Wednesday, March 30, 2011

Next Generation

This won't be an argument for why Captain Picard is better than Captain Kirk (and anyway, why choose?).  This will instead be a post about why we should be looking towards new nuclear technologies and winding down the old.  We have a bad habit of decrying the problems of power plants built 40 years ago, and projecting those problems onto new plants.

There is some merit to this tactic in the case of the various flavors of Light Water Reactors that may be built in the future, as they are simply safer versions of old reactors.  However, there are other technologies out there that have higher inherent safety than a LWR.

There are, in my opinion, a few major contenders for technology: Liquid Fluoride-Thorium Reactors (LFTR, pronounced 'lifter', a type of Molten Salt Reactor), and flavors of Pebble Bed Reactors.

Saturday, March 26, 2011

Things are looking rough for Fukushima Daiichi, but not all bad news

Earlier this week, some workers at the Fukushima  plant suffered from radiation burns when highly contaminated water got inside their protective clothing, as they waded towards a repair site. This prompted the ever cautious Japanese officials to warn that this might indicate a partial loss of containment.

My initial feeling about this was that it was very unlikely. Possible, yes, but not terribly likely, given that a breach of the pressure vessel would have drastically impacted efforts to circulate cooling water (pressure would drop rapidly and significantly, and probably stay down, regardless of how much water was pumped, for instance, which would be immediately detectable).  It appears that my gut feeling was correct.  While they haven't pinned down the source of the water yet, I'd put my money on damage to the reactor cooling system, which has likely developed a number of leaky valves, gaskets or pipes.  The cooling system plumbing has been exposed to multiple hydrogen explosions, earthquakes, debris, and the corrosive effects of seawater. Enough water has been moving through it for a long enough period that even a relatively small leak of water containing fission products from the reactor will have had time to accumulate to dangerous levels inside the plant.

This radioactive water poses a problem to workers, first and foremost, and will significantly complicate repair efforts.  Unfortunately, it may also pose a fairly significant environmental risk, depending on its source.  If the leaks are occurring in places where the leaked water can come into contact with hot components, or if the leaks are a mixture of steam and water directly downstream from the pressure vessel, then a small, but significant amount of  fission products (the main concerns are Cesium and Iodine, but in the long term, primarily Cesium 137, which has a half life of 30 years and has a decay chain that includes gamma decay) may be being dispersed from the plant.  Even small amounts can accumulate over time in the near vicinity of the plant, and make uses like agriculture problematic for the near term future. It should be stressed that only water soluble products are likely to end up in the cooling water, so that means no plutonium or uranium are likely to be dispersed by the leaks, which is a very good thing.

Friday, March 18, 2011

The Fukushima Nuclear Crisis, and a Crisis of Journalism

This was not what I had intended to write about in this blog, but better to begin writing in it than not writing in it, I suppose.  I will turn soon enough to matters of urban ecology, bees, soil preservation, and all manners of such goodies.

But right now I will be talking about Japan, nuclear power, and journalism.

Because frankly, much of the coverage of the situation has been deeply infuriating, as it boils down to a great deal of uniformed fear-mongering, at a time when there are other aspects of the disaster could bear more focus.  Even my beloved PBS Newshour has been guilty of this to some extent, though they have for the most part been quite reserved in their pronouncements, and their experts have mostly actually been experts.

But it's a clear indictment of the state of mainstream journalism, that they mostly can't get it together, and are choosing to focus on what is the flashiest, but ultimately likely to be the least important aspect of the aftermath of the Japanese quake and tsunami.