Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

First contact made with melted nuclear fuel at Fukushima plant

asahi.com

Post reply on HN
Print view View original

91–100 of 222 posts

Re: First contact made with melted nuclear fuel at Fukushima plant

#91

Post by darkpuma »

ChuckMcM wrote: post #17

While I realize it was likely impractical to meltdown reactors just to develop the technology to clean them up, I find the process here pretty interesting. A lot of good engineering has gone into the effort, and the engineering challenges (and risks) of post runaway reactors has gotten a lot more data. The Chernobyl folks just entombed everything, which is a one approach, even though they can "walk up to"[1] the rema…

Could crushed borosilicate glass be used as concrete aggregate when constructing containment buildings?

Edit: apparently yes: https://www.ncbi.nlm.nih.gov/pubmed/28189090

Re: First contact made with melted nuclear fuel at Fukushima plant

#93

Post by Asparagirl »

People should check out Safecast, which is a citizen-led open data network for monitoring and publishing radiation readings, including an open API:

https://blog.safecast.org/

They're using low-cost open hardware, including Arduino:

https://github.com/Safecast/General/wiki/Safecast-Devices

Here's their latest heatmap (well, radiation map) for Japan, centered on the Fukushima area:

https://safecast.org/tilemap/?y=37.14&x=140.67&z=8&l=0&m=0

Re: First contact made with melted nuclear fuel at Fukushima plant

#95

Post by Asparagirl »

Asparagirl wrote: post #93

People should check out Safecast, which is a citizen-led open data network for monitoring and publishing radiation readings, including an open API: https://blog.safecast.org/ They're using low-cost open hardware, including Arduino: https://github.com/Safecast/General/wiki/Safecast-Devices Here's their latest heatmap (well, radiation map) for Japan, centered on the Fukushima area: https://safecast.org/tilemap/?y=37.14…

They also got volunteers to take radiation readings in and around the Santa Susanna Mountains near Los Angeles, to verify that radioactive waste from an old reactor meltdown there was not kicked up during the recent wildfires. (It was not, luckily.)

https://safecast.org/tilemap/?y=34.16&x=-118.735&z=11&l=0&m=...

Re: First contact made with melted nuclear fuel at Fukushima plant

#96

Post by howard941 »

m_mueller wrote: post #71
ChuckMcM wrote: post #17

While I realize it was likely impractical to meltdown reactors just to develop the technology to clean them up, I find the process here pretty interesting. A lot of good engineering has gone into the effort, and the engineering challenges (and risks) of post runaway reactors has gotten a lot more data. The Chernobyl folks just entombed everything, which is a one approach, even though they can "walk up to"[1] the rema…

Obviously it couldn’t melt through to China but AFAIK the way Czernobyl played out was that they had to somehow stop it from melting down to a flooded basement due to the fear of a long lasting series of hydrogen explosions that could have been truly disastrous for the region, if not Europe. Thus I think that the true worst case has so far never happened: A reactor without any of the modern safeguards (such as boroni…

Are there lessons we can take away from further studies on the ancient reactor at Oklo? (see https://www.scientificamerican.com/article/ancient-nuclear-r... for ex)

Re: First contact made with melted nuclear fuel at Fukushima plant

#98

Post by mimixco »

rabidrat wrote: post #89
cgrand-net wrote: post #22

Earlier quoted context omitted.

> The truth is that accidents like this can never be cleaned up or salvaged. While global warming is easily solved. Coal or nuclear are both bad but differently. Which one is less bad depends on your risk model

If climate change truly is incompatible with global civilization, I would rather have some defunct coal plants laying around than spent nuclear fuel. Nuclear maybe would have helped us avoid the worst of climate change if we had adopted it at a broader scale sooner, but at this point I think we have to be planning for post-civilization scenarios.

You might want to read "The Moral Case for Fossil Fuels" for a slightly less dire perspective.

Re: First contact made with melted nuclear fuel at Fukushima plant

#99

Post by pfdietz »

petschge wrote: post #45
ChuckMcM wrote: post #17

While I realize it was likely impractical to meltdown reactors just to develop the technology to clean them up, I find the process here pretty interesting. A lot of good engineering has gone into the effort, and the engineering challenges (and risks) of post runaway reactors has gotten a lot more data. The Chernobyl folks just entombed everything, which is a one approach, even though they can "walk up to"[1] the rema…

Boron actually mostly acts as a neutron poison, i.e. it absorbs neutrons. That way further (stimulated) decay of other nucleii that were hit by a neutron is eliminated and the chain reaction stops, reducing the production of thermal energy. A moderator on the other hand inelastically scatters neutrons, converting some of the kinetic energy of the neutrons to heat and leaving a slower neutron. Moderators are used in r…

> A moderator on the other hand inelastically scatters neutrons,

Most moderators elastically scatter neutrons. What other kind of collision could there be with a hydrogen nucleus?

Re: First contact made with melted nuclear fuel at Fukushima plant

#100

Post by tomatotomato37 »

petschge wrote: post #61
roywiggins wrote: post #57

Earlier quoted context omitted.

Gamma radiation goes through everything. The only thing that stops it is mass and distance. You can only wear a certain amount of lead before you collapse. The amount of radiation is just too high.

Gamma radiation not so much simply makes it through everything, but it does indeed take a lot of shielding to attenuate to save level if there is enough radiation to begin with. The fact that it interacts with stuff is actually what makes it dangerous. If it went through every thing it would not interact with the worker either and would not pose a thread to them. Btw. there is a type of radiation that is practically…

>Impossible to shield against, but also completely harmless if you are not standing right next to a super nova

There was actually a fun what-if based on that: https://what-if.xkcd.com/73/

Post reply on HN