Recent content by Cire

Our first good view of what happened under the RPV. http://www.asahi.com/ajw/articles/AJ201804270041.html

The best way to clean that up is to dissolve it and slurp it out. I am amazed that the handle is in such good shape. How do you get a handle in that good condition under the pedestal? It had to have fallen through a large hole sometime after the reactor sludge cooled. I can't image it...

I'm trying to think of another industrial/power complex that could have survived a 9.0 quake and 49 foot wave with so little death from the failure of the plant. More people (workers) have been killed in the cleanup by accident then people have been killed by the power plant itself and the...

Nitric acid seems completely appropriate for the job. The RPV itself is clad in stainless steel (308/309) and most of the internal plumbing is inconel. Both are resistant to Nitric acid. You simply control the dissolution rate of the fuel debris by varying the concentration of the acid. I...

We have plenty of concrete there. We can afford to dissolve a bunch of it if needed. The fuel / fragments have much higher surface area per volume then the foundation does. You could also pre-treat the foundation concrete with a rubber sealer like Kalrez from DuPont or a Silicone. A spray...

I believe there was probably some leakage of water/steam through the penetrations while the reactor was at pressure and overheating. I think only a small portion of the fuel pellets where transported this way. I believe most are down at the base of the RPV. A good place to go back too is...

The pictures from under the reactors do not show an environment that was subjected to a corium melt and heat soak. There are way too many small features visible that would have melted and slagged down to the bottom. You can't melt through a 10" steel vessel, transport TONS of steel melting...

Looks like the Muon scan is done for Reactor #2. http://www.tepco.co.jp/en/nu/fukushima-np/handouts/2016/images/handouts_160728_01-e.pdf

Found what looks like tepco's 2016 road map.. Does anyone know a translation to this? http://www.tepco.co.jp/nu/fukushima-np/roadmap/images1/images1/d160128_08-j.pdf

That's nothing more then FUD and propaganda disguised as a poorly written article. Where is the fuel? If it's not in the bottom of the reactor vessel its under it. It's not on Mars, its not on the west coast of the United states. Giant mutant fish and flowers didn't eat it. Do we need to...

If you watch the video right when the value spikes there is a hiccup in the video feed. I think you what happened was a power transient/glitch or equivalent that spiked the system for a few miliseconds. You see the heavy averaging of the radiation value as it starts to drift back down. So...

The image at 0:59 into that last video looks exactly like what you see when a pot of lead cools and hardens. It looks like there is a shelf under the grate at that location.

How should a cold shutdown on a reactor that suffered core damage and a hydrogen explosion look like? I feel the plants are in a much more stable condition then one would expect for the amount of damage they took.

If you don't have a copy yet, go find an early addition of "Rocket propulsion elements" by George Sutton. The book is a valuable resource. Several years back now I built a fairly large (for amateurs) liquid rocket engine and eventually flew a vehicle with it. A video of that flight can be...

This idea isn't quite nuclear engineering and might be more suited for someone still in school. But I'll mention it anyways. A fun project that covers both fields would be a true random number generator using radioactive decay to stimulate a sensor. You generate random bits that you feed...