We have been waiting several months to find the space for the following…an explanation of what the term “sievert” means, with respect to radiation exposure, and relate it to a more-commonly understood parameter…the BTU.
Sievert – The amount of penetrating radiation which produces the equivalent biological effect of 10,000 ergs of pure energy deposited per gram of body tissue. Since 10 billion ergs equals 1 BTU, a sievert of exposure deposits one-millionth of a BTU per gram. For the average 80 kilogram person, this would be a total of 0.08 BTUs. The defining parameter for all units of radiation exposure is energy deposition, and says nothing about its effect on genetics.
– The above is a combination of the overlapping definitions of REM and Gray, since the definition universally used for “sievert” merely state its equivalence to 100 REM and/or one Gray.
– Technically, the above is specific to the three penetrating forms of radiation (x-ray, gamma, neutron) which can pass through the skin and deposit energy to the underlying living tissue as it migrates through. 90% of the energy gets deposited, and the rest exits the body as weakened radiation.
– The other two types of radiation concerning nuclear power plant releases, beta and alpha, cannot penetrate the skin, and are not external sources of whole body exposure. They can be internal sources of exposure through ingestion of beta or alpha emitters. Cesium 134 and 137 each release both beta and gamma. Internally, beta radiation has the similar energy deposition properties as gamma. Externally, beta is harmless.
– The effects of internal exposure to radiation is no different than external (penetrating) exposure.
Now, back to Fukushima…
- As of today, the combined operation of the two waste water decontamination systems at Fukushima Daiichi have processed 100,000 tons of waste water. This would be a cause for celebration if it were not for the discovery that water is now leaking into the plant’s building basements at a rate equal to the volume of water being cleaned up. Regardless, the 100,000 tons of processed water is a milestone that ought to be noted.
- NHK World headlines “Typhoon Roke Spares Fukushima Plant”. The article states “Typhoon Roke has inflicted no major damage to the crippled Fukushima Daiichi nuclear power plant,” which is an exaggeration in itself. The level of impact to the plant complex was so trivial that no other news service even mentioned it! TEPCO reports there have been minor increases in the waste water levels of the building basements due to rainwater seepage, and a few site cameras experienced electronic glitches.JAIF stopped writing their own updates some two months ago, and have been copying NHK reports into their daily posting ever since. Two months ago, NHK would not have posted something with a negative rhetorical connotation. It has become rather frequent recently. Maybe JAIF should reconsider its update decision?
- Prime Minister Yoshihiko Noda told an international audience at the United Nations, in New York, that he is committed to making Japan’s nuclear power plants the safest in the world. However, his comments on Japan’s energy shortage have slight but significant differences between news sources. For example, Japan Times says Noda wants restarts of currently-idled nukes to begin by this spring, whereas Asahi Shimbun says he wants the restarts to begin by next summer. On the other hand, the Wall Street Journal reports Noda saying, “From spring through next summer, we must bring (Japan’s idle nuclear reactors) back up as best we can.” If “by next summer”, then all currently operating nukes will have been idled, in addition to those now biding their time. More severe energy shortages will surely happen. But, if “by this spring”, there will be an overlap between restarts and shutdowns which might ease the expected shortfalls. Regardless, Noda also told the WSJ, “If we have a power shortage, it will drag down Japan’s overall economy”, which Japan Times interprets to mean “a bid to avert a massive power shortage that could deal a potentially fatal blow to the economy.”
- Chubu Electric, operators of the Hamaoka nuclear power station ordered shut down by then-PM Kan out of earthquake fears spawned by Fukushima, has begun construction of a nearly 60 feet high, one mile long tsunami protection barrier around the Hamaoka complex. If the numbers are correct, it will be one of the largest contiguous man-made structures ever built. When completed, Chubu Electric feels it will close the book on Hamaoka concerns and the six-unit complex can be placed back into operation.
- Today, Japan Times has a lengthy article about the current nuclear vs. solar/wind debate in Japan. Two problems immediately jump out at us. First, the cost of each form of electric generation using government numbers, shows nuclear to be half the cost of wind and 8 times less than solar. Nuclear critics say these numbers are bogus because they don’t include the costs of nuclear waste disposal or nuclear accident insurance. Both objections are themselves bogus, with respect to Japan. The Japanese have their spent fuel recycled in France and the refurbished fuel is returned to Japan for re-use. The “waste” atoms (fission fragments) are encased in high density glass (sintered) for future deep burial…when there’s enough of it to make burial worthwhile. Regardless, the Japanese government’s numbers do, in-fact, include these costs.Second, TEPCO’s having to pay out compensation to all government-mandated evacuees, as well as footing the entire bill for accident recovery at Fukushima Daiichi power complex, makes the accident liability (insurance) issue moot. In fact, it literally destroys the nuclear liability issue world-wide, since we now have an example of what really happens (outside of the old Soviet Union) with respect to accident liability. The operating company pays the bill! Accdient insurance is rapidly becoming a non-issue.
There is also a glaring omission from the Japan Times article…there is no mention of the huge areas of Japan’s land that must be covered with solar cells and/or giant windmills in order to replace their existing nuclear capacity.
Hiroshima syndrome update…
Much of the western Press has covered yesterday’s presentation in New York City by a Japanese woman, Sashito Sako, who said she was forced to evacuate from her farm due to the nuclear accident. The presentation, announced weeks ago on line and located in downtown New York, attracted about 70 people. The problem with Sato’s presentation is that her farm, near the town of Kawamata, is not in an evacuation zone, and more than a dozen kilometers from the nearest contaminated area boundary. She wasn’t “forced” to evacuate at all. It’s another phobic fear of radiation story.