Everytime one of these reactors has a problem we hear the refrain: - "oh that's an old/foreign/crap design which noone makes anymore" - "the people running the reactor are poor/corrupt/stupid/culturally different" - "and this would never happen to any of our other reactors"
the cynic in me thinks how many other badly design reactors are out there being run by people who are - either now or in the future - not up to the task? Regards, Saul On 18 March 2011 14:22, Eric Smith <desm...@santafe.edu> wrote: > Jochen and everybody, hi, > > I don't know if it has already been covered on this thread, and I > understand that the following comment is not central to the main theme. But > to group Chernobyl with other reactor failures has one element that is > potentially problematic. Chernobyl was a carbon-moderated reactor, in > contrast to (as far as I know, all other) modern reactor designs, which are > water-moderated in one way or another. The problem, of course, with carbon > moderation is that if the reactor overheats, the carbon doesn't reduce that, > and if it hits flashpoint, the carbon is inflammable and ultimately > explosive. So you get this massive chemical explosion vaporizing and > distributing your fuel/waste mixture. > > In contrast, water-moderated reactors, if they overheat, boil off the > moderator. Since, in either of these reactors, the point of the moderator > is to slow neutrons to an energy that can be captured for fissioning, when > the moderator is lost, the neutrons remain fast, and mostly escape, which > should mostly or entirely shut the reaction. This isn't as complete a > quench as the cadmium absorber rods that can be used for some kinds of > active control, but it should still make most of the difference that keeps > the reaction within what the containment system was designed for. > > There are a lot of details about this that I don't know, so I don't > understand what the modes are that lead to continued reactor heating even > when the moderator should have been removed. This includes not > understanding what went wrong in the research facility in Japan a few years > ago, that led to the bubbling pot of fuel that had to have holes shot in it > from high-powered rifles outside the building to sufficiently spread the > material to go permanently sub-critical. > > For me, the most worrisome reactor in the world right now is in St. > Petersburg. it is the same design and age as Chernobyl (I believe), and is > not only a potential disaster for Russia, but for Finland, Sweden, and > northern continental Europe. That would be my candidate for replacement. > > Eric > > > > > ============================================================ > FRIAM Applied Complexity Group listserv > Meets Fridays 9a-11:30 at cafe at St. John's College > lectures, archives, unsubscribe, maps at http://www.friam.org > -- Saul Caganoff Enterprise IT Architect Mobile: +61 410 430 809 LinkedIn: http://www.linkedin.com/in/scaganoff
============================================================ FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org
