Wonderful footage of Fukushima Unit 1 being constructed in the 1960s. Part one shows the original ocean and soil surveys, laying the sea wall and the bulldozing of the cliffs to bring the site down to sea level (19m05s):
Part 2 has ok auto-translate subs. It shows more cliff demolition, GE...
According to areas marked red in this TEPCO pdf, they seem to be estimating severe concrete damage to ~27% of the pedestal concentrated around the doorway. Plus the pedestal inner walls.
The pdf source says 2016 though, so it's possible that further damage has been observed in later...
Hey all, I was going over some old posts today and was saddened to realize that Jim Hardy had passed away. I remember him being popular here and I'm sure he'll be much missed.
My initial reason for going back was to recall exactly where things had left off and what the main unanswered questions...
I talked about it back in 2017, the process is called spalling. Great visual demonstration of it here:
and in depth explanation here. Basically extreme heat causes moisture and air pocket pores trapped inside the concrete to expand into steam which explodes the surface concrete off. Varying...
Good article and translation
Hard to believe it’s been an entire decade. Tepco recently posted a 53 minute long slide presentation on their website. It’s all in Japanese but from the images seems to chart their evolving picture of the melt out progression from the 3 cores and where data suggests...
I think when you design and sell a plant based on the notion that it is too safe to fail, you can’t really then go on to clearly and explicitly plan for an event in which then does. It’s like the unsinkable Titanic not having enough lifeboats for the all passengers on board, once you bill a...
There’s a new 49 minute feature by NKH investigating some sustained high level radiation releases that occurred from the plant during the accident but have never been clearly understood or explained:
https://youtube.com/watch?v=CwlvPRpq7aw
It’s very well done with a lot of work gone into tie...
You can see the new metal/ sheild clad walking surface erected over the original refuelling floor here. One of the techs appears to be using a Geiger counter to measure the amount of radiation coming up from below as they walk over it.
Something I wrote in my spalled concrete post back in March:
This is the part that doesn't add up. On the video it looks like they basically lower the camera all the way down until it hits the surface of the sediment. If it was a loose amalgamation of materials as spalled concrete normally is...
The muon results already came back showing no significant amount of fuel remaining in the unit 3 RV. In Tepcos report they say:
The evaluation at present shows possibility that some fuel debris remain inside the RPV, but massive and high density material has not been found.
85% remaining in...
You know I didn't write that right? You know that's a finding quoted verbatim from an Oak Ridge paper and is reconfirmed in multiple NRC, Los Alamos and IAEA investigations using actual reactor grade steel, actual reactor components and fuel materials right? Besides the papers I linked, there...
Similar signs have been observed in Unit 1 and Unit 3 with signs of a suspected fuel puddle exiting the pedestal in Unit 1 and strong indications of a molten hot fuel exit yet relatively intact CRD structure in Unit 3. The Unit 3 images were captured in the latest investigation using that...
The characteristic fuel splatter distribution observed in the Unit 2 robot investigation. It's in my #1397 post and Jim Hardys #1402 post.
As I said before, the 02:02 - 02:22 mark of Sotans NHK video offers a very plausible explanation of how you can have both this distinct wide spread...
You can find pretty much everything relevant to this by googling 'Mark 1 BWR Lower Head'. The actual progression of the meltdown was probably discussed earlier in the thread and is a bit outside the scope we're looking at here but off the top of my head I would suggest BWR LOWER PLENUM DEBRIS...