Hearing reporting that the last explosion took out the pumps that could bring seawater into the reactor vessel, meaning the cores are or will eventually be uncovered. This means a meltdown is only really a matter of time. This has happened twice before at Three Mile Island, where the secondary containment held the core and very little contamination of the site occurred, and Chernobyl where the reactor blew up, caught on fire, and spread radiation through half a continent and contaminated an area the size of New Jersey. This should be more like a TMI event, though the damage here is going to be measured in billions of dollars to clean up the mess even if it’s limited to the site, which it should be.

One Response to “Meltdown?”

  1. Harold says:

    Side note: the PSH concept is particularly useful right now….

    Anyway, here’s the International Nuclear Event Scale to help put things into perspective. We’re talking about Level 4 events that may shade into Level 5 (TMI).

    The RBMK design used at Chernobyl has among many other problems the use of burnable graphite as the moderator (in them water is a neutron poison). That’s not going to be a problem here, it’s very hard to see anything beyond very local releases of seriously amounts of dangerous radioactive material (modulo iodine, but if you can get people potassium iodide tablets that’s probably OK, but of that’s course iffy in the aftermath of the greater disaster).

    Having the facades of two containment chambers blow off is a new thing; on the other hand it shouldn’t do more than scratch the paint on their surfaces. My concern here is not so much that they’ve lost the pumps (we can hope more might be brought in) but that the explosions damaged the piping etc. coming out of the containment chambers so that making new connections will be difficult.