.
Title: Re: Chernobyl Mega Arch Tomb
Post by: Asterix, the former Gaul. on 15 January, 2017, 08:25:16 am
Interesting that apparently it will produce 1 Gigawatt compared with Hinckley C 0.32 Gw.

Admittedly such a straight comparison might be too simplistic!
Title: Re: Chernobyl Mega Arch Tomb
Post by: Hot Flatus on 15 January, 2017, 10:08:05 am
I spent a week in the Soviet Union 2 months before Chernobyl went pop. I've always hankered after returning to that epoque, with its imagery and atmosphere straight out of a George Orwell novel, and Priypat was possibly one of the last opportunities. A sort of radioactive timecapsule. I did investigate a the possibility of a trip about 15 years ago, but I've missed the boat on that one, I think.
Title: Re: Chernobyl Mega Arch Tomb
Post by: Jaded on 15 January, 2017, 10:12:43 am
The arch could not be a solar panel as once it is in place it is too dangerous for humans to go in it or on it. It has been built to last quite a few generations. Then someone will have to build and even bigger one, unless the magic robot arm has managed to break up enough of the reactor debris to make it 'safe'.

Title: Re: Chernobyl Mega Arch Tomb
Post by: mattc on 15 January, 2017, 10:19:08 am
It's a brilliant film, for those that havent seen it!  :thumbsup:

I was surprised at the time how little coverage the event got - I just happened to see the BBC4 fil in the listings by accident and watched it.

The arch could not be a solar panel as once it is in place it is too dangerous for humans to go in it or on it.
True, but;

If it has one farking-great S-facing side, it might be feasible for Robby-robots to just roll over and lean some panels against it. I know that's non-trivial, but it seems a much more easily solved engineering problem than that of fitting the actual tomb!
Title: Re: Chernobyl Mega Arch Tomb
Post by: Jaded on 15 January, 2017, 11:19:21 am
There's so much land there that can't be used for anything else, so no need to make life hard, or put the arch at risk.
Title: Re: Chernobyl Mega Arch Tomb
Post by: Asterix, the former Gaul. on 15 January, 2017, 01:25:15 pm
Solar power to rise from Chernobyl's nuclear ashes (https://www.theguardian.com/environment/2017/jan/12/solar-power-to-rise-from-chernobyls-nuclear-ashes)

12 January 2017
Title: Re: Chernobyl Mega Arch Tomb
Post by: Wobbly John on 15 January, 2017, 01:37:44 pm
Interesting that apparently it will produce 1 Gigawatt

Pity it won't produce 0.21 gW more...

https://www.youtube.com/watch?v=mjCRUvX2D0E

 :demon:
Title: Re: Chernobyl Mega Arch Tomb
Post by: Canardly on 15 January, 2017, 01:48:14 pm
Isn't the core of this still working its way downwards?
Title: Re: Chernobyl Mega Arch Tomb
Post by: Torslanda on 15 January, 2017, 02:54:19 pm
I'm no expert but it appears, 30 years on, it's stopped cooking. All four of the reactors have/are being decommissioned, according to Wiki the site is expected to be dismantled by 2065
Title: Re: Chernobyl Mega Arch Tomb
Post by: spesh on 15 January, 2017, 04:48:42 pm
Isn't the core of this still working its way downwards?

It's not - while a molten reactor core will not play nicely with concrete, simple thermodynamics says that it can't retain its heat indefinitely:

Quote
The fast erosion phase of the concrete basemat lasts for about an hour and progresses to about one meter in depth, then slows to several centimeters per hour, and stops completely when the melt cools below the decomposition temperature of concrete (about 1100 °C). Complete melt-through can occur in several days even through several meters of concrete; the corium then penetrates several meters into the underlying soil, spreads around, cools and solidifies

https://en.wikipedia.org/wiki/Corium_(nuclear_reactor)#Corium-concrete_interactions

Properly-designed nuclear power plants make provision for the worst-case scenario of a full meltdown by incorporating a space in the basement of the reactor housing where a molten core can flow into and spread out, thus increasing its rate of cooling.

https://en.wikipedia.org/wiki/Core_catcher

The Chernobyl corium is contained (it didn't burn through to the soil outside), but the space in which it solidified wasn't originally intended for that purpose - when the reactor exploded, it was actually full of water:

Quote
... after the reactor was destroyed and began to burn, a liquid corium mass from the melting core began to breach the concrete floor of the reactor vessel, which was situated above the bubbler pool (a large water reservoir for emergency pumps, also designed to safely contain steam pipe ruptures). The RBMK had no allowance or planning for core meltdowns, and the imminent interaction of the core mass with the bubbler pool would have produced a massive steam explosion, likely destroying the entire plant (vastly increasing the spread and magnitude of the radioactive plume). It was therefore necessary to drain the bubbler pool before the corium reached it. However, the initial explosion had broken the control circuitry which allowed the pool to be emptied. Three volunteer divers were required to manually operate the valves necessary to drain this pool, and later images of the corium mass in the pipes of the bubbler pool's basement reinforced the heroic necessity of their actions.

https://en.wikipedia.org/wiki/Nuclear_meltdown#China_syndrome

Any concerns about the Chernobyl corium stem not from it eating through the basement, but from self-irradiation and environmental attack weakening the lava deposits, though it turns out that they are leaching uranium at a lower rate than was previously feared:

Quote
It is unclear how long the ceramic form will retard the release of radioactivity. From 1997 to 2002 a series of papers were published which suggested that the self irradiation of the lava would convert all 1,200 tons into a submicrometre and mobile powder within a few weeks.[41] But it has been reported that it is likely that the degradation of the lava is to be a slow and gradual process rather than a sudden rapid process.[40] The same paper states that the loss of uranium from the wrecked reactor is only 10 kg (22 lb) per year. This low rate of uranium leaching suggests that the lava is resisting its environment. The paper also states that when the shelter is improved, the leaching rate of the lava will decrease.

https://en.wikipedia.org/wiki/Corium_(nuclear_reactor)#Degradation_of_the_lava
Title: Re: Chernobyl Mega Arch Tomb
Post by: Mr Larrington on 16 January, 2017, 01:45:10 am
You mean there's no chance of it coming out in the bog next to the Oval Office in a week's time?

Bah!
Title: Re: Chernobyl Mega Arch Tomb
Post by: woollypigs on 27 June, 2020, 07:52:56 pm
Hmm are we about to have another ?

https://www.nytimes.com/reuters/2020/06/26/world/europe/26reuters-nuclear-particles-baltic.html

https://twitter.com/SinaZerbo/status/1276559857731153921?s=20

or is that just a left over from the thing - what ever it was - on the military base last year?