Several E-mailers have asked; if decay heat is dropping so much, why have the spent fuel pools continued to heat up and why are the reactors still heating up? The drop-off is mathematically exponential, which means the drop-off is fast at the beginning, but the continuing drop-off slows as time passes. The by-product isotopes with half-lives less than a day are radioactively wiping themselves out (all will be gone in about nine days) and the lower-concentration of longer-half-life isotopes will become the prominent heat generators. It’s the reverse of Al Gore’s “hockey stick” description of carbon dioxide build-up.
The Nuclear Energy Institute web page referenced yesterday, points out that decay heat can still measurably heat up water for up to six months after it leaves the reactor, albeit very, very slowly after a week of decay. The point I’m trying to make is that as each day passes, the heat generation rate drops, and the risk of further reactor fuel damage drops with it. This is not being broadcast by the news media, and seemingly not being explained by utility spokespersons in Japan. Plus, the fear of drying out the spent fuel pools (any of them) is largely unfounded because they are not boiling, but are/were rather evaporating. And, with 16 feet of water above the spent fuel cells in the pools, it would take many days for the evaporation to drop water levels to the tops of the stored cells. The water sprays, and helicopter drops, getting a lot of news media play are to keep the pools filled. The notion that these sprays and water drops are to cool the reactors themselves is quite improbable, unless the several feet thick steel-reinforced concrete containment around the reactors was broken open. There is no evidence of any containment breaches, so there rationally seems to be no way an external water spray could actually cool any of the reactor vessels at Fukushima.
Now for perhaps the best news since the accident started…the emergency power generators for Units 5 & 6 are running and supplying power to both power plants. This allows the reactor and spent fuel pool cooling systems to operate. The fuel pool in Units 5 & 6 had heated to 68 degrees C (~155 F), but are currently below 36 C (~97 F). News media reports implying that the systems might not work when electricity was restored were unfounded. There currently is no info on the status from TEPCO or the Japanese government as to the status of Unit No.2 to get the electrical system re-energized from the emergency cable. This is probably due to the lack of timely communication by the Japanese utility (TEPCO) and or the government in Japan, which is inexcusable. Timely, full disclosure status reports ought to be made on a routine basis, including any and all work in progress. It may not be the “juicy” reports that make scary headlines, but the world needs to know. They have everything to gain and nothing to lose by doing this. If this were an American power plant complex, the information flow to the press and public (internet updates) would be many, many times better. It’s required by American emergency plans.
Fortunately another knowledgeable source, the Nuclear Industrial Safety Agency (NISA) has reported that they believe the emergency power cable will be energized very soon, and the situation at Unit No. 2, and the other three stricken units should be mitigated (eased) late today. It is not only Unit No. 2 that will be powered by the emergency cable, but the cable will allow all six units at Fukushima to be interconnected with power from the cable and all of the power plant’s emergency cooling systems re-energized. The NISA report has been published through Bloomburg News Service. (ref. 1)
On another previously unreported event, an E-mailer has written to me that the Asashi newspaper reports holes have been “punched” in the roofs above the refueling decks of Units 5 & 6, to prevent hydrogen gas build-up. This does not mean hydrogen gas generation is actually happening in these two units. There is no information with which to say yes or no, at this point. But it does strongly indicate that all precautions to prevent the possibility of a hydrogen explosion destroying the outer building shells are being taken.
It has also been widely reported that “radiation” has been found on foodstuffs growing on a few farms in Fukushima Prefecture. The way this is being reported is necessarily misleading, and demonstrates the high level of ignorance we are dealing with concerning radioactivity. I’ll try to be brief. The vast majority of the radioactive elements being released to the atmosphere are the inert gasses Krypton and Xenon. Their inert chemistry makes it impossible to for them to be deposited on foodstuffs, or on people either and they cannot be ingested. The minor fraction of the elements being released are not inert, specifically Iodine and Cesium. Their chemistry is very much like fine dust, similar to the white powder one might get on furniture at home from using portable humidifiers in the winter. You can’t see the dust coming from the humidifier itself, but over a period of a few days the build-up on furniture is visibly noticeable. The Iodine and Cesium dusts from Fukushima are much, much finer and in much, much lower concentration than the humidifier analogy. This is called “contamination”, and should not be identified as merely “radiation”. It’s impossible to see with your eyes, but the incredibly sensitive radiation detectors available to the world can easily detect the contamination. Relatively invisible? Yes. Insidious? Absolutely not.
The low-concentration, microscopic Iodine and Cesium particles in the air are being deposited on some of the growing foods in the Fukushima Prefecture, similar to the deposition of white dust from a portable humidifier. These particles are not, nor cannot make the foods themselves radioactive. It’s not the food that’s radioactive…it’s the impossible-to-see (with the naked eye) radioactive dust on it. All that’s needed is to wash the foodstuffs thoroughly, and the “radiation” will be removed…correctly put, the contamination will all be washed away. The food will be totally safe to eat. It should be pointed out that this has been found on but two or three farms, and it is not the case with all the farms around Fukushima….at least not at this point in time.
One report of tiny traces of Iodine detected in one Fukushima town’s water supply is a different chemical process altogether. The Iodine dissolves in the water, so it cannot be washed off, if you will. However, Iodine is chemically very reactive, so water softeners and in-line filters should remove the Iodine very efficiently. Besides, the miniscule levels reported would make unfiltered water safe to drink, to be technically correct. But for those phobic about radiation, filter it and drink it without fear. Regardless, the levels being reported are vanishingly small.
As explained on several topic pages of this website, the universe is naturally radioactive. Our food is naturally radioactive. Our water is, too. The contamination levels on the growing foods at the affected farms of Fukushima ought to be compared to the concentrations of natural radioactive isotopes found in widely consumed foods. I would suggest the Potassium-40 (K-40) concentrations found in bananas and broccoli. I would also point out that the K-40 in the bananas and broccoli cannot be washed out of the food, while the contamination from Fukushima can be totally washed off. As for the water, the radioactive level of a glass of Iodine-contaminated water ought to be compared to drinking water containing radon levels (very common in home wells around the world) that have never hurt anyone.
The bottom line is this. The vast majority of the people in the world are deeply ignorant of radioactivity and the ubiquitous nature of naturally radioactive material in our universe. They don’t know the subtle but significant differences between radiation-itself and contamination. They don’t know that every bite of food and swig of water is naturally radioactive. They have no idea that the common referral of “fallout” to power plant radioactive emissions is patently false. Radioactive fallout comes from nuclear bomb blasts, not power plants. This ignorance includes the reporters covering the Fukushima accident, and (I would suspect) many of the “officials” being interviewed by the Press. TEPCO ought to be holding educational sessions for the news media, and the media subsequently educating the public about what they have learned. But alas, this is not happening in Japan, and the world suffers needlessly because of it. Hopefully that much needed education will begin here.
One final positive note from one of the most prestigious news media outlets in America…The Washington Post. This morning it has an article entitled “5 myths about nuclear energy” that is entirely correct on the first four, but more than a bit questionable on the fifth…”Better technology can make nuclear power safe”. It already is safe. Their fifth “myth” contradicts their first, which says nuclear energy is safe. However, they are entirely correct saying nukes are not terrorist targets, both democrats and republicans favor more nukes in America, and nuclear energy is not the key to energy independence.
References:
- “Fukushima No. 4 Reactor Doused as Tokyo Electric Attempts to Restore Power”; http://www.bloomberg.com/news/2011-03-19/japan-s-tepco-seeks-to-restore-power-to-damaged-nuclear-plant.html
- “5 myths about nuclear energy”; http://www.washingtonpost.com/opinions/5-myths-about-nuclear-energy/2011/03/15/AB9P3Oe_story.html
