The news has had many good, bad and dumb reports on what has happened in Japan. I am not a nuclear expert, but this is the information that I am aware of and hope to make a bit of sense to all of it.
First off, background radiation levels over the past two days have been between 6 and 8 microRoentgens per hour per my PM1703m, and hovering between .09 and .13 microSeiverts per hour as measured on my PM1208 Geiger Counter wristwatch. I will be monitoring this over the next few weeks closely. If there is any rise in background radiation I will report it.
I have been strangely absent from blogging, and it has been due to personal lack of time. My family comes first, work second, and my website and hobby third or lower on the list.
Worth mentioning, prevailing winds from Japan may take between 1 to 6 days to reach the western coast of the US, and from there a day or two to reach Oklahoma. So it is critical if any radiation is to be detected, that I watch carefully over the next few weeks.
So, that leaves, what happened? Everyone is aware of the earthquake that occurred off the coast of Japan. It may have been between 8.4 and 9.1 magnitude. This in turn caused a tsunami. The 5 reactors at two nuclear power plants were designed to SCRAM (Safety Control Rod Axe Man, a term that originated from the first nuclear reactor were a man was designated to hit a rope with an axe to allow control rods to drop into the first nuclear reactor's core to shut it down), Trip, or in layman's terms shut down in the event of an earthquake, and for the most part, it appeared that they did. The reactors are shut down by graphite rods which pop up, into and in between the uranium fuel rods found in the reactor, typically the shutdown will take 4 seconds. The control rods are spring loaded typically, so no power is necessary to insert the rods. The control rods stop or absorb neutrons from striking uranium atoms, so fission stops, for the most part.
The problem is this, after a reactor stops, there are typically other radioactive isotopes present, Cesium 137, Strontium 90, Xenon 86, Iodine 131 and many others, so the reactor will continue to produce heat from nuclear decay. Also, the control rods will stop a majority of the neutrons from splitting atoms (fission), but not all, so some nuclear reactions will continue. If the reactor has not been recharged recently, there is more heat originating from lighter, and much more radioactive isotopes.
The reactors still need to be cooled, in the case of the Fukushima Daiichi Reactors, which are Boiling Water Reactors (BWRs) they of course use water as a coolant. Some reactor designs use Sodium, Lead , or Potassium as a coolant. Others may use Carbon Dioxide or Helium as a coolant. What really surprised me, is Hillary Clinton's response, she in an unsolicited fashion sent “reactor coolant” to Japan. One would think the Japanese with 55 nuclear reactors and surrounded by an ocean, would have good old H20. Another possibility would be that the press misreported what was really sent, Borax, Boric acid or boriated water. Is used in a BWR to further stop nuclear reactions. Boron has a tendency to stop nuclear reactions like the control rods, and soak up more neutrons to further stop the fission process. Again though, one would think in a nation with 55 nuclear power plants, that they would have plenty of boron, boric acid, borax on hand (borax is very common). My guess it was just a political ploy.
Why are there cooling problems? Simple, the water still needs to be circulated through out the reactor core, even during shutdown to get rid of heat. The reactor is not turning the turbines, so no electricity for the pumps. All nuclear reactors have back up power supplies and a back up generator or two, however, the diesel generators had been damaged or swept away by the tsunami that ensued following the earthquake. It is unclear if the pumps where operating, or operating with less efficiency, on back up battery power. There was word that workers where switching out batteries and two diesel generators where being sent to the site.
This is where the reports begin to get unclear, especially regarding reactor number one at Fukushima Daiichi. Apparently pressure 50 % greater than normal was reported, and as a result the pressure needs to be released from the reactor vessel. Supposedly the radioactive material had been filtered from the steam, but they needed to vent the gas or steam, so the core was vented to bring pressure levels back to normal. However, what was released was not only water vapor, but tritium (an isotope of hydrogen). Tritium is radioactive, but it is not a really nasty isotope. It is a weak beta emitter. Yes, it is radioactive, however the radiation is very weak and special radiation detectors are needed to detect it. Workers that are exposed to it and may have tritium in their bodies are given beer (yes, beer can be the cure for things other than bad memories) or copious amounts of water to flush it from their systems.
Drudgereport.com was the first to to come forward with horrible news. Radiation Levels in the control room were reported to be 1,000 times normal, and at the gate of the plant 8 times normal. Sounds scary, however it does not indicate that there where lethal levels or even harmful levels of radiation. In fact, in an update I recently got, highest reported radiation was 11 milliRountgens per hour, hardly a fatal dose, or even harmful for that matter. Significant, since background is usually 1,000 times less.
Other reports indicated that Cesium 137 and Iodine 131 had been detected during the venting. This is significant since it indicates that there could be damage to the reactor core.
Overnight, there was an explosion at the plant. Hydrogen gas, which is inflammable, and Oxygen, had built up in the containment building. Fortunately only the containment building was damaged, it appears and from what we have been told the reactor itself is intact. This is good news, so many of the radioactive nasties inside the reactor core are still there.
Seawater and Boric acid are being pumped into the core of the reactor, and it appears that we are out of the proverbial woods, if the recent reports are correct and accurate.
It will be very interesting to see what the post incident assessment will be. So Far the IAEC ranks this disaster Scale 4, Three Mile Island was a 5, on this scale 7 is the worst (Chernobyl).
If the reactor exploded, or if does, what can one do to protect themselves? Assuming you are not in the direct path, here is my advice if you are concerned about ingesting radioactive isotopes:
1) The news will fear monger, no ifs, ands or buts about it. However be aware that any fallout that reaches the US will be diluted quite a bit.
2) If you do not eat lots of seafood or lots of seaweed, you may be slightly Iodine deficient. Iodized salt does help, but your thyroid is very sensitive to radiation.
3) Several of the substances found in fallout are Strontium 90, Cesium 137, and Iodine 131 as well as other Isotopes. Radiation in small quantities may not be a significant hazard, however, we have been trained by uneducated news and uneducated teachers that any increase in radiation over background is a hazard. This may not be the case, The French Rivera and Ramsar, Iran, as well as beaches in India all have natural background radiation levels that inhabitants are exposed to on an annual basis that are higher than Nuclear Power Plant workers are allowed to receive on an annual basis!
4) if you are worried, you can protect yourself by the following: Use “No Salt” this will protect you somewhat from excessive uptake of Cesium 137; also you want to protect your thyroid, dunk your index finger up to the first knuckle in Iodine (Do not Drink the Iodine! This stupid practice has been shone in TV series and movies). This will load your thyroid with Iodine so less Iodine 131 will be absorbed by the thyroid.
If you have allergies to seafood and Iodine, consult with your Physician on topical use of Iodine!
In closing, I still support the use of nuclear power. We will learn from this event, and learn to create new safeguards, or even safer running and more efficient nuclear reactors.
I will also continue to monitor background radiation rates, currently it is only 7 microRoentgens per hour...