Japan's Damaged Reactor Has High Radiation, No Water 282
mdsolar passes along this quote from an Associated Press report:
"One of Japan's crippled nuclear reactors still has fatally high radiation levels and hardly any water to cool it, according to an internal examination Tuesday that renews doubts about the plant's stability. A tool equipped with a tiny video camera, a thermometer, a dosimeter and a water gauge was used to assess damage inside the No. 2 reactor's containment chamber for the second time since the tsunami swept into the Fukushima Dai-ichi plant a year ago. The probe done in January failed to find the water surface and provided only images showing steam, unidentified parts and rusty metal surfaces scarred by exposure to radiation, heat and humidity. The data collected from the probes showed the damage from the disaster was so severe, the plant operator will have to develop special equipment and technology to tolerate the harsh environment and decommission the plant, a process expected to last decades."
Re:INSIDE THE CONTAINMENT CHAMBER (Score:5, Informative)
even TEPCO can manage a thermometer.
50 degrees is a bit too cool to melt through feet of concrete.
Re:TFA (Score:5, Informative)
Re:INSIDE THE CONTAINMENT CHAMBER (Score:5, Informative)
A better reference than TFA, the report from TEPCO: "Reference Result of the dose measurement in the second investigation inside of Primary Containment Vessels, Unit 2, Fukushima Daiichi Nuclear Power Plant" [tepco.co.jp] with the precise location of measurements and the last report (Mar 27,2012) from TEPCO regarding Unit 2 of Fukushima Daiichi: [tepco.co.jp]
- At 10:10 am on March 26, 2011, we started injecting freshwater to the reactor and are now injecting fresh water by a motor driven pump powered by the off-site transmission line.
- At 2:59 pm on September 14, 2011, in addition to water injection from feed water system, we started water injection from piping of core spray system to the reactor.
The current water injection amount from the reactor feed water system is approx. 2.7 m3/h and that from the core spray system is approx. 6m3/h.
- At 5:21 pm on May 31, 2011, we started cyclic cooling for the water in the spent fuel pool by an alternative cooling equipment of the Fuel Pool Cooling and Filtering System.
- At 8:06 pm on June 28, 2011, we started injecting nitrogen gas into the Primary Containment Vessel.
- At 6:00 pm on October 28, 2011, a full operation of the PCV gas control system started.
- From 9:40 am to 12:30 pm on March 26, the water level and water temperature inside the PCV of Unit 2 was investigated with the industrial endoscope. As a result, the water level was confirmed to be 60 cm from the bottom of the PCV and the water temperature was confirmed to be in the range of approx. 48.5 to 50.0 .
- At 12:10 pm on March 27, the amount of injected nitrogen into the PCV was adjusted from 0 Nm3/h to approx. 5 Nm3/h as the internal investigation of the Unit 2 PCV was finished.
- At 10:46 am on December 1, 2011, we started the nitrogen injection to the Reactor Pressure Vessel.
- At 11:50 am on January 19, 2012, we started the operation of the spent fuel pool desalting facility.
TEPCO should be blamed for their negligence in not raising the height of the seawalls and leaving two big nuclear power stations at the mercy of a tsunami, the executives that didn't do it are 1 year late to jail, but after march their engineers have dealt with the nuclear emergency as good as possible.
Re:INSIDE THE CONTAINMENT CHAMBER (Score:3, Informative)
And that's just solar / cosmic irradiation due to the altitude and therefore doesn't even count the exposure from natural concentrations of uranium (and therefore radon). Denver also so happens to be quite the hot spot for that, more so than any other large city/metro.
Re:INSIDE THE CONTAINMENT CHAMBER (Score:0, Informative)
that's weird, because all the searching i've done after reading your comment has consistently shown that denver averages at or below 1 micro sievert/hour. so you're only off by a margin of six. if you can find anywhere whatsoever showing a dose in or around denver that's above 5 usv/hr, i'd be incredibly interested!
not to mention the radiation in denver will only be external, and not the much, much, much more dangerous internal emitters that damage the body directly instead of (mostly) dead skin. such as all the plutonium, uranium, americium, cesium and strontium that's turning up in japan's food supply. also there's the iodine that wafted over the whole country, and now 30% of children tested around the plant have unexpected, unusual lumps on their thyroids.
but whatever, they're japanese, so it really doesn't matter anyway.
Re:INSIDE THE CONTAINMENT CHAMBER (Score:4, Informative)
While it's true that radiation will mess with electronics, measuring things like temperature can be done reliably even in the core of an operating power reactor, which is a much harsher radiation environment than this. For instance, an off-the-shelf type-K thermocouple will last a year or two in-core before transmutation causes serious problems.
In this case, the trick is to keep the circuitry out of that kind of radiation but wires, high voltage, and most metals and ceramics will be fine for a while. A good fiber-optic scope will last maybe an hour before becoming too opaque, and you can keep the CCD etc. well away.
Re:~space (Score:4, Informative)
A fission nuclear bomb consumes a large part of its fissile fuel for its explosion
Not really, Fat Man converted about 20% of it's Pu load into energy; also of lot of radioactive elements were probably produced by the encasing during the explosion.
And it contains a small amount of it, to begin with
That's most certainly the point. Fat Man contained 6kg of plutonium. Tepco estimates that about 68 tons of fuel [enenews.com] melted in Fukushima reactor no 1 alone.
Re:~space (Score:4, Informative)
that's why the old ones are still running in many cases.
I don't believe that, and I think you are deluding yourself at best, dishonest at worst. The reason if much more probably because it's more profitable to let things go this way.
Well, reality got tedious and disagreed. Japan discontinued a bunch of new nuclear construction projects from the late 90s to early 00s. Fukushima's lifespan was subsequently extended. I'd say there's a definite cause and effect here.