In yesterday's installment about the 'endoscopy' of Fukushima Daiichi's unit 2 containment vessel in an attempt to discover where the core and water level might be:
da kamra dint werk gud
We discovered that the core was nowhere to be found, the tonnage of water being poured into the vessel wasn't where TEPCO thought it would be, and the expensive digital equipment rated to operate fine in high radiation/high heat situations didn't work very well at all. Seems the 1000 Sv/hr rad levels and thick steam in the vessel interfered with the game plan rather badly.
Today the Asahi Shimbun follows up with its article, First photos from inside Fukushima reactor released…
The No. 2 reactor was chosen for the first endoscope survey because radiation levels were comparatively low and the location of the piping used to insert the endoscope was known.
Yeah. The camera was rated to withstand 1000 Sieverts [100,000 Rem], but the actual radiation was so much higher that the camera was nearly useless due to radioactive 'snow'. Thus we are to surmise that ten times higher - say, a million Rem - is "comparatively low" if you're comparing the atmosphere in this containment vessel to getting skewered to the ceiling by a blown-out control rod from a critical reactor and having to have your head and hands encased in solid lead and stored in a high level waste facility for a hundred millennia or so. According to TEPCO, which by the way didn't bother to actually obtain a radiation reading while they were in there mucking around. Probably don't have a meter that could read that high anyway…
But a nice neutron detector with a long wire attached to the probe would at least have told them where the corium is. I guess they weren't really curious about that. It'll find water enough on its own, I guess.
And while we can all be grateful that TEPCO was able to find the piping used to insert the endoscope, we should perhaps question the apparent fact that they DON'T know where piping is on their other melted reactor units. I mean, look at the plant specs. I'm sure they're around Daiichi somewhere, or maybe in the TEPCO office files, or maybe NISA's file cabinet? Ask around, GE maybe has a copy somewhere. Sheesh.
Anyway, TEPCO did say that they'd release more photos and some of the video at some point, after they've analyzed it for their own purposes. And not to worry, they actually do plan to do a more detailed survey in the future…
The road map for decommissioning the reactors that was released toward the end of last year by the central government and TEPCO said the removal of melted nuclear fuel would begin after about 10 years. A more detailed survey of the inside of the containment vessel is set for 2017, and a similar survey of the pressure vessel has been set for about 2019.
Really? Get in for a look-see, find that neither core nor water is where it's supposed to be, then give it five to seven years before you check again? Who is writing the script for these lousy comedians?
just so there's no confusion about the deliberately confusing statements from TEPCO, they did not at any point in this evolution actually 'see' or detect a water level in the containment structure. Which means it is below the grate level on the conduits to the torus. They do not know what the water level in the torus is, but the conduits are at floor level. Thus water could NOT be covering corium on the concrete below the pressure vessel (where TEPCO "assumes" it to be). But since they also didn't find any corium, they're now "assuming" that both water and corium are in the same place (wherever that may be), and that the water's winning - somehow 'covering' the corium to a depth of ~12-15 feet. Oh… and not boiling or simply flashing to steam/gases. That would mean the corium is in "cold shutdown," I guess.
Now, Japan has long been noted for being at the cutting edge of all things geeky, including photography, digital anything, and even robotics. But even way, way back in 1982 - geek paleohistory - American technology managed to get a fine endoscopic view of the inside of the Three Mile Island unit 2 reactor vessel, while what was left of the core was still inside of it, just three years after the meltdown.
Maybe NRC Chairman Gregory Jaczko should call up counterparts in the land of the rising sun and offer them some good ol' American know-how (and the endoscope they used at TMI), so TEPCO can get a feel for where their cores are, sometime BEFORE the end of the decade or those cores hit groundwater and blow the reservation sky high, whichever comes first. Just a thought…