Today’s updates…
- Unit 1 reactor temperatures and pressures has risen slightly since yesterday, but not enough to cause alarm.
- Unit 2 & 3 reactor pressures and temperatures have continued to slowly drop. The two temperature readings on Unit 3 are 97 C at the upper feedwater nozzle and 107 C at the bottom of the reactor vessel (IAEA). In a few days, both should be below the 95 C criteria for cold shutdown condition. It will be interesting to see what occurs at that point.
- Pressure in the unit 1 primary containment is above atmospheric, probably due to the nitrogen injection, which seems to be continuing. Pressures in the 2 & 3 containments remain at atmospheric.
- 200 tons of low activity waste water remains to be discharged to the sea. This will be finished today and the storage of waste waters from the turbine basements can resume. It is estimated that there is 50,000 tons of water that needs to be removed from the 4 basements. TEPCO says they do not have sufficient storage capacity for all of it, so they are pursuing bringing in as many portable tanks as necessary to store all of the waters.
- Heavy, remote-controlled equipment has started to remove the debris from the three reactor buildings that had their external walls and roofs blown off by hydrogen explosions. All debris will be stored in safe locations at the plant site. Will the debris be sprayed with the previously reported suppressant resin and stored under plastic sheeting?
- To continue one of yesterday’s stories, I checked a listing of what may well be the only locations in Japan that continually monitor environmental radiation levels, for an indication of actual natural background levels. All of them are on the sea coasts of Japan. Why? Because they are all nuclear power stations. Geologically and geographically, inland levels are always higher than sea coast levels, plus nuclear plants are never built in urban areas where building materials would raise the detected levels. Regardless, six of the locations routinely have natural background levels above the “0.05-0.1” microsievert/hr range MEXT says is typical for Japan. The highest is 0.159 microsievert/hr level at Kashiwazaki Karira nuclear power station. Could yesterday’s higher reported levels like the 0.42 microsievert/hr level reported at Fukushima City be typical background for them, and not due to the Fukushima emergency? Regardless, IAEA reports that gamma doses within the 30 km emergency radius around Daiichi are decreasing, and gamma doses measured daily in all 47 prefectures in Japan “tend to decrease”.
- The Japanese Embassy in Beijing, has asked the Chinese to base their actions relative to Fukushima on “rationality and scientific findings”, and not on alleged public concerns about food contamination. Yesterday, China banned all foods imported from 11 Japanese Prefectures, including Tokyo which is more than 200 kilometers from Fukushima. China did this because of reports of trivial, non-health-threatening levels of contamination measured in foods from ten of the prefectures (except Fukushima prefecture, of course). Irrational fear of radiation is a prime example of the Hiroshima Syndrome at work in China.
- NHK Japan reports what might be the first anti-nuclear demonstration since March 11 took place yesterday in Tokyo. Demonstrators demanded the immediate and permanent shutdown of all nuclear plants in Japan. This demonstration has been planned for over a week by anti-nuclear groups from 8 Prefectures across Japan. NHK estimates there were about 2,000 protestors…out of 127 million people. This reflects a CBC article more than 2 weeks ago where it was reported that most people in Hiroshima were quite unconcerned about what was happening at Fukushima. They felt all the hoopla about Fukushima was a terrible over-reaction. It took the CBC reporter three days to find what might be the only anti-nuclear group in Hiroshima, which had a membership of 20 citizens (out of 1.1 million). Interesting, eh?
Did TEPCO Compromise Safety for Money at Daiichi?
This morning, TEPCO released data showing the height of the tsunamic surge which occurred March 11, at both the Daiichi and Daini nuclear power stations. Numerous news sources inside and outside Japan, as well as some so-called experts, have stated that the Daiichi nuclear plants had not been upgraded to withstand earthquakes and tsunamis like Daini had been upgraded, in order for TEPCO to save money. The so-called “proof” is that Daini suffered little or no damage and no nuclear emergency, while the same quake/tsunami resulted in the Daiichi emergency. The new tsunami data places these statements in severe question.
As it turns out, the tsunamic surge at Daiichi was about 15 meters (over 46 feet) which swamped all power plant structures except the Reactor Buildings. Units 1 – 4 were subjected to an “inundation depth” of more than 15 ft. (whatever that means) These numbers come from high water marks left by the tsunami on Unit 2 reactor building, and a cell phone video made by one of the plant’s workers. It seems the other two units at Daiichi were also inundated, but to a lesser degree, based on high water marks on their reactor buildings. This means that the enormous surge probably reached the emergency diesels of Units 5 & 6, even though the plant buildings are 10-15 feet further above the shoreline. At least one of the Unit 5 & 6 diesels started and operated sufficiently to prevent a complete loss of power accident the two units. This was with a tsunamic surge the diesels were supposedly not built to survive…but one did! Now, moving to the Daini tsunamic surge…it is estimated that the Daini surge was between 6.5 and 7 meters. This was also greater than the “design criteria” of a slightly less than 6 meter surge (18 feet), but the power station has survived quite well. Regardless, the tsunami at Daini was roughly half as deep and several times less powerful than Daiichi’s tsunamic surge. This makes the “TEPCO compromised Daiichi safety to save money” notions questionable, at best.
The new data also shows that even though the 10 nuclear plants at the two stations were not “designed” to survive such an extreme natural threat, their actual ability to survive was far, far greater than their “design criteria”. “Design criteria” are the minimum technical standards any builder must meet or exceed in order to be hired for the job. With nuclear plants, these minimum criteria are always exceeded…always! How much? Before Fukushima, it was mostly speculation, backed by sound engineering assumption. With Fukushima, mother nature has given us an inadvertent test of the exceptional capacity for nuclear plants to survive the worst mother nature can throw at them. Hopefully, there will be no entombment at Fukushima, so that experts can perform detailed analyses of the plant structures and find out the technical truth of Fukushima’s level of safety. It took five years to discover that TMI was a severe meltdown, and thirty years for the NRC to admit it. With Japan’s nuclear community, we would hope to get the truth much. much sooner.
