Recent content by jmelson

This seems a mistake. They had, depending on how you count, at least 3 or more separate failures related to electrical supply. They had transmission lines down, interruption of and damage to seawater pumps (interrupting both final heat sink for the reactor and most of the emergency Diesel...

Coal, etc. plants don't have a HUGE pot of hot water, they have many small tubes exposed to the hot flue gas. A defective tube can be plugged if it develops leaks, until the next major shutdown. The tubes corrode away and have to be periodically replaced, but that is a tractable overhaul...

I believe this is correct, fuel from the #4 reactor had been removed and placed in the pool a couple months (?) before the earthquake, to prepare for major work in the reactor vessel before refueling. Also, the pool was loaded with the fresh fuel to go in after the work was complete. Jon

http://genpatsu-watch.blogspot.com/2012/09/20129271730-1.html From there the camera progresses forward. Exactly now we are almost at the exact entrance of the PCV. The camera moved just a little forward into the inside of the PCV. Just after leaving the penetration, there is a structural part...

The 9.1 magnitude earthquake was certainly at the upper end of what Japan experiences, but they HAVE had earthquakes of this magnitude before. The 15 m tsunami run-up is guaranteed in Japan, you just have to wait long enough for one of those to hit your particular region. Their earthquake...

Well, that's THE problem. In fact, TEPCO cheapness is what CAUSED the accident, from the siting to the resistance to fortifying the plant against obvious hazards. But, TEPCO is so big, they SET national policy, not the other way around. And, this has been the clear situation for decades...

There WILL be fatalities from this accident, but it will be essentially impossible to know which persons died from it. In five, ten or maybe twenty years there will be a clear increase of cancers and related diseases. It certainly won't be a HUGE increase, like those laughably insane reports...

The Fukushima plant was not "defendable", in my opinion. Defenses might have helped, but the whole plan of the system was so fatally flawed that it would have taken insane effort to protect the plant as it was sited. And, fixing one of the major flaws would have required getting practically...

There indeed WERE fatalities at the plant, although not related to safety systems, but just people being at the lower levels of the buildings when the tsunami came in. it is kind of a miracle nobody was killed by falling debris, etc. when the explosions happened. This accident has caused...

Wow, what an understatement! Anybody who was analyzing safety should have put this together pretty easily. It seems the Japanese government allowed TEPCO WAY too much leeway to set their own rules and safety management. But, of course, anybody who was let into give Fushima Dai-ichi #1 a...

See also Challenger accident and Columbia accident. "It hasn't killed anybody yet, so it can't be a big risk." Jon

Ok, that seems a lot safer, but the problem is that repairing the FHM and being sure it is completely reliable will be a huge effort, due to the structural damage to the entire building. The FHM itself could be pulled out by crane and moved elsewhere for repairs, but the tracks it runs on have...

Ah ha! I expected that this was one of the big things they could start working with, unloading the SFP of #4, and that was going to require removing a lot of damaged equipment that would be in the way. Unloading the fuel from that pool will be a very tricky bit of work using a traditional...

Oh, come on! This is a building that was subjected to a powerful earthquake, then a mil-level explosion! Any use of the main crane or the FHM is pretty much out of the question. If the earthquake didn't damage the support rails, the explosion would have. Unless the rails were tested very...

If there's no recriticality, why the HELL are they adding boric acid? Jon