APR: your source for nuclear news and analysis since April 16, 2010

Sunday, May 8, 2011

Japan updates: Fukushima Daiichi, Hamaoka

-Chubu Electric intends to hold another board meeting very soon (probably early this week) to decide what to do about Naoto Kan's request to shut down all reactors at Hamaoka.

-TEPCO may enter No. 1 reactor building at Fukushima Daiichi any time now. Once discussions with the government agencies (and that means the national safety entities like NSC and NISA as well as the prefectural government) are complete, TEPCO will send workers into No. 1 building. Until then, let's look at some TEPCO video showing the setup at the pressurized air lock that's been set up. This appears to show both the large Alara Venti units filtering the building air (these are sheathed) and the small units pressurizing the air lock (not sheathed.)

We also have a new video this morning from TEPCO taking a much longer look in the spent fuel pool at No. 4 plant.

4:40 AM Eastern Sunday 5/8


  1. Any idea what the current release rate into the environment is (air/water) and which units are the worst offenders? Thanks

  2. Thanks Will. Your opinion on the events unfolding would be appreciated.

  3. Video 1: Wow. This is encouraging, and I'm sure those are great filters, but that rig looks seriously Apollo 13. The red numbers on the readout of the clipboard-style thing hanging from the units... do we know what it's measuring, and do we like these numbers?

    Video 2: I don't like seeing bubbles, but they are few and very tiny, perhaps of no consequence. It's great that the racks seem to be somewhat intact, but can we infer anything anything about the condition of the fuel?

    Thanks so much for this. Fascinating.

  4. @ashen: Probably cesium and iodine, but no data right now on actual concentration.

    @barrywilliamsmb: My opinion is that things are now finally looking agressive enough for me, after too long a period of planning more than acting.

    @catalyzt: That reading seems to be on an indicator that shows millisieverts, and I'm not sure exactly what they're reading. Normally for an airborne activity you take a fixed volume of air through a filter media (say, paper) and then measure the radiation from that filter to extrapolate airborne contamination. This must be an instantaneous readout. TEPCO says that the readings are 1/10th of that required for entry with full face masks, so on that balance I like what I'm seeing there. As far as the fuel stored in No. 4 we might say that there is probably not any sort of disastrous fuel failure .. but clearly we know that there is fuel failure. No signs of wide derangement or shifted fuel racks, which would indicate continuing structural failure of the pool itself are also encouraging signs. However.. TEPCO still needs to gusset the spent fuel pool structurally.

  5. On the spent fuel pool video -- is that a 'night vision' amplifier, or an infrared view, is the band identified anywhere?

  6. @hank: TEPCO didn't identify the type of camera they used, or any such thing. Sorry!