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Fukushima-type reactors in the USA

I was moving a bookshelf around my house this weekend when I found a copy of “Nuclear Power Reactors in the World,” an April 2000 publication by the IAEA.  (Don’t ask why I have this kind of crap lying around …) It struck me that people would want to know what reactors are “like” the Fukushima Daiichi reactors in Japan which have been causing all sorts of problems lately. Well, here goes:

View BWR 1970s reactors in the USA in a full screen map

The March 2011 earthquake / tsunami / reactor emergency brought to the public eye the dangers of “active safety” in engineered systems.  Elements of reactor design and operation which may have seemed appropriate in the 1960s (when these reactors were designed) now seem like “what were they thinking??” anachronisms to concerned laypersons.

Specifically, I’m talking about the need for electrical pumps to be in continuous operation to prevent reactor core overheating; use of water (hydrolysible into 2H2 and O2, explosive and reactive gasses) as coolant; use of cladding and fuel alloys that are subject to fire risk and enhanced toxicity (zirconium and MOX); and storage of spent fuel rods in top-floor containment pools subject to sloshing and evaporation and requiring electrical pumping. Keep in mind that all of the bad shit at Fukushima started happening after the earthquake and tsunami had passed, during a period where the active safety systems relatively slowly stopped working.

(Lots of folks don’t realize it, but you can build stable, passively safe, high tech systems, to a degree. Simple airplanes are built to fly themselves. If you’re up in the air piloting a Cessna in level flight at, say, 5000 feet, you could probably take a 10 minute nap and live to tell about it. Yes, there’s gravity involved, but the aerodynamics involved let the plane stay up there either flying (engine on) gliding (engine off) for quite a while with no requirement for constant input and management. Contrast this with something like the Joint Strike Fighter, where the plane is intentionally aerodynamically unstable and, without the constant inputs of a high-speed computer, would fall out of the air like a brick. We want reactors that are boring and Cessna-like, not delicate JSF divas that literally melt down without enough attention.)

(Non-geek version: the Fukushima-type reactors are like delicate plates spinning on top of poles.  You can’t just leave them be without expecting to break a lot of shit.  And they don’t tend to revert to safe or stable states when they break.)

The above map names the US-based reactors with BWR type (boiling water; arguably the most dangerous type still in service), manufacture by GE (GE, Toshiba, and Hitachi were the suppliers at Fukushima), and construction dates that include the 1970s (1969 in the case of Nine Mile Point).  This does not mean that you should freak out if you live near these plants.  But it does mean that, in the broadest sense, these types of reactors are subject to the same types of risks as the Fukushima reactors.  (Keeping in mind that even Fukushima was fine for 30+ years until a 9.0 earthquake.)

If you want to do something positive about nuclear power in general, don’t freak out or ask for all nukes to be banned. Instead, the nuke-minded citizen should:

  • …push for greater research on safer alternatives like pebble bed reactors.
  • …push your Congressional representatives to get off their asses and open up a real, centralized, better-than-inaction interim solution for the nation’s nuclear waste. (This gets rid of fuel rods sitting in ponds at the very place where they can do the most incremental harm when things go wrong…)
  • …pay, pay, pay. [Good] nuclear power will not be cheap. But it can be vastly improved from the Fukushima state of affairs. However, it will take enormous amounts of money for research, and the political will to eschew interim half-assed solutions (like putting cheap BWRs into service well into the 1970s, when other approaches were already either viable or in progress).

Some Gotchas with using svndumpfilter

A few things:

1. svndumpfilter can take multiple args, e.g.

$ svndumpfilter include /x /y /z > mydump

to include /x, and /y, and /z. It can’t, however, do both include and exclude at once. In theory, you can run multiple dumps when you later load them, so you could (sort of; see below) accomplish the sameish thing with

$ svndumpfilter include /x > mydumpx
$ svndumpfilter include /y > mydumpy
$ svndumpfilter include /z > mydumpz

2. HOWEVER, if you have ever MOVED a file within the repository between (in the example above), /x and /y, you can’t rely upon doing it piecewise. That’s because the references within the loading process during the load of /y will no longer be valid as they point to /x/whatever.

3. It is commonly suggested that one edit “Node-path:” entries within the dump in order to fix up directory structure issues. NOTE that you MUST also change “Node-copyfrom-path:” in the same manner. Trickily, Node-copyfrom-path is only present in nodes that were (surprise!) copied from another node. This is of course tied to 2. above.

What is all this about, you ask? Well, it turns out that if you have a single respository with a lot of sprawling projects all under /trunk, you might need to break them out. (For example, if you intend to upload your repository dump to someone like a CVSDude or Beanstalk).

The error message that got me was something like:

svnadmin: File not found: revision 91, path ‘/trunk/x/whatever’