This morning (America’s morning) there is more reputable news to report than since this all began on March 11 when the multi-unit power complex was inundated with a forty-foot high tsunami. There was no apparent damage from the 9.0 earthquake itself. We can now report with confidence that the power station’s inability to power up emergency systems, with the exception of short-lived batteries, was because the tsunami swamped and flooded all emergency diesels. Unlike most human-built structures along the tsunami’s “ground zero” coastline, none of the power complex buildings or emergency diesels were swept up and washed away. Recovery of emergency diesel power for Units 5 & 6 occurred after at least one of the diesels had been dried to insured to operate continually after being started. This took considerable time because these diesels are huge. They each can generate ~750 kilowatts of electricity (7500 100-watt light bulbs), which is more than enough to energize the emergency cooling system, put the reactor in cold shutdown, and keep it that way. These generators are many, many times larger than automobile or truck engines. Because of their large size, it has taken days to clean, dry and inspect the diesel internals. We have always known these emergency diesels were tough, but we are just beginning to realize just how tough. There is no information available, it seems, concerning the status or condition of the emergency diesels for the other four units. We can assume, however, that operators believe re-energization through the emergency cable is the fastest way to get re-powered.
Now, for a summary of the other news…
- The decay heat production continues to drop in the fuel cells of Units 1, 2, 3 & 4.
- Units 5 & 6 remain in a safe and stable cold shutdown condition. The emergency diesel generators energizing the electrical systems in 5 & 6 have been working as designed. Asahi, the second largest newspaper in Japan, has just reported that power from the emergency cable has been connected to the Unit 5 switchboard, and it’s diesel is no longer needed. Good things are beginning to happen fast.
- Work continues to re-energize the electric systems of Units 1 through 4. At this point, connection between the emergency power cable and Unit No. 2’s Temporary Power Panel is complete and energized. The electrical interconnection between Units 1 & 2 has also been re-energized from the Unit 2 Temporary Power Panel.
- The plan now is to first re-energize the control room of Unit 2. Up to this point, reports about the severity of Unit 2’s fuel damage have been purely speculative. With the control room re-energized, instrumentation in and around the reactor, inside the robust concrete containment, will be monitored for the first time since the tsunami hit. Units 1 & 2 share the same control room, so they should also be able to monitor Unit No. 1 reactor instrumentation for the first time in roughly 12 days. TEPCO hopes this will occur later today (Japan time). The painstaking task of restoring external power to the crippled power plants is slowed by radiation levels that are hindering the emergency operation.
- After the control room of Unit No. 2 has been re-energized, workers will check the condition of the water supply systems for the reactor and the spent fuel pool. They will continue checking for hydrogen concentrations, as well, to insure there will be no hydrogen explosions around the equipment when restarting. There is currently no estimation on how long this will take, but we can be sure the plant’s operating staff will get the work done as soon as humanly possible.
- A TEPCO press release says that they plan to have emergency power re-established in Units 3 & 4 in “a few days”. Asahi reports TEPCO as saying emergency power should be restored in Units 3 & 4 by Sunday.
- MIT reports that the Fukushima Units were designed (on paper) to withstand an 18 foot high Tsunami, which was the most extreme tsunamic prediction anyone could reasonably expect for that region’s geology. General Electric reports that their tsunamic assumptions for the Fukushima plants when they were built, were for considerably greater surges. TEPCO estimates that the tsunami of March 11 produced a wave height of more than 40 feet when it hit Fukushima. All plant structures withstood this monstrous wave with little or no damage. However, the transmission towers to and from the power complex did not fare well. They were destroyed. That, plus the flooding of the emergency diesels, resulted in a severe loss of electricity. It was the inability to regain electric power that has caused the damage to the affected reactor fuel cells and the subsequent hydrogen explosions that destroyed the external structures of Units 1, 3 & 4. Thus, we have witnessed a complete loss of electricity accident.
- Radiation levels at the power plant complex are in the millisievert range. When radiation monitors show an increase, the water cannons are opened up on the top of the nearest building that has had its roof blown off. This brings the water level in the spent fuel pool back to maximum. It does not mean the pool was dry, or that any of the stored fuel cells were exposed to the air. Here’s the reason why we see the radiation increase. Water is a very good radiation shield. A foot of water reduces radiation level by a factor of ten. Thus, when pool level drops a foot, radiation level around the pool goes up a factor of ten. The fuel pools at Fukushima store spent fuel for six years (not the three years I mentioned yesterday), so they have twice the number of fuel cells than would otherwise be the case. While their collective decay heat is relatively low, their loads of radioactive by-product atoms in the cells are still considerable. More fuel cells means higher radiation fields. One foot of loss means up to a ten times greater radiation field, and 2 feet of loss can mean up to a 100 times increase. This is why they are spraying so much water…keep the pools full!
- Asahi Shimbun, the on-line English edition of the second largest newspaper in Japan, reports that the emergency power cable which has been connected to Unit No. 2, was pieced together out of transmission lines that have not been used for perhaps 40 years. The creativity of the emergency teams at and around Fukushima is exemplary. A link to Asahi Simbun is below. Please compare and contrast Japanese news reporting with the embellished, ultra-spun, speculative reporting common to American news services. It’s startling.
- Finally, an E-mailer from Tokyo (an American) writes that while some Americans have left Tokyo, most have not! The E-mailer says the ones who left tend to be American news addicts, while those who stayed are those who avoid American news and stick to the Japanese sources. Many Japanese find American news reporting disgusting, while others find it darkly funny. Interesting, eh?
References:
- TEPCO News; Tokyo Electric Power Company; http://www.tepco.co.jp/en/press/corp-com/release/index-e.html
- Asahi Shimbun; http://www.asahi.com/english/newsfeatures.html
- MIT NSE Nuclear Information Hub; web.mit.edu/nse/; http://mitnse.com/
- World Nuclear News; http://www.world-nuclear-news.org/
