4 ms·

This rises a question in me: What did we do for Chernobyl? It was decades ago, so most of this technology didn't exists yet. Or it was not nearly as bad as Fuku

by Spittie 13y ago

This rises a question in me: What did we do for Chernobyl? It was decades ago, so most of this technology didn't exists yet. Or it was not nearly as bad as Fukushima?

ori_b 13y ago
Basically, we just covered Chernobyl with concrete and left it alone. As long as nobody goes near it, it's not doing any harm. According to the article, for political reasons, Japan wants to dismantle Fukushima, instead of simply neutralizing it, covering it up with concrete, and walling it off for a few decades before the cleanup happens. This is where the challenge comes from.
- snom380 13y ago
  Regardless of their plans, they still need to handle the leaking groundwater, which AFAIK wasn't a big problem at Chernobyl.
  - nknighthb 13y ago
    Also, the region around Chernobyl isn't exactly known for the frequency of major natural disasters like earthquakes, tsunami, and typhoons.
  - ori_b 13y ago
    Chernobyl definitely had concerns with groundwater contamination. There were significant amounts of strontium within the exclusion zone, and the core had melted down into the earth, although I don't think it reached the water table. However, from everything I can find, the migration through the soil tended to be extremely slow, making it a fairly local phenomenon. In the end, cleanup efforts were abandoned since they had low impact on human health or radioactivity outside of the exclusion zone, and were worse for the environment than simply leaving things. Unfortunately, I no longer have access to the journal subscriptions, so I don't have the full text of this, but I think this is the paper you want to read for an overview: http://onlinelibrary.wiley.com/doi/10.1029/96WR03963/abstract http://onlinelibrary.wiley.com/doi/10.1029/96WR03963/abstrac... The conditions are very different at Fukushima, mainly due to the proximity to the ocean, so I can't really give an educated summary of the challenges with that. One thing that you have to keep in mind, though, is that water is an excellent radiation absorber, and it's actually safe to go diving in active reactor pools as long as you're more than a couple of meters away from the core. I'd expect that the radiation in the ocean would disperse quickly and harmlessly. https://what-if.xkcd.com/29/ https://what-if.xkcd.com/29/
- iterationx 13y ago
  It's not easy to entomb the cores, since they have melted into the earth, and it is too radioactive for people or robots to go near.
nicktelford 13y ago
The two incidents are completely different: Chernobyl's reactor exploded (iirc, the graphite moderator caught fire); Fukushima melted down, which is essentially when the fuel gets so hot (due to lack of cooling, which the Tsunami took out) that it melts through the bottom of the reactor containment vessel.
- snom380 13y ago
  The core in Chernobyl melted down into the basement as well, fortunately it stopped there.
  - PythonicAlpha 13y ago
    Yes, but it seems to me, that the risk of further melt downs in Chernobyl is much lower and the core is more divided -- so the situation is stable without cooling. In Fukushima, the cores still have to be cooled, what makes the thing troublesome. You can't just bury a core that has to be cooled .... As much I remember, in Chernobyl the core stopped before it reached the ground water, because they digged below the core and made it stop -- risking and probably sacrificing further lives.
snom380 13y ago
http://en.m.wikipedia.org/wiki/Chernobyl_Nuclear_Power_Plant#Decommissioning http://en.m.wikipedia.org/wiki/Chernobyl_Nuclear_Power_Plant... The accident itself was worse and spread more radioactive material (the core exploded, the graphite ignited and spread a huge plume of smoke). But the cleanup effort if Fukushima will probably be worse because they are dealing with three reactors that still need cooling, leaking water etc.
InclinedPlane 13y ago
They erected a half-assed containment structure around the area and evacuated a huge exclusion zone around Chernobyl. For the record, it was much worse than Fukushima.
tsotha 13y ago
Chernobyl was much worse than Fukushima, for a lot of reasons. The reactor got away from the Soviets in a way the reactors never got away from the Japanese, though admittedly it was touch and go for a bit. Decades from now the cores will have been safely removed from the Fukushima reactors, the reactor vessels cut up and all of it will be safely stored in a nuclear waste dump. Chernobyl won't be in noticeably better shape than it is today. It will still be a concrete lid over a still-active meltdown.

by Spittie 13y ago

This rises a question in me: What did we do for Chernobyl? It was decades ago, so most of this technology didn't exists yet. Or it was not nearly as bad as Fukushima?

ori_b 13y ago

Basically, we just covered Chernobyl with concrete and left it alone. As long as nobody goes near it, it's not doing any harm. According to the article, for political reasons, Japan wants to dismantle Fukushima, instead of simply neutralizing it, covering it up with concrete, and walling it off for a few decades before the cleanup happens. This is where the challenge comes from.

snom380 13y ago
Regardless of their plans, they still need to handle the leaking groundwater, which AFAIK wasn't a big problem at Chernobyl.
- nknighthb 13y ago
  Also, the region around Chernobyl isn't exactly known for the frequency of major natural disasters like earthquakes, tsunami, and typhoons.
- ori_b 13y ago
  Chernobyl definitely had concerns with groundwater contamination. There were significant amounts of strontium within the exclusion zone, and the core had melted down into the earth, although I don't think it reached the water table. However, from everything I can find, the migration through the soil tended to be extremely slow, making it a fairly local phenomenon. In the end, cleanup efforts were abandoned since they had low impact on human health or radioactivity outside of the exclusion zone, and were worse for the environment than simply leaving things. Unfortunately, I no longer have access to the journal subscriptions, so I don't have the full text of this, but I think this is the paper you want to read for an overview: http://onlinelibrary.wiley.com/doi/10.1029/96WR03963/abstract http://onlinelibrary.wiley.com/doi/10.1029/96WR03963/abstrac... The conditions are very different at Fukushima, mainly due to the proximity to the ocean, so I can't really give an educated summary of the challenges with that. One thing that you have to keep in mind, though, is that water is an excellent radiation absorber, and it's actually safe to go diving in active reactor pools as long as you're more than a couple of meters away from the core. I'd expect that the radiation in the ocean would disperse quickly and harmlessly. https://what-if.xkcd.com/29/ https://what-if.xkcd.com/29/
iterationx 13y ago
It's not easy to entomb the cores, since they have melted into the earth, and it is too radioactive for people or robots to go near.

nicktelford 13y ago

The two incidents are completely different: Chernobyl's reactor exploded (iirc, the graphite moderator caught fire); Fukushima melted down, which is essentially when the fuel gets so hot (due to lack of cooling, which the Tsunami took out) that it melts through the bottom of the reactor containment vessel.

snom380 13y ago
The core in Chernobyl melted down into the basement as well, fortunately it stopped there.
- PythonicAlpha 13y ago
  Yes, but it seems to me, that the risk of further melt downs in Chernobyl is much lower and the core is more divided -- so the situation is stable without cooling. In Fukushima, the cores still have to be cooled, what makes the thing troublesome. You can't just bury a core that has to be cooled .... As much I remember, in Chernobyl the core stopped before it reached the ground water, because they digged below the core and made it stop -- risking and probably sacrificing further lives.

snom380 13y ago

http://en.m.wikipedia.org/wiki/Chernobyl_Nuclear_Power_Plant#Decommissioning http://en.m.wikipedia.org/wiki/Chernobyl_Nuclear_Power_Plant... The accident itself was worse and spread more radioactive material (the core exploded, the graphite ignited and spread a huge plume of smoke). But the cleanup effort if Fukushima will probably be worse because they are dealing with three reactors that still need cooling, leaking water etc.

InclinedPlane 13y ago

They erected a half-assed containment structure around the area and evacuated a huge exclusion zone around Chernobyl. For the record, it was much worse than Fukushima.

tsotha 13y ago

Chernobyl was much worse than Fukushima, for a lot of reasons. The reactor got away from the Soviets in a way the reactors never got away from the Japanese, though admittedly it was touch and go for a bit. Decades from now the cores will have been safely removed from the Fukushima reactors, the reactor vessels cut up and all of it will be safely stored in a nuclear waste dump. Chernobyl won't be in noticeably better shape than it is today. It will still be a concrete lid over a still-active meltdown.