Quote of the Day
Human beings, who are almost unique in having the ability to learn from the experience of others, are also remarkable for their apparent disinclination to do so.
Douglas Adams
The Japanese Nuclear Power Plant Crisis Continues
I watched Fox News coverage of the ongoing Japanese post-earthquake/tsunami, particularly with the 3 problem boiling water reactor systems. I thought the coverage was moderately alarmist in tone (e.g., Megyn Kelly); the coverage was uneven. There were a number of technical guests, one of whom exasperated me with "the world is complex" in terms of future crisis developments.
I started off yesterday's post recommending an MIT scientist's (Dr. Oehmen's) accessible writeup; Glenn Beck led his show off making reference to the scientist's post in question, providing an M&M's version.
I'll attempt to write a more readable summary. The core of several nuclear fuel rods are in a containment vessel filled with coolant; the coolant circulates about the nuclear rods, boiling the top of the water, generating steam which exits the vessel and drives turbine generators. The coolant is captured and eventually recycles into feedwater (replacement coolant) through nozzles at the top of the vessel; in normal operation the core is submerged a few feet below the coolant surface.
In the event of shutdown or disaster, the design arranges interspersing the fuel rods with control rods, which serves to mitigate the nuclear fission process. There are still heating processes going on for some time, and maintaining coolant level is critical; on a periodic basis, steam pressure must be relieved to maintain structural integrity. If the coolant is not adequately added to maintain coolant coverage of the fuel rods, exposure to air for a sustained period of time (say, 45 minutes or more) may compromise the fuel rod casing, resulting in a partial meltdown scenario and related radioactive byproducts, some with very limited lifetimes, others (like cesium and iodine) more serious. To control for the risk of radioactive products, boric acid, sort of a "liquid control rod", may be added to coolant. Hydrogen gas, generated from metal (casing)/water interaction, leaving the containment vessel, can become highly combustible resulting in the kinds of explosions and damage we have seen to the external structures. (A key issue is whether the explosions damage the containment vessel itself, among other things exposing radioactive coolant to potential evaporation and more direct contamination of the external environment.)
In global terms, the way that the Japanese nuclear power systems were designed reflects an engineering trade-off and assumptions similar to levee designs in the case of New Orleans (in reference to Hurricane Katrina). If I recall correctly, the levees were built to withstand a category 3 hurricane; engineers usually try to design to the worst expected case and add a fudge factor. Hurricane Katrina was much stronger and levees failed. The natural question, after the fact, was, why weren't the levees built to withstand a category 5 hurricane in the first place? In essence, there is a cost-benefit trade-off, and the incremental costs could be significant. In the case of the Fukushima reactors, the overall structure was designed to withstand a 8.2 versus an 8.9 (or subsequently corrected 9.0) Richter scale value. In other words, the basic structures withstood an earthquake roughly 8 times what they had been designed for. As designed, the fuel rods merged with the control rods, stopping nuclear fission. With main power down, the coolant circulation systems were powered by limited-duration batteries. They had additional diesel generators to kick in once the battery backups were depleted.
The second design issue involved structural defenses of the diesel generators against a tsunami; the tsunami-resistant walls failed to contain the actual waves, and it's thought that the ground-level diesel generators were rendered useless. Other battery-based or mobile generators have been deployed.
In emergency cases, coolant can be injected directly into the containment vessel; there was only a limited amount of freshwater available, and seawater has been used as a fallback coolant source. Seawater is corrosive and also includes elements which are more reactive to generated particles.
The current status, as I write, is the aftermath of a third explosion, this one involving reactor #2. There are mixed reports on whether the containment vessel has been ruptured. There are reports of issues in feeding coolant and/or opening vents. There have been reports of a fire and concerns about spent fuel rods in exposed pools. We can infer at minimum some partial melting damage has occurred based on elevated radiation levels in the general area around the plant.
I think the Japanese government is being proactively cautious; I do marvel at the discipline and grace of the Japanese people under these circumstances, no public panic.
The Equity Project: Thumbs UP!
I first heard of a similar concept under Michelle Rhee: offer teachers a six-figure salary, but in return they need to be held accountable and surrender the typical teacher union protections of tenure and various work rules.
I am somewhat skeptical about the level of compensation under TEP (a charter school which is publicly financed but run privately; teachers are paid well over $100K but work at will). I don't think it's necessary, for instance, to offer triple a veteran teacher's salary to get teachers. (For example, I think if you offer a teacher making $40K a package of $80K, you will still get a great response.) But I do like about TEP is its flat administration, a multi-faceted role, and the nature of performance evaluation--and, of course, it is refreshingly free of teacher unions and the collective bargaining issues (I've written a number of relevant commentaries during the legislative process of the recently enacted Wisconsin public union reform law). I was cheering for the teachers talking about the long hours and not giving up on students (which could have come from my own posts).
There were a few things I would have liked to hear addressed: there's more than subjective teaching evaluation measures like peer reviews. I was disappointed to hear standard test performance scores did not outpace other schools' results; I wasn't really satisfied with a response of "Give us 4 years; it takes longer than a year to see results"; I would have liked to hear more from him how he would assess his own efforts a success. I assume he might look at things like lower student attrition and above grade-level reading or math scores...
But for a mainstream media news organization to feature a story on charter schools not co-opted by teacher unions? Yes!
Political Humor
Due to the recession, there are now 15,000 fewer lawyers in the U.S. No one ever talks about the good things that come from a recession. - Jay Leno
[Not to mention the Democrats losing their House.]
The movie “Battle: Los Angeles” is unrealistic because America’s army goes all out to defend L.A. If aliens really attacked L.A., Americans would say “Take it.” - Craig Ferguson
[Some conservatives believe that Los Angeles is already occupied by aliens...]
Musical Interlude: My Favorite Groups
America, "Muskrat Love". What I remember about this song is that the Captain and Tennille scored a hit remake and performed it at a performance before the Queen of England, which caused a bit of scandal at the time; Toni humorously references the story in the second video.
